Tag Archives: render specialists

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.

How to achieve a brick-like finish on your EWI system: Brick slips

Are you fascinated by all the environmental benefits of external wall insulation, such as improved thermal performance, reduced energy bills and increased façade durability, but having doubts because you don’t want to let go of that beautiful brick aesthetic on your home? Then, brick slips are the product for you. While silicone render is available in several different grain sizes and thousands of different colours to allow you to create a personalised finish, you can instead choose brick slips as the final stage of your external wall insulation system – which are also available in various colours – to receive all the benefits of a system whilst enjoying the traditional aesthetic of exposed brickwork. If this sounds more like you, and you want to know more about brick slips, keep reading!

What are brick slips?

Brick slips are thin, acrylic tiles that are predominantly manufactured and cut from real reclaimed bricks. Much like a brick wall which is created by building brick upon brick, brick slips are applied to the wall one by one atop the adhesive to mimic real brickwork. They are highly flexible, meaning they can bend around corners to recreate the edges of bricks, and available in various natural colours and textures, again much like real brick. Brick slips can be applied both internally and externally but have grown in popularity as the final stage of an external wall insulation system to receive the benefits of external wall insulation without letting go of the traditional brick aesthetic.

Brick slips provide further benefits to an external wall insulation system if you live in an area where there is a high risk of mechanical impact such as on a busy road. Due to their brick-like nature, they have a great ability to withstand damage from mechanical impact and are very hard-wearing. They are also weatherproof and UV-resistant, meaning their colour won’t fade over time. So, if your current brickwork is looking a little tired, brick slips – along with the added benefits of external wall insulation – are the way to go.

How are brick slips installed?

Our brick slips are extremely simple to install. We offer a special adhesive that comes in five different colours and is specifically designed for use with the brick slips to create a long-lasting, reliable bond between the brick slips and the substrate. The adhesive is the most important part of the installation process as it will ensure the solidity of the installation.

When installing brick slips on top of an external wall insulation system, you must first install the basecoat and mesh on top of the insulation boards. Then, the special brick slip adhesive must be applied using a notched trowel. Following this, the brick slips can be applied to the adhesive in the form of a standard brick pattern, staggering the bricks and leaving a space of around 10mm between each brick both vertically and horizontally. As mentioned earlier, the bricks can be bent around corners owing to their flexibility, or you can cut them to your desired shapes.

What are the different types of brick slips?

Here at EWI Store, we offer several types of brick slips to cater to every taste:

  • Bavarian Castle. Our Bavarian Castle brick slips are of a beautifully clean and modern light grey colour which offer a noticeably fantastic facelift to any home. Their colour also offers an excellent contrast to wooden doors and window frames for a modern look with a traditional touch.
  • Cedar Hill. Our Cedar Hill brick slips offer a more conventional aesthetic, combining hints of dark red and brown, as you would imagine real brickwork to look. The Cedar Hill brick slips are perfect if you are seeking to achieve a traditional look whilst updating the look of your home.
  • Charcoal. Bold and modern, our Charcoal brick slips are the perfect solution if you are looking to make your house stand out from the crowd. The Charcoal brick slips will look fantastic when combined with white windows and doors.
  • Yellow Stock. If you are looking to brighten the façade of your home in an understated fashion, Yellow Stock brick slips are the ones for you. These brick slips look excellent all year round and remain timeless.
  • Siberian White. Bright and modern, our Siberian White brick slips are a fantastic option if you are seeking a complete refresh of the façade of your home. White will work with any colour of doors and window frames; white for a clean finish, and black or any other colour to create a contrast.
  • Wentworth Mixture. Similarly to Cedar Hill, our Wentworth Mixture brick slips mimic the appearance of traditional bricks owing to their natural red-brown colour. Whether you already looking to update your current brickwork or are for an understated look, Wentworth is for you.
  • Westminster. Our Westminster brick slips offer a bright, natural aesthetic with their neutral stone-like colour adorned with hints of red and black. Like Yellow Stock, Westminster provides a timeless look whilst giving your whole home a facelift.

So, if brickwork is to your taste and external wall insulation sounds like an excellent solution for you, then brick slips are the option for you! As you can see, our range of brick slips means that we can cater to every taste, allowing you to achieve your desired brick-look finish. If you have any questions about our brick slips and how they work with external wall insulation, please do not hesitate to contact our talented Sales Team who will be happy to help!


What does it mean to be BBA-approved?

Did you know that, here at EWI Store, we stock a range of BBA-approved products? If so, then you know that we are guaranteed to offer high-quality, long-lasting and aesthetically pleasing solutions to cater to your render and external wall insulation needs. If not, you might be wondering: what does BBA-approved mean? Well, you’re in the right place; BBA approval is a huge deal, and that’s why we’re so proud to hold such and share what it means with you here!

What is BBA?

The British Board of Agrément (BBA) is a certification body within the construction industry that assesses the quality of a company’s products, services and systems through extensive research, auditing, inspection and testing. Throughout the industry, a BBA status is highly regarded by building control, government departments, architects, local authorities, specifiers and industry insurers like the NHB and used by manufacturers as a symbol of authority, validating that any product that gains BBA approval can be trusted. Here at EWI Store, we stock the entire EWI Pro range, many products of which have gained BBA approval.

How do you gain BBA approval?

The BBA testing process can take anywhere between several weeks to 18 months depending on the kinds and number of assessments that need to be taken. Nonetheless, once a manufacturer has been awarded their certificate, it doesn’t end there; the BBA requires that all manufacturers are reviewed and are subject to organised surveillance. To gain their BBA approval, EWI Pro’s render and external wall insulation products that comprise their most common external wall insulation systems – Mineral Wool and EPS – underwent rigorous laboratory tests, on-site evaluations, product inspections and quality management checks. As a result, EWI Pro has long gained marketplace acceptance with their BBA approval, which is why we are so proud to offer their products and be trusted by homeowners and installers.

While assessing EWI Pro products, the BBA checked for the following factors:

  • Durability

This includes performance after hygrothermal cycling and colour change measurements after UV exposure.

  • Energy efficiency and thermal performance

This includes thermal transmittance/U-value (guarded hot box) and thermal conductivity and resistance (heat flow metre).

  • Hygrothermal testing

This includes heat/rain and heat/cold cycling (ETAG 004 environmental chamber) and heat/spray and freeze/thaw cycling (MOAT 22).

  • Mechanical testing

This includes resistance to soft body impact, resistance to hard body impact, perforation test, resistance to pull through of fixings, flexural strength, compressive strength and bond strength.

  • Water penetration and water vapour permeability

This includes water vapour permeability and water absorption (capillarity).

  • Wind Loading

This includes wind uplift.

What does this mean for EWI Store?

As the leading UK render specialists who strive to offer the best possible choice of materials from trusted manufacturers and established brand names, the BBA approval on EWI Pro’s products validates that we only offer high-quality, long-lasting and aesthetically pleasing solutions for your next render project.

Our range of BBA-approved products

All the products that comprise a Mineral Wool and EPS external wall insulation system are BBA-approved. EWI Pro Mineral Wool and EPS external wall insulation systems consist of grey and white EPS insulation boards which mechanically fixed to the substrate wall with a supplementary adhesive, fibreglass reinforced basecoat and a render finish. After the boards have been secured to the wall with adhesive and the required number of mechanical fixings, the basecoat is applied using a trowel over the boards to the required thickness, followed by the reinforcing mesh which is fully embedded within the basecoat. After the basecoat has fully cured, a primer (depending on the finishing coat) is applied, followed by the render finish.

You can shop the full range of EWI Products in our store here.

Get in touch

Want to know more about BBA approval? While we think we’ve covered a good amount, we’re always happy to answer any questions you may have not just related to BBA approval, but anything related to our products and services. Click here to find our contact details and get in touch with one of our specialists!


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.

How to clean and maintain your render

If it’s been a while since your house was rendered, you might be thinking that it looks like it needs a little clean. If so, you’re probably right: over time, it’s only inevitable that the façade of your home will begin to look a little dirty, dreary and dull, especially if you’re in a high-exposure area. By that, we mean your home is exposed to excess levels of wind-driven rain, causing the development of dampness, algae growth and mould. So, if you have noticed any black or green markings on your home, how do you go about cleaning it? It all depends on the type of render you already have on your home. In this blog, we’re going to cover how to clean off dirt alone, how to clean before painting and how to clean before re-rendering your home.

How to clean dirt, mould and algae growth off your render

If your house is just looking a bit grubby, it might simply need a wash-down. This can first be achieved by soaking a cloth in soapy water and wiping the surface area. If this hasn’t quite done the trick, you can go a little further by using a pressure washer with a mild detergent; however, be sure to adjust the settings to a fan-spray setting to avoid etching and damaging the render.

Alternatively, if your render façade has developed mould and algae growth, you should consider using a moss or algae killer. One of the oldest organisms on earth, algae tend to be the first organic growth to show up on your home; the longer it remains on the render surface, the more it will feed on the moisture and minerals within the surface. If it has reached this point and the amount of algae growth is excessive, you may need to hire a specialist to remove it for you; garden centre biocides are simply not powerful enough to remove the algae on their own.

Owing to its self-cleaning properties, our Silicone Render effectively resists organic growth and therefore requires very little maintenance over the course of its lifetime. Nonetheless, lighter colours are more likely to be susceptible to showing dirt; in this case, the best method for cleaning the render is to use soapy water and a sponge as and when. We offer thousands of colours for our Silicone Render; from calm and neutral to bright and vibrant, you can have any colour you like and, if you clean it as and when, it will remain looking fresh for years to come! If this sounds appealing, take a look at our Coloured Render Sample Pots.

How to clean your render before painting it

If you’re looking to paint or repaint your render, you can follow the same steps as above to clean it in preparation for the paint coat. It’s vital to ensure that it is cleaned properly to avoid any dirt, mould or algae growth from seeping through the paint and causing further issues down the line.

Once your render façade is cleaned properly, you’re going to want to choose a long-lasting, self-cleaning paint to, again, prevent issues regarding dirt and algae growth down the line. Our Silicone Paint is a high-performing masonry paint that is designed to be painted over an existing render to refresh the façade.

How to maintain your render

If you’ve recently had your home rendered – or you’re looking to have it rendered – with one of our specialist Silicone Renders, you’re in good hands; as mentioned, thanks to their self-cleaning properties in addition to their advanced flexibility, our Silicone Renders are designed to last for years to come. Nonetheless, if organic growth is your biggest concern, our Premium Bio Silicone Render is the render for you. What sets this render apart from others in our collection is its ability to actively break down signs of organic growth due to its enhanced vapour permeability. Again, this render can be tinted to absolutely any colour of your choice, including any RAL, NCS or Pantone tones; so, not only does it guarantee an aesthetically pleasing finish, but a long-lasting solution for your render façade!

If this isn’t enough, or you’re in a high-exposure area, you can enhance the protection of your home with our Nano Drex Protect – Render Guard. This product is designed to create a breathable barrier to prevent organic growth, discolouration and water ingress, prolonging the render façade’s lifespan even further – what more could you want?!

The main features of Nano Drex Protect include:

  • its hydro-protect formula;
  • it’s long-lasting;
  • it’s easy to apply;
  • it’s freezeproof; and
  • it’s vapour permeable.

Before applying Nano Drex Protect, as you would when painting or repainting, ensure that the render is cleared of dirt and anything that might reduce the contact between the product and the render. Any surface covered in mould, organic growth or moss should first be treated with EWI-360 Fungicidal Wash, which takes just 24 hours to kill all microorganisms on the substrate.

Get in touch

Interested in rendering or re-rendering your home, or wondering how to go about cleaning its façade? Our experienced Sales Team will be happy to assist with any enquiries you may have! Find our contact details here.

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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      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!