Tag Archives: external wall insulation

Top Tips for Preventing Cracked Render

There’s no doubt that cracked render can be incredibly disappointing and frustrating, especially for homeowners that have just had their houses re-rendered. There are many reasons as to why render might crack, be it due to weathering, the incorrect use of materials, rising damp and the like. As a renderer, it’s important to ensure that all your bases are covered to prevent cracking and achieve a long-lasting finish. In today’s post, we’re going to give our best installation tips to ensure that cracked render is a matter of the past!

Prevent Cracked Render with Substrate Absorptivity Tests

The first step in any render installation is to check the absorptive capacity of the substrate. This is an essential step because porous substrates can absorb water out of your render very quickly, which can in turn affect its adhesion and ultimately – you guessed it – cause cracked render. 

The substrate absorptivity test that we recommend is to wet the wall with water and check the rate at which it is absorbed. You don’t want the substrate to be oversaturated with a low absorptive capacity because the render won’t stick but, equally, you don’t want it to immediately absorb the water.

If your substrate is highly absorptive, we recommend lightly dampening the walls with a fine mist of water, then performing the test again. Be careful not to oversaturate the walls!

Use the Right Primer

Following this, a good primer is essential for limiting the absorptive capacity of the substrate and ensuring that it is stable, thereby preventing cracked render. We recommend using the EWI-301 Water-Based Primer or the EWI-302 Deep Penetrating Primer which is ideal for newbuild brick and blockwork.

A good primer will also work to ensure that the substrate doesn’t absorb too much water from your materials. The EWI-310 Universal Primer, for instance, contains quartz aggregate which helps to create a mechanical key to aid adhesion.

Reinforce with Fibreglass Mesh

We recommend using Fibreglass Mesh in all the render systems that we offer; you can embed the mesh in the first pass or within the basecoat layer.

Fibreglass Mesh enhances the tensile strength of the render, keeping it nice and sturdy so that it can withstand any movements within the building structure and therefore resist cracking. The mesh is cut into strips and overlapped on all sides so that there are no gaps where cracks can form.

If you want to take the crack resistance up a notch, we highly recommend using Panzer Mesh within your system as this is incredibly high-strength.

Don’t Forget Your Beading

We sell lots of different types of beading, all designed to be embedded within the render to reinforce certain areas. For example, our Corner Bead helps to provide a nice sharp finish at the corners of the render system whilst also providing reinforcement against impacts. Also, our thin-coat render system beads tend to have a mesh wing to spread the reinforcement across a larger surface area, while the scratch render beads have just the hard uPVC without the mesh. Other types of bead we offer include: 

Movement Joints

Movement joints need to be reinforced using a render movement bead. These are used where there is a large expanse of render (more than 12m). It’s installed vertically and is embedded within the basecoat layer to stabilise the render and ensure that any cracking is prevented. 

Stress Patches are Essential

Areas above and below openings (around windows and doors) need to be reinforced with strips of Fibreglass Mesh to distribute and resist stresses. The mesh should be cut into strips that extend past the stress patch by at least 50cm. It should be embedded in the middle of the basecoat or the first pass.

And, there you have it! We hope you found these tips useful for preventing cracked render. If this has been an issue for you in the past, be sure to refer to these tips to prevent it from occurring again in future. If you have any questions, do not hesitate to contact our experienced sales team who will be happy to help!

EWI Store are the leading UK render specialists, offering a range of high-quality Render and External Wall Insulation products. We take a whole-system approach to external wall insulation, stocking all the materials required to help installers achieve a stand-out result. Our selection of products is constantly growing as we strive to offer our customers the best possible choice of materials from trusted manufacturers and established brand names.

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    Can I Install External Wall Insulation on a Cavity Wall?

    At EWI Store, we receive many enquiries from homeowners who are very interested in installing EWI. However, there is often confusion as to whether it is possible to install EWI on a home with existing cavity wall insulation. In today’s post, we’re going to be tackling this question to see if we can clear things up!

    What is Cavity Wall Insulation?

    If your home was built after the 1920s, it’s likely that it will have been built with a cavity between the two exterior walls.

    The main purpose of this cavity was to prevent damp crossing over from the outside through to the interior walls, but it wasn’t until later that people realised it could be used for another purpose. Nowadays, cavity walls are often retrofitted with an insulation material in order to increase energy efficiency and reduce the amount of heat lost through the walls.

    In today’s housing stock, cavity wall insulation (CWI) seems to be the default method of wall insulation however, this isn’t to say that there haven’t been people with negative experiences of it. Damp and condensation have often been reported as a side effect of CWI, usually occurring as a result of cold bridges caused by poor installation. There are therefore many people who are quite rightly wary of CWI, so they instead look elsewhere for their wall insulation solutions.

    What is External Wall Insulation?

    If your home was built before the 1920s, then it’s likely to be a solid wall property. These properties present a bit of a challenge in terms of increasing energy efficiency because there is no cavity to fill, so homeowners either have to opt for no insulation (and high energy bills), internal wall insulation (IWI) or external wall insulation (EWI).

    EWI provides the best solution for this type of building, as it is fitted onto the outside walls by securing the insulation boards with adhesive and fixings. A protective render is then applied to the insulation boards to create a weatherproof seal.

    Unlike IWI where the thickness of the insulation is severely limited by how much floor space you can give up, EWI allows users to install insulation as thick as 200mm onto the outside walls of their properties.

    Further to this, the effectiveness of CWI is dictated by the amount of insulation that can actually fit within the cavity – some cavities are just 50mm wide, so the benefits of insulating this are pretty slim.

    EWI, therefore, offers increased potential for homes to massively up their efficiency. Unfortunately, it’s commonly assumed that homes with cavity wall insulation are: a) insulated well enough, and b) cannot have EWI as well as CWI.

    To see what materials you will need and how much EWI may cost, visit our Materials Calculator Tool.

    Can I have both EWI and CWI?

    In fact, if you have CWI, then EWI is likely to reduce any problems with damp caused by the cavity wall insulation. This is because EWI completely envelopes your home in a weather-proof blanket, preventing water from entering through the exterior walls and keeping the temperature of the walls nice and warm. Because EWI wraps around the entirety of the exterior walls, there are no gaps and therefore thermal bridging is kept to a minimum.

    So, because the internal temperature of the walls increases, the chances of damp and interstitial condensation are reduced. If there were any cold spots within the cavity wall insulation before, then the EWI will counteract the effect of these by maintaining a warm wall temperature.

    If you currently live in a cavity insulated house and you want to upgrade the wall insulation even further, get in touch! We can talk you through the process and offer you our technical expertise.


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      Is External Wall Insulation Soundproofing?

      Noise pollution can be incredibly frustrating. Whether it’s from road traffic, railway networks, aircraft or just plain old noisy neighbours, measures can be taken to increase the soundproofing capabilities of your home.

      External wall insulation (EWI) is excellent for soundproofing. Not only does EWI improve the thermal performance of your property, but certain types of insulation can also dramatically improve the acoustics of a building. We’re going to be talking a bit about the negative impact of noise pollution on human health, and which external wall insulation system is best for preventing this.

      What are the effects of noise pollution?

      Noise pollution has proven to significantly affect children, adults and the elderly. According to research carried out by Rockwool, noise pollution can cause stress and fatigue due to disturbed sleep patterns. In turn, this can lead to health problems and a slower rate of development for children.

      The Best Insulation for Soundproofing

      If you live in a solid wall property, it’s unlikely that your home will be adequately soundproofed. This is because, generally, homes are built with insulation in the walls (cavity wall insulation) that absorbs the sound and protects the house against noise pollution. EWI is a great choice if you live in a solid wall property, or even if your property just needs an extra soundproofing boost.

      Mineral Wool insulation is the best one to go for if soundproofing is a concern. Renowned for having excellent insulating capabilities, the insulation not only reduces the amount of noise entering your home but is also all the more effective due to the fact that it is installed externally. The entire insulation system seamlessly envelopes the house and is, therefore, a highly effective solution against sound pollution. We recommend using the Mineral Wool insulation at a thickness greater than 200mm.

      Of course, with a Mineral Wool external wall insulation system, it’s not just the soundproofing capabilities that you reap the rewards of. Mineral Wool has excellent thermal insulating capabilities, is class A1 fire rated (the highest standard!) and is also very breathable. So, overall, this is a very healthy insulation material for buildings!

      How is the insulation installed?

      If you are new to the idea of EWI, it’s very simple!

      • The Mineral Wool is doubly secured to the external wall using both our Premium Basecoat adhesive and metal pin mechanical fixings.
      • Once the boards are secured to the wall, the Premium Basecoat is again applied on top and fibreglass mesh is embedded within the basecoat for extra crack resistance and tensile strength.
      • Once the basecoat is dry, a render primer is painted on and left to dry.
      • After this, a thin coat render is applied on top of the basecoat to create a decorative finish.
      • The overall result is a higher performance building in many respects, and an aesthetically pleasing, brand new finish!

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        The Lloyds Bank British Business Excellence Awards

        We did it! EWI Store has been shortlisted as a finalist in The Lloyds Bank British Business Excellence Awards in the category Small-To-Medium-Sized Business of the Year. This award celebrates resilience and innovation within some of the UK’s best businesses and we are so proud to have been shortlisted for this prestigious award!

        What is The Lloyds Bank British Business Excellence Awards?

        Attracting a variety of organisations, from small startups to large corporations, the Lloyds Bank British Business Excellence Awards is the largest and most comprehensive business awards programme in the UK. These awards acknowledge businesses that find new ways to support their communities and where employees thrive in times of hardship. This prestigious award is only awarded to businesses that are able to demonstrate clear processes aimed at supporting their local communities.

        What Have We Achieved This Year?

        Many have struggled over the past year and, to further support our community of homeowners, installers and architects, we have invested heavily in our training. This training is aimed at both new and experienced installers who are looking to either gain the necessary skills for the industry or to maintain their professional development and keep up to date with the latest processes and techniques. This year, we created an educational CPD (Continual Professional Development) programme aimed at architects which we have successfully had approved by the Royal Institute of British Architects (RIBA). This shows that our CPD course is of high quality and meets the very stringent criteria that are required to gain RIBA approval.

        Here at EWI Store, we handpick only the highest quality products to sell in our stores. We stock the full range of products from EWI Pro who are well known for their supreme range of silicone renders. Their Premium Bio Silicone Render is an award-winning render, resistant to cracking, biological growth and discolouration and thereby providing a stand-out finish for years to come. By selecting only the best products, we ensure long-lasting and high-quality results for our community.

        As usual, we would like to thank all our customers for their continued support. Make sure to keep your eyes peeled for future announcements!

        Is External Wall Insulation Expensive?

        Many of us here in the UK are interested in the idea of External Wall Insulation, with a vast range of benefits both environmental and financial it is easy to understand why. The biggest reservation many people have is regarding the upfront cost of the External Wall Insulation installation process. In today’s blog, I will explain the costs and hopefully put your financial worries to rest!


        The process of External Wall Insulation has many components; the price accounts for the required insulation materials and labour costs. The cost of EWI materials will depend on the size of the project but also what EWI materials you choose. Not only do the prices of materials vary, but some materials require fixings and some require adhesive which will also need to be accounted for within the price. This means that the cost of your EWI system will depend entirely on the specific needs of your project.


        Calculating the cost of the External Wall Insulation Materials

        As explained above, there are a lot of components to consider when calculating the price. Luckily, we have a great solution for you; not only do we have a fantastic team on hand who can provide you with a quote, but we also have an easy-to-use EWI Materials Calculator tool that takes all of the faffs out of the calculation process. If you would rather have a helping hand and some guidance, just give us a call on 02033974067.


        What is the EWI Materials Calculator?

        The EWI Materials Calculator is an online tool that enables homeowners, installers and architects to quickly and accurately calculate the correct EWI materials needed to meet their requirements for their next project. The calculator will ask a series of questions to gather how much the system will cost depending on your needs.

        Average External Wall Insulation costs:

        EWI Typical Cost
        Mid-terrace house £4,000 – £6,000
        Semi-detached house £8,000 – £10,000
        Detached house £12,000 – £14,000 +


        This may seem like a scary amount for some but if your property has solid walls, you could save between £115 and £360 a year by installing External Wall Insulation. This means, over time, the External Wall Insulation will start to pay for itself. You have to remember that not only will you save on your heating costs, but you will also reduce the amount of CO2 emissions your property emits into the atmosphere which will help the environment. Your External Wall Insulation job will also be finished with your choice of render and colour, providing additional value if your brickwork is damaged, worn down and in need of a makeover.

        If this still sounds like too much for you, there is government-backed support that you could be eligible for. Currently, there is a subsidy called the Energy Company Obligation (ECO) which was launched in December of 2018. The scheme runs until the 31st March 2022 and focuses on customers with low incomes and considered to be in vulnerable situations e.g. living in fuel poverty. Under ECO, grants are available to cover all or part of the cost of energy efficiency measures. Ask your energy provider for more information on this scheme.

        Trade Installers get fantastic prices and warranties on the system

        As an installer, you may well be eligible for our trade discount prices too; so, not only will you get a BBA-approved external wall insulation system delivered directly to the site, but also the materials you need at a great price. As a trade partner, we are also able to offer system warranties provided the installers have been on our free training course. Be sure to sign up to our Trade Account for free to receive your discounts!

        So, there you have it – if you need some help calculating the material requirements for an EWI job, give us a call or use our EWI Materials Calculator today!


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          How to Apply OCR

          How to Apply One Coat Render

          There is a wide variety of one coat renders available on the market, often chosen by homeowners due to the fact that it is a cost-effective solution while being considerably better than sand and cement render.

          We’ve recently started stocking EWI Pro’s EWI-265 OCR, which is a one-coat, cement-lime render, ideal for application using a spray machine. The product is a great solution for creating a smooth surface prior to applying masonry paint, so have a read about how to apply it!

          OCR Installation Guide: Substrate Preparation

          If the original substrate does not have a good key, we recommend using the EWI-310 Universal Primer, which contains quartz aggregate to provide a rough surface for the render to adhere to.

          Once the substrate has been primed, it may need levelling. If it’s particularly uneven, we recommend the use of the EWI-269 Lightweight Basecoat, which can be applied up to 25mm thick in one pass. The product should be mixed with 5 litres of water per 25kg of dry mix. Once combined, the basecoat should be applied at the required thickness to level off the wall. We recommend embedding a layer of Fibreglass Mesh into the basecoat to ensure its stability. Leave to dry completely before applying any further materials.

          Applying OCR

          If the substrate doesn’t need levelling, you can apply OCR straight off. The bag needs to be mixed with 5.5 litres of water, and it should then be applied at a thickness of 5-15mm (usually this is dependent upon how even your substrate is). If you didn’t apply a levelling layer to begin with, you should embed mesh into the OCR instead.

          Choosing your Decorative Finish

          OCR is not through-coloured, so a decorative finish will need to be applied on top. Many people opt for a painted finish to achieve a smooth surface texture; we recommend the use of our EWI-005 Silicone Paint, which is a highly hydrophobic masonry paint. This particular paint repels water and is very breathable, so it’s a great choice for ensuring that the render is totally sealed in.

          Silicone Paint can be tinted to create any colour, and we can even match to NCS and RAL colours.

          Interested in OCR or have any questions? Our experienced Sales Team will be happy to assist with any enquiries you may have! Find our contact details here.





          If you’re looking for an approved installer to carry out the work for you, fill out the form below and we will be in touch. We upload blog posts every Tuesday and Thursday, so keep up to date with our blog and social channels to find out more!

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            Is External Wall Insulation Safe

            Is External Wall Insulation Safe?

            Customers often call us to ask whether external wall insulation is safe to install on their homes. EWI Pro systems are BBA-approved, which means that they have been rigorously tested by the British Board of Agrément, who have deemed that they are safe and suitable for installation onto UK homes.

            In today’s blog post, we will discuss how our external wall insulation systems have been designed to ensure the highest level of safety. 

            Securing External Insulation Boards – Dual Fixing

            The EWI Pro system is designed so that the external wall insulation boards are fixed to the substrate using the dual-fixing method of both adhesive and mechanical fixings. This ‘belt and braces’ design ensures the stability of the system so that in the unlikely event that the adhesive fails, the fixings are still there to hold the boards up. 

            The EWI Pro system also consists of two adhesives of different strengths. For example, our Premium Basecoat (EWI-225) is our strongest adhesive and is always used with Mineral Wool insulation boards that are much heavier. Alternatively, the EPS Basecoat (EWI-220) is ideal for use with lightweight foam insulation boards such as EPS and XPS. Ensuring that the adhesive is of the correct strength for the weight of the insulation board is essential for a safe and secure system. 

            Fire Safety of External Wall Insulation Materials

            How fire safe your system is will greatly depend upon the type of insulation that you choose. 

            Rockwool Mineral Wool boards are rated as Euroclass A1 non-combustible and are the safest insulation material you can have installed on your property. The Rockwool insulation boards work to contain the fire and prevent it from spreading throughout the building. As well as this, they don’t release toxic emissions or smoke when exposed to fire.

            The EPS system has been designed in such a way so that in the event of a fire the EPS would simply melt within its cement-based plaster enclosure. The mechanical fixings would support and hold the structure in place, so although the system wouldn’t withstand the fire, it wouldn’t contribute towards the spread of it.

            Fibreglass Mesh for Reinforcement

            We often talk about the use of reinforcement mesh in the context of ensuring that the render topcoat doesn’t crack. However, Fibreglass Mesh plays an important role within the external wall insulation system, enhancing its tensile strength to keep the boards securely tied to the wall.

            Fibreglass Mesh strips are embedded within the basecoat layer and are overlapped by 10cm across each edge. This creates an added layer of reinforcement that spans across the entire surface area of the system.



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              How to calculate the cost of an External Wall Insulation system

              Calculating the cost of an external wall insulation (EWI) system is not as simple a task as you might think; the price not only accounts for the insulation materials but also the installation of the system, labour costs, square meterage (for example, our reinforcement mesh comes in 50m rolls while a bag of EWI-220 Adhesive will cover 3m2 of the wall), the choice of decorative finish and so on. What’s more, not only do the prices of materials vary, but some materials require fixings and some adhesive which will also be included in the price. Therefore, the cost of your EWI system depends entirely on the needs of your project. So, how does one go about calculating the cost of their EWI system?

              Calculating the cost of the External Wall Insulation Materials

              At EWI Store, we have just the solution for you. Not only do we have an excellent team on hand who will be happy to provide a quote – simply give them a call with some rough measurements of the area that needs to be insulated, and they can quickly calculate the EWI materials you need using their expertise – but we also have a fantastic tool available at your fingertips…

              The EWI Materials Calculator

              Whether you have experience with external wall insulation, or you’re keen to have a go, you can use our accurate, easy-to-use EWI materials calculator!

              What is the EWI Materials Calculator?

              The EWI Materials Calculator is an online tool that enables homeowners, installers and architects to quickly and accurately calculate the correct EWI materials needed to meet their requirements for their next project. The calculator will ask a series of questions to gather how much the system will cost depending on your needs.

              The questions the EWI Materials Calculator will ask are as follows:

              The information you need for the EWI Materials Calculator

              You can choose between three options depending on what you are interested in: eco, premium and standard. This relates to the decorative finish you want on your walls.

              •  Amount of metres squared needed

              To calculate the number of metres squared needed, multiply the width by the height of each wall you are going to insulate. Do not subtract windows or doors; this will give you an incorrect result as our calculator considers wastage in the final calculation.



              So, whether you are a homeowner looking to install external wall insulation or apply a fresh new render façade to your home, a solid wall insulation installer looking for an easy-to-install product (at a great price) or an architect looking for a way to vastly improve the thermal efficiency of an old property, you have come to the right place.

              Trade installers get fantastic prices and warranties on the system

              As an installer, you may well be eligible for our trade discount prices too; so, not only will you get a BBA-approved external wall insulation system delivered directly to the site, but also the materials you need at a great price. As a trade partner, we are also able to offer system warranties provided the installers have been on our free training course. Be sure to sign up to our Trade Account for free to receive your discounts!

              So, there you have it – if you need some help calculating the material requirements for an EWI job, give us a call or use our EWI Materials Calculator today!

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                Applying Render to OSB

                How one should go about applying render to OSB is a question that we get asked on a near-daily basis. The simple answer is that applying render directly onto the OSB is not an ideal situation – it’s important to remember that at the end of the day, OSB is wood.

                Nevertheless, there is a solution for rendering OSB, and we’re going to talk you through the best way you can do this!

                Rendering OSB: Render Carrier Board

                When rendering any substrate, especially when rendering OSB, consideration needs to be taken as to the suitability of the substrate for the materials that you are using. OSB is not completely waterproof and will inevitably absorb water from the basecoat, which can cause the wood to warp, eventually hindering structural integrity.

                To avoid this, the best solution is to use a render carrier board. However, the render carrier board needs to be attached to battens, rather than to the OSB directly. This is because the two separate fabrics (the RCB board and the OSB) need ventilation between them to allow moisture to escape, and to avoid a situation where water builds up between the two materials. An air gap between the two is therefore necessary for the reduction of condensation.

                The best course of action is to:

                • First, staple a breather membrane onto the OSB substrate – this will help prevent the build-up of condensation on the surface of the wood.
                • Next, install timber battens on top of the OSB (the positioning of the battens will depend upon the size of the render carrier board you are using).
                • Once these are in place, you can secure the render carrier boards onto the battens with wood screws.

                The spacing of the boards will depend on the type of render carrier board you are using, but generally, you would leave 4-5mm between each board.

                After the boards are in place, the gaps between them need to be covered over by a render carrier board tape. We recommend a tape that is breathable with a self-adhesive membrane, so it will prevent water vapour from gathering in the gaps between boards.

                Basecoating the Render Carrier Boards

                Render carrier boards don’t require priming because they are specially designed for being rendered, so you can go straight into applying the basecoat with no problems.

                Although it is possible to use the 220 Basecoat Adhesive, we recommend using the 225 Premium Basecoat as a basecoat for extra strength and breathability. At this stage, the necessary beading required for the structure is sunk into the basecoat along with fibreglass mesh – remember to overlap each strip of fibreglass mesh by about 10-15cm.

                Allow the basecoat to set for a period of 24-48 hours, before priming the basecoat with a Render Primer. The type of primer you use will depend upon the type of render, for example, if you were to render using Silicone Render (we recommend this one for buildings that require a high level of breathability), you would need to use our SiSi Render Primer. This can be painted on and then left to dry for 12 hours.

                Rendering the Basecoat Layer

                After all that essential preparation of the OSB and RCB boards, you are finally ready to render. Using our ready-to-use Silicone Render, apply it onto the substrate using a trowel. The render should go on at a thickness that matches the chosen grain size – for example, if you’ve chosen a 1.5mm grain size finish, then you should apply the render at 1.5mm thick.

                Once distributed across the surface, rub up the surface of the render with a plastic render float to bring out the texture and achieve a consistent finish, then leave to dry for 24-48 hours. 

                Struggling to chose a Silicone Render colour from our selection? Order a colour sample here.


                Want to learn more? Come to one of the EWI Pro training centres!  More information found in the video below.


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                  Try before you buy with our Render Colour Samples

                  As if the entire home renovation process isn’t stressful enough, choosing the right colour and textured finish for the new façade of your home can be daunting. You want to choose a façade that will not only look good, but also last for years to come. That’s why, here at EWI Store, we offer both Silicone Render Colour Sample Pots and Render Colour Sample Charts to assist you in choosing the right façade for you! What’s more, our friends at EWI Pro also offer a Silicone Render Colour Sample Pouch! Read on to learn about each of these types of samples and how they will aid your decision in choosing the right render façade for you.

                  What is a Silicone Render Colour Sample Pot?

                  A Silicone Render Colour Sample Pot is a product available from EWI Store as a means of testing the colours of our silicone renders before making a purchase. The pots contain 750g of Silicone Silicate Render, our most popular silicone-based render, in a default grain size of 1.5mm; our most popular grain size.

                  Here at EWI Store, our renders are available in absolutely any colour – that’s right, any colour, including any RAL, NCS or Pantone shade. That’s a lot of choices, so, if you’re contemplating a colour, it’s wise to test it first!

                  We can offer our Silicone Render Colour Sample Pots in any colour of your choice; just let us know which colour you’d like to see, and our talented team will use our state-of-the-art mixing facilities to tint it for you!

                  Once the render from the sample has been applied, it needs at least 48-72 hours to dry and set to represent the final colour finish. Therefore, do not form a judgment of the colour when the product has only just been applied – give it a little time, and you will soon see your colour choice in all its glory!

                  What is a Render Colour Sample Chart?

                  A Render Colour Sample Chart is an EWI Pro product stocked at EWI Store that showcases real render swatches in a sturdy, compact booklet in our top 36 colours. It is a particularly handy resource for our installers to figure the best finish for their projects, but also offers a great means for seeing a range of colour options for your home. We always recommend choosing a few shades from our Render Sample Colour Chart before ordering a Pot or Pouch.

                  What is a Silicone Render Colour Sample Pouch?

                  A Silicone Render Colour Sample Pouch is available to order from our friends at EWI Pro to get a feel of the grain sizes we offer. The sample comprises a small plaque with the desired grain size, and it’s available to order for FREE! That’s right: you can simply put in a request to order a sample in the grain size of your choice, and they will be in touch to get the sample to you.

                  Our Silicone Render Colour Sample Pouches are available in 4 grain sizes: 1mm, 1.5mm, 2mm and 3mm. Each of these grain sizes presents a slightly different textured finish – the larger the grain size, the rougher the façade – which can also impact the final colour finish. Therefore, this sample allows you to see and feel what the final render façade could look like on your home!

                  Order one of our Samples today!

                  So, what are you waiting for? If you are looking to render your home, be sure to order a sample – be it a Silicone Render Colour Sample Pot, Silicone Render Colour Sample Pouch or Render Colour Sample Chart – and start making a decision today.

                  Still stuck for choice?

                  If you’re still stuck for choice or have any other questions regarding our render samples, colours or anything else, you can talk to one of our talented Sales Representatives who will be happy to recommend any colours and aid you in your decision. You can contact our team via email at [email protected] or by telephone at 02033974067. We’re always happy to help!

                  EWI Store are the leading UK render specialists, offering a range of high-quality Render and External Wall Insulation products. We take a whole-system approach to external wall insulation, stocking all the materials required to help installers achieve a stand-out result. Our selection of products is constantly growing as we strive to offer our customers the best possible choice of materials from trusted manufacturers and established brand names.

                  Repointing mortar or External Wall Insulation: Which do I need?

                  Mortar refers to the substance that ‘glues’ bricks together and helps to protect walls from water ingress and heat loss. It has a long and successful history, with the earliest record from Israel which is thought to date back as far as 10,000 years, and many other examples of age-old mortar still exist today. For instance, if your house was built pre-1930, it’s likely that it was built with lime mortar; alternatively, if your house is a new build, it was probably built with Portland cement. Needless to say, mortar can eventually begin to crack, meaning it needs to be either ‘repointed’ – that is, filled in or repaired – or you should have external wall insulation installed on your home.

                  Here at EWI Store, we’re often asked lots of questions about mortar, with the most common being “what is mortar made of?”, “is mortar the same as cement?” and “is mortar waterproof?”. In today’s blog, we’re going to answer all these questions by explaining how mortar is made, the main types of mortar and how to tell whether it’s time to repoint your property or have external wall insulation installed.

                  What is mortar made of?

                  Mortar is comprised of materials such as cement, sand and water, and sometimes lime, to create a high-quality substance to seal bricks together. It is either mixed on-site using a concrete mixer or manufactured in a factory off-site by expert suppliers.

                  What’s the difference between lime mortar and Portland cement?

                  Lime mortar is generally produced by burning calcium-based raw materials; in the UK and Ireland, chalk and limestone are most commonly used. When these materials are heated to about 850oC, the heat removes the carbon dioxide, leaving calcium oxide or ‘quicklime’. The quicklime is then submerged into the water for weeks or months to create a lime putty, or ‘slaked lime’, which is then mixed with sand and water to create the lime mortar.

                  Portland cement was invented around the 1820s by heating limestone with clay, mixing it to create a slurry, then heating it again. This formula achieved quick drying times, which helped it gain its commercial recognition and become the favoured additive to residential and commercial lime mortars.

                  Is mortar the same as cement?

                  Understandably, the name “Portland cement” can cause confusion in that it sounds like… well, cement. However, cement is a binding powder that is never used alone; it is a component of both concrete and mortar, as well as tile grout and thin-set adhesive. Therefore, cement is an element of mortar, so mortar and cement are not synonymous with one another. To break it down even further, here are the differences between cement, concrete and mortar:


                  • Binding component of both concrete and mortar
                  • Comprises limestone, clay, shells and silica sand
                  • Hardens and gains strength when mixed with water


                  • Used for building foundations, slabs and masonry
                  • Comprises cement, sand and gravel
                  • Forms into a flexible mould


                  • Substance that ‘glues’ bricks and blocks together
                  • Comprises sand, cement, water and sometimes limestone
                  • Not used as a sole building material

                  Is mortar waterproof?

                  When rain comes into contact with exposed walls, the water can freeze in the bricks and the surrounding mortar which expands the mortar, thereby causing damage. Not only does this freeze-thaw weathering look unappealing but, the longer it’s ignored, the more likely it’ll lead to a cold and damp house. Therefore, if you can see cracks in your mortar, you might want to consider repointing your property.

                  How much does repointing mortar cost?

                  Repointing generally costs between £20-£40 per metre squared depending on the condition of the brickwork. In addition, scaffolding may add to the cost. Working out the square meterage of your external walls is easy: you just need to go outside and measure the length and height of the wall, then multiply the two numbers together.

                  The alternative to repointing mortar: External wall insulation

                  If you’re considering investing in repointing, it would be extremely worthwhile to go that bit further and consider having external wall insulation installed onto your home. Both external wall insulation and thin-coat renders will provide a weather-tight seal on your external walls, as well as enhance their appearance, increase thermal qualities and reduce energy costs. It might be more expensive but think of all the long-term benefits! If your property is a cavity wall property, learn more about why you should have external wall insulation installed on your cavity walls here.

                  Is mortar needed in External Wall Insulation?

                  If your property has uneven substrates and you’re considering having external wall insulation installed, Levelling Mortar is the perfect product for preparing an even substrate before applying an external wall insulation system. Levelling Mortar is a polymer-modified sand and cement mixture which can be used for repairing and filling cavities and walls, making for an easy installation and application of external wall insulation and render. Read more about the stages of an external wall insulation system here.

                  We hope this blog was useful in clarifying the purpose of mortar, the difference between lime mortar and Portland cement, the permeability of mortar and whether you need to repoint your mortar or go for external wall insulation. If you have any questions, do not hesitate to comment below or ask our lovely Sales Associates!

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                    Installing External Wall Insulation

                    Want to spruce up the look of your property? Fed up with the temperature fluctuating in your home? Looking for a way to cut those energy bills? Then, look no further than external wall insulation. The EWI Store team are here to answer all your unanswered questions about external wall insulation and render solutions; find our contact details here to get in touch.

                    Shop all your external wall insulation needs now!

                    Can you apply render in hot weather?

                    As we approach the summer months, you might be wondering whether the hotter weather may impede your plans to apply render to your property – and rightly so. If applied in the right conditions, render can drastically improve the aesthetics of your home but, if applied in the wrong conditions, the aesthetic may not appear as you’d hoped. Read on to learn when and how you should apply render to your home.

                    In the past, we’ve received several complaints from homeowners regarding how their render has dried; the most common including the appearance of pinholes and drying faster than expected. Issues like these can be the result of the render being applied in too hot weather conditions or direct sunlight as the product has specific temperature margins within which the product will work at its best. The temperature margins tend to be around 5˚C – 25˚C, but each render’s margins may vary, so you should always check your product packaging to determine its specific temperature requirements.

                    These issues, then, do not reflect the quality of the products but the fact that they were applied in inadequate conditions. Although pinholes may occur over time, there is normally a reason for their occurrence. For instance, if a render primer has not been applied, especially in warmer weather, the likelihood of pinholes increases. As the basecoat is very dry and porous, it will absorb the moisture from the render very quickly, thereby massively increasing the risk of pinholes. Render primer, however, prevents this from happening by creating a barrier between the render and basecoat.

                    Another reason why pinholes might occur is due to the product drying too quickly. And, again, if a render primer has not been applied, this only exacerbates the problem. To avoid this, apply two coats of the render primer; this creates a stronger barrier between the basecoat and the render, further preventing the basecoat from absorbing the moisture.

                    Pinholes can affect most types of render – including silicone render, acrylic render and other thin-coat renders – however, switching to a different product based on this risk alone is not the ideal solution. Not only are pinholes a risk in any type of render, but you may not achieve the aesthetic look you were going for because some renders look very different from each other. What’s more, you will be deprived of all the amazing benefits renders have to offer; for example, a silicone render is extremely flexible, breathable and hydrophobic, unlike many other renders.

                    Although pinholes are unsightly, they are not the only aesthetic problems that may occur as a result of applying render in poor weather conditions. As the render, naturally, would dry much faster in hotter temperatures and direct sunlight than it would in normal temperatures, this would reduce the amount of time to correctly apply the product; this may lead to an unfinished or uneven texture.

                    It takes four men around three hours to apply 200 square meters of render. By not having enough time to apply the render, you may not be able to use the correct technique; this may result in an uneven textured finish which, in turn, can create the appearance of discolouration. The correct way to apply the render is in circular motions rather than in strips; this will help create that smooth, uniform texture that you envisioned your render to appear like.

                    The best way to reduce any of the issues mentioned is, of course, to apply the render in the correct temperatures and use the above techniques to help minimise the chances of pinholes occurring.

                    If you plan to complete your project in the middle of summer, the key is to get up early and get going! We have many installers who will start the process as bright and early as 5 am – it might not sound ideal, but it will be worth it in the long run. If possible, avoid applying render in the middle of the day as this is when the sun is at its hottest. Another technique – which may seem a little bizarre at first – is to work by avoiding the sun. What we mean by this is to follow the shadows and apply the render on the shadowed areas; as the angle of the sun changes, these shadows will move and so should you! This means you can keep applying your render while staying away from the glaring sun.

                    If you are interested in learning the correct process for applying render, you can enquire about attending one of our market-leading training courses or watch our YouTube video ‘Applying Silicone Render In Hot Weather’.

                    Don’t let these small risks put you off. There are no long-term side effects or damage to your property that can occur with pinholes; the problem is purely visual. If you can avoid pinholes by following the advice of this blog, you will notice all the wonderful advantages to rendering your property. Check out our blog The Benefits of Using Silicone Render to learn more.

                    If you have any questions, our Sales Team will be happy to help! You can find our contact details here.

                    Why you should have External Wall Insulation on your Cavity Walls

                    Whether your house should occupy cavity wall insulation (CWI) or external wall insulation (EWI) is an age-old question that still leaves homeowners confused. While it seems obvious that CWI should be installed on cavity walls and EWI on solid walls, there are many benefits to having EWI installed on your cavity walls. Of course, the decision ultimately comes down to what best suits both your budget and your property; however, with CWI’s history of creating issues surrounding damp and mould compared to EWI’s aesthetically pleasing and energy-saving properties, it’s clear why EWI is quickly becoming the favoured choice.

                    If you’re still torn on which type of insulation would be best for your home, we’ve compiled a little guide on the advantages and disadvantages of both CWI and EWI to aid your decision.

                    Advantages of Cavity Wall Insulation

                    If CWI is the only option for you, it does offer some benefits:

                    • CWI does not alter the external appearance of your property
                    • CWI helps to reduce your energy bills
                    • CWI keeps your house warmer in the winter
                    • CWI helps to reduce your carbon footprint
                    • CWI is very quick and easy to install
                    • CWI is cheaper than EWI

                    Disadvantages of Cavity Wall Insulation

                    If you are considering CWI, it is important to consider these factors:

                    • CWI is at risk of being improperly installed by underqualified installers
                    • CWI has been known to trap moisture and cause dampness when poorly installed
                    • CWI restricts the amount of insulation that can be installed (dependent upon the size of the cavity), making it less effective than EWI
                    • CWI is not suitable for all buildings (i.e. solid wall structures)

                    Advantages of External Wall Insulation

                    In contrast, EWI offers many benefits:

                    • EWI massively improve the façade of a property due to the decorative topcoat
                    • EWI has no restriction as to how much insulation can be installed (you can get up to 200mm+)
                    • EWI regulates the thermal comfort of your home, thereby reducing energy costs
                    • EWI materials such as Rockwool have soundproofing capabilities as an added advantage
                    • EWI has minimal risk of dampness and condensation issues
                    • EWI does not cause thermal bridging
                    • EWI prolongs the lifespan of the building by protecting its exterior walls
                    • EWI increases the value of the property in terms of its energy efficiency and external appearance
                    • EWI requires very little maintenance
                    • EWI is suitable for virtually any property type

                    Disadvantages of External Wall Insulation

                    Though not strictly disadvantages, there are some things to consider before installing EWI:

                    • EWI is more expensive than CWI due to the number of materials required and the higher level of skill required to install it, but its long-term benefits make it worthwhile
                    • EWI requires skill to install to ensure it is safe and won’t cause problems further down the line, so you need to be careful as to who you hire
                    • EWI can be difficult to get planning permission for on older properties as it creates a completely new exterior
                    • EWI may need the occasional touch up to ensure the render topcoat remains fresh, but this can be easily completed by giving it a little wash and by using our Silicone Paint

                    The verdict: Why you should choose External Wall Insulation

                    If you already have CWI installed and it’s not as effective as you would like it to be, you can certainly have EWI installed as well. By doing this, not only will you achieve two layers of insulation but any thermal bridges within the existing CWI will be negated by the EWI. Together, CWI and EWI will achieve maximum aesthetic and thermal performance.

                    Nonetheless, the downside is that you can’t have one without the other; trying to install EWI onto an empty cavity wall will achieve very little given that the air within the cavity will be heated up before escaping. Therefore, if you don’t have CWI insulation already, be sure to have that installed first, then consider EWI at a later date.

                    To conclude, EWI offers an array of benefits to an insulated cavity wall property; it greatly increases the thermal comfort, massively enhances the façade and even prolongs the lifespan of the building, to name a few. If you’re looking for more advice on having EWI installed onto your home, do not hesitate to reach out to our technical team who are available to help every step of the way!

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                      How to fix cracked render

                      While sand and cement render is still commonplace on many properties throughout the UK, it has one major issue: it is prone to cracking. Traditionally six parts sand and one part lime, sand and cement render is typically applied at a thickness of around 20mm and coated with masonry paint to complete the aesthetic. While lime can enhance flexibility, this render is still not flexible enough to withstand natural movements of a building (namely, expanding in the summer and shrinking in the winter), therefore causing ‘hairline’ cracks. Such cracks can not only impact the overall aesthetic of a property but also lead to water ingress, causing further issues down the line, including dampness, heat loss and mould. If you’ve noticed cracks of any kind on the façade of your property, you’ve come to the right place as we’re going to explain how to fix cracked render.

                      If you’ve read our blog comparing sand and cement and thin-coat render systems, you’ll know that thin-coat renders are extremely flexible and therefore far less likely to crack than sand and cement render. As mentioned, sand and cement render is typically applied at a thickness of around 20mm; in contrast, thin-coat renders are exactly that: thin-coat, meaning that they range from 1mm to 3mm in thickness depending on the grain size chosen. What’s more, our thin-coat render systems are comprised of a flexible basecoat, embedded with fibreglass mesh for extra strength and crack resistance, then finished with a thin-coat render for a smooth, aesthetically pleasing finish. Going forward, we highly recommend choosing a thin-coat render system as their flexibility, durability and crack resistance is second to none.

                      Depending on the size, severity and stage of development of the crack(s) on your property, there are several options for fixing cracked render.

                      cracked render

                      1. Fixing completely damaged render

                      If the render is damaged all over (namely, full of cracks or peeling away), you have two options:

                      • Start again

                      The best solution for fixing cracked render is to start again! While this might not be what you wanted to hear, putting any other materials on top of cracked render is akin to using glue: it is only a temporary fix and, over time, the cracks will only continue to expand and worsen. Therefore, we always recommend stripping the existing render back to the brickwork, but we appreciate this may not be an option due to the time and cost implications.

                      • Add a thin layer of EPS insulation

                      The next best solution is to add a thin layer of EPS insulation (20mm or 30mm) to the wall; this first needs to be attached with adhesive, then anchored using mechanical fixings. Before adding the insulation board, try to remove any very loose render and make good the surface with a Levelling Mortar. Then, once the insulation boards are in place and the adhesive has set, you carry on the rest of the system as normal. On top of the insulation boards, apply a 6mm-thick basecoat layer with embedded reinforcing fibreglass mesh followed by a thin-coat render topcoat to provide a decorative finish. For more information on how much this render system typically costs, be sure to check out this blog on the cost of coloured render per square metre.

                      Essentially, applying a thin layer of EPS means that you are creating a new, stable substrate onto which you can apply the thin-coat render system. Also, it means that you will boost the thermal performance of your home, albeit this is relative to the thickness of the layer of insulation.

                      2. Fixing cracked render on just one panel

                      If only one panel – that is, one side of the house – is cracked, we recommend first filling the crack with our Levelling Mortar, then applying fresh layers of a basecoat and a topcoat render to that one panel. Hopefully, the panel in which the crack has occurred doesn’t comprise the whole side of the house caused naturally by, for instance, a downpipe, which can disguise where the new render meets the old render. The breathability of the basecoat, combined with the flexibility of the render topcoat, should provide a crack-free solution.

                      3. Fixing small cracks

                      There are some cases where a very small crack has occurred that needs fixing; for example, when a car has ‘gently’ hit the wall. In this situation, you have a couple of options.

                      Firstly, you can remove a square of render around the affected area and apply a basecoat and render topcoat to this area. This involves taking an angle grinder and cutting a clean square around the impacted area. The downside to this option, however, is that scarring where the new render meets the old render is inevitable as a consequence of the thinness of the new render. The square, marked out using rendering tape, ensures that the scar looks neat regardless.

                      The other solution for fixing a small crack is to apply a basecoat to the whole panel and re-render the property; again, this requires a bit more work, but you won’t be able to see where the original crack in the render was. This provides a nicer finish than marking out the square (as above).

                      We often see customers order additional buckets of render to make repairs on cracked or damaged render to simply ‘touch up’ the affected area but, 99% of the time, this will result in unsightly, visible scarring. That’s why we always recommend following one of the methods described in this blog depending on your circumstances.

                      Which thin-coat render should I go for?

                      Here at EWI Store, we offer four thin-coat coloured renders to choose from:

                      • Silicone Render: Silicone Render is a premium, modern coloured render that is available in hundreds of colours. Silicone Render is a very popular choice because it offers hydrophobic properties, meaning that it repels water, dirt and organic growth, thereby requiring very little maintenance. Silicone Render is also extremely easy to apply because it comes ready to use, so you can apply it straight from the pot. Read more about Silicone Render here.
                      • Silicone Silicate Render: Silicone Silicate Render is our most popular hybrid-silicone render. Silicone Silicate Render is our best-value render, offering the key benefits of a thin-coat render as well as the breathability, vapour-permeability and self-cleaning properties of silicone. If performance and functionality at a great price point are priorities, Silicone Silicate is a great choice.
                      • Acrylic Render: Acrylic Render is very similar to silicone, except it doesn’t provide the same breathability. It’s a solid middle-ground thin-coat render because it still provides the same flexibility and is great at holding onto colour pigment. So, this is also a fantastic choice if you are looking to fix a cracked render. Read more about Acrylic Render here.
                      • Mineral Render: Mineral Render is a dry-mix thin-coat render. This is a very popular choice if you live in a cold or rainy climate because mineral render is extremely fast-drying. The only downfall about this render is that you need to paint over it with silicone paint to seal it in because, if it’s left exposed to the elements, it can develop lime bloom due to its inclusion of Portland cement. Read more about Mineral Render here.

                      At EWI Store, we are very happy to provide help with cracked render. The best way to resolve this is to send photos to [email protected] so that we can provide bespoke, expert advice on how to best fix the cracked render!

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                        Can you paint over K Rend?

                        Is your house currently rendered in K Rend? Has it been a while since your house was rendered? Is it looking a bit dull and dirty? If this sounds all too familiar, then it might be time to consider refreshing the façade of your property. Simply painting over the render might sound like the most obvious way to achieve this, but there’s slightly more to it than that. This blog unpacks how to go about painting over a property rendered in K Rend but not before explaining what K Rend is to help you identify the type of render on your property in case you’re not sure.

                        What is K Rend?

                        Due to its renown, K Rend is often confused as the umbrella term for all types of render when, in fact, it is a brand of render. Here at EWI Store, we stock K Rend Silicone K1 Monocouche Render and K Rend Silicone TC15 Topcoat. K Rend Silicone Render is water-repellent, polymer-modified and self-coloured, meaning it is available in a variety of colours so you can achieve your desired coloured finish.

                        How long does K Rend last?

                        While K Rend looks fantastic upon application, it can eventually look a bit grubby due to prolonged exposure to the elements. If you can see black, red or green streaks anywhere on the façade, this is a sign of biological growth and an even bigger sign that it simply needs a good clean; a simple jet wash should do the trick. It is vital to get rid of any biological growth before painting over the render as it can continue to grow under the paint, defeating the purpose of refreshing the face of the property. Nonetheless, too high pressurised water can cause damage to the surface of the property, so it is worth considering hiring a professional to clean it for you.

                        How can I paint over K Rend?

                        Once your property is clear of dirt and biological growth, it can be painted. However, while it is possible to paint over K Rend with standard masonry paint, it is advised to consult with a professional who can recommend more compatible paints as masonry paint can compromise the render system. For instance, our Silicone Paint works with our Silicone Render to offer advanced breathability, flexibility and durability, which can also be tinted to match the very same colour as the current façade or to absolutely any colour you like, including any RAL and NCS colour. If you need assistance, you can contact our experienced technical team here!

                        The verdict…

                        So, to answer the question at the beginning, you can paint over K Rend. However, some factors need to be considered before doing so, such as the condition of the render before painting (does it need a good clean?) and the type of paint to use over K Rend (which should be discussed with a professional). Once these factors have been considered, your property can be given a lovely refresh! Don’t forget that you can contact our knowledgeable team regarding any other questions you have, or fill in the form below to send your request.

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                          Stages of Installing an EWI System

                          Stages of installing an EWI system

                          You might have heard about external wall insulation (EWI) through the likes of… well, us, or seen it in action whilst it’s being installed on your neighbours’ homes, but what you might not be so familiar with is how it’s installed. Here at EWI Store, we aspire to ensure that all our customers are fully informed about our EWI systems, including how they are installed in certain ways and why, and that what’s this blog is for. Here’s a simple step-by-step guide on how to install an EWI system.

                          Wall preparation

                          Before any work can begin, the external walls must be prepared. The preparation required varies depending on the condition of the building. In most cases, a simple scrub will do, but sometimes the existing external wall coating needs to be removed entirely. If you are installing EWI onto a smooth surface, then you will need to use our EWI-310 Universal Primer to allow the adhesive to stick to the walls. Alternatively, if the wall surface is uneven, the EWI-260 Levelling Mortar must be used to prepare the wall. To remove any organic growth, consider using a fungicidal wash.

                          Starter tracks application

                          Once the wall has been prepared, it is time to apply the starter tracks. The types of starter tracks to be applied depend on the EWI system being installed. The correct starter tracks should be applied to the walls above the DPC (damp-proof course). The starter tracks not only allow for the easy installation of insulation to the walls but also protect the surface of the insulation from weather, damp and other damage. The clip-on profile should be attached to aluminium starter tracks to create a neat finish between the starter track and the insulation.

                          Insulation application

                          After the starter tracks, the basecoat should be applied to the insulation using our modified dot-and-dab method (three dots in the middle and a layer all around the perimeter). For reference, the EWI-220 EPS Basecoat can be used as an adhesive. Use a notched trowel to spread the basecoat evenly across the back of the insulation board. The basecoat should be about 4-5mm thick. When placed on the wall, mechanical fixings should be used to enhance the security of the insulation (6 fixings per square metre of insulation). Allow 2-3 days for the basecoat to set before installing the mechanical fixings.

                          Beading and Verge Trims application

                          Before adding the basecoat, all beading must be applied. Beading is used to reinforce weak or impact-prone areas within the system, helping to prevent damage and reinforce structural integrity. Each beading has its own special function and area of application:

                          • Corner beads: Corner beads are embedded with mesh which sinks into the basecoat. Corner beads reinforce the external corners of the EWI or render-only system.
                          • Movement beads: Movement beads are used inside the corners of thermal insulation systems to create a permanent and weather-proof sealant of vertical movement joints.
                          • Bellcast beads: Bellcast beads are designed to provide a clean, natural stop to the render just above the DPC. The bellcast bead also propels water from the wall.
                          • Render movement beads: Render movement beads should be used where there is an expanse render area. The render movement bead should be applied vertically and is designed to prevent cracking within the render through thermal expansion and compression.

                          Basecoat and mesh layer application

                          After 2-3 days, another layer of the basecoat should be applied with a notched trowel over the top of the insulation boards at a thickness of 5-6mm. Then, fibreglass mesh is embedded into the basecoat in vertical strips using the flat edge of a notched trowel. Each vertical strip of fibreglass mesh should overlap its neighbouring vertical strip by approximately 10-15cm. At EWI Store, we recommend using fibreglass mesh because it increases the tensile strength of the system and goes an extra step further in preventing cracks and impact damage.

                          Render Primer application

                          Render primer is classed as an optional step, but to enhance durability and adhesion, we highly recommend applying a render primer to the basecoat. The render primer you use will depend on the render topcoat. For instance, if you’re using our Silicone Silicate render, the Topcoat Render Primer is the most suitable. Alternatively, for our Acrylic render, the Mineral and Acrylic Primer is most ideal. This should be painted on and then left to dry for 12 hours; check out our blog all about our primer range for a deeper insight into render primer and its properties.

                          Render application

                          Once your final basecoat layer is dry, the final step is to apply the render. When we talk about render, we are referring to our thin-coat render range. The thickness of the render determines how thick the layer should be on the wall. For instance, if you select one of our Silicone Renders with a thickness of 1.5mm, the render should be applied no thicker than 1.5mm from the surface of the wall because, even though our renders are extremely flexible, durable and breathable, this can hinder the EWI system. At EWI Store, our range of advanced silicone renders can be tinted to absolutely any colour, catering to any taste and enhancing the external appearance of your property whilst also improving its thermal comfort.

                          And, there you have it! Although this is a very basic installation guide that should be used merely for informative purposes, we hope you found this blog helpful in explaining the stages of installing an EWI system. Every installation is different so, if you have any further questions about installing EWI on your property, do not hesitate to call our technical team who are always happy to assist!

                          Monocouche Render vs. Silicone Renders

                          As you might have noticed, we offer a variety of advanced render systems here at EWI Store, the most popular being monocouche and silicone. Both monocouche and silicone render provide a decorative finish on the external walls of a property whilst also improving its thermal comfort. The result of the external appearance, however, greatly depends on the type of render chosen. In this blog, we discuss the main differences between monocouche and silicone render so that, if you are torn as to which one to choose for your renovation, we can assist in the decision-making process!

                          Monocouche Render

                          There are a wide variety of monocouche renders available on the market; here at EWI Store, we stock EWI Pro, K-Rend and Enewall. The key characteristic of monocouche render is that it is a through-coloured, thick-coat render. Monocouche render is very often compared to sand and cement render because it contains cement however, it is very different in terms of texture and characteristics.

                          Monocouche render tends to offer a chalkier finish than other renders. To provide the finished facade, the render is usually scraped to create a pitted effect. Available in a range of colours (natural and bright), it’s a very popular choice for homeowners who are looking to create a chalky, flat finish.

                          Silicone Render

                          Silicone render is a highly flexible, breathable and durable render that comes ready to use in 25kg buckets. Unlike monocouche render, silicone render is a thin-coat render, meaning it is applied very thinly on top of a reinforced basecoat. Although readily available in a standard white, silicone render can be tinted to absolutely any shade. Here at EWI Store, we have specialist tinting equipment that enables us to match to any RAL, NCS or Pantone colour, meaning we can cater to absolutely any taste. Silicone render can be used as a standalone system straight onto brick or applied onto external wall insulation boards to provide a decorative finish.

                          One of the main advantages of silicone render is that it is crack-resistant. The silicone properties within the render, coupled with the way it is applied, means that it is far less likely to crack than monocouche render.

                          Now that you know the difference between monocouche and silicone render, you might be wondering how much each cost to install. If so, we’ve got you covered: check out our blogs on monocouche scratch render cost per square metre here and coloured render cost per square metre here to get an idea as to how much you’re looking at.

                          We offer a variety of advanced silicone-based renders, including Nano Drex Silicone Render, Premium Bio Silicone Render, Silicone Render and Silicone Silicate Render. If you’re interested in trying any of these, be sure to give us a call and our lovely Sales Representatives will be happy to help!

                          If you’re looking for an approved installer to carry out the work for you, fill out the form below and we will be in touch. We upload blog posts every Tuesday and Thursday, so keep up to date with our blog and social channels to find out more!

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                            Can You Paint Over Silicone Render?

                            Have you had your Silicone Render for quite some time now? If so, you might be wondering how best to give it a little refresh. Here at EWI Store, we’re often asked how Silicone Render can be maintained to continue to exude a stand-out finish. Although Silicone Render has advanced self-cleaning properties, that doesn’t mean that it’s not completely susceptible to gathering dirt over time. To solve such, a gentle clean with a jet wash is perfect now and then however, houses that are likely to become dirty more easily – that is, those on busy roads or in highly-vegetated areas – may need to be painted over. That said, you might be wondering whether you can use standard masonry paint on top of Silicone Render. The simple answer is, while no one can stop you from doing so, it is highly recommended to use Silicone Paint instead. Keep reading to find out why.

                            Why use Silicone Paint on top of Silicone Render?

                            Silicone Render is a specialist, breathable render product ideal for application on external wall insulation systems where a breathable insulant, such as Mineral Wool, is being used. Therefore, while you technically can use standard masonry paint on top of Silicone Render, we recommend that you use Silicone Paint because it is also highly breathable. A standard masonry paint might not have such breathable properties which would completely nullify the render system’s ability to allow water vapour to pass through its surface, while a breathable Silicone Paint would work with the Silicone Render to continue to offer optimum performance.

                            The best thing about our Silicone Paint is that it is available in thousands of colours. If your current render system is coloured and you’re afraid that you won’t find a colour to match, never fear – our Silicone Paints can be tinted to absolutely any shade! That way, not only will the Silicone Paint still cater to your taste, but it will also freshen up the entire façade of the property and extend its lifespan.

                            How to apply Silicone Paint onto Silicone Render

                            Before you apply Silicone Paint to your render, there are a few preparatory steps that must be taken to ensure a flawless finish. First, you’ll need to clear the render of any dirt or grime. If the walls have been painted previously, you’ll need to remove any flaking paint using either a jet washer or a wire brush. Also, be sure to apply tape to areas that need protection from the paint, such as window and door frames.

                            Silicone Render is incredibly flexible and therefore highly unlikely to crack. However, if you notice any minor cracks, these too need to be filled.

                            We recommend applying the paint using a standard brush and roller, starting at the top and working your way downwards to catch the paint as it drips and runs. Silicone Paint can be applied in multiple coats, so once the first is dry (after about 12 hours), you can go over it with as many coats as desired. However, beware that – if your render has a finer grain size – the more coats of Silicone Paint you apply, the less visible the grain size will become.

                            So, if you’re looking to paint over your Silicone Render, look no further than Silicone Paint. Silicone Paint is the perfect solution for allowing your render system to continue to offer optimum performance, refresh the façade of your property and extend the façade’s lifespan. If you’re looking for a complete guide on how to maintain your render finish, be sure to check out our blog on how to look after your render finish here. As usual, if you have any questions, do not hesitate to contact us or comment below!


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                              FREE COLOUR CHART

                              Receive a FREE Render Colour Chart (and beanie)!

                              As a thank you to all our loyal customers and advanced installers, we at EWI Store are offering FREE Render Colour Charts AND EWI Pro Beanies! Our Render Colour Chart is a fantastic resource for customers and installers alike, so you don’t want to miss out on this opportunity. If you’re wondering what a Render Colour Chart is, or equally how to receive your free copy, keep on reading!

                              What are Render Colour Charts?

                              At EWI Store, we understand that choosing the right render colour for your property can be a difficult decision; it’s hard to visualise exactly how the colour you want – or think you want – will look on the finished facade. And, when you hear that we offer thousands (yes, thousands) of colour choices, you can feel even more overwhelmed. That’s where our Render Colour Charts come to save the day!

                              Our ability to tint our render to absolutely any colour, including any RAL, NCS or Pantone shade, means that we cater to absolutely every taste. Our Render Colour Chart is available for our entire thin-coat render range, allowing you to visualise realistic colours and textures before making your final decision.

                              Our Render Colour Chart is not just a leaflet with small images; it is a durable, compact hardback brochure that provides official swatches of different render colours and grain sizes. Our installers find them to be an extremely handy resource, so you don’t want to miss out on receiving one for FREE!

                              How can I receive my free Render Colour Chart?

                              If you are not already registered with us, you will first need to create a trade account with us. Click here to register your account with us. If you are already registered with us, simply make sure you are logged in to your account.

                              Then, to receive your free Render Colour Chart, simply go to your cart and enter the code colourchart21 in the text box. What’s more, you will also receive a free EWI Pro Beanie AND free postage with your free Render Colour Chart – what a deal!

                              On behalf of everyone at EWI Store, we want to thank you for your custom and loyalty. We hope you enjoy your free gifts!

                              Coloured Render Cost Per Square Metre

                              Here at EWI Store, we offer a vast range of coloured renders to both improve the look of your home and cater to every taste. Our renders can be tinted or matched to absolutely any colour, including any NCS, RAL and Pantone colour, allowing for maximum colour customisation. What’s more, with their advanced breathable, flexible and self-cleaning properties, rest assured our renders will offer your property the utmost protection.

                              Choosing a coloured render for your property can be overwhelming. That’s why we offer colour charts and render tester pots to assist you in deciding which colour is best for you before making a purchase. However, once you’ve made the all-important decision as to which colour you’d like, you’re probably wondering: how much will it cost? Well, wonder no more, as we’re here to help!

                              Calculating the cost of coloured render per square metre

                              To work out exactly how much coloured render you will need for your property, we first need to work out the approximate square meterage of the property.

                              Working out the square meterage of your external walls is easy: you just need to go outside and measure the length and height of the wall, then multiply the two numbers together. This needs to be repeated for each wall you intend to render, then totalled all together; this total will give you the external wall area.

                              Priming the substrate

                              Assuming the substrate is standard masonry, we recommend that you use our Water Based Primer, which costs around 30p per square metre.

                              Applying the Basecoat and Mesh

                              Then, we need to take into account the basecoat layer, which goes on before the coloured render to smooth out the external wall and aid adhesion. Fibreglass Mesh is also embedded in the basecoat. One bag of our EPS Basecoat will cover 4 to 5m2, which will cost £2.40 per m2. The Fibreglass Mesh, which will be embedded within the basecoat, will cost approximately 70p per square metre.

                              Using a Render Primer

                              Now, we need to consider how much render primer your property will require. For a Silicone Silicate system, you’ll need our EWI-333 SiSi Render Primer, which can also be tinted to match the colour of the render for extra opacity and pigmentation.

                              A large 21kg bucket of Render Primer will cover approximately 60m2. This means that the primer will come to roughly 80p per square metre.

                              • Top Coat Primer – 20kg

                                £67.00 (incl VAT)

                              Choosing a render

                              Let’s assume you want to go for a Silicone Silicate Render. First, we need to calculate how much Silicone Silicate Render costs per square metre.

                              For instance, one bucket of Silicone Silicate Render – with a grain size of 1.5mm – will cover between 9 and 10m2, which is roughly £4.90 per square metre.

                              When buying your render, remember that coverage will vary based on the grain size that you go for; the larger the grain size, the more product you will need because it will provide less area coverage.

                              Silicone coloured render

                              Beading per m2

                              Finally, we find that beading usually costs approximately £2 per square metre, although this can vary depending on the property.

                              The total cost of Silicone Silicate coloured render system per square metre

                              Altogether, the cost of a Silicone Silicate Render system per square metre approximately come to £10.80. Bear in mind that this is an approximation. Nonetheless, if you were to multiply this number with the square meterage of your property, you should get an idea as to how much the materials will cost for installing coloured render on your home!

                              Which coloured render do I choose?

                              We have a huge range of coloured renders to choose from, all of which are BBA-approved and of the highest quality on the market.

                              We also provide tester pots that allow you to test different colours. It’s always best to see the coloured render in-person to ensure that you are happy with your decision before it’s applied all over your property.

                              Our thin-coat-coloured renders are bestsellers. We offer:

                              • Silicone Render/Silicone Silicate Render: Silicone Render is a premium, modern-technology coloured render which is available in hundreds of different colours. It is a customer favourite as it offers hydrophobic properties, meaning that it repels water, dirt and organic growth. Silicone Render is also ready-to-use, making it super easy to apply; it can be applied straight out of the box! Read more about Silicone Render here.
                              • Acrylic Render: Acrylic Render is very similar to Silicone Render, except it doesn’t provide the same hydrophobic properties. Saying that, it still provides the same flexibility as other thin-coat renders and is great at holding onto the colour pigment; it’s a solid middle-ground thin-coat render. Read more about Acrylic Render here.
                              • Mineral Render: Mineral Render is a dry-mix, thin coat render. This is a very popular choice if you live in a cold or rainy climate because mineral render is extremely fast-drying (you can’t apply other renders in cold or wet conditions as they take longer to dry). However, this render needs to be painted afterwards with silicone paint to seal it in because, if it’s left exposed to the elements, it can develop lime bloom due to its inclusion of Portland cement. Read more about Mineral Render here.
                              • Monocouche Scratch Render: Monocouche Scratch Render is a thick-coat, through-coloured render. It is more traditional but does require extra work to install; it needs to be applied in two passes to provide extra strength and cannot be applied in wet or humid conditions. Monocouche Render also needs Fibreglass Mesh embedded within it to provide extra strength and flexibility, ultimately making it crack-resistant. Then, once it’s dried, it needs to be scratched back to achieve the desired texture. If our monocouche system is of interest to you, check out our blog Monocouche Scratch Render Cost Per Square Metre for a detailed insight into how much you’re looking at with this system.

                              How much does Coloured Render cost to maintain?

                              Let’s say, 10 years down the line, you want to give your render a bit of a refresh; Silicone Paint is a great way to do this as it can be matched to the exact colour of your existing render. To learn more about why Silicone Paint is best for refreshing an existing polymer-modified render, you can read this blog. However, in terms of sprucing up your render, a 15l bucket of Silicone Paint typically covers 60 to 70m2. Therefore, you’re looking at around £3 per m2.

                              So, what do you think? Does Coloured Render sound right for you? Was this blog helpful? Be sure to comment with your thoughts and questions, should you have any, below – again, we’re here to help!



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                                Applying Render to Cement Board

                                What are cement boards?

                                Cement boards, also known as “render carrier boards” or “weather carrying boards”, are sheets comprised of cement and reinforcing fibres used as tile backing boards as a base for render and external wall insulation. Combined with magnesium, an oxide coating and fibreglass mesh, cement boards create a solid surface that can withstand extreme weathering, including rain, wind and snow. What’s more, cement boards do not rot or swell when they encounter water, meaning they can stand the test of time even on the exterior of a property. The most common cement boards on the market for render are Aquapanels, Renderflex and Siniat boards.

                                Applying render to cement boards

                                Cement boards can be finished in numerous ways however, one of the most effective ways is to apply render. Not only does render enhance the external appearance of a property, but it improves its thermal performance and thereby reduces energy costs. With that, let us explain how to apply render to cement boards!

                                Step one: Priming the cement boards

                                The first step to applying render to cement boards is to prime the boards. We recommend using our EWI-310 Universal Primer as the presence of silicate in the render creates an excellent adhesive for the basecoat of the render (to learn more about how primers work, make sure to check our complete guide to EWI Primers). The Universal Primer comes in 20kg buckets, and each bucket can cover between 60 and 80m2 depending on the absorption from the cement board. The primer should be applied to the cement board using a brush or roller; its red colour allows you to see clearly where on the wall it has been applied. For best results, allow the primer to dry completely before applying the next layer.

                                Step two: Applying the basecoat

                                After the primer, applying the basecoat to the cement board is relatively easy. Firstly, an adhesive must be applied; our adhesives come dry, meaning they must be mixed with water before application. We recommend using either EWI-220 Basecoat Adhesive or EWI-225 Premium Adhesive depending on how solid you would like the facade. Upon being mixed with water to form a grey putty, the adhesive should be applied with a notched trowel. For best results, use a 10mm-sized notched trowel for applying a 6mm-thick layer of adhesive to the cement board.

                                Once the adhesive has been applied, the fibreglass mesh can be embedded within the adhesive; it is this mesh that makes our render systems so flexible. The fibreglass mesh comes in rolls which must be applied vertically, overlapping one another by 10cm, within the adhesive; this can be achieved by drawing the flat edge of the notched trowel up from the bottom of a wall to pull the adhesive through the holes of the mesh. Our EWI-66645 Orange Fibreglass Mesh rolls are 50cm in length, 1m in width and cover 50m2.

                                As the render topcoat is so thin, it is vital to ensure that the basecoat is completely smooth. If the basecoat is still not completely smooth even after the mesh has been embedded, the easiest solution is to produce a very wet adhesive mix to apply to the basecoat.

                                Step three: Priming the basecoat

                                Once the fibreglass mesh-embedded adhesive is completely smooth, the wall needs to be primed ready for the render. The primer used depends on the type of render however, provided you match the primer with the render, the principle is the same. For example, our EWI-333 Silicone Silicate Primer comes in either 7kg or 2kg buckets and can be applied using a paintbrush or roller, with the 7kg bucket covering approximately 20m2 of the wall and the 2kg bucket 70m2.

                                • Top Coat Primer – 20kg

                                  £67.00 (incl VAT)

                                Step four: Applying the render

                                As soon as the basecoat primer is dry, it is time to apply the render!

                                The majority of EWI Pro renders are thin-coat renders, so the thickness of the topcoat is determined by the grain size of the render. For instance, our EWI-040 Silicone Silicate Render comes in four different grain sizes – 1mm, 1.5mm, 2mm and 3mm – so, if you are to purchase a 2mm-thick Silicone Silicate Render, the topcoat should be applied no thicker than 2mm thick. We have received various reports of the render being applied too thick and thereby impinging on the desired finish, so it’s vital to remember that the thickness of the render itself and render facade must match!

                                With that in mind, make sure to apply the render to the cement board with a trowel as you can pull off any excess with the trowel, too. Once any excess has been removed, leave the render for five minutes, then work the render in a circular motion using a plastic float to achieve the desired finish.

                                And that’s how render is applied to cement boards! If thin-coat render systems are of interest to you, make sure to check out our blog on coloured render costs per square metre for an accurate idea as to how much the materials for such a system typically cost. If you have any questions, do not hesitate to comment below or contact us!


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                                  The Best Masonry Paint? Silicone Paint

                                  Are you interested in re-rendering your property and seeking high-quality masonry paint to coat the render for a fresh, modern finish? Then look no further than Silicone Paint! At EWI Store, we often receive enquiries about our Silicone Paint, the most common being “what is Silicone Paint?”, “what is Silicone Paint used for?” and “what’s the difference between Silicone Paint and Silicone Render?”. If you’re wondering the same, don’t worry – we’re going to cover everything you need to know about Silicone Paint right here, right now!

                                  What is Silicone Paint?

                                  Silicone Paint is a high-performance masonry paint that can be used for painting over either an existing Silicone Render to refresh the facade, or over our Mineral Render to seal the render. It is highly breathable, waterproof and resistant to environmental pollutants, making it perfect for homes in busy or humid environments where render alone may be susceptible to organic overgrowth. Silicone Paint is also available in thousands of colours, catering to every taste!

                                  What is the difference between Silicone Paint and Silicone Render?

                                  The names are self-explanatory; Silicone Paint is a masonry paint topcoat, while Silicone Render is a type of render finish. Their only similarity is that they both contain Silicone which provides numerous benefits, but we’ll come to those a bit later!

                                  While our thin-coat renders come in various grain sizes, ranging from 1mm to 3mm, our Silicone Paint is completely smooth, meaning it can be applied on top of an existing render without disrupting its texture.

                                  As with our Silicone Paint, our Silicone Render is hydrophobic, meaning it repels water, dirt and organic growth. However, even with all these capabilities, render can eventually look tired after so many years. That’s where Silicone Paint comes in; not only does it offer the render a decorative refresh, but also an extra layer of protection with its same hydrophobic properties, prolonging the render’s lifespan.


                                  Why use Silicone Paint?

                                  As we know, the ingress of water is detrimental to external wall insulation and render-only systems. In external wall insulation, the presence of water can reduce the system’s thermal capabilities and lead to freeze-thaw damage. In a render-only system, it can dampen the internal walls, especially in solid wall properties, damaging the overall render. Therefore, as part of external wall insulation or render-only systems, Silicone Paint is particularly beneficial; its breathability allows water to escape through the surface of the paint. Also, its vapour permeability makes it frostproof, meaning it won’t damage the surface of the paint.

                                  At EWI Store, we always suggest to our customers that our Mineral Render should be sealed with high-performance masonry paint like Silicone Paint. Mineral Render is our fastest-drying render, making it perfect for cold climates. However, its ingredients mean that, if exposed to the elements for too long, it can be susceptible to lime bloom. That’s why Silicone Paint is necessary as a topcoat; it prevents water from travelling through to the render and forming lime bloom.

                                  Silicone Paint can be matched to the Silicone Render underneath!

                                  If you’ve used one of our coloured Silicone Renders, then you can buy a Silicone Paint in the same colour to match! Here at EWI Store, we offer a same-day colour mixing service using our Render Colour Machine, which can tint Silicone Paint to thousands of colours. So, even if your render is not from EWI Pro, we can still match the colour to give it a refresh!


                                  As well as exteriors, Silicone Paint is great for interiors!

                                  Up to now, we’ve talked a lot about Silicone Paint can be used as a masonry paint as a render top coat to offer both a protective and decorative finish. However, as for exteriors, Silicone Paint is also great for interiors!

                                  Given that it’s waterproof, we’ve encountered many people who have used Silicone Paint in their bathrooms, making it perfect for combatting condensation on bathroom walls. Likewise, we’ve heard that people who have previously suffered from damp problems in their homes have used Silicone Paint as a deterrent, limiting the chances of such issues in future. One of our team members has even used Silicone Paint on his garden wall to prevent organic growth! In our opinion, all the above are great ways to utilise Silicone Paint.

                                  Get in touch to buy Silicone Paint!

                                  We’re always happy to answer any questions about our products. If you’re interested in using Silicone Paint for your home, don’t hesitate to give us a call so we can discuss its suitability for your situation; we can work out exactly how much you’ll need depending on the square meterage of your property.


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                                    Replacing Pebbledash with Coloured Render

                                    Pebbledash is perceived by many as an outdated look for a property; it was frequently used during the post-WW1 housing crisis as a means of covering up quickly-built, slap-dash properties. If you live in the UK, you are most likely to have come across a pebbledash building and, while it’s a durable building method, it’s definitely an acquired taste.

                                    What is pebbledash?

                                    The pebbledash effect is created by applying a layer of mortar (usually sand and cement) to an external wall and literally throwing pebbles at the wall. Pebbledash houses are still dotted all over towns and cities in the UK and can often have a somewhat dilapidated look. Over time, the pebbles can drop from the wall, leaving the mortar exposed to the weather and therefore vulnerable to absorbing water and causing damp issues. Also, due to its unpopularity, pebbledash can reduce the value of a property purely for its lack of aesthetic appeal. This is why coloured render is vastly more popular because it’s much nicer to look at. Our coloured renders can be customised to absolutely any colour of your choice and can be ordered online or over the phone!

                                    How can I replace pebbledash with a coloured render?

                                    While we’re not hating on pebbledash (much), you might want to consider re-rendering your property, whether you’re moving into a new home, updating the look of your current property or both. However, as one of our frequently asked questions here at EWI Store, we recognise that there is a knowledge gap on how to apply render on top of pebbledash. That’s why we’ve made this blog – to tackle the question for all you pebbledash homeowners!

                                    The short answer is that, unfortunately, you cannot replace pebbledash with coloured render by applying coloured render directly on top of the pebbledash. Saying that, there are several ways around it that you may wish to consider.

                                    Essentially, there are three possible options for removing pebbledash:

                                    Option 1: Removing the pebbledash

                                    The first option is to attempt to remove the pebbledash by hacking it off. However, the main downfalls to this option are that the brick underneath is at risk of being damaged, and there is no guarantee that you will achieve a smooth finish. If this is the best or only option for you, be very careful about who you hire to tackle the task; make sure they are experienced in removing pebbledash. If your pebbledash is forcibly removed, this can really damage the underlying wall and invalidate your house insurance. It’s also important to note that, even after all this, you still wouldn’t be free to apply coloured render directly on the wall. Building regulations stipulate that if you strip it right back to the original brick, then you’ll need to insulate before rendering with a coloured render.

                                    Option 2: One Coat Dash Cover (OCDC) to cover up pebbledash

                                    The second option is to use the One Dash Coat Cover (OCDC) to completely smooth over and cover up the pebbledash to achieve a clean slate. This product is specifically designed to be applied on top of pebbledash, and it can then be painted or rendered to achieve a modern appearance. The good thing about the OCDC is that it is breathable, so it will allow any trapped moisture within the underlying pebbledash to escape. It can also be applied up to 20mm in one pass (up to a maximum of 50mm), so it’s guaranteed to smooth over the pebbledash nicely!

                                    Option 3: Insulate then render over pebbledash

                                    A beneficial way of ridding the pebbledash look is by installing 20mm (or thicker, but the thicker you go, the more expensive) external wall insulation (EWI) boards over the top of your pebbledash. This is a great option because the EWI will give you added insulation, which can save you money on bills in the long run.

                                    By installing EWI boards, you will also save time and money because hacking off the pebbledash won’t be necessary. Instead, you can simply secure insulation boards over the top of the pebbledash using adhesive and mechanical fixings. Once you have done this, you can apply the render of your choice on top of the insulation boards and achieve a far more pleasing outcome.

                                    Which coloured render can I use to replace my pebbledash?

                                    There are so many options for replacing your pebbledash with coloured render that it can be quite overwhelming. We want to give you a clear idea of what each coloured render can offer so that you can make the right choice to suit the needs of your property and your personal taste.

                                    Thin Coat Coloured Renders to Replace Pebbledash

                                    Thin coat renders are a great option for when removing your pebbledash and replacing it with coloured render. Because they are thin-coat, they offer a level of flexibility that ensures that your coloured render finish stays crack-proof for years to come. Thin coat coloured renders are also highly breathable, so they will help to prevent problems with damp and mould on your walls.

                                    They also come in different grain sizes, which determines the textural finish that the coloured render will offer you – the bigger the grain size, the more textured the finish that you’ll achieve. If you have simply removed your pebbledash, then you may want to go for a larger grain size as this makes any imperfections in the basecoat less noticeable. Read our blog Coloured Render Cost Per M2 for an idea of pricing!

                                    There are three options that you can choose for thin coat coloured renders:

                                    • Silicone render/Silicone Silicate render: Silicone Coloured Render is a premium, modern technology coloured render – which is available in hundreds of different colours. Silicone is a very popular choice because it offers hydrophobic properties – which means that it repels water, dirt and organic growth – so it probably requires about the same maintenance as pebbledash (very little). Silicone render is also super easy to apply because it comes ready to use, so you just apply it straight out the pot. (Read more about Silicone Render here).


                                    • Acrylic render: Acrylic Coloured render is very similar to silicone, except that it doesn’t provide the same hydrophobic properties. It’s a solid middle-ground thin coat render because it still provides the same flexibility, but it’s also great at holding onto colour pigment. This is a fantastic choice if you are looking to replace pebbledash with a coloured render. (Read more about Acrylic Render here).


                                    • Mineral render: Mineral Coloured render is a dry-mix, thin coat render. This is a very popular choice if you live in a cold or rainy climate (as many pebbledash homeowners do – Scotland, coastal homes!) because mineral render is extremely fast drying; you can’t apply other renders in cold/rainy temperatures because they take longer to dry. The only thing about this render is that you need to paint it afterwards with silicone paint to seal it in. This is because, if it’s left exposed to the elements, it can develop lime bloom due to the presence of Portland cement. (Read more about Mineral Render here)

                                    Thick Coat Coloured Renders to Replace Pebbledash

                                    Thick coat renders are far more traditional but, as the name suggests, they do lack flexibility and breathability because they are applied in a much thicker layer. Once you’ve removed your pebbledash, you can use our Monocouche Scratch Render. Note: thick coat renders aren’t suitable for application on top of insulation boards.

                                    • Monocouche scratch render: Monocouche scratch render is a thick coat, through-coloured render. It is more traditional, but does require extra work to install it. This is because the Monocouche needs to be applied in two passes for extra strength and cannot be applied in wet or humid conditions. Monocouche render then needs fibreglass mesh embedded within it to provide extra strength and flexibility (which means it will resist cracking) and then, once dried, it needs scratching back to achieve the desired texture. Read our blog Monocouche Scratch Render Cost Per M2 for an idea of pricing!

                                    To conclude…

                                    If you are a pebbledash homeowner, looking to re-render, or potentially even install EWI, then we have everything you will need. Check out our materials calculator or get in touch with us directly and we can point you in the direction of one of our fantastic approved installers!

                                    Are you a fan of Pebbledash? Leave a comment below…

                                    Let’s debate: pebbledash or no pebbledash? Leave a comment below with your opinion; is pebbledash outdated and ugly, or is it a relic from our past that we should preserve for traditional purposes? For those in favour of the pebbledash look, we might have something just for you.


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                                      Can I install EWI onto my flat?

                                      There seems to be a bit of a gap in information out there about whether it is possible to install external wall insulation (EWI) onto a flat, so we wanted to answer this question for you and provide as much information as possible for any flat-owners who are considering EWI!

                                      In most cases the answer is yes, you can install EWI onto a flat. However, usually the insulated render system is sealed at the top where it meets the soffit of the roof. So, on a groundfloor flat the insulation must be sealed at the top by other methods. This is because if it isn’t sealed, the exposed edges of the insulation can allow for water to seep behind the back of the insulation boards which can in turn effect the integrity of the EWI system, and water can then also enter the property through the walls causing problems with damp and mould.

                                      We would recommend that EWI is most ideal for people who own a ground floor flat. This way, the EWI is at least sealed at the base so to prevent too much heat loss and water ingress, and the EWI will most likely be less noticeable.

                                      So how do you install external wall insulation onto a flat?

                                      Installing external wall insulation onto a flat is a slightly different process than with a normal house. This is because if the top of the insulation is exposed, i.e. does not meet the soffit of the roof, then certain actions will have to be taken to ensure that the EWI on your flat is water-tight.

                                      There are a few options to consider in order to achieve a water-tight finish:

                                      With the upper ledge of your insulated render system exposed, you will always need to use a verge trim to protect the EWI from water exposure. One option is using a basic verge trim which screws into the wall above the EWI. However, this is not entirely water tight because the top of the verge trim is not sealed, so you will need to use a sealant along the upper edge of the external insulation to prevent water running down its back.

                                      The second option is using a Grind-in verge trim. As the name suggests, this is a verge trim with the length of its upper edge inserted into the wall surface. However, you have to first damage the surface of the existing wall to insert the verge trim, and the result is that it’s still not completely watertight. This method is therefore still a bit risky.

                                      We suggest that the best option is to use lead flashing with a normal verge trim. This doubles up the waterproofing so that the lead flashing protects the verge trim, and the verge trim protects the top of the EWI.

                                      As for the base of the external solid wall insulation, if it’s exposed (because your flat is not on the ground floor), then we recommend the use of white PVC so that it will look nicer for your neighbours below to look up at.

                                      Pro’s of installing external wall insulation onto your flat

                                      EWI is a great way to save energy on your heating bills. Most flats have electric heating, which is far more expensive than gas heating. This means that heat loss through the external walls of a flat is much more problematic for you as the homeowner, because you then need to spend even more money on re-heating the flat. EWI can dramatically reduce the amount of heat being transferred through the walls of your flat and save you a lot of money on energy bills every year.

                                      As well as this, people who live in flats are often in a more built-up area which suggests more noise from road traffic. For people living on ground-floor flats this is potentially more of an issue and can be exceedingly unpleasant, so installing insulated render can greatly improve the amount of noise that enters your home.

                                      People living in flats are also the most likely candidates to be struggling for space. EWI takes up absolutely none of the internal floor space, which means that your property will not lose any value due to a decrease in the size of its rooms and you will still have plenty of moving around space!

                                      Cons of installing EWI onto your flat

                                      If you install external wall insulation onto your flat, depending upon the thickness of the insulation boards, it could mean that the external walls of your flat will physically stand out from the rest of the building and the necessary verge trim may not be a particularly attractive feature to look at. Also, depending upon the external walls of the rest of your building, you might need to spend more to ensure that your render matches the overall look of the building. There are a number of ways you can do this, for example we offer a variety of very realistic looking brick slips which could work really well at blending the EWI on your flat in.

                                      Most flats are lease-hold only, so you would likely need to ask for permission to install EWI, which is potentially a long and difficult process. It can be an expensive job for a small property and is not guaranteed to be as energy efficient as if you were to insulate an entire house, for example. Also, you will have increased scaffolding costs if your flat is on an upper level.

                                      People who live flats live in very close quarters with their neighbours, so any work being done to your flat is likely to be more disruptive. Upset neighbours may therefore complain about any disruption during installation time, and may not be all too pleased with the finished look.

                                      The best thing to do when considering an EWI installation is to seek professional advice. We recommend that you hire a surveyor to discuss the feasibility of installing EWI onto your flat. Our staff are all extremely knowledgeable about EWI, and are always happy to help in any way. For any enquiries, please do not hesitate to call us here at EWI Store.

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                                        Is External Wall Insulation worth it in 2021?

                                        2021 is here, and with it comes a lot of uncertainty and worry. For homeowners out there, it can be a difficult decision whether or not to make an investment in something like external wall insulation – while the benefits of EWI are vast, it’s not a cheap process.

                                        We’ve put together a list of reasons for why external wall insulation is worth investing in, so read on if you want to be convinced…

                                        Rising Energy Prices

                                        Some of the biggest concerns for people are the threat of energy prices rising even higher than they already are. Energy prices go up by 5% each year, and with Brexit applying pressure to all sectors, it’s likely that we will see a change in energy prices.

                                        In these circumstances, you can either vow to switch off everything and cope with it, or you can be ahead of the game. Invest in an energy-saving measure such as external wall insulation, and you can ensure that any future money spent on heating was well-spent rather than wasted.

                                        Housing Crisis

                                        In 2019, new-build properties where being vastly criticised for their apparent low-quality. There are definitely pros and cons of investing in new-builds, however, their resale values tend to be static for the first five years. Investing in older properties that require a little bit more TLC is the preferable choice for many buyers; external wall insulation is a great way to boost the efficiency and subsequent value of the property, bringing it in line with new-build standards while also giving it a bit of a facelift

                                        Climate Change

                                        Climate change is being talked about more and more in the media, portrayed as a looming threat that needs to be dealt with immediately. This leaves everyday people on the ground wondering what on earth they can possibly do to prevent this oncoming disaster, besides the standard solutions.


















                                        External wall insulation is a good option to go for, especially for those who live in properties with very low energy efficiency. EWI will reduce your energy consumption, improve your carbon footprint and save you money on bills – it’s a no-brainer. There are even EWI systems that are environmentally friendly, such as our Wood Fibre insulation system.

                                        2021 is looking to be a year of uncertainty, but we hope that this won’t stop people investing in being more environmentally conscious and energy aware. If you’re curious about external wall insulation and how exactly it’s installed, give us a call and we would be happy to have a chat with you.


                                        Best Performing External Paint – EWI Pro Silicone Paint

                                        What are External Paints?

                                        External paints have a variety of uses. They can be used on several different surfaces including but not limited to concrete, render, pebbledash, metal, and soft wood.

                                        A good exterior paint can improve your homes external appearance and protect it from temperature changes, moisture and fading. External Paint is essentially the ‘go to’ product for covering most rendered building facades. It’s decorative and protective.

                                        EWI Pro Silicone Paints

                                        Looking for the best performing external paint? Here at EWI Store we supply a range of EWI Pro Silicone Paints including EWI-005 Silicone Paint, EWI-007 Nano Drex Silicone Paint and EWI-006 Premium Bio Silicone Paint.

                                        EWI Pro Silicone Paints are high quality and can be used both internally and externally. All EWI Pro Silicone Paints are frost-proof, vapour permeable, hydrophobic, resistant to algae growth and ideal for use with Mineral Render or as a standalone finish.

                                        EWI Pro Silicone Paints are high-performance External Masonry paints. They can be painted over an existing render to refresh the facade and create a finish that appears brand new, or they can be used to paint over our Mineral Render to seal the render in.

                                        Application is dependent on the weather conditions, EWI Pro Silicone Paint should ideally be applied 3-7 days after you have applied the Mineral Render to the substrate. Doing this will make sure that a strong chemical and physical bond forms between the Mineral Render and the external paint.

                                        Why use a Silicone Paint externally?

                                        Silicone Paint provides a highly breathable finish which makes it perfect as part of a render or EWI system. It is known that water ingress and moisture is detrimental to rendered homes and to external wall insulation.

                                        If water manages to ingress into the external wall insulation system, it has the potential to reduce its thermal capabilities and can damage the system during the freezing and thawing process. Ingress of water within a render-only system is especially bad, as this water will cause damage to the render. There is a risk this moisture will seep into the walls of the property and inevitably cause damp patches on the internal walls, particularly with solid wall properties.

                                        This is where Silicone Paint comes in. Silicone Paint creates a protective barrier against this issue. The breathability of the Silicone Paint allows moisture and water to escape through its surface and prevents moisture from passing through, this is because the silicone properties within the paint repels water vapour. Because of its vapour permeability, Silicone Paint also has frost-proof qualities (This means frost will not cause damage by settling on its surface or within the actual Silicone Paint itself.)

                                        We always suggest sealing Mineral Render with a high-performance External Paint. Mineral Render is our fastest drying render, making it perfect for use in cold climates, however, its ingredients mean that if it’s exposed to the elements for a significant period of time it can be susceptible to lime bloom. This is why it becomes necessary to apply Silicone Paint over the surface, to prevent water from passing through and causing the formation of lime bloom on the render beneath.

                                        What Colours are Available?

                                        EWI Pro Silicone Paints are available in a multitude of different colours. Here at EWI Store we are able to colour match any RAL or NCS colour. This means we have a highly competitive range when compared to other external paint suppliers. We can match even the finest nuance of colour. Below are the colour options available online at ewistore.co.uk

                                        Colour OptionsColour OptionsColour OptionsColour options

                                        If you are interested in EWI Pro Silicone Paints we have paper colour charts which we give out free of charge to help give you a visualisation of the colour, just bear in mind that these charts are not a 100% accurate representation which is why we recommend ordering a coloured sample pot before committing to that colour.

                                        Choosing Your Perfect Silicone Render Colour

                                        After reading about all the amazing benefits rendering your home can provide, you have come to the conclusion that Silicone Render is the render of choice, but with all the available colour options you can’t decide what to choose.

                                        Fear not, you have come to the right place! In this blog I will be discussing our Silicone Render colour range here at EWI Store.

                                        We have an extensive range of colours because we are able to colour match any RAL or NCS colours. This means we have a highly competitive range when compared to other render suppliers. We take colour matching seriously and can match even the finest nuance of colour.

                                        Silicone Renders are an ideal choice when colour longevity is an important factor to you. Our range of Silicone Renders come pre-coloured and have self-cleaning and anti-bio growth properties which means your colour will stay clean and bright for longer. Our Silicone Renders are also UV resistant which helps prevent colour fade.

                                        Is white too bright?

                                        Many people choose to avoid a pure white render in fear of it appearing too bright in the summer months. Luckily, we are able to offer a range of white and off white shades including but not limited to Pure White, Platinum, Ice, Ivory and Linen.

                                        To see our full online range please take a look at our Silicone Renders. Choosing an off-white shade may be what you are looking for as this will give you that clean white finish whilst not being as bright as the brightest shade.

                                        If you do opt for our ‘Pure White’ shade then you can choose between grain sizes of 0.5mm-3mm. This texture may give your white a more diffused look preventing the shade reflecting too much light in the summer months.


                                        Looking for something bolder?

                                        Perhaps you are looking for a dark grey or a bright orange, whatever you are looking for we have got you covered!

                                        Something to consider when opting for a more unusual colour choice is ensuring that this colour will complement the surrounding area, don’t worry if you make a mistake choosing a colour though, as you can always cover this up with our coloured Silicone Paint.


                                        Fancy Mixing it up?

                                        Maybe you do not just want one colour, maybe you want to enhance a particular part of your house. Why not choose a contrasting colour, like black against white, or if you are feeling really adventurous, blue against orange?

                                        If you are still unsure on what colour to choose, try out our Colour Render Tool. This tool enables you to test out different render colours on real photos of your home. If you need a bit of help figuring out this tool, then check out our YouTube Tutorial.

                                        Colour Guides

                                        If you are interested in our Silicone Render, we have paper colour charts which we give out for free to help give you a visualisation of the colour, just bear in mind that these charts are not a 100% accurate representation as these have a smooth finish.

                                        If you are looking for an accurate colour representation, then consider visiting us in-store to have a look at our colour sample chart or buy one online at ewistore.co.uk. This chart is more accurate due to the grainy texture and the fact they are made from our actual render.

                                        We also offer Coloured Render Sample pots.

                                        For more information consider watching our YouTube video

                                        How to get that ‘new build’ look on your home

                                        How to get that ‘new build’ look on your home

                                        Does your house need that extra bit of love this year? Then you’re in the right place, this blog will tell you all about how to get that clean finish “new build” look on your home. This past year we have all spent more time indoors than usual, but that doesn’t mean we can’t give that little bit of attention to the exterior of our homes.

                                        Whether it’s insulating your home to reduce those heating bills, adding a new coat of render with a bold new colour, or even smoothing over that old pebbledash here at the EWI Store we have everything you could possibly need to achieve this!

                                        Rendering your home

                                        So, first things first, what are the benefits or rendering your home? Rendering your home has many advantages, from protecting the brickwork from damp and damage, to modernising the outside aesthetics of your house. Rendering your home may also offer another layer of insulation, keeping your home warmer in the winter months and reducing energy bills.

                                        There are many different types of render such as Cement Renders, Lime Renders, Polymer based Renders, Monocouche RendersAcrylic Renders, and Silicone renders.

                                        Silicone renders are growing in popularity due their unique properties over other types of render. Silicone renders are breathable, flexible, hydrophobic, and self-cleaning!

                                        The breathability of you render is important because it means that if moisture ever manages to get behind your render, it will be able to get out again, whereas if your render was not breathable, the moisture would stay behind the render, and potentially cause damage to your walls and render.

                                        Houses tend to swell in the summer and shrink in the winter months which can cause your render to crack. Cracking is not just worrisome for aesthetic reasons as cracks will create a moisture pathway for rain and moisture to get behind the render system. Once there, moisture can penetrate deeper and cause further cracking. The flexibility that silicone render offers, means that it is very resistant to cracking, more so than any other render and will stand the test of time.

                                        Insulating your home

                                        Externally insulating your home will reduce the amount of heat escaping through your walls, hence will save you money on your heating bill. This also means your home will warm up faster, last longer and reduce carbon emissions.

                                        As a result of keeping your walls warm and dry, the External wall insulation can protect the houses structure and improve its weatherproofing, which will in-turn prevent damage and keep your home looking fresh for longer.

                                        With different insulation solutions available, why should you use external wall insulation?

                                        External wall insulation can be applied with a variety of decorative finishes. This means that not only are you insulating your home, but you are also altering and improving its aesthetics. When externally insulating your home, you can choose between a multitude of different colours and several different textures.

                                        Externally insulating your home will cause some disruption, however when you compare this to the disruption caused by Internally insulating your home, it is significantly less and won’t reduce the size of your rooms, unlike Internal wall insulation.


                                        Covering up pebbledash

                                        Pebble dash became extremely popular in the 1920’s due to an increase in demand for homes to be built. This led to builders cutting costs and used pebbledash to cover up poor brickwork. In present this has resulted in a dated, and for many an unsightly look that many homeowners are looking to remove.

                                        Re-rendering pebbledash without removing pebbledash can be difficult if the right materials aren’t accessible. Removing pebbledash is a painful process, because removing the render requires hard work with a hammer and chisel, with the added risk of damaging the original brickwork. Typically, pebbledash is made from a sand and cement render – an incredibly unforgiving material that was often applied as a means of covering up a bad build job.

                                        OCDC is a product that is specifically designed to be applied on top of pebbledash, and it can then be painted or rendered to achieve a modern, updated appearance. The good thing about the OCDC (One Coat Dash Cover) is that it is breathable, so it will help any trapped moisture within the underlying pebbledash to escape. It can also be applied up to 20mm in one pass (up to a maximum of 50mm), so it’s guaranteed to smooth over the pebbledash nicely!



                                        COVID-19 Update

                                        Due to recent announcements we have taken into consideration the Government’s advice and taking all necessary measures to protect the safety and security of our staff, customers and the wider public.

                                        The current health epidemic has impacted most British businesses and has had a significant downward effect on the Construction Industry that we operate in. Many of the building sites across the country have shut and a significant number are closing down on a daily basis. As a result of this downturn in activity we are doing our best to maintain key operations to support our existing customers.

                                        Here is a list of measures that we have implemented, following the Government’s advice:

                                        • Deliveries direct to all remaining sites to carry on as usual – although we endeavour to avoid direct contact by taking names rather than asking for signatures.
                                        • A limited number of Warehouse staff to remain to support our ongoing customer orders, with social distancing measures imposed in our Chessington and Aylesbury branch’s.
                                        • Customers can still use the Chessington or the Aylesbury branch to collect, but they must produce full orderpaperwork and wear a face covering at all times when entering the branch.
                                        • In both aylesbury and Chessington branch’s, our trade counter is in full operation with acrylic screens put in place to protect you and our team.

                                        Our sales team are available via phone to help you with any queries before you decide to visit one of our branches. We are doing absolutely everything to keep everyone safe and to protect the public during this national emergency. However, we are also committed in supporting the customers that are carrying on with their ongoing projects.Our stock for products is very good, with good levels of supply across the range. Our tinting and range of colours on finishes is still in full operation.

                                        The Best Render to use in Winter

                                        Rendering in winter is a challenge that all professional renderers face. Choosing the right materials that can be used in low temperatures is particularly tricky, especially when there is an expensive risk of render failure.

                                        We have a range of solutions for making sure that nothing can go wrong even in the winter months, so keep reading to find out about the best renders to use in winter!

                                        Using Mineral Render in Winter

                                        Mineral Render is a great choice for winter installations. It’s essentially the dry-mix version of our thin coat renders; it has grains within the render and it’s applied in a very thin layer. The only thing that makes this render different is the fact that it contains portland cement, which enables it to dry a lot faster than our other thin coat renders.

                                        Faster drying times in winter are essential, as temperatures drop overnight, and wet render exposed to freezing conditions leads to render failure. Mineral Render does require painting with Silicone Paint, but despite the added cost of this it’s a much more effective material to use in the winter months.

                                        What sets mineral render apart from silicone renders, is the way in which it dries. Mineral render dries by a chemical reaction rather than water evaporation like silicone renders, which means it can dry quickly even in the winter months.

                                        Using the Winter Adhesive

                                        The Winter Adhesive is a basecoat designed for use down to temperatures of zero degrees. That means that it’s perfect for those winter months when the weather is miserable and work is continuously stalled due to low temperatures.

                                        The basecoat is essentially the same as the EWI-220 EPS Basecoat Adhesive in that it can be used as an adhesive for securing EPS insulation boards to a substrate, so the plus side is that it also helps to enable the installation of EWI in cold climates.

                                        Using the Render Accelerator in Winter

                                        Winter installations tend to be all about drying times, and the render accelerator really helps with this issue. It’s essentially an additive that you mix into your ready-mix render before applying as normal – the accelerator speeds up the process of drying before the wet render can be affected by the weather. The render accelerator works great with our range of silicone renders. Silicone renders dry by water evaporation which means they need a helping hand during the colder months, render accelerator is the help silicone renders need, making them more usable during the winter.  

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                                          We are Supporting the Poppy Appeal!

                                          What is our involvement?

                                          We are delighted to announce we are supporting the British Legion’s Poppy Appeal this year. With the support of EWI Pro, we are delighted to announce that we will be donating £1 for every £100 spent on EWI Pro products through EWI Store directly to the Poppy Appeal.

                                          Impacts of Covid-19 on the charity

                                          While COVID has impacted all of us this year, much of the fundraising carried out by the British Legion is reliant on face to face collections and with the COVID restrictions in place this has had a dramatic impact on what they have been able to do.

                                          What is The Poppy Appeal?

                                          The British Legion help members of the Royal Navy, British Army, Royal Air Force, veterans and their families.

                                          While discussing our charity partner this year, several of our employees were vocal with regards to their support of the Poppy Appeal.

                                          Shane- “I’ve joined British Legion to support our past and present veterans. It’s important to me to carry on collecting for the British Legion as they supported my family, when my grandfather was killed in
                                          El-alamein on 27th of November 1941, at age 23.”

                                          Matt- “I am delighted that EWI Store are supporting the Royal British Legion Poppy appeal this year as this is very close to me having personally served in the Royal Navy as a Gunner and coming from a family with many members that served within the British Armed forces.”

                                          Joe- “As an ex Royal Navy Stoker I fully support adopting the RBL. I have ex shipmates who used their services after the Falkland War and their support was vital.”

                                          If you would like to donate directly to the Poppy Appeal, please click here.

                                          Thermal Render vs. External Wall Insulation

                                          Our insulation systems are often referred to as ‘thermal render’ or ‘external wall insulation.’ This type of system is made up of physical insulation boards, such as EPS, which are secured to the external wall with adhesive and mechanical fixings, before render is applied on top to achieve a decorative finish.

                                          Thermal render, on the other hand, is an actual render product with low thermal conductivity. This is often specified on the package, for example, our Lightweight Basecoat has a thermal conductivity value of 0.47(W/mK). This essentially means that the basecoat itself will help to slow down the rate of heat transfer. This means that less of the heat from inside your home will be able to escape.

                                          Advantages of External Wall Insulation

                                          If you’re looking to gain thermal performance out of your renovation project, then we really recommend installing external wall insulation. The main advantage of choosing this over a thermal render is that the external wall insulation boards come in a range of thicknesses, so the potential for performance is much greater.

                                          Choosing external wall insulation also means that you get a choice in the type of insulation boards that you go for. We offer EPS, Kingspan K5, Mineral Wool or Wood Fibre, all of which offer different levels of thermal conductivity and therefore have different insulating capabilities.

                                          The insulation material itself can also provide other benefits. Our Mineral Wool insulation comes from Rockwool and has acoustic insulating capabilities as well as excellent fire performance (it’s rated as Euroclass A1 noncombustible).

                                          In terms of comparing this against a thermal render, you’re getting advanced thermal performance, the choice of how much insulation you install, and you can choose a material that will provide your home with other advantages. The thermal render on its own will offer the slightest of insulating benefits, but really it needs to be used in conjunction with a cavity wall insulation or internal wall insulation to see any real effect.

                                          How is Thermal Render Installed?

                                          We do however understand that thermal render is a significantly cheaper option than external wall insulation. If you already have cavity wall insulation then you may decide to just go ahead with the thermal render. There are a few of these products on the market, one of them being our Lightweight Basecoat.

                                          The good thing about the Lightweight Basecoat is that it can be installed up to 50mm thick in two passes. You would embed a fibreglass mesh within the first pass, leave it to dry out a little and then apply the second pass. Once this has set completely, you can then apply a thin coat render or a Silicone Paint on top to achieve a decorative finish.

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                                            Installing Render and EWI During the Winter Months

                                            Installing Render and EWI During the Winter Months

                                            We typically consider the rendering season to be from the start of March to the end of November, but over the past few years, we are noticing more and more of our installers braving the British Winter and installing render systems right through the year.

                                            Winter obviously tends to be cold, but we also get lots rain and sometimes even snow! All of these conditions can have a negative impact on your work and affect the products you are using. This is why it is crucial to select the appropriate products when installing during the colder Winter months.

                                            Winter products at EWI Store

                                            Here at EWI Store we sell a range of products to allow you to render / apply EWI during the Winter months – we look at some of these in a bit more detail below.

                                            Winter Adhesive

                                            Winter Adhesive is a great and versatile product –  it can be used as both a basecoat and an adhesive – similar to EWI-220. However, the advantage of Winter Adhesive (EWI-221) is that it can be used down to temperatures of zero degrees Celsius, where as the EWI-220 EPS Basecoat can only be used down to 5˚C.

                                            The Winter Adhesive is ‘stickier’ to use and goes off that much quicker than the standard basecoats, making it a must for installing in the very cold.

                                            EWI-221 Winter Adhesive is:

                                            • Waterproof
                                            • Frost-proof
                                            • High Grip
                                            • Contains microfibres for increased flexibility
                                            • Hydrophobic

                                            Render Accelerator

                                            Silicone render is one of our most popular products here at the EWI Store. This is because it offers incredible performance in terms of flexibility, breathability and durability. Silicone Render can be used from +5°C to 25°C, but in the Winter months it can take 2-3 days to cure.

                                            EWI-020 Render Accelerator can be used to speed up the drying time of our Silicone Renders. It is a liquid additive that gets added to the bucket of render and helps prevent costly render wash-off.

                                            When installing Silicone Renders, we always recommend checking the weather forecast to ensure the days following application are dry so the Silicone Render has a chance to cure properly before any adverse weather, but the render accelerator also helps form a protective skin on the render again helping to protect it.

                                            Silicone render is:

                                            • Weatherproof
                                            • Resistant to algae and plant growth
                                            • Frost-proof
                                            • Hydrophobic
                                            • Vapor-permeable
                                            • Nano-enhanced
                                            • Self-cleaning

                                            Mineral Render

                                            If Silicone Render isn’t your cup of tea, don’t despair!

                                            Mineral Render is also an excellent option in colder conditions. Our Silicone renders cure when the water evaporates out of them, which is why they struggle to go off in the winter as the cooler / humid conditions slow the rate of evaporation (although accelerator helps!).

                                            Luckily, Mineral render cures using a chemical reaction (in the same way cement cures) and therefore dries regardless. Mineral Render can give you the same look and breathability that Silicone Render can offer, however you do have to paint it with Silicone Paint once the mineral render is installed. Please note that unlike the Silicone renders that come in ready-to-apply buckets, the mineral render needs to be mixed with water prior to application. Please follow the preperation instructions on the back of the bag before install.

                                            Mineral Render is:

                                            • Waterproof (once sealed with Silicone Paint)
                                            • Frost-proof (once sealed with Silicone Paint)
                                            • Vapour-permeable
                                            • UV-resistant
                                            • High grip

                                            Additional Advice

                                            As amazing as these products are, you still need to be sensible when choosing what conditions to work in.

                                            • Always check the weather forecast, you should avoid rendering in rain, snow, and wet conditions and ideally ensure the weather the few days after the install is dry too.
                                            • Never try and apply Silicone Render if the temperature is less than 5°C.
                                            • Always try and protect the surfaces that are being rendered with scaffold sheeting.
                                            • Always ensure surfaces are protected against wash-off, so for example the floors should be covered with Correx etc as once the Silicone render cures it is almost impossible to remove!

                                            Thermal Conductivity & U-Values

                                            When you start looking at solid wall insulation as a potential solution for your home or commercial premises, you may come across the terms ‘thermal conductivity’ and ‘U-value’. In this article we are going to try to shed a little light on what they both mean!

                                            Thermal conductivity

                                            Thermal conductivity measures the ease with which heat can travel through a material by conduction, conduction being the main form of heat transfer through insulation. Thermal conductivity is often termed the λ (lambda) value.

                                            The thermal conductivity is a constant for a particular material – it is not impacted by the thickness of the material. Although when comparing different materials, products with lower thermal conductivity values are better insulators (i.e. will be better at slowing heat loss).

                                            At EWI Store we sell three different types of insulation (although there are more types available in the market). The table below shows the different thermal conductivity values for these materials:

                                            Insulation Material Thermal Conductivity
                                            Expanded Polystyrene (EPS) 0.031 W/mK
                                            Extruded Polystyrene (XPS) 0.034 W/mK
                                            Rockwool Dual Density Boards 0.036 W/mK

                                            So based on the lowest thermal conductivity being the best insulator, from the table above, you can see EPS is the best insulator.

                                            Now – thermal conductivity is useful, but we also need to incorporate the thickness of the insulation into the calculation. The thicker the layer of insulation, the slower the rate of heat loss and also the better at retaining heat a building will be. This is where the U-value comes in. The U-value signifies the heat lost through a given thickness of a particular material. This allows you to directly compare types and thicknesses of insulation.

                                            The calculation is as follows:

                                            U-value = Thermal conductivity / thickness (where the thickness is measured in metres).

                                            When you are comparing U-values, a lower number is better – i.e. a lower U-value signifies less heat loss through a material; therefore it is a better insulator.

                                            EPS insulation

                                            U-values and building regulations

                                            Building regulations often provide a U-value number that needs to be achieved when building certain elements of a property. So for example when retrofitting external wall insulation on an old solid wall property, you need to achieve a U-value of 0.3W/m2K or lower. This can be achieved with any insulation material, although the thickness of the particular material will vary; for example when you are using EPS on a solid wall property, 90mm will suffice – but if you were going to use Rockwool, you would require 110mm.

                                            Now, to get a true U-value figure you need to take into account all the different elements that make up the wall: the internal plasterboard, bricks or block work, insulation materials, and even the thin render top coats – they all very slightly change the u-value number.

                                            So there you have it – hopefully that makes understanding U-values and thermal conductivity a little easier! If you would like us to calculate U-values to help you determine the thickness of insulation you require, then please let us know.




                                            Acrylic Render vs. Mineral Render vs. Silicone Silicate Render

                                            Here at EWI Store, we source our renders from EWI Pro who offer a broad range of BBA Approved renders. Whether it’s a classic Silicone Render or a traditional Monocouche render you’re after, we can cater to all requirements!

                                            Nevertheless, the most popular renders within the EWI Pro catalogue are the Mineral Render, Acrylic Render, Silicone Silicate Render. As you might expect we get asked a lot what the difference is between these types of render and which is the best? Well, in this blog we thought we would try and explain the differences so you can pick the right render for your next job! If you’re looking at getting an idea of how much coloured render costs per m2, then check out our blog post which gives a really comprehensive idea of all the components.

                                            Mineral Render

                                            Our EWI Pro Mineral render is the only one to come as a dry mix – you need to add water to it before applying it. It also requires painting afterwards, which means it is a bit more time intensive to install. So why do people use it? Well there are a few reasons – firstly it is cheap in terms of material costs. Secondly mineral render dries much quicker than all the other types of render we offer so if you are installing in wet climates (I know most of the UK is normally under the water!) the this is the stuff to use – by the same token, this quick drying render is the one to use if you are installing in particularly humid or cold conditions since it will help minimise wash-off (when the render doesn’t stay in place due to rain or other unforeseen weather conditions!).

                                            In terms of installs around the country, Mineral Render is particularly popular in both Wales and Scotland due to temperature and volume of rain. If you are doing the install yourself and it is during the summer months, the other renders just require the one coat (the colour is within the render itself) so you won’t have to paint anything once the render has been applied. Mineral render is also breathable and therefore compliments our Rockwool (Mineral Wool) insulation very well.

                                            Once the Mineral Render has been applied it needs to be painted with our EWI pro Silicone paint which will provide a long lasting barrier to the elements and obviously can be coloured to your requirements.

                                            Acrylic Render

                                            What is Acrylic Render? Well for years has been the installers render of choice – it is essentially a render containing acrylic resin. Acrylic Resin is a type of plastic and added to render it helps offer better stain and water resistance as well as greater resistance to cracking. Our acrylic render comes pre mixed; this means that it can be applied straight on to the substrate (e.g. wall) without mixing it first with water. We sell the EWI Pro acrylic render pre mixed with your colour of choice and what is really great about it is when you opt for a vibrant colour, the acrylic render will hold this colour for a long time without fading (the other renders and the Silicone Paint will fade over time so may require painting every 10 years or so).

                                            Acrylic Render is the most cost effective render when you consider the labour and material costs – requiring just one application. If you are looking for the best value system then this in our opinion is the best and certainly a huge improvement on the old sand and cement renders of the past – it is flexible and will last 20 years plus. Before you use the acrylic render though just a couple of things to consider – firstly it is not breathable. The Acrylic Resin / plastic in this render means that nothing is going to get through it, therefore it is definitely not worth putting it on a breathable insulation product like our Rockwool or Wood Fibre as it sort of defeats the point! In addition, EWI Pro Acrylic render is not worth installing when the weather isn’t very good, so cold or wet as it takes longer to dry than the Mineral Render system. Finally Acrylic render is not as resistant to the elements as our Silicone Silicate render, so there will be some maintenance required like cleaning over time.

                                            Silicone Silicate Render

                                            This is now our installer’s render of choice – the EWI Pro Silicone Silicate render is ready mixed (much like our Acrylic Render) and therefore can be applied straight to the substrate. It is comprised of Silicone resin and Silicate. Once installed on the wall the Silicone Silicate render is hydrophobic, which basically means it repels water and therefore can be considered self cleaning in that the water will simply run off it.

                                            The Silicone Silicate render comes in a few various different textures, but by far our most popular is the 1.5mm render (read our full guide to render grain sizes). This means that within the render, it has Silicate granules just 1.5mm in diameter, so it can be applied extremely thinly on the wall – the advantage of this is that it is extremely flexible, so the house moves and the render moves with it. It simply won’t crack!!

                                            Again, much like the Acrylic render we don’t advise installing this render during the harsh winter months or when it is raining as the system does take a few days to cure – but once installed it should be maintenance free for over 20 years although it make require the odd pressure spray from time to time to keep it nice and clean. The EWI Pro Silicone Silicate render is completely breathable so is the ideal partner for our mineral wool insulation products.

                                            If you would like to get a quote for any of these materials try our new materials calculator by clicking on the picture below

                                            All the renders we sell in the EWI Pro Insulation System range are BBA Approved –  Products that receive Agrément Certificates are recognised by building control, government departments, architects, specifiers and industry insurers. It’s a mark of quality, safety and reliability that provides reassurance that the product’s fit-for-purpose.

                                            To learn more about the BBA and the EWI Pro Insulation System products please click here.

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                                              Green Homes Grant Scheme and EWI Store

                                              The Green Homes Grant Scheme and External Wall Insulation

                                              In July 2020,  the UK Government announced a new green homes grant scheme, which is designed to give homeowners and landlords up to £5,000 of funding towards energy saving measures for their properties in England. The £2 billion scheme launched on the 30th September 2020, with external wall insulation being one of the main energy saving measures that home occupiers will be able to take-up to significantly improve the thermal comfort of homes.

                                              Insulation measures are the most effective way of increasing the energy efficiency of your property. Whether this is loft, cavity or solid wall insulation. For example, installing 90mm of insulation on the external walls of your property can reduce your heating bill by 30%!

                                              To qualify for the grant of up to £5,000 the improver must also contribute up to one third of the final contract costs for the works, otherwise it maybe deemed invalid




                                              What happens if I cannot afford to make a personal contribution to the cost of the works?

                                              If you cannot afford to make a contribution, the Government is giving up to £10,000 total support for home owners who are in the low-income group. You can then whole project fully funded and you do not need to make a personal contribution.

                                              You can qualify for the Green Home Grants low-income scheme (up to £10,000 support) if you receive at least one of the following benefits:

                                              • Income based Jobseekers allowance (JSA)
                                              • Income based Employment & Support Allowance (ESA)
                                              • Income Support (IS)
                                              • Pension Guarantee Credit
                                              • Working Tax Credit (WTC)
                                              • Child Tax Credits (CTC)
                                              • Universal Credit (UC)
                                              • Disability Living Allowance (DLA)
                                              • Personal Independence Payment (PIP)
                                              • Attendance Allowance
                                              • Carer’s Allowance
                                              • Severe Disablement Allowance
                                              • Industrial Injuries Disablement Benefit
                                              • Contribution based Jobseekers allowance (JSA)
                                              • Contribution based Employment & Support Allowance (ESA)
                                              • Housing benefit

                                              If you don’t receive any of these benefits then the total support will be capped at £5,000.

                                              Green Homes Grant is now live and how does it work?

                                              The Government launched the Green Homes Grant scheme in September. In summary here are the qualification criteria as listed on the www.Gov.co.uk website:

                                              • you need to reside in England;
                                              • be a homeowner (including long-leaseholders and shared ownership);
                                              • own a park home on a residential site (including Gypsy & Traveller sites);
                                              • you could be a residential landlord in the private or social rented sector (including local authorities and housing associations)

                                              This scheme does not cover new build homes. It is only available to the retrofit sector.

                                              To qualify for home improvements under this scheme you must install at least one primary measure, and any unused funds can then be used to part fund either a secondary or another primary measure. External wall insulation is a primary measure, therefore provided it is selected for the home improvement to improver should receive this funding.

                                              For additional reading on the Green Homes Grant, this can be found on the Simple Energy Advice website found here.

                                              Additional information regarding insulation measures

                                              According to the scheme rules installing external solid wall insulation to a wall, you must insulate all suitable space on that wall elevation. The Government advises all the external walls to be insulated (not a requirement), but in practice you can choose 2 walls, less or more.

                                              If you have a semi-detached for example and you have already insulated one or two of the walls, then you can utilise the grant to insulate the final wall. You cannot use the grant to remove and replace existing wall insulation like cavity wall insulation, but you can use the excess funds to install other insulation measures like loft or floor insulation.

                                              EWI Store products are compliant with the Green Homes Grant scheme

                                              It is understood, that in order to apply for the Green Homes Grant scheme, approved applicators and products will need to be used. The good news is that our external wall insulation systems are BBA approved and therefore ready for use in the scheme. Likewise we also have nationwide network of approved installers who will be able to do the works and access the £5,000 grant.

                                              It is worth mentioning that the scheme is open to anyone that owns a home (including park home owners) – however the property must be based in England to be eligbile. The Grant is non-means-tested, so provided you own the property you are good to apply!

                                              EWI Pro External Wall Insulation Systems

                                              EWI Store offer a wide range of EWI Pro External Wall Insulation Systems. EWI Pro are a system designer and manufacturer, prodcuing specialist external insulation and thin coat render systems.

                                              EWI Pro Insulation Systems has two systems that are certified to the BBA, which are the EPS EWI System and the Mineral Wool EWI System. The BBA is the British Board of agreement and certifies the products and systems, so they are “fit-for-purpose” for the retrofit improvements that are being recommended.

                                              In their testing of the systems, the BBA carries out a set of robust tests that examine the products for their longevity, fire resistance, water penetration and many more. All the products and systems are rigorously tested in the respective factories that produce them so that the quality control in maintained at all times.

                                              Basically, you can rest assured that if you do decide to use the EWI Pro family of products for your next project, they are some of the best available on the market!

                                              All the Materials you need we can supply!

                                              If you want to know the benefits of using Rockwool Insulation over EPS then check out our blog ‘Why use Rockwool in your EWI System?‘ or ‘The Advantages of Rockwool Insulation‘.

                                              How Do I Apply?

                                              Step 1: Go to the Simple Energy Advice (SEA) website to check what low carbon or energy efficiency heat improvements can be made to your home.

                                              Step 2: Contact us at EWI Store so that we can find you a local accredited installer and give you price quotes.

                                              Step 3: Apply for the voucher on the Government website

                                              Contact us for more information

                                                CALL US:

                                                Chessington Branch: 02033 974067

                                                Aylesbury Branch: 01296 821067

                                                EMAIL US:

                                                Sales Enquiries: [email protected]

                                                Technical Enquiries: [email protected]

                                                Are you an Installer?

                                                Check out our Green Homes Grant Scheme blog for Installers.

                                                Best way to install K1 Silicone K-Rend scratch render

                                                K-Rend is a household brand name associated with the application of scratch or monocouche render to a property. This product has a scraped texture or finish and should strictly be applied directly to a masonry wall including brick, block or an existing rendered surface. When installing the K-Rend scratch render, there is no better solution that choosing the K1 Silicone scraped texture.

                                                In this blog we look at different ways that the K-Rend K1 Silicone scraped texture can be installed to different masonry substrates.

                                                How to install the K1 Silicone K-Rend to brickwork?

                                                An existing brick wall is probably the most common type of masonry structure in the UK. It is still the most popular way to finish an external wall by using decorative brickwork to finish off the construction. Now some brick walls in the UK are well over 100 years old and over time some brickwork tends to weaken and lets in penetrating water. The water coming through the wall can cause issues to internal plasterwork and other problems to the property.

                                                To avoid these problems, the K-Rend K1 Silicone scraped finish is enhanced with “silicone”, which creates a barrier to rainwater – helping prevent further damage to the brick.

                                                The first step of the K1 Silicone K-Rend installation process is to get a good sense of the wall that is going to be worked on. Using the beading, namely 14mm-16mm beading profiles for stops, corners and drips – install them onto the walls that are due to be rendered. Do not use spray foam to hold the beads in place as this may cause product performance issues further down the line – we recommend using a small amount of the cementitious product to hold the beads in place.

                                                The substrate may then require further preparation, including a fungicidal wash and a substrate primer. Substrate primers typically work in two ways – firstly they help aid adhesion between the substrate (in this case brick) and the render being applied. They also help regulate the moisture absorption by the brickwork, giving time for the render / basecoat to cure correctly. When applying K1 Silicone K-rend to a brick surface we would recommend using the K-Rend R7 Acrylic Primer. This can be applied mechanically with a spray machine or using a roller/ brush.

                                                When the R7 Acrylic Primer has dried, we would then apply the K-Rend HP12 Base Coat with the alkali resistant fibreglass mesh. The HP12 is probably K-Rend’s most well known polymer modified basecoat product, that is robust enough to use on a number or preparation or undercoat application processes.

                                                The HP12 Base Coat should be mixed water, using the appropriate water content on the back of the bag. It can then be applied with the rendering tools. If you are using a spray machine, then use the water pressure settings as recommended. In this installation the HP12 should be applied 6-8mm thick in one pass. You then cut the fibreglass mesh and place it into position on top of the spread-out basecoat.

                                                Before putting on the scraped coat you must ensure that this HP12 Base Coat layer is fully dry. The fibreglass mesh needs to sit close to the surface of the base coat build-up. When embedding the mesh, ensure each strip overlaps at least 100mm on the edges. If you come across any openings like the windows, door or even surface boxes, then use additional fibreglass mesh in each corner to act as reinforcement patches. These need to be applied in every corner and should sit at 45 degrees to the opening, and remember these are on top of the strips of overlapping mesh!

                                                You may ask what the purpose of the mesh is at this point? Well – it helps with the render’s structural integrity and also ensures the final K1 Silicone scratch coat has a solid surface to bind to.

                                                When the mesh is in position, use a scarifier tool to make scratches in the surface of the HP12 basecoat, which would ensure the substrate would provide a nice key.

                                                Having waited a good 24-48hours for the HP12 to set, you are now ready to apply the final K1 Silicone scratch render.

                                                Mix the K-Rend K1 Silicone scratch powder in a bucket with the appropriate amount of water if you are looking for a hand-application. For machine use, follow the instructions on the bag and ensure you have set the machine to the correct settings. The product is then ready for the application.

                                                Apply the K1 Silicone scratch render onto the substrate liberally trying to achieve a thickness of 10-12mm on the wall. Using an I-bar or a speed skim level off the surface so that the lines have been flattened out. The K1 Silicone scratch render needs to be firm, but not completely dry before the next stage can be completed, so we normally recommend going back to site the next day to produce the final finish.

                                                Using the scratch pad or the scraped trowel take off approximately 2mm off the surface of the K1 Silicone render to leave a nice scraped finish. Take off any dust residue with a brush.

                                                Obviously use your judgement and in the colder months you many need to wait a little bit longer for the product to set properly for it to be scraped off.

                                                How to install the K1 Silicone K-Rend to dense blockwork?

                                                Building new construction like extensions requires the use of dense blockwork (7N or above) rather than brickwork, which tends to be quite expensive. It is very popular to the finish the external layer of this blockwork with the K1 Silicone render, taking costs out of the construction process.

                                                The initial preparation of the K1 Silicone K-Rend installation process is very similar to when installing the product onto brickwork. Using the stop bead, corner bead and bellcast bead pin them to the walls in the appropriate sections. You can use 14mm, 15mm or 16mm beading profiles for this job. Do not use pink grip or spray foam, rather try and use some of the product, namely the HP12 basecoat or the K1 Silicone scratch render to stick them off. If you are doing this, you need to make sure you leave the product to set a bit prior to the application of any other layers.

                                                If you are worried about substrate suction given the new blockwork in place then use K-Rend R7 Acrylic Primer. This will help with the product work time and allow the applicator to properly skim it. The primer can be applied mechanically with a spray machine or using a roller/ brush. Allow this to dry.

                                                Then use the K1 Silicone render bag and mix it with the correct water content – use a paddle mixer. If you are using a spray machine, then follow the correct machine settings according to bags. The first pass of the K1 Silicone render should be 8mm thick. In this layer you will need to cut up the alkali resistant fibreglass mesh and install it into the product. Make sure that when installing the mesh, it is overlapped at least 100mm on each edge and additional reinforcement is installed around openings.

                                                You do not need to fully push the mesh through as another layer of K1 Silicone render will be applied on top as the finishing coat. You may choose to notch or scratch the surface with a scarifier to provide a better key for the next part of the install process.

                                                Remix the K1 Silicone render or set the machine again to the same settings. When the product is ready to apply or spray you ensure that approximately 10mm of product applied in this second pass. Do not allow the first layer to dry out or fully set – this step should be performed “wet-on-wet”.

                                                When the 10mm thickness has been achieved, then level off the surface. You can use a range of tools to do this. We recommend using a spatula trowel, an I-bar or a speed skim leveller. You should then wait up to 24 hours for the product to set before attempting to scrape this off the wall.

                                                Using a scrape tool or scratch pad, take off the 2mm of skin formed on the surface of the product taking back to the beading profile. If you have used 16mm beads then this will be taken back to the 16mm depth. When scratching off the surface try to use your judgement and in the warmer months you many need to work quicker, because if the product hardens off too much, it maybe tricky to work with the following day.

                                                How to install the K1 Silicone K-Rend to lightweight blockwork?

                                                You may also render onto lightweight blockwork or clay blocks, but you may need to use a slightly different basecoat to help with this installation process. We recommend using the K-Rend HPX basecoat product but be aware that this is not always in stock, so check with us instore or on the phones to that we may suggest any alternatives.

                                                However, the installation process would be very similar if installing to common brickwork.



                                                Why use Fibreglass Mesh in Render Systems?

                                                Fibreglass Mesh is an essential component of our render systems. It helps to provide strength and flexibility to our thin coat render systems, ensuring that the render remains crack resistant for years to come.

                                                Fibreglass Mesh is made of neatly woven fibreglass thread. This type of mesh is widely used in plastering and rendering for wall reinforcement, external wall insulation and roof waterproofing. We offer different weights of mesh depending on the intended use and, typically, heavier mesh provides more impact resistance within the render system. At EWI Store, the heaviest mesh we sell is our Panzer Mesh at 350g/mand this is often used in areas that are likely to endure heavy impacts e.g. a wall where a football is kicked against it.

                                                All of the mesh we sell is alkali-resistant. This helps prevent it from being broken down by the chemicals in the other mortars and adhesive materials.

                                                Where do you put the Fibreglass Mesh in render systems?

                                                The Fibreglass Mesh is embedded within the basecoat layer within both render and external wall insulation systems. The mesh needs to be embedded within the basecoat while it is still wet, and we always recommend getting the mesh embedded within the middle of the layer of the basecoat, rather than too close to the surface or sitting right next to the wall.

                                                In thin coat render systems, the basecoat thickness is normally between 4-8mm, so installers tend to have different embedding techniques.

                                                A notched trowel can be used to apply the basecoat to the wall at the required thickness and then the mesh can be tapped into the basecoat. A straight-edged trowel can then be used to ‘pull’ the adhesive through the mesh by applying pressure to the basecoat.

                                                Other installers will apply a thinner first pass of adhesive, then tap the mesh in place, then apply a second layer of the basecoat. Either method is absolutely fine however, if you do go with the second method, ensure the first pass of basecoat has not dried before applying the second pass of mesh; the mesh needs to be embedded within a fully wet product.

                                                Overlapping mesh in basecoat

                                                During weather and temperature changes, the external walls of your home expand and contract minutely due to the heating and cooling processes. Mesh is used to help the system ‘flex’ with these building movements to help prevent cracking. 

                                                All our mesh comes with markings 100mm from each end. This marking illustrates the overlap of the mesh required when installing it. Each strip of the mesh needs to overlap the last by 100mm otherwise cracks can appear in this area over time.

                                                The mesh provides additional strength to all thin coat render systems and helps prevent cracking, so we highly recommend it if you want to ensure the structural stability of your system!

                                                Below is an example of a buildup for Render-Only on a brick substrate which demonstrates where the Fibreglass Mesh fits into the process. 

                                                To see how we test the strength of our Silicone render system with and without mesh, please watch our YouTube video “Silicone Render Impact Test“.


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                                                  The Importance of Render Repair

                                                  Our homes are precious to us, our first consideration is most often an aesthetic one. If it looks bad why would we want it? The outer layer of your property- the first thing you see is the render, so this plays an important part in defining the shape and appearance of your home. Cracks are unsightly anyway but repairing these will have a massive and satisfying trans-formative impact. Not only visually but will help your render last longer and will keep it weatherproof.

                                                  Homes are, to many, an extension of themselves. So, what happens when the exterior of your home has been looking a bit lackluster recently? Your home may need a bath! One of the best ways to clean your rendered home is to use a pressure washer with a mild detergent, just be careful to adjust the settings on your pressure washer to a fan setting to avoid etching and damaging your render surface. This will help if your home is looking a bit grubby.

                                                  Just like any building material, Render will need maintenance and repair occasionally. Certain factors can result in the render cracking and separating from the wall. After a while organic growth can affect your render too, early stages of organic growth results in green and red staining on your render.

                                                  If your render has been invaded by moss and algae, then you should consider applying a good moss and algae killer. Algae is one of the oldest organisms on earth and tends to be the first organic growth to show up on your home. It will feed on the moisture and minerals on the substrate. If it reaches this stage, then your home may need specialist treatments to remove it. Garden centre biocides will not be powerful enough to remove the algae on its own.

                                                  If you are new to Render and haven’t yet rendered your home then you should consider EWI-076 Premium Bio Silicone Render if organic growth is a concern of yours. This render has an advanced resistance to algae and plant growth.

                                                  What about cracked Render?

                                                  Have you ever walked past a crusty old looking house that has cracked and stained render? This extent of damage is avoidable by maintaining and repairing the rendered finish. Not only is this unsightly but poses massive concern for the brickwork beneath.

                                                  Even small cracks in your render can create a pathway behind the render and allow water to penetrate between the render and brickwork. The water will eventually penetrate the brickwork and will create damp areas in your internal wall.

                                                  This will create ugly damp marks in your home, but can also lead to mould growth, which could affect your health, especially if you already have underlying health conditions.

                                                  Water ingress in your brickwork will also cause problems in the winter months. This is because of a process known as ‘freeze-thaw damage’. This is because as water freezes it also expands, which causes the bond between your render and brickwork to blow. The result is your render no longer being bonded to your wall; render may start to flake off from your walls. This can also lead to damage to your underlying brickwork.

                                                  To fix hairline cracks paint may be enough but for thicker cracks you will need to use thicker products. For example you can try the EWI-051 Fin Plast if it is sand and cement or you could use the EWI-225 if it is silicone or acrylic. You should add a strip of mesh on the top like a plaster and then when it is dried, you should feather in the acrylic or silicone render. If you are not comfortable in filling these yourselves, then there are many professional services to choose from. Fill in our survey at ewistore.co.uk and we will help you find a suitable installer.

                                                  What can cause cracked render?

                                                  Your home expands in the summer and compresses in the summer. This means if your render does not have enough flexibility to allow for this movement then cracks may occur. You can reduce the chances of this occurring by choosing a silicone-based render because it is the most flexible. Depending on the type of render on your property, this may not be avoidable. This is because certain circumstances may exasperate the movement of your home.

                                                  Things like having heavy work/ renovation done- the vibrations from drilling can cause your render to have hairline cracks. Other things that may contribute to cracking in your render could be foundation and subsidence issues or if you have a new build property. This is because new builds tend to take a few years to settle in.

                                                  Another thing to make sure of when rendering your property, is that it is applied properly. Application errors can also cause cracks to form or your render to separate from the substrate.

                                                  Do I need to do render maintenance?

                                                  It is extremely important to maintain your property. Render has a tolerance and is weather resistant, but if you do not address problems as they appear then they can take a toll on your render. Making sure you maintain your gutters or fixing any leaks is an important step in maintaining your render.


                                                  Can You K-Rend Over Painted Render?

                                                  What is K-rend?

                                                  People often confuse ‘K rend’ as a product but ‘K rend’ is in fact a brand that has a large range of render products. These products are manufactured by a company called ‘Kilwaughter’ which is the chemical manufacturer parent company based in Northern Ireland.

                                                  What renders do they offer?

                                                  They offer a range of FT one coat topcoats, this topcoat is a cement based, polymer modified render. Having silicone as a component of this product enables it to have higher water repellency, which in turn means that less dirt will be able to adhere to the surface, meaning it will be clean for longer and lower maintenance than other types of render. This offers similar properties to other silicone-based topcoats for example, although not cement based, EWI Pro’s EWI-075 Silicone render will offer you long lasting results, a self-cleaning and low maintenance finish.  Enewall fine scratch render is very similar to the K-rend FT 1 scrape render in all aspects so may be a good alternative.

                                                  Can you k-rend over painted render?

                                                  So, you want to K rend your home, but you already have old painted render that would be costly to remove. So, what are your options, and can you just render over the top?

                                                  The answer is yes technically, however there are certain things you need to be wary of. K rend is a heavy product so whether its suitable or not depends on the weight of your original paint. If the original paint on your wall is too heavy and not very strong then everything will just fall off the wall. This means you need your installer to analyse and test your current paint to ensure they are comfortable in rendering over the top without worrying about paint peeling off.


                                                  To help avoid this we do sell a primer called EWI-310. Using this primer will help to secure the new K rend to the wall however the primer can only do so much and does not replace a substrate in good condition. If the paint is too smooth, then you may need to use a primer with grit. you can use ‘scrim and pin’ fixings to help tie the new render to the wall – these are basically fixings that go through the existing render and into the brick / block beneath, but it isn’t ideal solution. Likewise, you could apply insulation and anchor that to the wall, then apply a thin coat render system (K-rend’s TC15 or EWI Pro EWI-075) but if the painted render is too weak then ideally it needs to be removed despite the extra labour costs this will incur, in the long run this will save you money in repairs if your render does end up coming off from the walls.


                                                  Different Methods to K- rend over painted render

                                                  If your home is already rendered and painted, then you can choose to remove this layer first before adding new render. This option can be costly as you will incur more labour costs during the removal process and can cause damage to the brick or block work beneath. To help with these damages after removal, you can apply and install a base-coat. EWI Pro’s EWI – 225 Is a good option for this. First install the EWI-225 base-coat and then embed some fibreglass mesh to support the base-coat. With the base-coat your K-rend does not need to be as thick so you can apply it 10-11mm thick and once dry scratch it down (using a render scratching float) to 8mm thick.

                                                  If the paint on your wall is stable enough then you can apply the K-rend straight onto the wall. You can apply 18mm and once dry you scrape down to 15mm. Most installers choose to apply this in two stages as the weight of the product can cause it to sag. On day 1 they would apply up to 10mm, embedding fibreglass mesh in between and then the next day applying a further 8mm. They would then scratch this down. You can choose to apply the product using a spray machine or by hand.