Tag Archives: Insulation

Applying Render to OSB

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

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

Rendering OSB: Render Carrier Board

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

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

The best course of action is to:

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

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

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

Basecoating the Render Carrier Boards

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

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

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

Rendering the Basecoat Layer

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

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

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

 

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

 

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Stages of Installing an EWI System

Stages of installing an EWI system

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

Wall preparation

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

Starter tracks application

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

Insulation application

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

Beading and Verge Trims application

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

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

Basecoat and mesh layer application

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

Render Primer application

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

Render application

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

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

Monocouche Render vs. Silicone Renders

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

Monocouche Render

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

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

Silicone Render

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

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

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

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

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

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Coloured Render Cost Per Square Metre

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

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

Calculating the cost of coloured render per square metre

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

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

Priming the substrate

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

Applying the Basecoat and Mesh

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

Using a Render Primer

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

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

  • Top Coat Primer – 20kg

    £67.00 (incl VAT)

Choosing a render

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

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

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

Silicone coloured render

Beading per m2

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

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

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

Which coloured render do I choose?

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

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

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

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

How much does Coloured Render cost to maintain?

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

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

 

 

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Applying Render to Cement Board

What are cement boards?

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

Applying render to cement boards

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

Step one: Priming the cement boards

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

Step two: Applying the basecoat

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

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

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

Step three: Priming the basecoat

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

  • Top Coat Primer – 20kg

    £67.00 (incl VAT)

Step four: Applying the render

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

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

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

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

 

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Sand and Cement, Monocouche and Silicone Render: Which is best?

Of the 28 million properties in the UK, a large proportion are rendered, or at least coated, with some form of protection like pebbledash. However, while pebbledash was vastly popular pre-1930, this aesthetic is now largely considered outdated, making render the go-to for creating a clean, modern look. In this blog, we investigate why render is so popular and the best products to create an incredible finish on your property or home.

 

Originally, UK properties were built with either brick or block. Over time, however, the mortar fusing the bricks together would break down due to natural weathering. Replacing the damaged mortar – known as re-pointing – is incredibly time consuming and, as such, very expensive. Therefore, a feasible alternative to re-pointing a property is to apply render. Render acts as a protective layer for a property; not only does it disguise the existing damaged mortar, but it provides a new facade for the brickwork, offering a clean, modern finish.

 

Traditionally, sand and cement render – typically six parts sand, one part cement and one part lime – was applied to the surface of a property. This render would be applied at a thickness of about 20mm and be coated with paint to complete the aesthetic. As with mortar however, the issue with these traditional renders was that, over time, they would crack due to the natural movements of the buildings by season, expanding in the summer months and shrinking in the winter months. While the addition of lime was intended to provide flexibility to adapt to such movements, the render was still not flexible enough to withstand these movements, causing hairline cracks. Such cracks cause further issues as they would provide an entry point for water to travel behind the render system and, as such, cause it to come away from the wall.

 

In the 90s, several manufacturers introduced a render known as “monocouche”, French meaning “one coat”. Monocouche render is easier to use than sand and cement render as it is premixed, typically four parts sand and one part cement with various other additives; all you need to do is add water. It is applied at a similar thickness to sand and cement render however, once applied, it is scraped to provide a chalkier finish. Monocouche render always uses white Portland cement as the binder; the white base allows for the manufacturer to add a coloured pigment to the render, meaning it does not require paint on top. As such, monocouche became increasingly popular in the 2000s, becoming the go-to product for those looking to render their properties.

 

Again, monocouche render ultimately comes with its downfalls. Firstly, as with sand and cement render, the thickness of monocouche render means that it cannot withstand the seasonal structural movements of the building, therefore causing cracks which again create an entry point for water. Secondly, while monocouche looks fantastic on application, it becomes a hot bed for algae growth as it encounters water. The biological growth on the monocouche can quickly lead to discolouring so, while it initially looks great, it quickly starts to look messy and requires a lick of paint to keep it looking fresh.

Then, in early 2000 came silicone renders – sometimes referred to as thin-coat renders – from Eastern Europe. Silicone render fundamentally differed from sand and cement render and ultimately replaced monocouche render. As opposed to a 20mm-thick render, the silicone render maxed out at 7mm and consisted of two main layers: a 4-6mm cementitious basecoat with embedded fibreglass mesh, and a silicone render topcoat typically at 1.5mm thick, although 0.5mm, 1mm, 2mm and 3mm grain sizes are also available. The fibreglass mesh in the basecoat is vital; it provides the render system the ability to flex with and absorb a building’s natural movements, making it crack-resistant – the defining factor and main benefit of silicone render.

 

Much like paint, silicone renders can also be tinted to any colour, providing infinite design options to apply to your property or home. Monocouche renders do come in various colours however, since pigments need to be added in the factory, they are very limited. So, if you need to match a specific colour – for instance, RAL-7016 anthracite grey – then silicone render is the obvious choice as it can quickly be tinted to match the required colour.

 

What’s more, silicone renders are hydrophobic, meaning that they possess self-cleaning properties which repel water. This means that, whenever it rains, the rain carries away any dirt particles from the render system, so the facade stays cleaner for longer. The EWI Pro Premium Bio Silicone render also has added slow-release biocides within the render, helping to prevent biological growth, which is especially useful if the render is being applied in areas of high vegetation.

 

Finally, unlike sand and cement and monocouche renders, silicone renders are lightweight, meaning that they are ideal to use in conjunction with external wall insulation systems. The weight of sand and cement and monocouche renders can pull the face of the insulation away and are therefore not recommended to be applied on top of insulation materials.

 

As this blog has established, render technology has changed significantly over the last 30 years. Whether you have a property that has existing damaged render that needs an upgrade, or even a new build like an ICF or a timeframe building on which you desire an advanced render system, then look no further than silicone render. With a silicone render system, you can rest assured that the facade will not crack over time and will likely stay much cleaner than either sand and cement or monocouche render, therefore providing a render system that will last for years to come.

Replacing Pebbledash with Coloured Render

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

What is pebbledash?

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

How can I replace pebbledash with a coloured render?

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

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

Essentially, there are three possible options for removing pebbledash:

Option 1: Removing the pebbledash

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

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

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

Option 3: Insulate then render over pebbledash

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

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

Which coloured render can I use to replace my pebbledash?

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

Thin Coat Coloured Renders to Replace Pebbledash

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

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

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

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

 

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

 

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

Thick Coat Coloured Renders to Replace Pebbledash

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

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

To conclude…

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

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

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

 

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Can I install EWI onto my flat?

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

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

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

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

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

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

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

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

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

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

Pro’s of installing external wall insulation onto your flat

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

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

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

Cons of installing EWI onto your flat

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

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

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

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

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