Tag Archives: EWI

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.

 

The Importance of Corner Beading in Rendering

Corner bead is used on all external corners on render-only systems. It is a pretty important component of the render/external wall insulation system and in this blog we look at what it is, where it is used and why!

What are corner beads?

Corner beads tend to be made from rigid PVC, moulded into a 90-degree angle. The PVC has lots of holes within it so when it is embedded with the adhesive, the adhesive can travel through it and completely immerse the corner beads, helping to hold them in place. Sometimes corner beads come with mesh wings attached to the rigid PVC; these can be covered with adhesive, again helping to keep the corner beads in place.

At EWI Store we offer several different types of corner beads, depending on the situation and the type of render being used. Our main corner beads are either:

• For use in thin coat render systems (the corner beads are completely buried within the thin cost render system). These come with or without mesh wings attached to the PVC.

• For use in monocouche scratch render systems (beads protrudes out of the render on the corner).

The above example is the EWI-65520, it is mesh,  it has no nose and is 2.5m in length.

What is the reason for using corner beads?

Corner beads are used in render systems for 2 main reasons:

• Corner beads reinforce and protect external corners – this includes around windows and doors, as well as at the corner of the property.

• Corner beads provide a nice sharp finish when rendering.

Corner beads add an extra layer of protection for external corners, which often take a lot of knocks. The layer of impact-resistant plastic provided by corner beads reinforce stress points and allows render to be flexible without cracking. It is amazing the number of knocks that the corners of buildings take. Using corner beads ensure that even if knocks do occur, then the system will be able to withstand the impact.

Corner beads are also used to provide sharp 90-degree angles on the corners of buildings. Trying to free form a 90-degree angle is difficult and although some renders decide not to use corner beads, we would never advise it! Corner beads are relatively cheap in the scheme of things and so it makes sense to use them to ensure you can get that perfect angle on the property!

Above is a Flexible Arch Bead, it is the EWI-66500, it has no mesh and is 2.5m in length. This bead easily bends to reinforce curves and arch forms. The Arch Bead fixes to the profile of the curve, giving you a smooth strong finish.

How do you embed corner bead?

If using a thin coat render system, then corner beads are embedded using either the EWI-220 Adhesive or the EWI-225 Premium Adhesive. It is completely embedded within the adhesive/basecoat layer, but be sure not to wrap the basecoat mesh around the corner – instead run the mesh up to the rigid PVC moulded plastic. This ensures you don’t ‘round’ the corner when installing the corner bead. For a visual demonstration of this process please watch our YouTube video “EWI-220 EPS Basecoat Application”.

Above is an example of a corner bead that you would use for monocouche scratch render systems. The above example is the EWI-63300, it has a 6mm nose (that part that will protrude out of render), no mesh and is 2.5m in length.

With monocouche scratch render, the scratch render is taken up to the corner of the bead, but the bead still shows through the render. You can therefore get different colours of monocouche scratch render corner bead – get in touch for options!

Above is the EWI-65620, this type of bead is shown in the linked demonstration video above. It is also known as a Panzer corner bead. This bead is used for internal corners, it has extra strength for additional movement and is used for both external wall insulation and render only.

Corner beads make your life easier during installation, increases the lifespan of the system and gives a better looking final result – so make sure to use them when rendering or installing EWI systems!

Looking for Render Supplies in Aylesbury?

Looking for Render Supplies in Aylesbury?

Are you looking for render supplies? Look no further than EWI Store!
We are specialist render suppliers – supplying a huge range of thin coat Silicone renders, Monocouche renders (including K-rend renders and Weber renders) and external wall insulation (EWI) systems. Building on the success of our Chessington branch, we are delighted to announce that EWI Store Aylesbury is now open! Our new 15,000sq ft warehouse is located on Faraday Road, HP19 8RY, allowing us to better serve North London and the midlands with fantastic quality renders at unbeatable prices.

Why to buy render from EWI Store Aylesbury?

As specialist suppliers of Silicone Renders and Moncouche / Scratch renders, our team have a great deal of knowledge on what to use and where to use it – so looking to apply render to insulation boards? Looking for breathable render systems? Our fantastic team will have all the answers!
The additional space in our new unit has allowed us to become your local K-rend supplier, EWI Store Aylesbury carries a large volume of HP12, K-Mix and K1 Scratch Render in various popular colours.  As specialists in thin coat silicone renders, we also offer the award winning EWI Pro thin coat renders. We have tinting facilities on site, so whatever the size of the order, we can have your render tinted to the colour you want within minutes.  It is not just K-rend and EWI Pro renders we offer though – EWI Store Aylesbury also stocks Rockwool, Jablite, Knauf and Sika products all available for collection and dispatch.  Our rendering tool range is great too! We have partnered with brands like Refina, Ox Tools and Regal & Barnes to provide choice, operating precision and quality.
Our aim is to be the one stop shop for all your rendering needs – so no longer do you need to chase round lots of different stores to get the bits you need to get the job done.

EWI Store deliveries are now even ‘quicker’

Obviously we would love to welcome you in branch, however we also appreciate that many installers want to get materials delivered directly to site. We have therefore greatly increased our delivery capabilities to ensure that whether you are looking for renders in Luton or K-rend in High Wycombe, we can serve you quickly and professionally. We have also partnered with reliable national and international couriers, so should your project be a little further afield – we still have it covered! We are delighted that we have removed the bottleneck for so many installers – we can get you coloured render, be it K-rend TC15 or one of the EWI Pro Silicone Renders to your site the very next day, regardless of volume!

Technical support and training available in Aylesbury

We have always been Governed by transparency and providing easy to access consumer information, as we believe that a more informed end-user is a more empowered user that will contribute to providing the best possible outcome. Just like in our Chessington branch, technical support and training will be available in Aylesbury. By ensuring that installers are trained and well-rehearsed in the products and systems that we offer, it allows our customers to achieve better results. We are happy for our customers to pop-in and have a chat with us at any time. Our sales support and Technical Sales Managers can run through the whole installation process, talking about product combinations require to achieve a competent and well-constructed end-result. The training days are unique as we not only run through the theory but will give the trainee the opportunity to have a go at applying the products onto the test wall areas.

EWI Store keeps prices fair and not compromising quality

Although we have made a sizeable investment in upgrading our operating capabilities, we will not be increasing customer prices. We strive to be cost-effective because we are constantly striving for innovation and delivering the end service in the most efficient way, cutting that unnecessary overhead burden to pass the benefits to the end-customer.

So, if you are looking for render supplies in Aylesbury – visit us at EWI Store!

Is K Rend a System or a Product?

What is render?
Render is applied on external walls to seal them off against harsh weather conditions, or an opportunity to give your property a face-lift. Early rendering was a messy business, slapped on the walls using sand and cement and finished with coloured paint. Over the years, render technology has evolved greatly, giving a much larger choice of colours and finishes -enabling tailoring to specific environments.

For instance, hydrophobic renders can protect properties in damp environments from water penetration and weathering. Also, the renders contain flexible polymers, helping the surface retain its structure without cracking very easily.

Traditional render is subject to wear and tear and if not regularly maintained and repaired, can leave the building in an awful condition. Cracks may appear on older render systems, which may then cause damp and water penetration.
The thinner coat renders tend to use fewer bags material , which is why in most cases they have a tendency to be less expensive to install than thick coat renders.

What is K Rend?

K Rend‘ is often used in the external insulation business as a catch-all term for render. Just as the personal cassette player was most known as the ‘Walkman’ throughout most of the 1980’s and 1990’s, K Rend has the similar brand recognition.

K Rend in fact is ‘only’ a brand with a large range of various renders, manufactured by Kilwaughter, the chemical manufacturer parent company in Northern Ireland. K Rend traditionally produced ‘thick coat’ renders like dash receivers and Monocouche and has recently also ventured into the family of silicone render products.

K Rend render is a water-repellent, breathable solution – low maintenance and available in most colours.

Despite its reputation, it is only one brand amongst several external rendering products within the market. There are dozens of other systems that can be sourced and installed that do the same job.

What is the difference between K Rend and other render manufacturers?

As mentioned, K Rend traditionally manufactured traditional English thick coat renders, whilst in Europe thin coat flexible renders were significantly more popular. Over the years, various acrylic and silicone thin coat solutions have made it to these shores and are now growing in popularity. Several houses have been successfully retrofitted with these solutions.

Whilst K Rend also produces thin silicone renders, the European manufacturers probably have a longer history of using thinner coat products. However, K Rend stands up well against competitors’ products.

Both K Rend and other manufacturers now specify a flexible bead or mesh inserted into the base coat adhesive before the final layer of render is applied. However, since K Rend does not have a full external wall insulation system, beading is optional where it is mandatory on many other render systems. It is our view that the more flexible the render layer, the longer its lifespan, because it will be less susceptible to movement and surface cracking.

Does K Rend offer an external wall insulation solution?

Whilst K Rend can be used as the render based system on top of insulation, the brand itself does not have a certificate for an external wall insulation system (ETICS). This contrasts with many of the thin coat systems, which also come together with the external insulation system.

More and more, older homes are not just going through the re-rendering process, but homeowners are also upgrading the thermal efficiency of their properties as well as updating the render at the same time. It is a less expensive way to re-render, as with external insulation the homeowner or occupier should look to understand that heat cost savings over time would go some way to pay for the cost of the job.

K Rend and other render brands

We believe that certain renders will work in certain situations. For example, many properties in South Wales and Western Scotland are pebble-dashed and the K Rend offers the perfect solution to repeat this process. Also, some architects may specify Monocouche thick render scratch finish, and in these cases, it is reasonable to want to go for the K Rend system.

Just be aware there are other render manufacturers also exist which offer similar products to K-rend like EWI Pro Insulation Systems, Johnstones and Sto.

Why Use External Wall Insulation?

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 it’s 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, 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 wont reduce the size of your rooms, unlike Internal wall insulation.

Disadvantages of Internal wall insulation

Internal wall insulation also comes with additional risks and limitations over External wall insulation. For one it is less effective than External wall insulation and does not offer the same protective qualities. Internal wall insulation can make securing things to walls difficult. Stud walls are capable of holding heaving fittings, but if you have used insulation boards, the fittings need to be able to penetrate through them, then into the wall behind.

As discussed above this method also reduces the size of your room. The thicker you insulate your home the smaller your rooms will become. This means you are limited in the extent you can insulate your home.

Using Internal wall insulation means your home is far more likely to be affected with damp problems. Wet rot and mould can build up quickly on the inside of the masonry (the face that the insulation is fixed to) This can create hazardous spores, which will be breathed in by the occupants, and has the potential to create, or exacerbate existing health problems.

Another major concern when dealing with Internal wall insulation, is that a sufficient amount of warmth will not pass through the insulation and into the dwelling, (which normally keeps your walls dry) this means your walls will become damp and water ingress can turn to frost and damage your brick work, a process known as ‘freeze thaw damage’.

Disadvantages of External wall insulation

There are few reasons against External wall insulation especially when compared to Internal wall insulation. Some of the reasons may be purely aesthetic, for example if you are fond of your brick work. This is because by externally insulating your home, you are covering the outside of your house with insulation materials, that will need rendering to create a polished and protective Finnish.

If you live in a flat this may also not be a realistic option, as the insulation would not be effective without also insulating the rest of the block. This is often not possible so in this instance you may turn to Internal wall insulation.

In some cases you may also need to be granted planning permission from your local council, to have your home externally insulated, so in this case you may also need to consider Internal wall insulation. In most cases we would recommend External wall insulation unless you are included in the above examples.

What Insulation Materials can be used for External wall insulation?

there are a lot of suitable materials for this procedure, so you will not feel limited for choice! You can choose between EPS, Kingspan, phenolic resin, wood-fibre, cork and mineral wool. You may decide to use EPS (expanded polystyrene) as this is a popular option, and is one of the most cost effective materials.

External wall insulation must abide by strict building regulations, which will have an affect on the material you choose. Solid wall insulation needs to have a U-value of 0.30 watts/m2k. The down side of EPS is that it requires a thicker amount of this material to achieve the same thermal performance/ U-value compared to Kingspan.

Mineral wool may be your preferred choice because by nature Mineral wool is moisture-resistant, and it is able to keep its insulating properties even when wet. Mineral wool is also good at blocking sound so means your building will have less acoustic invasion.

One of the best advantages of this material is its heat-resistant qualities- It will not burn until the temperature goes above 1000°C. Just ensure if you chose Mineral wool that you do not use an Acrylic render to Finnish, due to its lack of breath-ability, compared to the Mineral wool which will defeat the purpose of using Mineral wool in the first place.

Wood-fibre is a fantastic option as it is the most breathable, and natural insulation material, however this system is very pricey compared to the EPS system.

How To Cover Up Old Pebbledash

How do I get rid of pebbledash?  

Pebbledash became extremely popular in the 1920s due to an increase in demand for homes to be built. This lead to builders cutting costs and used pebble-dash to cover up poor brickwork. At present, this has resulted in an outdated and, for many, unsightly look that many homeowners are looking to remove. 

If the right materials aren’t accessible, re-rendering pebbledash without removing the pebbledash can be difficult. 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.

With the growing popularity of coloured render, pebbledash has taken a bit of a hit of late, with pebbledashed house prices falling to reflect a national dislike. Nonetheless, as long as the pebbledash is in good condition, there is no reason this can’t be rectified without the expensive process of removing it.

       

 

How to re-render pebbledash without removal

So, how do you re-render pebbledash without removing the pebbledash render? There are a couple of ways you can do this which we are going to explore…

 

1. Smoothing over the pebble-dash with One Coat Dash Cover (OCDC)

One of the best ways of re-rendering pebbledash without removing pebbledash render is by smoothing over it with our One Coat Dash Cover (OCDC). This is the ideal material to use because it can be applied at a thickness of 20mm without compromising structural integrity. You wouldn’t want to put a non-breathable material on top of the pebbledash because water needs to be able to escape from the walls, otherwise, you may find yourself in an unpleasant, waterlogged situation.

The first step in re-rendering your pebbledash is to ensure that any loose stones are rubbed off.

The next step is to prime the pebbledash using the 310 Universal Primer. This will limit the absorptive capacity of the pebbledash render and ensure that any dust is settled; it also provides a good grip for the basecoat to adhere to.

Once the primer has been left to set for 12 hours, you can go ahead and start preparing the OCDC for application. One 25kg bag needs to be mixed with 5 litres of clean water, using an electric paddle mix. Once mixed, leave for 2-3 minutes before re-mixing and then apply to the substrate using a plastering trowel. We recommend embedding Fibreglass Mesh within the basecoat, overlapping each strip by 10cm to ensure crack resistance and tensile strength.

Once the initial coat of 5-20mm has set, apply a ‘tight coat’ using a plastic, metal or felted float. After this has set, we advise applying a thin coat render such as Silicone Render; this is highly breathable and is available in a wide range of colours, so will provide an aesthetically pleasing finish. To learn more about this technique please check out our YouTube video ‘One Coat Dash Cover’.

 

2.Externally insulating on top of the pebbledash

Another method of re-rendering pebbledash without removing pebbledash render is to apply insulation boards to the existing pebbledash. Even 20mm of EPS insulation secured to the exterior of the property can increase its thermal efficiency and create a smooth surface for a fresh layer of render to be applied to. The method of preparation is the same: any loose pebbles should be removed and the wall should be primed with the Universal Primer.

The insulation boards should then be secured to the substrate using the 225 Premium Basecoat. This should be applied to the whole of the back of the insulation boards – we don’t recommend doing the dot and dab method for applying insulation to pebble-dash. Mechanical fixings should also be used to secure the insulation boards to the pebbledash.

Once the boards are set in place, you should have essentially created a new substrate for re-rendering pebble-dash without removing pebble-dash. The best practice is to rasp to EPS to achieve a smooth surface and remove the oily top layer, and then you can apply your render basecoat. We recommend using the Premium Basecoat for extra strength, embedding fibreglass mesh within the basecoat to ensure a strong and stable surface for the render. Finally, you can prime the basecoat using the SiSi Render Primer, leaving it to dry for 12 hours before applying either the Silicone or Silicone Silicate render.

And there you have it! Two easy ways to re-render pebbledash without removing the pebbledash render.

 

 

 

 

 

 

    Approved Installers Request Form

    Your Name*

    Your Email*

    Your Number*

    Your Postcode

    Additional Information

    I would like to receive news and offers from EWI Store

    The Benefits Of Using Silicone Render

    Why render my 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 Renders, Acrylic Renders, and Silicone renders.

    What is so great about 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 breath-ability 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.

    As stated above, having moisture penetrate through your render can cause serious problems and damage, but luckily Silicone render is extremely waterproof. This causes water to bead up on the surface, and once this bead is heavy enough to run down, it will take dirt with it , meaning it is also self-cleaning! this will keep your render looking fresh long term.

    Some silicone render products also contain cleaning agents which attack bio-growth like the ‘EWIPRO Premium Bio Silicone Render‘ which is ideal in high vegetation areas or areas with increased exposure to organic matter. This prevents bio-growth and keeps the render looking clean and fresh for longer.

    Silicone renders come in a wide range of colours and grain sizes. This enables you to choose what textured finish you want. Thin coat renders can be applied to a thickness of 1mm -3mm which offers maximum flexibility and breath-ability. Coloured render enables you choose between more subtle or bold colours. With all these options you can customise your property the way you want it.

    Silicone render is one of the newest and best performing renders which is reflected in the price as it is slightly more costly than the other types of render, however we would definitely recommend it because of its low maintenance and long lasting properties will save you time and money in the future. Silicone renders have a life expectancy of around 25 – 30 years depending on the quality of application.

    Silicone renders come pre-mixed which means that the product will always be mixed to a consistent ratio and wont vary from pot to pot. Silicone render is also one of the easiest renders to apply. This product has a lot to offer for both ease of application and for quality and appearance.

    silicone render

    Silicone Render

    Silicone Render

    Silicone Render  Basecoat

    Silicone Render beading

    What is Silicone Render?

    There are many different types of render on the market, all with different properties. The range includes older sand-cement style renders, to scratch renders, and thin coat renders. Silicone Render is a ‘thin coat render’, which means that it is applied on top of a basecoat at just a few millimetres thick. Silicone render is becoming ever more popular these days, so in today’s blog post we’re going to explaining a little bit about it.

    Why choose Silicone Render?

    There are many big advantages to using silicone Render – there really is little competition when it comes to quality of finish. Let’s take a look at some of the major advantages:

    • Silicone is breathable – Where cement and acrylic renders completely seal off the wall and prevent it from breathing, silicone is very breathable.
    • Silicone is self coloured – Unlike other renders that must be painted after curing, silicone render has the colour mixed into it, meaning just one coat and the job is done. Having the render pre-coloured means that it lasts longer and won’t show if it is scratched, as the colour runs through the whole top-coat. (for an idea of the cost of silicone render per square metre, read our dedicated blog post here)
    • Silicone is easy to apply – Where other renders have a painting stage, thin coats can be done in just a few hours on a properly prepared wall. Despite a slightly higher cost, your job will be done in much less time than a traditional render.
    • Above all else, silicone looks great! It leaves the property looking like a new house.

    How is it applied?

    Silicone is a one-application thin coat render. It is dead easy for a qualified renderer to apply this render to a fully prepared wall. On a typical wall, a basecoat should be applied to create a strong, stable and level surface with which to render. Once the base coat has dried, the silicone can be applied using a plastic float to create a thin and smooth finish.The thickness of the silicone top coat should be the same as the grain size of the render. So a 1.5mm Silicone Render will be 1.5mm thick on the wall. The layer has to be applied in one go on each elevation otherwise you could end up with patches and lines where the render has been joined.

    If you are interested in downloading an install guide you can click here. 

    Different types of Silicone Render

    You will have noticed that we offer several types of Silicone Render:

    • EWI-040 Silicone Silicate Render
    • EWI-075 Silicone Render
    • EWI-076 Premium Bio Silicone Render
    • EWI-077 Nano Drex Silicone Render

    All of these renders are manufactured by EWI Pro who specialise in this type of thin coat render.

    There are 3 key characteristics that all silicone renders display, they are hydrophobic (repel water),  they are breathable and they are flexible and as you go down the list (i.e. from EWI-040 to EWI-075 and so forth) the renders show higher levels of these characteristics so basically you are getting a better product.

    What does Silicone Render cost?

    Each of the silicone renders has a different price point which you can see below, but it is worth mentioning that all silicone renders are going to cost more than acrylic render, because you are getting a vastly superior product. 

    Typically though, since a bucket of the 1.5m grain render covers 10m2, when you consider the other products required like basecoat and mesh, you are going to be paying between £10 – £15 per m2 – which is comparable to monocouche / scratch renders. 

     

    How much thin coat render do you need for a typical house?

    This is going to come down to the area of wall you are looking to cover. The render comes in 25kg pre-mixed buckets, and each bucket at our standard 1.5mm finish will cover around 8 square metres of wall. For an average semi-detached house of say, 80m, you are looking at around 10 buckets of render. If you go for a finer grain size of 1mm, the render will go further, covering 11-12m of wall each. Thicker 2mm render will cover less area, so you need to take this into account when you are working out the quantities you need.

    Who makes Silicone Render?

    There are several brands available on the market, but we recommend the Silicone renders from EWI Pro . As mentioned the specialise in Silicone renders and also they are well priced and offer all of the advantages we have mentioned above. Plus we offer colour tinting and next day delivery on this product.

    Where can I purchase Silicone Render?

    You can buy our EWI Pro Silicone Render via our store – just click on the item below AND as a little thank you for visiting our website, simply use the code ‘SiliconeR’ at checkout to get a 15% discount to Silicone Render applied to your basket.

    Can I get Silicone Render in cream, grey and magnolia?

    The great thing about EWI Pro Silicone Render is that there is a huge range of colours available to choose from. You can order a free colour chart, pick your colour and this will be mixed up and sent out to you the next day in most cases, using our own delivery drivers, not couriers.

    You can buy EWI Pro Silicone Render online, in-store or by giving us a call. For any further questions, we are always happy to help so leave a comment down below!

      Approved Installers Request Form

      Your Name*

      Your Email*

      Your Number*

      Your Postcode

      Additional Information

      I would like to receive news and offers from EWI Store

      thin coat render

      Coloured Render vs. Insulated Render – Ultimate Guide

      As we are well into the 2020s, the demand for insulation, external decorative products and coloured render is rising. The 2020s has seen another generational shift, as renderers are moving away ever more away from traditional cement and choosing various coloured render or insulated render products.

      In this industry, the terms ‘coloured render’ and ‘insulated render’ are talked about a lot. The terms are often used interchangeably, however subtle differences do exist and in this blog we are going to take a look at these in a bit more detail, so that the appropriate solutions can be used on your next and upcoming project.

      What is coloured render?

      Coloured render refers to render that is coloured right through it’s final decorative coat in one uniform appearance. Sand and cement render is not coloured render. When we refer to coloured render we usually refer to the EWI-010 Acrylic Render and the EWI-075 Silicone Render (also known as thin-coat renders), which form the final finish as part of a multi-layer build-up; or we refer to EWI-090 Monocouche Scratch Render, which is also coloured through and can be applied either on its own or on top of a basecoat preparation layer. Our coloured renders can now be matched to NCS colours as part of our colour matching service!

      Acrylic Render, Silicone Silicate Render, Silicone Render, Premium Bio Render and Nano Drex Render are all examples of coloured renders. Coloured renders are also referred to as thin-coat renders. 

      The next section talks about the nuances in the family of coloured renders. 

      What are the differences in the coloured render types?

      The acrylic or silicone renders usually come in wet bucket form and are manufactured in a standard white colour. To produce the coloured render, the acrylic or silicone renders go through a tinting machine, which consists of a pigment dispenser and a shaker. The coloured pigment is dispensed into a bucket in a controlled environment and this bucket is shaken-up by the shaker to produce one uniform colour throughout.

      Monocouche scratch renders, come in a dry format, usually in 25kg bags – these are pre-mixed in different colours, and need to be mixed with clean potable water to make it ready for application.

      Since monocouche render is pre-mixed with different colours, you will probably not be surprised to learn that the numbers of colours available with this type of render is limited. In fact, when going with a monocouche coloured render, you can pick from about a dozen or so different colours, but if you opt for the thin coat coloured renders you can literally pick from thousands of colours.

      Achieving different types of finishes

      Another difference between monocouche and thin coat renders is the type of finish that is achieved. While the thin coat renders, usually leave a textured, slightly grained type finish, the monocouche scratch renders achieve a pitted effect, by effectively leaving little scratches on the surface (hence often referred to as scratch coloured render). Both finishes look great, so choosing which coloured render to go for normally comes down to which look the end-user prefers.

      However what we have found that since the turn of the 2020’s more and more customers are turning towards the thin coat coloured renders due to their additional hydrophobic and flexible qualities.

      Difference in application procedure

      The other differences between the two different coloured renders is how they are applied to the wall. The scratch render is in applied at a thickness of 18mm and scratched back using a scratch render scraper to give a final thickness of 16mm. Conversely the thin coat renders are applied at a thickness of 1-3mm onto a flexible basecoat layer (basecoat + embedded mesh). This means that a bucket of thin coat render will go far further in terms of coverage than a bag of monocouche scratch coloured render when applied to the wall.

      Our dash receiver is also bagged like the monocouche scratch render and comes in different colours, but the decorative pebbles that stick on the outer surface form the main part of the decorative feature so the amount of actual dash receiver you can see is limited.

      The “dash look” is rather dated and was quite popular in the 1970s and 1980s. However we do still have requests occasionally is parts of Wales or Scotland. 

      The second part of the blog now explores what insulated render is.

      What is insulated render?

      Very often when we refer to insulated render, we refer to a coloured through render backed on an external wall insulation material. This external wall insulation material can either be lightweight EPS, stone wool (mineral wool), K5 phenolic or wood fibre insulation board. The insulated render part is the final decorative layer that sits on top of the reinforcement layer, which in turn sits on top of the insulating material.  The whole system in therefore an example of an insulated render system or a external wall insulation system (EWI).

      Insulated renders as parts of external wall insulation systems first introduced the “coloured render” component to the UK as part of the overall concept in the early 1990s. 

      What are the differences in the insulated render types?

      There are differences in insulated render types, which are characterised by the differences in the build-up – starting from the insulation material, to the reinforcement layer and then a variation in the decorative look.

      For example, insulated renders can use one of the following insulating materials: EPS, Mineral Wool, K5 phenolic and Wood fibre insulation. Phenolic insulated has the best thermal insulating value followed by the EPS, Mineral Wool and then the Woodfibre. On timber backed systems you would want to go for something like the woodfibre, whereas if you are insulating traditional brick, then you have a choice of all four depending on the individual choices and preferences.

      Basecoats and reinforcement mesh may vary to achieve a different preparatory coat ready to receive the final coat. Basecoats can either be in the grey or white adhesive types. Also, the system build-up may contain a slight variation in the weight of the fibreglass mesh, with one coat mesh or two coat mesh being used for different impact resistance requirements.

      Achieving a nice and level basecoat is absolutely crucial in getting the best type of aesthetic finish on the final silicone or other thin coat texture. In addition depending on the use of the wall being reinforced, 2 layers or fibreglass mesh can be installed or a panzer mesh instead of one regular level of mesh to give the overall wall additional structural strength. 

      Coloured renders like the thin coat silicone or acrylic can sit on top of an insulated render system and work very well. Monocouche scratch render can also sit on top of the reinforcement layer, but it is not commonly specified due to the weight/ load of this final coat of the coloured through render. Some manufacturers do specify monocouche or scratch render on top of insulation, but we are a bit sceptical on its long term performance due to the load and flexibility issues.

      Can the render itself be ‘insulating’?

      In certain and rare circumstances, the coloured render itself can contain special insulating properties, which when used as part of the render build-up can be considered an insulating render. These coloured renders don’t necessarily have an insulating material behind it. An example of a coloured render that is also an insulated render, is using a basecoat that contains a certain amount of the following ingredients (not limited to this list): perlite, EPS, cork or aerogel, and the product itself has a declared lambda value (ƛ) on the product packaging.

      Remember the lower the lambda the better the insulating property of the material. For example the K5 Phenolic board has a declared lambda of 0.018-0.020 whereas the Mineral Wool is 0.036. Therefore we can conclude that the K5 phenolic board is a better insulator than the Mineral Wool for a given level of thickness.

      An example build-up of coloured render with insulating properties: the EWI-520 Insulating Basecoat (limited availability and special orders only) with a layer of fibreglass mesh to give the layer flexibility; finished off with 1.5mm of the EWI-075 Silicone Render.

      Limitations of insulated render materials

      Although the insulated coloured render in this example has insulation properties, it would not replace the degree of insulation associated by installing a full external wall insulation system. You could install this type of system in areas of difficult access or where it would be tricky to thicken the walls by a certain degree due to width (boundary) restrictions around the property.

      Additionally you may want to use the insulated render on the window reveals, where applying a 20mm insulation board is not a practical situation. You can also have these details between openings and facias & gutters. 

      Coloured renders and insulated renders in summary

      As discussed above coloured renders and insulated renders are used interchangeably in the industry but you do have subtle differences. Coloured render refers to the cement-based plaster applied either as a basecoat and a thin-coat decorative finish; or to a one-coat Monocouche Scratch Render applied in one pass onto the substrate. Therefore there would be additional external insulating boards stuck on the substrate waiting to receive the coloured render itself.

      Insulated Render usually refers to an external wall insulation system that not only contains a coloured render, but an insulation material that is adhered to the substrate. This insulation material can EPS, Mineral Wool, K5 Phenolic or Wood fibre insulation.

      Coloured render can also have insulating properties, but it must be declared on the packaging. However this can be used to take the edge of a substrate rather than as a prime insulating material for the purposes of thermal insulation. I.e. applying 100mm of insulating cement based plaster is just practical. 

      2020’s outlook for coloured render

      We are finding that the 2020’s have brought about a significant increase in demand for coloured render finishes either as a render itself or with an insulating board applied. Sand & cement while still widely used is slowly being phased out due to the fact that once applied does not have the benefits offered by coloured and insulated renders.

        Approved Installers Request Form

        Your Name*

        Your Email*

        Your Number*

        Your Postcode

        Additional Information

        I would like to receive news and offers from EWI Store

        Materials Required for Insulating Below the DPC

        1. Priming Below the DPC:

        If you’re installing your XPS insulation system below the DPC of a brickwork substrate it will need priming with the Water Based Primer. We recommend applying this to the substrate by roller or brush. However, if you are rendering onto a very smooth substrate then we recommend applying the EWI-310 Universal Primer, as this contains aggregates which will provide a rough surface for the basecoat to adhere to. Ensuring that your substrate is adequately prepared is essential to ensuring that your render system will last.

        Coverage rates:

        5 litres covers 15-30m2 depending on the substrate.

        Drying times:

        1 coat takes 4 hours to dry.


        3. Preparing the Adhesive

        Because the DPC area is so prone to damp, we recommend the use of Aquabase as this is a highly water-resistant basecoat/adhesive. Aquabase a very versatile, dual-purpose product that can also be used in the subsequent basecoat layer. The adhesive is applied to the entirety of the back of the board using a notched trowel. 

        Coverage: 

        1 x 25kg bag covers 4/5m2

        Drying times: 

        24-48 hours


        4. Applying the XPS Insulation Boards

        XPS insulation boards are ideal for below the DPC because they offer a closed-cell structure which makes them more waterproof and impact-resistant. We sell XPS by the square metre in a range of thicknesses. For insulating a solid brick wall the general recommendation to reach building regulations is to opt for a 110mm thickness. A really flat surface will need to be achieved while mounting the boards to ensure a smooth topcoat. We recommend using a spirit level to regularly check that everything is flat. 

        Coverage:

        1m2


        5. Installing the fixings

        EWI Pro recommends that you install one fixing per corner, with an additional two in the middle of the insulation board. Plastic fixings should be used with the XPS insulation system as they significantly reduce thermal bridging. The fixings are available in a wide range of lengths to accommodate different thicknesses of insulation.

        Coverage:

        Plastic pin fixings are the recommended fixing for XPS insulation. These come in boxes of 200 or 100 depending on the length.


        6. Applying the Beading:

        Beading is essential for reinforcing external areas that are more prone to damage, for example, the corners and the areas around windows and doors. The required beads will depend on the property and which particular areas need reinforcing. We have a broad range of render beads that should be selected and applied as necessary, our beads are uPVC and are designed to be embedded within the basecoat layer. For real security against condensation and cold spots, you may also want to use a foam tape in between the starter track and the top of the insulation boards.


        7. Applying the Basecoat:

        For insulating below the DPC with XPS insulation, we recommend using the EWI-226 Aquabase in the basecoat layer again for added protection against damp and water penetration. 

        Coverage rates:

        1 x 25kg bag covers 4/5m2

        Drying times:

        24-48 hours


        8. Priming the Basecoat:

        A render primer should be used to increase the adhesion of the render to the basecoat and can be tinted to match the colour of your render for increased opacity. The type of primer will depend on the type of render you are using. When using Mosaic Render, we recommend using the Mineral & Acrylic Primer which comes in two different bucket sizes.  

        Coverage:

        1 x 7L bucket covers 20m2

        1 x 21L bucket covers 60-70m2

        Drying times:

        12-24 hours


        10. Applying the Render Topcoat:

        Once the primer is dry, the render topcoat can be applied. We recommend using the EWI-050 Mosaic Render as this is very durable and waterproof, which makes it perfect for below the DPC. Mosaic Render is available in a range of colours to achieve a unique finish. 

        Coverage:

        1x25kg bucket covers c. 3-4m2

        Drying times:

        24 hours (+)


          Approved Installers Request Form

          Your Name*

          Your Email*

          Your Number*

          Your Postcode

          Additional Information

          I would like to receive news and offers from EWI Store

          What Size Bead Do I Need For a Thick Coat Render?

          Choosing the correct beads is essential to ensuring that your render system looks crisp and sharp at every angle, while also remaining impact resistant and structurally sound. 

          We’ve put together a list of beads that are ideal for use with thick coat renders such as the Enewall Scratch Render, which is a monocouche that is designed to be applied in two passes.

          Corner Bead Without Mesh

          Our corner beads are available with or without mesh. The key difference between the two is that typically you’d use a corner bead without mesh for scratch renders and thick coat renders. The corner bead below is available with a 6mm, 11mm or 14mm nose depending upon the thickness that you’ll be applying the render at.

          The main point of the corner bead is to get a crisp edge at 90-degree angles. This can be particularly tricky when applying really thick renders.

          Bellcast Bead

          The bellcast bead is designed to create a clean, reinforced line where the render finishes. It can also be used at the bottom of the wall to provide a drip, which directs water away from where the render finishes. This lessens the risk of water penetration and helps to keep the render at the bottom of the wall clean and damp-free.

          Bellcast bead is great for two-coat renders, as it’s available in 11mm. Once embedded into the first pass of the two-coat render, the bead will help to create a nice sharp edge at the bottom of the wall.

           

          Render Movement Bead

          Render movement bead is ideal for use where you have a large expanse of render (over 12m). It is used for render only systems and is installed vertically along the wall to prevent the render from cracking. Essentially it enhances the tensile strength of the render system. 

          Render movement bead should be embedded within the first pass of the render.

          Blue Fibreglass Mesh

          Although this isn’t technically a bead, we’ll give it a mention because it’s great for thick coat render systems. Blue Fibreglass Mesh offers a wider mesh weave which is fantastic at enhancing the tensile strength of a thick coat render system. As we know, thick coat renders may look great but they are less flexible than thin coat renders, which means that it’s harder to make sure that you don’t get hairline cracks. 

          Embedding a Blue Fibreglass Mesh within your thick coat render will massively help to ensure that your render finish remains crack-free for years to come. We can’t recommend it enough if you’re looking for extra stability.

          Those are just a few of the beads that we offer for thick coat render systems. If you’re looking for a bit more information about what beads should be used where give our technical team a call!

            Approved Installers Request Form

            Your Name*

            Your Email*

            Your Number*

            Your Postcode

            Additional Information

            I would like to receive news and offers from EWI Store

            insulating a detached house

            How to Insulate a Detached House

            Choosing the Right Insulation for Detached Houses

            As with any installation, insulating a detached house first involves choosing the type of insulation that you want to use. This decision can depend upon a number of factors, whether it’s based on the thermal performance of the material or how suitable it is for your particular property. Here are the salient points for each of our insulation materials:

            Kingspan K5

            • Thermal conductivity: 0.020 (W/mK)
            • This is much more expensive than EPS, but a lesser thickness is required to reach the same U-values (60mm of K5 vs. 90mm of EPS). Great for if you are lacking external space.

            EPS (Expanded Polystyrene)

            • Thermal conductivity: 0.032 (W/mK)
            • Cost effective, lightweight and with excellent performance. Our most popular insulation board.

            Mineral Wool

            • Thermal Conductivity: 0.036 (W/mK)
            • Manufactured by Rockwool, our Mineral Wool insulation is completely non-combustible, breathable and with acoustic insulating capabilities.

            Wood Fibre

            • Thermal conductivity: 0.038-0.043 (W/mK)
            • Breathable, natural and very eco-friendly. This is ideal for timber-frame houses.

            XPS (Extruded Polystyrene)

            • Thermal conductivity: 0.038 (W/mK)
            • More expensive than EPS, but with better compressive strength and greater resistance to water. Installers tend to use XPS for insulating below the DPC, with EPS above the DPC.

            Insulating the chimney breast

            With a detached house, you’ll often find that the house has a chimney breast that will require externally insulating. If the chimney breast is in-use or is likely to be in the future, then it needs to be insulated using Mineral Wool insulation. This is because Mineral Wool is completely non-combustible, so when the chimney gets very hot during use your external wall insulation system remains completely safe.

            Extending the Roof Line

            Whether it’s detached or semi-detached, many installations involve extending the roofline to ensure that the roof adequately overhangs the insulation. If this isn’t the case, verge trim needs to be used to ensure that the system is completely watertight.

            Verge trim is installed underneath the soffit to extend the overhang of the roof and ensure that water runs directly off the front of the system, rather than running down the back. If water manages to get behind the system it can cause serious damage, which needs to be avoided. Verge Trim is, therefore, an essential item to prevent this.

            Insulating Above a Porch Roof

            Detached houses often have a porch roof or a secondary roof where there is a ground-floor extension. On these properties, lead flashing tends to be applied to the area where the wall meets the roof. When insulating a detached house that has a porch roof, it’s essential that the lead flashing is re-installed on top of the insulation to prevent water gathering underneath where the insulation meets the roof. The lead flashing will enable the water to run directly down the wall and off the roof without causing any issues.

            Insulating Bay Windows

            If you’re insulating a detached house with a bay window, there are a few ways you can do this. Unfortunately, starter track isn’t designed for bay windows, but you can adapt your uPVC Starter Track to fit the bay window by cutting slits in the base so that it will bend to fit the wall.

            Sometimes the bay window sill does not have enough of an overhang in order to house the EPS insulation. In this situation, you have two options: you can either extend the window sill so that the EPS will fit underneath, or if the window sill is wide enough you can use a 60mm Kingspan K5, which will offer the same thermal performance as the EPS.

              Approved Installers Request Form

              Your Name*

              Your Email*

              Your Number*

              Your Postcode

              Additional Information

              I would like to receive news and offers from EWI Store

              polymer render

              What is Polymer Render?

              Polymer render is essentially just a term for a render that contains ‘polymers’ as part of its ingredients. Different polymers can give the product different characteristics, often enhancing flexibility and increasing weatherproofing capabilities. The technology behind polymer renders is fairly new, but they are steadily starting to overtake the common sand and cement render in terms of popularity. In today’s post, we’re going to explore the different types of polymer renders within the EWI Pro range, and explain a little bit about the different characteristics that they offer.

              Benefits of Polymer Renders

              • Hydrophobic
              • Elastic
              • Highly adhesive
              • Typically through-coloured
              • Pre-mixed
              • Vapour permeable (depending on the type of render)
              • High impact resistance

              EWI Pro Polymer Renders

              EWI Pro offers a range of polymer renders. We often refer to these as ‘thin coat renders’ due to the method of application. Thin coat polymer renders are applied in an incredibly thin layer directly onto a basecoat layer. The EWI Pro polymer renders that we sell all come pre-coloured and ready-to-use in 25kg tubs. They also contain grains (in a range of sizes to choose from) so that you can decide on the type of textured finish that you want.

              Because of the fact that it contains silicone, Premium Bio Silicone Render falls into the category of polymer renders. The silicone within the render means that it is highly flexible, vapour permeable and also in the case of the Premium Bio, extremely hydrophobic and self-cleaning. This is ideal for areas where there is a high level of vegetation and a bigger risk of organic overgrowth.

              Silicone render can be considered as the next step down from the Premium Bio in terms of performance. This is our classic render, offering vapour permeability, flexibility, and self-cleaning capabilities. Silicone render is a classic choice for a premium, long-lasting finish.

              Silicone Silicate render is our best value polymer render in terms of the level of performance it offers. This is a hybrid render, as it is a mixture of both silicone and silicate and subsequently offers the same level of breathability as our other silicone-based renders but with less of a self-cleaning effect.

              Our acrylic polymer render differs from our silicones. It’s extra UV resistant, so it will retain colour pigment really nicely, and it’s also great for impact-resistance. Acrylic render is a standard classic choice and is great if vibrancy in colour is an important factor. However it does lack the vapour permeability that the silicones provide, so this is probably something to consider for long-term performance.

              Reinforcing Polymer Render

              All of our polymer renders the need to be applied on top of a reinforced basecoat. Fibreglass Mesh is embedded within the basecoat at the application stage to enhance the tensile strength of the whole system. Therefore, the render alone without this basecoat reinforcement layer will not provide a long-lasting finish.

              It’s also important to apply these renders onto a completely smooth surface because they are applied at a thickness that matches the chosen grain size (so between 1-3mm), so any slight unevenness in the substrate behind will be completely visible underneath the render.

              Polymer modified renders are without a doubt the future of rendering, so give us a call if you’re interested in having this type of render installed on your property!

                Approved Installers Request Form

                Your Name*

                Your Email*

                Your Number*

                Your Postcode

                Additional Information

                I would like to receive news and offers from EWI Store

                Materials Required for Mineral Wool External Wall Insulation

                1. Priming the Substrate:

                If you’re installing your Mineral Wool insulation system onto a brickwork substrate it will need priming with the Water Based Primer. We recommend applying this to the substrate by roller or brush. However, if you are rendering onto a very smooth substrate then we recommend applying the EWI-310 Universal Primer, as this contains aggregates which will provide a rough surface for the basecoat to adhere to. Ensuring that your substrate is adequately prepared is essential to ensuring that your render system will last.

                Coverage rates:

                5 litres covers 15-30m2 depending on the substrate.

                Drying times:

                1 coat takes 4 hours to dry.


                2. Installing the Starter Track

                When it comes to starter track, you have two options. Opt for aluminium starter track with a clip-on stop bead if you are looking to cut down on costs. Alternatively, if you want to ensure that thermal bridging is kept to an absolute minimum, we recommend using uPVC starter track. Both are available in a range of widths to house different thicknesses of insulation and are drilled into the wall above the DPC.

                Coverage rates: 

                UPVC starter track is available in 2m lengths.

                Aluminium starter track is available in 2.5m lengths.


                3. Preparing the Adhesive

                Mineral Wool insulation is much heavier than EPS and therefore requires the use of EWI Pro’s strongest adhesive, the EWI-225 Premium Basecoat. This is a very versatile, dual-purpose product that can also be used in the subsequent basecoat layer. The EWI-225 is also breathable and therefore will not interfere with the vapour permeability of the Mineral Wool.

                The adhesive is applied to the back of the board using the dot and dab method. This will allow you to get a nice flat surface for the render topcoat. 

                Coverage: 

                1 x 25kg bag covers 4/5m2

                Drying times: 

                24-48 hours


                4. Applying the Mineral Wool Insulation Boards

                Mineral Wool insulation boards are high-performance and very effective. We sell Mineral Wool by the pack in a range of thicknesses. For insulating a solid brick wall the general recommendation to reach building regulations is to opt for a 110mm thickness. Mineral Wool can be tricky to install as you can’t rasp away imperfections (unlike EPS). A really flat surface will need to be achieved while mounting the boards to ensure a smooth topcoat. We recommend using a spirit level to regularly check that everything is flat. 

                Coverage:

                1m2


                5. Installing the fixings

                EWI Pro recommends that you install one fixing per corner, with an additional two in the middle of the insulation board. Metal fixings should be used with the Mineral Wool insulation system as they will support the weight of the boards. The fixings are available in a wide range of lengths to accommodate different thicknesses of insulation.

                Alternatively, for advanced fire-safety, we recommend the use of our metal lamella firebreak fixings. These are great for insulating high-rise structures.

                Coverage:

                Metal pin screw fixings are the recommended fixing for Mineral Wool insulation. These come in boxes of 200 or 100 depending on the length.

                7 fixings are required per m2.


                6. Applying the Beading:

                Beading is essential for reinforcing external areas that are more prone to damage, for example, the corners and the areas around windows and doors. The required beads will depend on the property and which particular areas need reinforcing. We have a broad range of render beads that should be selected and applied as necessary, our beads are uPVC and are designed to be embedded within the basecoat layer.


                7. Applying the Basecoat:

                For Mineral Wool external wall insulation systems, we recommend using the EWI-225 Premium Basecoat again for the basecoat layer, as this saves on material waste. EWI-225 should be applied at a thickness of 6mm.

                Coverage rates:

                1 x 25kg bag covers 4/5m2

                Drying times:

                24-48 hours


                8. Embedding the Mesh:

                Fibreglass Mesh is embedded within the basecoat for extra reinforcement. This will ensure the system remains crack resistant.

                Coverage rates:

                1 x 50m2 roll covers 42.5m2 when overlapped

                Our standard mesh is sold either by the m2 or in rolls of 50m2.


                9. Priming the Basecoat:

                A render primer should be used to increase the adhesion of the render to the basecoat and can be tinted to match the colour of your render for increased opacity. The type of primer will depend on the type of render you are using. For a Silicone Silicate system, we recommend using the SiSi Render Primer which comes in two different bucket sizes.  

                Coverage:

                1 x 7L bucket covers 20m2

                1 x 21L bucket covers 60-70m2

                Drying times:

                12-24 hours

                • Top Coat Primer – 20kg

                  £67.00 (incl VAT)
                • Top Coat Primer – 7kg

                  £37.25 (incl VAT)


                10. Applying the Render Topcoat:

                Once the primer is dry, the render topcoat can be applied. We recommend using either the Premium Bio Silicone Render, Silicone Render, or Silicone Silicate Render. These are intended for creating a decorative finish; they are through-coloured with grains suspended within the mixture in a range of different sizes to achieve the desired texture.

                Premium Bio Silicone is our highest performing render, offering advanced self-cleaning capabilities that tackle any signs of organic growth on the substrate, and extra UV resistance for a long-lasting finish. Silicone Render is the ideal choice for a quality long-lasting finish as it has nano-silicone particles which are great for maintaining a clean facade. Silicone Silicate is excellent value, also offering vapour permeability. All of these options are highly flexible, so are ideal for ensuring that there are no problems with cracks.

                Coverage:

                1.0mm grain size: 1x25kg bucket covers c. 10m2

                1.5mm grain size: 1x25kg bucket covers c. 7-10m2

                Drying times:

                24 hours (+)

                  Approved Installers Request Form

                  Your Name*

                  Your Email*

                  Your Number*

                  Your Postcode

                  Additional Information

                  I would like to receive news and offers from EWI Store

                  Materials Required for Kingspan K5 External Wall Insulation

                  1. Priming the Substrate:

                  If you’re installing your Kingspan K5 insulation system onto a brickwork substrate it will need priming with the EWI-301 Water Based Primer. We recommend applying this to the substrate by roller or brush. However, if you are rendering onto a very smooth substrate then we recommend applying the EWI-310 Universal Primer, as this contains aggregates which will provide a rough surface for the adhesive to adhere to. Ensuring that your substrate is adequately prepared is essential to ensuring that your insulation system will last.

                  Coverage rates:

                  5 litres of EWI-310 Water based primer covers 15-30m2 depending on the substrate.

                  20kg of EWI-310 Universal primer covers approximately 50m2 depending on the substrate.

                  Drying times:

                  1 coat takes 4 hours to dry.


                  2. Installing the Starter Track

                  When it comes to starter track, you have two options. Opt for aluminium starter track with a clip-on stop bead if you are looking to cut down on costs. Alternatively, if you want to ensure that thermal bridging is kept to an absolute minimum, we recommend using uPVC starter track. Both are available in a range of widths to house different thicknesses of insulation, and are held in place with screws positioned at 300mm centres. The starter track is installed on the wall just above the DPC.

                  Coverage rates: 

                  UPVC starter track is available in 2m lengths.

                  Aluminium starter track is available in 2.5m lengths.


                  3. Preparing the Adhesive

                  Kingspan K5 insulation is heavier than EPS and therefore requires the use of EWI Pro’s strongest adhesive, the EWI-225 Premium Basecoat. This is a very versatile, dual-purpose product that can also be used in the subsequent basecoat layer. 

                  The adhesive is applied to the back of the board using either the perimeter and dabs method or by using a notched trowel to cover the whole of the board. Both of these can be seen in the picture below – however we recommend using the first method if the underlying surface is not perfectly flat as the adhesive will be able to absorb these inconsistencies in the wall. 

                   

                  The boards are staggered (like a brick pattern on a wall) and also are interlocked at corners. 

                  Coverage: 

                  1 x 25kg bag covers 4/5m2

                  Drying times: 

                  24-48 hours


                  4. Applying the Kingspan K5 Insulation Boards

                  Kingspan K5 insulation boards are high-performance insulation boards, offering far better thermal insulating properties than EPS or mineral wool. We sell Kingspan K5 by the board in a range of thicknesses. For insulating a solid brick wall the general recommendation to reach building regulations is to opt for a 60mm thickness. Kingspan K5 can be tricky to install as you can’t rasp away imperfections (unlike EPS). A really flat surface will need to be achieved while mounting the boards to ensure a smooth topcoat. We recommend using a spirit level to regularly check that the boards are being applied flat on the wall. As mentioned, applying adhesive around the perimeter of the K5 board allows you to absorb imperfections within the wall surface. 

                  Coverage:

                  0.72 m2 per board.


                  5. Installing the Fixings

                  EWI Pro recommends that you install one fixing per corner, with an additional two in the middle of the insulation board. Metal fixings should be used with the Kingspan K5 insulation system as they will support the weight of the boards. The fixings are available in a wide range of lengths to accommodate different thicknesses of insulation, but we recommend the fixing is at least 40mm longer than the thickness of the insulation to ensure it gets a decent hold in the brick or block. 

                  Coverage:

                  Metal pin screw fixings are the recommended fixing for Kingspan K5 insulation. These come in boxes of 200 or 100 depending on the length.

                  7 fixings are required per m2.


                  6. Applying the Beading:

                  Beading is essential for reinforcing external areas that are more prone to damage, for example, the corners and the areas around windows and doors. The required beads will depend on the property and which particular areas need reinforcing. We have a broad range of render beads that should be selected and applied as necessary, our beads are uPVC and are designed to be embedded within the basecoat layer.


                  7. Applying the Basecoat:

                  For Kingspan K5 external wall insulation systems, we recommend using the EWI-225 Premium Basecoat again for the basecoat layer, as this saves on material waste. EWI-225 should be applied at a thickness of 6mm – this can be achieved using a 10mm notched trowel.

                  Coverage rates:

                  1 x 25kg bag covers 4/5m2

                  Drying times:

                  24-48 hours


                  8. Embedding the Mesh:

                  Fibreglass Mesh is embedded within the basecoat for extra reinforcement. The fibreglass mesh gives the K5 external wall insulation system strength and flexibility – ensuring the system remains crack resistant for years to come. 

                  The mesh comes in 50m long rolls and is 1m wide. The mesh is marked at each end and this shows the overlap that you should be achieving when embedding mesh across the wall surface.

                  Coverage rates:

                  1 x 50m2 roll covers 42.5m2 when overlapped

                  Our standard mesh is sold either by the m2 or in rolls of 50m2.


                  9. Priming the Basecoat:

                  A render primer should be used to increase the adhesion of the render to the basecoat, and can be tinted to match the colour of your render for an increased opacity. The type of primer will depend on the type of render you are using. For a Silicone render system, we recommend using the SiSi Render Primer which comes in two different bucket sizes. This render can be applied with either a roller or a paintbrush. 

                  Coverage:

                  1 x 7L bucket covers 20m2

                  1 x 21L bucket covers 60-70m2

                  Drying times:

                  12-24 hours

                  • Top Coat Primer – 20kg

                    £67.00 (incl VAT)
                  • Top Coat Primer – 7kg

                    £37.25 (incl VAT)


                  10. Applying the Render Topcoat:

                  Once the primer is dry, the render topcoat can be applied. We recommend using either the Premium Bio Silicone Render, Silicone Render, or Silicone Silicate Render. These are intended for creating a decorative finish; they are through-coloured with grains suspended within the mixture in a range of different sizes to achieve the desired texture.

                  Premium Bio Silicone is our highest performing render, offering advanced self-cleaning capabilities that tackle any signs of organic growth on the substrate, and extra UV resistance for a long-lasting finish. Silicone render is the ideal choice for a quality long-lasting finish as it has nano-silicone particles which are great for maintaining a clean facade. Silicone Silicate is excellent value, also offering vapour permeability. All of these options are highly flexible, so are ideal for ensuring that there are no problems with cracks.

                  To learn more about the EWI Pro renders head over to ewipro.com

                  Coverage:

                  1.0mm grain size: 1x25kg bucket covers c. 10m2

                  1.5mm grain size: 1x25kg bucket covers c. 7-10m2

                  Drying times:

                  24 hours (+)


                    Approved Installers Request Form

                    Your Name*

                    Your Email*

                    Your Number*

                    Your Postcode

                    Additional Information

                    I would like to receive news and offers from EWI Store

                    Materials Required for EPS External Wall Insulation

                    1. Priming the Substrate:

                    A brickwork substrate tends to be very porous, and so it will need priming with the Water Based Primer. We recommend applying this to the substrate by roller or brush. However, if you are rendering onto a very smooth substrate then we recommend applying the EWI-310 Universal Primer, as this contains aggregates which will provide a rough surface for the basecoat to adhere to. Ensuring that your substrate is adequately prepared is essential to ensuring that your render system will last.

                    Coverage rates:

                    5 litres covers 15-30m2 depending on the substrate.

                    Drying times:

                    1 coat takes 4 hours to dry.


                    2. Installing the Starter Track

                    When it comes to starter track, you have two options. Opt for aluminium starter track with a clip-on stop bead if you are looking to cut down on costs. Alternatively, if you want to ensure that thermal bridging is kept to an absolute minimum, we recommend using uPVC starter track. Both are available in a range of widths to house different thicknesses of insulation, and are drilled into the wall above the DPC.

                    Coverage rates: 

                    UPVC starter track is available in 2m lengths.

                    Aluminium starter track is available in 2.5m lengths.


                    3. Preparing the Adhesive

                    The EWI-220 creates a strong, long-lasting adhesion, securing the boards to the substrate for years to come. There are a couple of options when it comes to choosing your EPS adhesive:

                    • EWI-210: a standalone adhesive for EPS. Not to be used in the basecoat layer. (mix each bag with 6.3l of water).
                    • EWI-220: a multi-purpose basecoat/adhesive for EPS, can also be used in the basecoat layer with mesh. (mix each bag with 5.8l of water).
                    • EWI-221: a multi-purpose basecoat/adhesive for EPS, ideal for use in the winter months at temperatures down to 0 degrees. (mix each bag with 6.3l of water).

                    The adhesive is applied to the back of the board using the dot and dab method. This will allow you to get a nice flat surface for the render topcoat. 

                    Coverage: 

                    1 x 25kg bag covers 4/5m2

                    Drying times: 

                    24-48 hours

                    (also available in bulk)


                    4. Applying the EPS Insulation Boards

                    Our EPS insulation boards are lightweight, easy to install and very effective. We sell EPS by the square metre in a range of thicknesses. For insulating a solid brick wall the general recommendation to reach building regulations is to opt for a 90mm thickness. Graphite EPS tends to develop an oily outer layer, so it’s important to rasp it to get rid of this and ensure that the basecoat adheres properly. Rasping also offers the added benefit of enabling you to smooth out any imperfections in the surface. 

                    Coverage:

                    1m2


                    5. Installing the fixings

                    EWI Pro recommends that you install one fixing per corner, with an additional two in the middle of the insulation board. Plastic fixings should be used with the EPS insulation system as they significantly reduce thermal bridging. The fixings are available in a wide range of lengths to accommodate different thicknesses of insulation.

                    Coverage:

                    Plastic pin fixings are the recommended fixing for EPS insulation. These come in boxes of 200 or 100 depending on the length.

                    7 fixings are required per m2.


                    6. Applying the Beading:

                    Beading is essential for reinforcing external areas that are more prone to damage, for example, the corners and the areas around windows and doors. The required beads will depend on the property and which particular areas need reinforcing. We have a broad range of render beads that should be selected and applied as necessary, our beads are uPVC and are designed to be embedded within the basecoat layer.


                    7. Applying the Basecoat:

                    For EPS external wall insulation systems, we recommend using the EWI-220 EPS Basecoat for the basecoat layer, as this saves on material waste. TThe EWI-220 and EWI-221 contain reinforcing fibres, which guarantee a longlasting finish.

                    Coverage rates:

                    1 x 25kg bag covers 4/5m2

                    Drying times:

                    24-48 hours

                    (also available in bulk)


                    8. Embedding the Mesh:

                    Fibreglass Mesh is embedded within the basecoat for extra reinforcement. This will ensure the system remains crack resistant.

                    Coverage rates:

                    1 x 50m2 roll covers 42.5m2 when overlapped

                    Our standard mesh is sold either by the m2 or in rolls of 50m2.


                    9. Priming the Basecoat:

                    A render primer should be used to increase the adhesion of the render to the basecoat, and can be tinted to match the colour of your render for an increased opacity. The type of primer will depend on the type of render you are using. For a Silicone Silicate system, we recommend using the SiSi Render Primer which comes in two different bucket sizes.  

                    Coverage:

                    1 x 7L bucket covers 20m2

                    1 x 21L bucket covers 60-70m2

                    Drying times:

                    12-24 hours

                    • Top Coat Primer – 20kg

                      £67.00 (incl VAT)
                    • Top Coat Primer – 7kg

                      £37.25 (incl VAT)

                    10. Applying the Render Topcoat:

                    Once the primer is dry, the render topcoat can be applied. We recommend using either the Premium Bio Silicone Render, Silicone Render, or Silicone Silicate Render. These are intended for creating a decorative finish; they are through-coloured with grains suspended within the mixture in a range of different sizes to achieve the desired texture.

                    Premium Bio Silicone is our highest performing render, offering advanced self-cleaning capabilities that tackle any signs of organic growth on the substrate, and extra UV resistance for a long-lasting finish. Silicone render is the ideal choice for a quality long-lasting finish as it has nano-silicone particles which are great for maintaining a clean facade. Silicone Silicate is excellent value, also offering vapour permeability. All of these options are highly flexible, so are ideal for ensuring that there are no problems with cracks.

                    Coverage:

                    1.0mm grain size: 1x25kg bucket covers c. 10m2

                    1.5mm grain size: 1x25kg bucket covers c. 7-10m2

                    Drying times:

                    24 hours (+)


                      Approved Installers Request Form

                      Your Name*

                      Your Email*

                      Your Number*

                      Your Postcode

                      Additional Information

                      I would like to receive news and offers from EWI Store

                      How to Remove Render

                      There are a number of reasons people choose to remove the render from their homes. Whether it’s cracked sand and cement render that is causing problems with damp, or old dilapidated pebbledash that just looks tired and outdated. There are a few things that you can do to either remove the render or cover it over, so keep reading for our best advice!

                      Removing Existing Render 

                      Old render will need removing with traditional tools, such as a hammer and chisel. There is some specialist equipment on the market today, but if you don’t have access to these then standard tools will do the job. 

                      Using this method to remove the render means that you have to be really careful not to damage the underlying substrate, as this could create more work for you later down the line when you need to repair it. Any damage to the underlying substrate also means that you will most likely need to re-render the wall, and you may even need to use a levelling coat to get the substrate nice and flat again. 

                      Hiding Render with External Wall Insulation 

                      If removing the render puts the building at too much risk, then your next option is to install external wall insulation boards on top. As long as the existing render is sound and stable (i.e. not likely to fall off the wall) then this method is a great means to an end. 

                      You can make this as cheap as possible by merely using a 20mm thick EPS insulation board, which won’t do much for the energy efficiency of the building but will certainly help provide a flat surface for re-rendering. Alternatively, if you want to go all out then you could install 90mm and reap the rewards.

                      For this method, you will need to buy fixings that go through the insulation board and far enough back that they penetrate the actual brickwork/blockwork underneath. Once the boards are in place, a thin coat coloured render should be applied on top as a means of protection against the weather. 

                      Using the One Coat Dash Cover to Cover over Pebbledash

                      One Coat Dash Cover (OCDC) is a quick and easy solution to covering over pebbledash instead of removing the render itself. It’s a lightweight, lime-based basecoat which can be applied up to 50mm thick in two passes. This means that if the pebbledash is waterlogged, it will be able to dry out naturally as OCDC is very breathable and won’t trap the water. 

                      You can finish OCDC in any way that you like, whether you choose to use a thin coat render, lime render or a traditional masonry paint, it’s important to use breathable materials to allow any trapped moisture to escape.

                        Approved Installers Request Form

                        Your Name*

                        Your Email*

                        Your Number*

                        Your Postcode

                        Additional Information

                        I would like to receive news and offers from EWI Store

                        Types of Rendering Mesh

                        Orange Fibreglass Mesh – Thin Coat Render

                        An integral component in both EWI and render systems, the orange mesh is ideal for embedding within the basecoat layer to improve the crack-resistance of the system. The mesh is cut into vertical strips and is embedded into the basecoat layer using the flat-edge of a trowel. Each strip will need to be overlapped by 10-15cm along all edges.

                        EWI Pro’s Orange Mesh is a strong and flexible 165g fibreglass reinforcing mesh. It works by increasing the overall tensile strength of the underlying basecoat so that any movements or fluctuations within the underlying substrate will not cause cracks. 

                        The fibreglass material that the mesh is made from is resistant to water, alkali and age damage, which means it’s the most long-lasting solution for crack-resistance. This particular mesh is designed for thin coat render systems as it has smaller holes within its structure. This is because, in thin coat render systems, the basecoat is applied in a thinner layer of around 6mm,  which means that less basecoat needs to be pulled through the holes of the mesh in order for it to sit within the middle of the basecoat layer. 

                        Blue Fibreglass Mesh – Thick Coat Render

                        The blue mesh that we stock is designed to be installed with thick coat renders. This can be anything from your traditional sand and cement to your monocouche renders. The blue mesh is more heavy-duty than orange and has larger holes to enable the user to pull more material through during the process of embedding it into the render. 

                        The blue mesh is also ideal for if you’re using EWI Pro’s lightweight basecoat, as this can be applied up to 25mm thick in one pass. Again, the mesh helps to ensure that the render topcoat remains intact and crack-free, ensuring a long-lasting finish.

                          Approved Installers Request Form

                          Your Name*

                          Your Email*

                          Your Number*

                          Your Postcode

                          Additional Information

                          I would like to receive news and offers from EWI Store

                          Where To Get an External Wall Insulation Quote

                          Try Out The Materials Calculator For a Free Quote

                          The External wall insulation materials calculator is a quick and easy online tool that provides you with a quote for the cost of the materials required for your project.

                          To complete the materials calculator, all you need to do is simply provide the details of the type of property you have, the square meterage, the type of insulation material that you want and the type of render. 

                          Once you’ve filled in all your details, you’ll be provided with a list of the external wall insulation materials as well as a quote. It’s incredibly easy to complete and takes only a couple of minutes, so definitely check it out for an accurate external wall insulation materials quote.

                          Request an EWI Pro Approved Installer

                          Getting a quote for external wall insulation materials is one thing, but the actual cost of labour is another. 

                          At EWI Store we have a database of approved installers who have completed the EWI Pro training course and who we recommend to interested homeowners.

                          If you’re looking for someone trustworthy to do the work for you, we strongly suggest opting for an approved installer, as they will be familiar with our materials, their work will be top quality and will adhere to our high standards.

                          When you get in touch with us to request an approved installer, we’ll typically give you the details of three installers who work within your area. They can then provide you with an external wall insulation quote and you can choose the installer that you feel suits you best. If you’re looking for an installer, fill out the form below and we will be in touch!

                            Approved Installers Request Form

                            Your Name*

                            Your Email*

                            Your Number*

                            Your Postcode

                            Additional Information

                            I would like to receive news and offers from EWI Store

                            What to Tell Your Neighbours Before Installing EWI

                            Telling your neighbours about building work can always be a bit of a tricky conversation. External wall insulation involves a few weeks of work on the exterior of your property and you can expect that during that time there may be a little disruption, especially if you live in close quarters with your neighbours. 

                            Going through the installation process will mean that your home is a more comfortable temperature during the winter and summer months, your heating bills are reduced and the external appearance of your property is updated and improved. No doubt it’s worthwhile for you, but your neighbours may not see it that way, so we’ve put together a brief list of things that you will need to inform them of prior to the commencement of the works. 

                            Parking may be more difficult

                            This is especially the case if your property or your neighbour’s property doesn’t have a driveway. Installers will often drive vans and materials will usually be delivered in a Luton van, so warn your neighbour that parking may be tricky for the duration of the installation.

                            It will probably be noisy at times

                            Erecting scaffolding, hammering and drilling in fixings and all the other details that go into an EWI installation all have one thing in common: noise. 

                            External wall insulation isn’t the noisiest job you could be having done (knocking down walls and building an extension would be much worse), nevertheless it’s likely to be a little bit busier and noisier in the area.

                            We recommend you inform your neighbours a couple of weeks in advance so that they know to expect it. The increase in noise will very likely occur during working hours, so you can reassure them that it won’t be going on late into the evening. 

                            There will be some dust and mess

                            Depending upon how simple the installation is, it’s likely there will be a level of dust and mess. EWI is installed using dry-mix adhesives which are very dusty before they’re mixed with water. Insulation off-cuts are also a common occurrence during an installation; EPS, in particular, can be quite messy when it’s cut with a knife as the polystyrene tends to disintegrate. Similar to the basecoat and adhesives, the render topcoat can drip so the installer should take precautions to protect the area surrounding the property. 

                            Scaffolding will likely be required

                            Unless you live in a bungalow it’s highly likely that scaffolding will be required to complete your project. Scaffolding is quite an eyesore so it’s courteous to warn your neighbours of its expected presence. If you live in a semi-detached home your neighbours will be particularly affected by the presence of the scaffolding and so will need to be notified in advance. 

                            The works are expected to last for at least two weeks

                            One of the best things about installing EWI is that the work shouldn’t take more than a couple of weeks to complete. Most of the delays are caused by drying times (e.g. you have to wait 24 hours for the adhesive to dry before you can install the fixings). The only thing that can cause delays is poor weather conditions, but other than this the whole process is quick and relatively easy.

                              Approved Installers Request Form

                              Your Name*

                              Your Email*

                              Your Number*

                              Your Postcode

                              Additional Information

                              I would like to receive news and offers from EWI Store

                              Celotex GA4000 Internal Insulation

                              If you’re in the process of renovating your home, or you’re simply looking for ways to reduce your energy bills by making your home more energy-efficient, internal insulation is always the best place to start. 

                              Whether it’s your loft, floors or walls that require insulating, we have one product that can do all of the above.  

                              Celotex PIR Internal Insulation Board

                              Introducing the Celotex GA4000 internal insulation board! A PIR insulation board with a rigid core and aluminium foil facings on both sides, Celotex GA4000 is a highly versatile product that can be used for a range of internal applications.

                              The awesome thing about this type of insulation board is that it is available in such a vast array of thicknesses (the GA4000 goes from 50 to 100mm), so you can choose a size that is suitable for the amount of space that is available within your home. Furthermore, if you’re worried about the environmental friendliness of PIR/foam insulation materials, the Celotex GA4000 boards are also very eco-friendly, having been manufactured with no environmentally hazardous blowing agents.

                              Where is Celotex GA4000 Used?

                              The Celotex GA4000 boards are designed for use throughout your building project, as they are very easy to handle and install. Typically, this type of insulation board is targeted at cut-to-fit areas such as between rafters and joists. This enables users to achieve lower U-values using just a single sheet of insulation. According to the manufacturer’s website, Celotex GA4000 can be used in the following areas:

                              • Flat roofs
                              • Pitched roofs
                              • Ground floors including solid concrete, block and beam, suspended timber joist and with underfloor heating.
                              • Timber frame walls
                              • Steel frame walls
                              • Retrofit on solid wall masonry and timber structures

                              Thermal Performance of Celotex Insulation

                              Celotex GA4000 PIR insulation boards are some of the best performing internal insulation boards on the market. With a thermal conductivity of 0.022 W/mK, the insulation boards are designed to eliminate thermal bridges and effectively slow down the rate of heat loss, offering buildings long-term energy savings.

                              Celotex GA4000 – Available at EWI Store!

                                Approved Installers Request Form

                                Your Name*

                                Your Email*

                                Your Number*

                                Your Postcode

                                Additional Information

                                I would like to receive news and offers from EWI Store

                                How Much Does Rendering Cost?

                                The cost of having your house rendered can vary depending upon several factors. First, the type of render you opt to have installed will make a difference in the overall cost of the project. Secondly, the size of your property will dictate the amount of material required, so naturally the larger the property the more expensive it will be. 

                                We always recommend getting a quotation from at least 3 installers prior to going ahead. This way you can compare prices and find an installer that you trust. If you need help finding trustworthy installers in your area, give us a call and we can put you in touch! We have a database of installers who have undergone our rigorous training course and who we recommend to other customers like you.

                                One of the biggest cost-conscious decisions you will need to make is the choice of render. We’re going to talk you through a range of options and explain the benefits of each. 

                                Sand and Cement Render

                                Sand and cement render is the cheapest option available, and as such it’s possibly one of the worst choices in terms of longevity. Sand and cement render is an incredibly inflexible material that cannot withstand the slight fluctuations that a building naturally makes because it’s applied in such a thick layer.

                                The second issue with sand and cement render is that it’s not breathable and can very easily become waterlogged once cracked. Essentially what this means is that once water gets into the material it will struggle to evaporate out and will eventually cause damage (i.e. blown render or penetrating damp on the internal walls).

                                Monocouche Render

                                Monocouche render is the next step up from sand and cement, costing around £12 bag. Rather than coming as separate ingredients that the installer needs to mix on-site (i.e. the sand and cement), the monocouche render comes readily prepared in one bag, all it needs is mixing with water. 

                                The key benefit of the monocouche is that it’s through-coloured so there’s no need to paint it afterwards. Unlike sand and cement render, which is perfectly smooth, monocouche provides a natural stone-effect finish as it is scratched back to create a textured effect.

                                One downside to the monocouche render is that again it’s applied in a thick layer, which makes it more likely to crack. Modern technology has enabled us to produce breathable monocouche renders, however once the render cracks it still becomes very difficult to regulate the movement of moisture in and out of the substrate.

                                Acrylic Render

                                Acrylic render is somewhat different from the previously mentioned renders, as it is classed as a ‘thin coat render.’ Acrylic is the cheapest of our entire range of thin coat renders, coming in at just £29.97 ex. VAT per bucket. The render itself is applied in a very thin layer of 1-3mm (depending upon the grain size), on top of a reinforced basecoat which is around 6mm thick. This means that the maximum total thickness of the render system is 9mm – far less than your average 15mm+ for sand and cement. The thinness of the render means that it is far more flexible and able to compensate for any movements within the underlying substrate, so the chance of cracking is massively reduced. Thin coat renders come ready to use straight out of the bucket; they are through-coloured in a range of shades (much like paint) and are applied by trowel.

                                Acrylic render is a non-breathable thin coat render, but out of all the thin coat renders it is the most impact resistant.

                                Silicone-Silicate Render

                                Once you start getting into the ‘silicones’ category, you’ll notice that prices begin to rise due to its greater performance. Silicone Silicate is a hybrid silicone thin coat render, costing £52.45 ex. VAT per bucket. This is our best value thin coat render due to the performance it offers at the price point it comes in at.

                                Much like the acrylic, it comes ready to use in a tub – pre-coloured and pre-mixed. It’s highly versatile but also great value, offering the key benefit of breathability. While it does possess less self-cleaning capabilities than our full silicone render and our Premium Bio Silicone Render, Silicone Silicate does offer a long-lasting, aesthetically pleasing finish.

                                Silicone Render

                                If you want top-quality and top performance, then you can’t go wrong with our Silicone Render – £57.23 ex. VAT. People tend to pay more for the full silicone render as it is a notoriously high-performance render. It offers breathability, crack resistance and self-cleaning capabilities which provide the reassurance of a long-lasting finish.

                                Buyers commonly assume that ‘K Rend’ is the only silicone render product, when it’s just one brand of silicone render. Don’t fall into that trap, as there are plenty of other manufacturers of silicone render on the market who all offer a range of finishes and colour choices.

                                Premium Bio Silicone Render

                                The Premium Bio Silicone Render is our top of the line, breathable thin coat render, offering advanced self-cleaning capabilities, enhanced impact resistance and increased UV protection. This means that it provides a long-lasting, crack-resistant finish that will remain vibrant in colour for years to come. Because the Premium Bio offers absolutely everything, it’s our most expensive option, coming in at £70.41 ex. VAT per bucket.

                                  Approved Installers Request Form

                                  Your Name*

                                  Your Email*

                                  Your Number*

                                  Your Postcode

                                  Additional Information

                                  I would like to receive news and offers from EWI Store

                                   

                                  Why Has External Wall Insulation Made My Home Damp?

                                  Damp After External Wall Insulation

                                  External wall insulation is a great way to improve the energy efficiency of your home by reducing the rate of heat loss through your walls. The great thing about EWI is that it wraps around the entire exterior of your home, enveloping the heat inside. 

                                  EWI is much less likely to cause damp than other methods of insulating (such as cavity wall insulation) because there are far fewer breaks within the material – EWI is known as a continuous insulation method. 

                                  However, correct installation is key. External wall insulation consists of rigid insulation boards (as opposed to a foam) that are secured to the exterior walls of the building using adhesive and mechanical fixings. The hugely important part here is that there are no gaps between the boards and no areas where water might penetrate. 

                                  Thermal Bridges

                                  In the context of external wall insulation and damp, the reason we talk about avoiding gaps between the boards and breaks within the insulation is because thermal bridging can occur. During installation, any gaps should be filled using a spray foam adhesive which will act as an insulator.

                                  Thermal bridges are essentially places where there is a higher rate of heat transfer than the surrounding materials, which results in an overall reduction in thermal insulation of construction. Thermal bridges are responsible for up to 35% of thermal losses and increased condensation and mould growth.

                                  Take for example an insulation system where gaps have been left between the boards. The temperature within the gap is going to be a lot colder than the surrounding insulation boards, which means that condensation will gather in that area and damp will occur.

                                  Poor Quality Insulation

                                  Damp insulation means ineffective insulation. Not only this, but moisture gathering behind the insulation boards can lead to erosion of the adhesive, which can cause serious damage to the system.  

                                  If you start to notice damp on your internal walls, then this could be a sign that water is getting behind your EWI system. Signs of damp caused by external wall insulation should be an immediate cause for concern, and a professional should be called out to assess the situation promptly. 

                                    Approved Installers Request Form

                                    Your Name*

                                    Your Email*

                                    Your Number*

                                    Your Postcode

                                    Additional Information

                                    I would like to receive news and offers from EWI Store

                                    How to Cover Tyrolean Render

                                    What is Tyrolean Render?

                                    Tyrolean render is a method of applying monocouche or sand and cement render to create a rough textured finish. The render is applied to the substrate in a thick layer, creating an initially smooth surface. This is then left to dry slightly before a second pass is applied using a tyrolean flicker gun. The finished effect looks similar in appearance to a roughcast render; it’s certainly some people’s cup of tea but others may prefer a smooth finish.

                                    The downside to this type of render application is that it is likely to crack because it is applied in a thick layer (usually around 16mm). As we know, buildings tend to expand and contract due to heating and cooling, and thicker renders are much less able to be flexible and withstand this. 

                                    What is OCDC?

                                    OCDC (also known as the One Coat Dash Cover) is our solution to covering over pebbledash and roughcast textured renders. It is a breathable lime basecoat that can be applied up to 50mm thick in two passes. The idea is that it can be applied thick enough to create a smooth surface, without trapping moisture behind it. So for a tyrolean render that is particularly waterlogged, it’ll be easy for the water to gradually evaporate out through the OCDC.

                                    Covering over tyrolean render with OCDC is a fantastic solution if you’re looking to update the look to your property. Once the OCDC is applied, it can be painted or a thin coat silicone render can be applied on top for a high-performance finish.

                                    Applying OCDC onto Tyrolean Render

                                    OCDC is very easy to apply. The product should be mixed with 5 litres of water using an electric paddle mix until it is an even consistency. It can then be sprayed onto the substrate or applied by hand using a trowel; the first pass should be applied at a maximum thickness of 25mm and strips of fibreglass mesh should be embedded within it. The second pass is then applied before the first pass has fully set, taking the total thickness to 50mm.  

                                    Once the OCDC has set, you can then apply your decorative finish. We really recommend using one of our silicone renders for this because they are very high performance and breathable, so they complement the OCDC well. These are available in a range of grain sizes, so you can achieve either a rough or smooth texture to replace the tyrolean render. Silicone-based renders are flexible, crack-resistant, and are self-cleaning so will maintain a clean finish for longer. 

                                    Alternatively, you can sponge up the surface of the basecoat and apply a paint finish instead. This will achieve a perfectly smooth surface and is a more cost-effective solution when compared to the silicone render finish. We recommend using the EWI-005 Silicone Paint, as again it is breathable and hydrophobic so will not hinder the passage of water from the underlying tyrolean render through the OCDC.

                                      Approved Installers Request Form

                                      Your Name*

                                      Your Email*

                                      Your Number*

                                      Your Postcode

                                      Additional Information

                                      I would like to receive news and offers from EWI Store

                                      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!

                                      Avoiding Silicone Sealant in EWI Systems

                                      Silicone sealant, often referred to as mastic, is a sealant used in hundreds of different applications. You will probably find it around the house sealing pipes and plumbing, gaps around doors and windows and perhaps around your bath and shower.

                                      Silicone sealant, not to be confused with Silicone Render, is also used to seal solid wall insulation on some properties.

                                      Where is Silicone Sealant used in EWI?

                                      There are several areas where an installer might use silicone. For example, you may see it around windows where the render meets the frame, on oversills where it abuts the wall and around verges where the trim meets the wall or the fascia.


                                      This isn’t ideal because most silicone will not bond with cement very well. On a job where the expected lifespan of the system is 30 years or more, you can be sure that the sealant will need replacing a lot more frequently than that. In an exposed position, this sealant may even perish within a year! That means water ingress behind the insulation and damp inside the property.

                                      How Can I Avoid Using Sealant?

                                      If that sounds like a problem, you might want to consider alternatives to sealant. The best option is to design your project to minimise the use of sealant. Beading is really important around windows, under window sills and at joints. Beading not only creates a good seal, but it also means you get a nice straight edge – and a professional finish. For example, our Reveal Beads come with either a sponge or rubber seal to minimise the use of mastics.

                                      Expanding foam tape is also another option to consider for minimising the use of silicones. The expanding foam tape can be used to create a weather-tight seal in structural and expansion joints in walls and around door and window frames. When installed into a joint, the tape will begin to expand to fill up the gap and smooth over minor imperfections and irregularities.

                                      At the roof line where the verge meets the fascia, it is usually possible to create a joint that is not fully exposed to the elements. You will probably still need to use some sealant, but creating a joint that is protected will mean the sealant lasts a lot longer.

                                      What Sealant Should be Used for EWI?

                                      If you have no choice but to use sealant, we recommend that it is kept to a minimum, and that you use a good quality sealant that will offer a long term solution. One of the best sealants on the market is CT1, which we stock. The difference between CT1 and standard silicone sealants is that this sealant adheres to plastic as well as to brick and cement. This means you will get a quality seal between areas like verge trims and walls.

                                      Whilst we would recommend trying to achieve a sealant-free profile, especially in areas where water is likely to interact with the joint frequently, we understand that this is not always possible, and in these cases a good quality sealant is a good alternative.

                                      Most importantly, don’t be put off insulating a property just because you are worried about sealant. If you are struggling to work out how to seal your job, just get in touch and we would be happy to advise about sealant, beading and verges, and how to create a profile that is protected from the elements.

                                        Approved Installers Request Form

                                        Your Name*

                                        Your Email*

                                        Your Number*

                                        Your Postcode

                                        Additional Information

                                        I would like to receive news and offers from EWI Store

                                        Do I Have to Extend my Roof for EWI?

                                        One of the questions that homeowners often have before going ahead with installation is whether or not they will need to extend their roofline to accommodate for the insulation boards. This is often a daunting, expensive-sounding prospect – but it doesn’t have to be.

                                        At EWI Store, we have solutions for all sorts of external wall insulation issues. One of these is our comprehensive range of Verge Trim. 

                                        What is Verge Trim?

                                        Verge Trim is a thin sheet of plastic or metal, designed to tuck up under the fascia board so that it can cap the insulation. All of our Verge Trims are made of powder-coated aluminium and are available in different sizes to house different widths of insulation. 

                                        Why is Verge Trim Necessary?

                                        The point of the Verge Trim is to make sure that rain runs directly off the face of the insulation, rather than running behind the system and causing damage. Insulation boards are sometimes very thick and don’t quite fit underneath the soffit. When this happens, it leaves a real risk of water ingress, which needs to be prevented with Verge Trim.

                                        What are the Different Types of Verge Trim?

                                        Over Sill Verge Trim

                                        The Over Sill, as the name suggests, is used to extend the length of an existing window sill to accommodate the insulation underneath. It’s essential that the window sill overhangs the insulation so that water will run straight off the face of the wall; any water ingress behind the system can lead to erosion of the adhesive and ineffective insulation.

                                        Dropdown Verge Trim 

                                        The Dropdown Verge Trim is designed to go under the soffit board. It is typically used for applications that require fixing from below. Again, this Verge Trim ensures that water falls away from the system while minimising the need for silicone sealants and expanding foam tape. 

                                        Upstand Verge Trim

                                        This type of Verge Trim is most suited to applications where it is fixed from above, for example, the connection to a flat roof or where the upstand can slide up behind the fascia board.

                                          Approved Installers Request Form

                                          Your Name*

                                          Your Email*

                                          Your Number*

                                          Your Postcode

                                          Additional Information

                                          I would like to receive news and offers from EWI Store

                                          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!

                                          External Wall Insulation for Homeless Shelter Project

                                          EWI Store is pleased to have recently supplied materials for a charitable organisation, Emmaus Bristol. 

                                          Emmaus Bristol supports homeless people, providing them with shelter and the opportunity to find meaningful work. Their goal is to overcome homelessness and achieve social change within the communities that they operate.

                                          Emmaus Bristol Project – Wood Fibre Insulation System 

                                          We were delighted to supply the materials for the project in Bristol. Our Wood Fibre external wall insulation system was used to renovate the exterior of the property and will ensure the thermal comfort of the residents while improving the energy efficiency of the building. The house will be used to accommodate people who are homeless or at the risk of homelessness. 

                                          The building contractor who was assigned to the job was Nook Housing – they also provided work experience for one of the Emmaus Bristol Companions (a person who is supported by the charity and who was formerly homeless). Thanks to this work experience, he has since gone on to paid work in construction and is living independently. 

                                          Inspirational Mural Painted on EWI Pro System

                                          One of the stand-out features of this project was the mural painted on the side of the EWI Pro system (see pictures below). This was completed by Michele Curtis and depicts Roy Hackett, a Jamaican born co-founder of the Commonwealth Coordinated Committee. 

                                          The mural was carried out as part of the Seven Saints of St Paul’s programme, an artistic movement whereby seven murals are being painted around the St Paul’s area of the city, depicting key people who shaped Bristol’s black community.

                                          Benefits of External Wall Insulation 

                                          • Increased thermal comfort year-round
                                          • Reduced energy bills
                                          • Improved external appearance
                                          • Environmental benefits
                                          • External – no internal floor space is required
                                          • Prolongs the lifespan of the building
                                          • Low maintenance

                                          Applying Render to a Steel Frame Building

                                          What are the Advantages of Steel Frame Buildings?

                                          Steel frame buildings are, as the name suggests, constructed of heavy-weight steel beams that are used to form the building shape and are then fitted together to create joints. A real benefit of this type of building is that it is extremely strong, durable and easy to assemble. The steel is made-to-measure, prepared off-site and then transported in parts. 

                                          There are many materials that can be used to form the exterior surface of the steel frame, but typically a sheathing board is secured to the frame before a cladding or render is installed on top. For non-residential buildings, Mineral Wool insulation is typically fixed to the sheathing board (with adhesive and fixings) and the thin coat render system is applied on top. For residential projects, Mineral Wool insulation is installed within a cavity, before a render carrier board is secured to the steel frame on the outside. Quite often you can find steel frame buildings with a brick cladding forming the exterior surface as well.

                                          Steel frame properties offer the added value of fire resistance, as steel is non-combustible and will not bend or warp. Combine this with our Mineral Wool external wall insulation system, and you’ve got yourself a building with excellent fire performance. Further to this, unlike timber frame buildings there’s absolutely no risk of rot and termites with a steel-frame – so you’re guaranteed structural integrity throughout its lifespan.

                                          Installing Render Carrier Board onto Steel Frames

                                          Usually, a render carrier board (RCB) will be installed into the steel battens to provide a surface that is ready for rendering. Depending upon the manufacturer’s instructions, a 3-5mm gap should be left between the render carrier board joints. A breathable joint tape should then be applied across each joint to prevent a build-up of condensation in these gaps.

                                          The render carrier board shouldn’t need priming prior to being rendered, as its surface is intended for render anyway. 

                                          Applying the Basecoat Layer to the Render Board

                                          We recommend that you use the EWI-225 Premium Basecoat when rendering a steel frame building. This is because it is breathable, high strength, water-resistant and has high elasticity.  To prepare the basecoat, simply mix each 25kg bag with 6.5 litres of clean, potable water using an electric paddle mix. Once fully combined, leave the mixture for 5 minutes and the re-mix again before it is ready for use. 

                                          The Premium Basecoat should be applied to the substrate using a notched trowel at a maximum thickness of 6mm. Beading should be embedded into the basecoat layer, as well as Fibreglass Mesh strips. Each strip of mesh should overlap its neighbouring strip by 10cm. It’s essential that the mesh is embedded into the middle of the basecoat so that there is no contact with the render carrier board underneath.

                                          Priming the Basecoat

                                          Before applying any render, the basecoat needs to be primed. This is to ensure strong adhesion and create a consistency of colour across the facade (our render primers are tinted to match the render). We recommend the use of EWI-333 which is the ideal topcoat primer for our silicone-based renders. Simply paint the primer onto the substrate using a brush or roller, and then leave for 12 hours to dry.

                                          Applying the Render Topcoat

                                          Technology has greatly improved the breathability of renders; we know that coloured renders are extremely popular these days, but breathability is a really useful characteristic of our thin coat renders, so we recommend the use of EWI-075 Silicone Render for steel frame buildings and render carrier board. The other added benefit is that this type of render can be tinted to create almost any shade, so if you’re really keen on a particular colour we can match it up for you. 

                                          The render should be trowelled onto the substrate at a thickness that matches the chosen grain size, so if you’ve chosen a 1.5mm grain it should go on at 1.5mm thick.  

                                          The trick with our thin coat renders is to rub them up with a plastic render float. Simply use circular movements to bring out the texture of the grain and get a nice even finish across the facade. 

                                          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!

                                            Approved Installers Request Form

                                            Your Name*

                                            Your Email*

                                            Your Number*

                                            Your Postcode

                                            Additional Information

                                            I would like to receive news and offers from EWI Store

                                            Mineral wool vs EPS vs Kingspan K5 vs Wood Fibre in Solid Wall Insulation Systems

                                            With external wall insulation becoming more and more popular, in this blog we are going to discuss the 4 main types of insulation you can use within the EWI System, along with the advantages and disadvantages of each.

                                            Mineral Wool (Rockwool) in Solid Wall Insulation Systems

                                            Most people are familiar with Mineral Wool in the context of loft insulation – the big rolls of insulation you see in your local DIY store. The Mineral Wool used externally is a little different, it comes in batts rather than rolls, and the wool fibres themselves are very dense so the boards can be applied vertically without drooping.

                                            We recommend the Rockwool Dual Density boards when using Mineral Wool in solid wall insulation applications – this Mineral Wool is made from molten rock and has lots of features that make it a great choice for your insulation project:

                                            • Rockwool is an architect favourite, mainly due to its breathability, which allows moisture to travel across the wall and helps dissipate damp from in the house.
                                            • Rockwool is non-combustible. The European Reaction to Fire Classification (Euroclass) system is the common standard for assessing the qualities of building materials in the event of a fire and the Rockwool Dual Density insulation boards used are CE-marked to achieve a Euroclass rating of A1 – the highest rating available.
                                            • Rockwool is renowned for its excellent soundproofing properties. The insulations open wool structure makes it ideal for absorbing and regulating noise in both residential and commercial buildings, lasting for the lifetime of the property. 
                                            • Rockwool has fantastic thermal insulating properties. When attached to the exterior of a property, 110mm of our dual-density slabs will take the U-value down to 0.3, which means the building will then conform to building regulations. For the occupants, it means improved thermal comfort since the property will stay at more even temperatures and also lower energy bills.

                                            There are a couple of things you might want to consider when deciding if Mineral Wool insulation is for you! Firstly, the boards are heavier than the other types of insulation that we are going to discuss, so it means a bit more work moving them around the site, and also a stronger adhesive (EWI-225) needs to be used to stick these to the substrate. Also despite being a good insulator, both Kingspan K5 and EPS have better thermal efficiencies, so you need more Rockwool to achieve the same u-values.

                                            We would always recommend using gloves when installing the Rockwool boards as the wool fibres can be really itchy.

                                            Expanded Polystyrene (EPS) in Solid Wall Insulation Systems

                                            EPS is our most popular insulation product because it is easy to use, good value, and offers great thermal improvements to the property. EPS itself is 98% captured air within a 2% cellular matrix, and it’s this trapped air that gives the product its fantastic insulating properties.

                                            EPS on wall

                                            Our EPS is also graphite enhanced (which gives it a grey colour), which further enhances its thermal performance. The insulation is available in a range of thicknesses (10mm increments from 20mm), however, if installing external wall insulation on an existing property, 90mm of insulation will normally suffice in bringing the U-value of the wall to 0.3. This is a significant improvement over the Mineral Wool.

                                            Of all the types of insulation we recommend for external wall insulation, EPS is the most cost-effective. This is probably one of the reasons it is so popular with homeowners, but the boards are lightweight and easy to cut and fit so are popular with installers too.

                                            The downside of EPS is its reaction to fire – according to EN 13501-1, its fire resistance is class E. This means the EPS insulation boards are combustible, although based on the fact polystyrene is a hydrocarbon, this is hardly surprising. The good news is that when used in external wall insulation systems, the EPS is completed embedded within the cement-based adhesive, meaning that the risk of the EPS coming into contact with air is minimal, which helps prevent it combusting.

                                            Kingspan K5 in Solid Wall Insulation Systems

                                            Kingspan is a market-leading manufacturer of optimum, premium and high-performance rigid insulation products. The Kingspan Kooltherm K5 is their external wall insulation board, specially designed to be used with masonry walls.

                                            The K5 insulation board contains a fibre-free rigid thermoset phenolic core which gives it unrivalled thermal performance.

                                            Whereas 90mm of EPS is required to hit a u-value of 0.3 (required value when retrofitting to existing buildings), only 60mm of Kingspan Kooltherm K5 is required.

                                            Therefore, for jobs where space is a premium (i.e. walkways between buildings) or the customer wants to minimise the depth of the reveal/insulation off the wall, then K5 is a great choice. Likewise, if you are trying to go above and beyond building regulations requirements, using like for like thicknesses of K5 (instead of EPS) will see the u-value reduce to less than 0.2, resulting in even greater energy savings within the building.

                                            As a result of the K5 having superior thermal performance, the price for this type of insulation board is higher than you would pay for EPS at the same thickness. When using Kooltherm K5 you are also required to use the stronger adhesive to attach the boards to the substrate, as well as the basecoat.

                                            Wood Fibre (Pavatex) in Solid Wall Insulation Systems

                                            Pavetex Wood Fibre insulation systems are the most sustainable way to insulate externally. The Pavatex is made from pine – a sustainable raw material – in the form of waste chippings, shavings and sawdust from sawmills.

                                            Due to its unparalleled breathability, Pavatex Wood Fibre Insulation is perfect when used for a timber-framed property because it is a vapour-open building material. It’s essential for a timber building to be able to breathe in order to prevent damp and maintain structural integrity. The Wood Fibre Insulation will regulate the passage of water through the building structure, allowing for the diffusion of moisture and preventing any detrimental moisture build-up within the property and the EWI system.

                                            In terms of thermal performance compared to EPS, Kooltherm K5 and Rockwool, the Pavatex does lag slightly behind. 120mm of Pavatex is required to hit the u-value of 0.3 when applying the insulation to a solid wall property, however, for some the eco-benefits of this type of insulation outweigh this.

                                            In conclusion – comparing Mineral Wool vs EPS vs Kingspan K5 vs Wood Fibre in solid wall insulation systems

                                            If you are looking for a good value insulation product, we would suggest looking no further than the EPS. This is what the majority of people will use (although it is limited to buildings that are 18m high).

                                            If you are worried about fire safety, then Rockwool mineral wool is the insulation product to go for, although it is slightly more difficult to install than the other products.

                                            If you are worried about space or have a project where every centimetre counts, then go for the Kingspan Kooltherm K5 insulation products, with their unrivalled thermal performance.

                                            If you are looking for the most sustainable insulation material, then Pavatex wood fibre insulation is the answer!

                                            What are the Downsides to External Wall Insulation

                                            Is EWI a Fire Hazard? 

                                            The EWI Pro external wall insulation is BBA approved, which means that it is completely safe. If you’re installing EPS boards, they will not burn once they are encased within a cement render, and our Mineral Wool boards are rated as Euroclass A1 non-combustible. 

                                            The system will need to be installed by a qualified installer to make sure that all elements are correctly catered to (i.e. Mineral Wool should be installed around flues and chimney breasts). 

                                            Is External Wall Insulation Unattractive?

                                            External wall insulation boards are professionally decorated using a thin coat render. This provides a waterproof surface to protect the system against the effects of the weather and provide a decorative finish. The renders come in a variety of grain sizes to achieve different textured effects; our most popular is a 1.5mm grain size as this creates a fairly smooth finish.

                                            Our thin coat renders can be tinted to create any shade, so if you’re looking for something very specific then we can arrange it!

                                            Does External Wall Insulation Cause Algae?

                                            If you live in an area where there is a high risk of exposure to organic growth, then we really recommend the use of our Premium Bio Silicone Render. This product actively tackles any signs of vegetation that occur on the surface of the render and it is completely hydrophobic, so water will roll straight off without leaving dirty streaks.

                                            Will External Wall Insulation Cause Mould? 

                                            The insulation boards used for EWI are designed to keep your walls nice and warm. This means that they are more likely to be dry and therefore mould is less likely to grow (mould occurs in damp, dark environments). 

                                            Is it Hard to get Planning Permission for EWI?

                                            External wall cladding is considered to be ‘permitted development’ on the grounds that the new cladding will be similar in appearance to the existing structure. Check out our dedicated post ‘do I need planning permission for EWI’ for a list of instances in which you will need planning permission.

                                              Approved Installers Request Form

                                              Your Name*

                                              Your Email*

                                              Your Number*

                                              Your Postcode

                                              Additional Information

                                              I would like to receive news and offers from EWI Store

                                              The Best External Wall Insulation System

                                              If you’re looking to install external wall insulation, it can be difficult to know which system is best, who is qualified to install it and which insulation materials you should use. It’s important to remember that when you choose a quality system, a quality installer is essential to make sure that it all stays in great shape.

                                              The key elements of an external wall insulation system are the insulation boards, the adhesive and the render finish. Let’s take a closer look at the different material choices.

                                              Mineral Wool, EPS, or Wood Fibre?

                                              At EWI Store, we stock lots of different types of insulation board including EPS, Mineral Wool, Wood Fibre and Kingspan K5. These all come in at different price points due to their different insulating capabilities.

                                              Expanded polystyrene insulation is probably the most common material used for external wall insulation. This is because EPS is very cost-effective, easy to install due to how lightweight it is, and it has excellent thermal capabilities. To reach building regulations on a solid wall property, a 90mm board of EPS will bring the building in line with the required U-values.

                                              Mineral Wool is the same material used in lofts and cavity walls, except for external wall insulation it is compressed into a rigid board. Mineral Wool has excellent fire resistance, is completely breathable and also offers acoustic insulating properties. It’s a high-performance material that is incredibly hard-wearing and can be used for most external wall insulation applications.

                                              Wood Fibre is fairly new to our range and is our most breathable and eco-friendly EWI material. Pavatex Wood Fibre is a completely renewable material with very low pollution levels. It is great for installation onto timber frame properties due to its high levels of breathability.

                                              Browse our full range of insulation materials here.

                                              What Type of Render?

                                              External wall insulation boards need to be finished with a protective thin coat render. Thin coat renders are very lightweight, flexible, crack-resistant, and they can be tinted to create any colour. We sell a few types of thin coat renders, each offering varying levels of performance.

                                              • Silicone Render/Silicone Silicate Render: Silicone 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 box. (Read more about Silicone Render here).
                                              • Acrylic Render: Acrylic Render is very similar to silicone, except for 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 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).

                                              Finding a Trusted Installer

                                              We work with a range of trusted installers up and down the UK who have undergone the EWI Pro training course. We can recommend you a few experienced installers who are experienced and familiar with our systems, so fill out the form below to get in touch!

                                                Approved Installers Request Form

                                                Your Name*

                                                Your Email*

                                                Your Number*

                                                Your Postcode

                                                Additional Information

                                                I would like to receive news and offers from EWI Store

                                                Weber Monocouche Installation Guide

                                                Weberpral Monocouche is a cult classic when it comes to thick coat renders. It’s renowned for creating a crisp, clean finish in a range of natural colours. In terms of installation, this product is highly versatile in the textures that it can create. Whether it’s a scratch finish, tyrolean or a dry dash finish, Weber monocouche can achieve it.

                                                At EWI Store, we’re very excited to have recently started stocking Weberpral Monocouche render, so we’ve put together a basic guide on how to install the render to create a scraped finish!

                                                What is Weberpral M?

                                                Weberpral M is a decorative, through-coloured, thick coat render. It is a very versatile product, as it can be finished in different ways to achieve a range of textures and finishes such as roughcast, scraped, dry dash or ashlar. It is a BBA Approved polymer-modified render that comes as a dry-mix in 25kg bags – a favourable choice when compared to sand and cement.

                                                Substrate Preparation

                                                Prior to application of the Weber Monocouche, you need to ensure that the substrate is stable, clean, suitably dry, sound and free from anything that may affect adhesion. The substrate needs to have the correct amount of suction; too little and the render won’t adhere properly; too much suction and the render will fail. You can test the suction of the substrate by spraying water onto it and visually inspecting the rate at which it is absorbed.

                                                If you find that the substrate has a high suction, it needs to be lightly sprayed with water and then tested again. This should be repeated until it has the correct suction. Be careful not to soak the wall excessively, as this can cause a reduced adhesion of the render.

                                                For very smooth surfaces, we recommend applying Weberend Aid as a key coat. This should be applied using a hawk and trowel, or using an open-hopper spray gun. A tight layer should be applied across the substrate before it is textured using a well-loaded roller.  

                                                Preparation of Weber Monocouche

                                                A 25kg bag of Weberpral M Monocouche should be mixed with 5-5.5 litres of clean, potable water using an electric paddle mix. Weber tends to recommend that you use as little water as possible (erring towards the 5-litre mark) so as to give a workable consistency.

                                                Application of Weber Monocouche

                                                Weberpral M should be applied in either one or two passes using either a spray machine or by hand using a trowel. The typical finish achieved using the Weber monocouche is a scraped finish; for this technique, the minimum thickness that should be achieved is 18mm, with a maximum thickness of 28mm.

                                                Weber recommends the use of Fibreglass Mesh for their monocouche system. The mesh needs to be embedded into the middle of the render – it shouldn’t make contact with the underlying substrate but equally, it needs to be embedded deep enough to avoid becoming visible once the render has been scratched back.

                                                When applying the render in two passes, we recommend applying the first pass and ruling it off to a perfectly flat finish, before going on to apply the next pass 1-2 hours later, before the first has fully hardened. The two layers should fuse together as one coat.

                                                To achieve the textured finish, the render should be scratched back 3mm before it has fully hardened – therefore a 28mm thickness would become 25mm, and an 18mm thickness would be scratched back to 15mm.

                                                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!

                                                  Approved Installers Request Form

                                                  Your Name*

                                                  Your Email*

                                                  Your Number*

                                                  Your Postcode

                                                  Additional Information

                                                  I would like to receive news and offers from EWI Store

                                                  Cavity Wall Insulation vs. External Wall Insulation

                                                  What is a Cavity Wall?

                                                  Developed in the early 20th century, cavity walls were introduced into building practices as a means of alleviating problems with damp.

                                                  As opposed to traditional solid wall properties, cavity wall properties were made up of two layers of brick with a gap in the middle of around 20-100mm wide. Cavity walls are therefore much wider than solid brick walls, which is one of the ways you can tell whether your property has cavity walls.

                                                  Another telltale sign of whether your property has cavity walls is the appearance of the exposed brickwork. If the bricks have been laid lengthways, you probably have a cavity wall.

                                                  What is Cavity Wall Insulation?

                                                  Cavity wall insulation is the process of filling the gap between the two layers of bricks with different types of materials. It’s fairly cheap to install and on the average house it only takes a few hours. Cavity wall insulation is cheap, easy to install and can save you plenty on your bills. Most properties in the country that are able to install this form of insulation have already had it done. Worth mentioning, however, is that the amount of insulation that you can install, and therefore the energy saving result, is completely dependent upon the size of the cavity.

                                                  Cavity wall insulation materials can range in price and vary according to whether they are being retrofit or newly installed. Modern properties will be built with rigid board insulation already in place. When insulation is retrofitted for an older property, usually people go for a fibreglass type insulation which is pretty cheap, or a polystyrene bead insulation, which is more expensive due to its higher insulating capabilities.

                                                  What is a Solid Wall?

                                                  A solid brick wall is two bricks wide, with each row of bricks interlocking to form a completely solid 9-inch brick wall. There is no gap between the bricks as with cavity walls, so to insulate it you can either add insulation to the inside or outside of the property (i.e. internal wall insulation or external wall insulation).

                                                  As with cavity walls, you can identify a solid wall by looking at the brickwork. If the bricks alternate between a mixture of header (short) and stretcher (long) bricks, you have a solid wall. If the property is rendered, check the width of the wall – if it is less than 260mm, chances are that the wall is solid brick. The vast majority of properties built prior to the 30s will be solid brick.

                                                  What is External Wall Insulation?

                                                  SWI is more expensive than cavity wall insulation, whether it’s internal or external, the price is more within the region of thousands than hundreds. There is some funding available for external wall insulation but unfortunately, it is very limited.

                                                  There is a range of options when it comes to external solid wall insulation, however, EWI boards are typically made of EPS, Mineral Wool, Phenolic or Wood Fibre. The insulation boards are secured to the wall using adhesive and screw fixings, and a decorative, weather-proof render is then applied on top.

                                                  Choosing external wall insulation is probably the best bet when comparing it with internal wall insulation and even cavity wall insulation. This is because you can gain greater energy saving benefits due to the fact that the thickness of the insulation that you install can be as thick as 200mm – you aren’t restricted by the thickness of the cavity or the loss of internal space.

                                                  Mineral Wool external wall insulation prior to the application of the render topcoat.

                                                  If you have cavity wall insulation already and you’re looking to increase your thermal performance even further by installing external wall insulation, check out our dedicated blog post ‘Can I Install EWI on a Cavity Wall?’

                                                  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!

                                                    Approved Installers Request Form

                                                    Your Name*

                                                    Your Email*

                                                    Your Number*

                                                    Your Postcode

                                                    Additional Information

                                                    I would like to receive news and offers from EWI Store

                                                    What do I Need to Render my Knauf Aquapanel?

                                                    The Knauf Aquapanel is an outdoor cement board, designed for the building and decorating of exterior facades. These render carrier boards are particularly strong and are ideal for withstanding even the most extreme weather conditions. If you’re planning on installing a render system onto the Knauf Aquapanel, then keep reading!

                                                    Today’s blog post is an installation and rendering guide for the Aquapanel. We’re going to be talking about how to install the boards and then how to apply the EWI Pro thin coat render system onto them.

                                                    Installing the Knauf Aquapanel Boards

                                                    To start off, Knauf Aquapanels need to be screwed onto vertical timber battens using 42-60ml self-drilling screws. You should use approximately 23 screws per board, and a 3mm gap needs to be left in between each board.

                                                    Once in place, a render carrier board joint tape should be applied to all of the joints, or alternatively, you can cut fibreglass mesh into strips of 10cm and secure these using a thin layer of the EWI-225 Premium Basecoat.  

                                                    Applying Render to Knauf Aquapanels

                                                    Now that the Knauf Aquapanels are prepared and ready to go, you can go straight into applying the thin coat render system.

                                                    First, the EWI-225 Premium Basecoat needs to be mixed with 6 litres of clean, cool water using an electric paddle mix until it is a smooth, workable consistency. This is our strongest basecoat-adhesive, and therefore it’s ideal for applications onto render carrier board as it will help to resist cracking.

                                                    Once mixed, the basecoat should be applied directly onto the boards at a thickness of 6mm. At this stage, you should embed the Fibreglass Mesh into the basecoat. It’s important that the mesh is embedded in order to enhance the tensile strength of the system – to do this you need to cut the mesh into strips and ensure that each strip is overlapping by 10cm on all edges.

                                                    Remember that you are applying a thin coat render, and therefore the basecoat needs to be perfectly smooth and flat so that any imperfections are not visible through the final render finish.

                                                    Once set, the basecoat will need priming with a render primer. This is optional, although we do recommend the use of a render primer if you have chosen an especially bright colour for the topcoat, as the primer can be tinted to match the render and will ensure an even coloured finish. The render primer should be painted onto the basecoat and then left until dry.

                                                    The final stage in the render system is the topcoat. Whether you’ve chosen the EWI-010 Acrylic Render or the EWI-076 Premium Bio Silicone render, the application is always the same. The render needs to be applied at a thickness that corresponds with your chosen grain size – so if you’ve chosen a 1.5mm textured finish then the render needs to be applied 1.5mm thick. Once the render itself is on the wall, it needs rubbing up using a plastic render float.

                                                    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!

                                                      Approved Installers Request Form

                                                      Your Name*

                                                      Your Email*

                                                      Your Number*

                                                      Your Postcode

                                                      Additional Information

                                                      I would like to receive news and offers from EWI Store