Author Archives: Alana

We are Supporting the Poppy Appeal!

What is our involvement?

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

Impacts of Covid-19 on the charity

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

What is The Poppy Appeal?

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

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

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

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

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

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

Installing Render and EWI During the Winter Months

Installing Render and EWI During the Winter Months

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

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

Winter products at EWI Store

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

Winter Adhesive

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

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

EWI-221 Winter Adhesive is:

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

Render Accelerator

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

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

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

Silicone render is:

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

Mineral Render

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

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

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

Mineral Render is:

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

Additional Advice

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

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

Thermal Conductivity & U-Values

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

Thermal conductivity

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

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

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

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

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

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

The calculation is as follows:

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

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

EPS insulation

U-values and building regulations

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

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

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




Acrylic Render vs. Mineral Render vs. Silicone Silicate Render

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

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

Mineral Render

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

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

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

Acrylic Render

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

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

Silicone Silicate Render

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

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

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

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

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

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

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Green Homes Grant Scheme and EWI Store

The Green Homes Grant Scheme and External Wall Insulation

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

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

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




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

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

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

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

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

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

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

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

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

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

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

Additional information regarding insulation measures

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

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

EWI Store products are compliant with the Green Homes Grant scheme

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

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

EWI Pro External Wall Insulation Systems

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

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

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

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

All the Materials you need we can supply!

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

How Do I Apply?

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

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

Step 3: Apply for the voucher on the Government website

Contact us for more information


Chessington Branch: 02033 974067

Aylesbury Branch: 01296 821067


Sales Enquiries: [email protected]

Technical Enquiries: [email protected]

Are you an Installer?

Check out our Green Homes Grant Scheme blog for Installers.

Fixing Cracked Render

One of the biggest issues with old sand and cement renders is that over time they crack. The cracks may start small but before long they can really ruin the look of your home – and they can also lead to water ingress.

Because thin coat renders are a fairly new trend when it comes to rendering, it’s more common that properties have an existing sand and cement render. As you will know if you’ve read our blog ‘Sand and Cement Render vs. Thin Coat Render Systems,’ thin coat render systems are much more flexible and are far less likely to crack than a sand and cement render. This is because our thin coat render systems are comprised of a flexible basecoat which has fibreglass mesh embedded within it for extra tensile strength and crack resistance, then a thin coat render is applied on top of this smooth basecoat. The render is called a thin coat render because, as the name suggests, it’s applied in an extremely thin layer of around 1-3mm thick (depending upon the grain size you go for and therefore the type of texture that you want to achieve). We would always recommend using this system going forward, as sand and cement renders are just unreliable in comparison.

For those who have had sand and cement render previously installed, we get a lot of people asking us what the best solution is to fix the cracked render. Well, you have a few choices, depending on the severity and size of the crack as well as how long it has been there:

cracked render

1. Fixing completely blown render across the entire property

If the render is falling off the walls everywhere you have two options:

Start again

The best solution for fixing cracked render is to start again! It’s probably not what you want to read, but putting any other materials on top of cracked render is akin to adding a plaster – it is only really a temporary fix and it’s likely that over time the cracks will just keep expanding and getting worse. We would therefore always recommend removing the existing render back to the brick work, but we appreciate many people won’t want to do this due to the time and cost involved.

Fix render by adding a thin layer of EPS insulation

The next best solution is adding a thin layer of insulation (20mm or 30mm) to the wall – this needs to be attached to the wall with adhesive and anchored to the wall using mechanical fixings. Prior to adding the insulation board, do try to remove any very loose render and make good the surface with Levelling Mortar (EWI-260).

Once the insulation boards are in place, and the adhesive holding them to the wall has set, then you carry on the rest of the system as normal. On top of the insulation boards, a 6mm basecoat layer should be installed (with reinforcing fibreglass mesh embedded within it), and a thin coat render finish should be applied on top to create a decorative finish. Read our blog ‘coloured render cost per m2‘ for more information on how much this render system typically costs by the square metre.

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

2. Fixing cracked render on one panel of wall

If there is just one area of the wall that is cracked, then we recommend filling the crack with our Levelling Mortar and then applying a fresh layer of basecoat and render to just that panel (i.e. a square house would have 4 panels, front back and 2 sides). Hopefully the panel in which the crack has occurred isn’t the whole side of the house, and there is a natural break, for example a downpipe, which can disguise where the new render meets the old render.

By installing a new layer of basecoat and then re-rendering the entire panel, it should ensure that the cracked render does not crack again in future. The flexibility of the base coat, combined with the flexibility of the render top coat, should provide a crack-free solution.

3. Fixing a very small crack or area of impact damage

There are some cases where a very small crack has occurred that needs fixing; for example maybe a bin has blown against the wall, or a car has ‘gently’ reversed into it. In this situation you have a couple of options. Firstly, you can remove a square of render around the affected area and basecoat and render this area. This involves taking an angle grinder and trying to remove a clean square around the impacted area.

Unfortunately, there will always be an issue of scarring where the new render meets the old render. This is a consequence of the fact that the render is so thin – there is simply no way the two sections can be blended together without visible scarring. The square (marked out using rendering tape) ensures that despite any scarring being visible it is still neat.

The other solution for sorting a small crack in the render is to basecoat the whole panel and re-render the property – again a bit more work but you won’t be able to see where the original crack in the render was, therefore it gives a nicer finish than marking out the square (as described above).

We often get people ordering additional buckets of render to make repairs on cracked/damaged render and they simply ‘touch up’ the affected area, but 99% of the time this will result in unsightly visible scarring. We would always recommend following one of the methods described above.

Which thin coat render should I go for?

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

  • Silicone 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 requires very little maintenance. 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).
  • Silicone Silicate Render: Silicone Silicate Render is our most popular hybrid-silicone render. Silicone Silicate Render is our best value render, offering the key benefits of a thin coat render as well as the breathability and vapour permeability that the silicone provides. Silicone Silicate also provides an element of self-cleaning capabilities. This is a great render if performance and functionality at a great price point are key priorities.
  • Acrylic render: Acrylic Coloured render is very similar to silicone, except for it doesn’t provide the same breathability. It’s a solid middle-ground thin coat render because it still provides the same flexibility, Acrylic render is also great at holding onto colour pigment. So this is also a fantastic choice if you are looking to fix cracked 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 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).

At EWI Store, we are very happy to provide help with cracked render – we recommend sending pictures to us at [email protected] and we can provide expert opinion on the best solution to getting the issue fixed!

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Can You Paint Over Silicone Render?

You may have had your Silicone Render for a good few years now and by this time it might need to be freshened up. A lot of people ask us how exactly they can make sure that their render stays fresher for longer, or indeed how they can maintain it a few years down the line. Gentle cleaning using a jet wash is perfect for every couple of years, but for those houses that are prone to becoming dirty, you may need to repaint.

With Silicone Render, you’ll find that it requires cleaning and painting much less regularly than your bog-standard sand and cement, but although it’s self-cleaning, this doesn’t mean that it’s totally immune to dirt and grime. How well your render maintains a clean finish completely depends upon the property itself, i.e. if you live next to a very busy road you’ll find that the Silicone Render gets dirty much more quickly. 

What Type of Paint do I use on Silicone Render?

Because Silicone Render is a specialist, breathable render product, you may be wondering whether your standard masonry paint is suitable for applying on top.

You can use masonry paint on the Silicone Render, however, we always recommend that you ensure it is breathable. We offer a Silicone Paint manufactured by EWI Pro which is ideal for application onto a Silicone Render. Because Silicone Render is breathable, putting a non-breathable paint on top would completely nullify its ability to allow water vapour to pass through its surface. 

The best part about the Silicone Paint is that it comes as a standard white, but we can tint it to match your existing render. This way you’ll be updating the look of the whole property with its fresh new appearance. 

How to Apply Silicone Paint onto Silicone Render

Before you start to apply your Silicone Paint onto your render, there are a few preparatory steps that you need to carry out. First, you’ll need to jetwash the render to get rid of any heavy dirt and grime. If the walls have been painted previously, you’ll need to remove any flaking paint using either the pressure washer or the wire brush. 

Silicone Render is incredibly flexible and therefore unlikely to crack, but if there are any minor cracks these need to be filled. Be sure to apply tape to areas that need protecting from the paint, such as window and door frames. 

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

 If you’re looking for a complete guide to maintaining your render finish, check out our blog post ‘how do I look after my render finish?’.


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Why use Fibreglass Mesh in Render Systems?

Fibreglass Mesh is an essential component of our render systems. It helps provide strength and flexibility to our thin coat render systems ensuring that the render doesn’t crack in the years to come. 

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

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

Where do you put the fibreglass mesh in render systems?

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

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

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

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

Overlapping mesh in basecoat

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

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

The mesh provides additional strength to all thin coat render systems and also helps prevent cracking so we would always recommend it.

Below is an example of a buildup for Render Only on a brick substrate – this demonstrates where the fibreglass mesh fits into the process. 

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


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Monocouche Render vs. Silicone Renders

The two main types of render that we stock are silicone renders and monocouche renders, both of which provide a decorative finish on the external walls of a property. Choosing different renders (whether it’s monocouche or thin coat) can mean that your property gains different advantages and a variety of decorative finishes.

In today’s blog post, we’re going to be discussing the key differences between monocouche render and thin coat render and hopefully it will help with the decision-making process if you are torn between the two!

Monocouche Render

There are a wide variety of monocouche renders available on the market (we stock EWI Pro, Weber and Parex), the key characteristic of this render being that it is a through-coloured, thick coat render. Monocouche render is very often compared to sand and cement render, and although monocouche does contain cement it is actually very different in terms of texture and characteristics.

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

Silicone Render

Silicone render is a type of render that comes ready to use in buckets. It’s tinted within the bucket (like a paint) and can essentially come in any shade – at EWI Store we have special tinting equipment so we can match any RAL or NCS colour. The silicone render system can be used as a standalone system straight onto brick, or it can be applied onto external wall insulation boards to provide the decorative finish.

Because of the fact that silicone renders are ‘thin coat renders’ (which means they’re applied in a very thin layer on top of a reinforced basecoat), they have the advantage of being especially crack-resistant. The silicone properties within the render, coupled with the way the render is applied, means that it is very flexible and less likely to crack than the monocouche render. There are also a few other key advantages of using silicone-based renders, including breathability and self-cleaning capabilities.

The next question is to ask how much both of these will cost to install. We have a couple of blog posts ‘monocouche scratch render cost per m2‘ and ‘coloured render cost per m2,’ so check those out to get an idea of how much you’re looking at.

We offer a variety of silicone-based renders, including Premium Bio Silicone, Silicone and Silicone-Silicate. Give us a call if you are interested in giving them a go!

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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The Importance of Render Repair

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

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

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

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

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

What about cracked Render?

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

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

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

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

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

What can cause cracked render?

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

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

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

Do I need to do render maintenance?

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


Replacing Pebbledash with Coloured Render?

What is Pebbledash?

Pebbledash is perceived by many as an outdated look for a property. This is because 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.

The pebbledash effect is created by applying a layer of mortar (usually sand and cement) to the external wall, and literally throwing pebbles at it to allow them to stick. Pebbledash houses are still dotted all over towns and cities in the UK and can often have a somewhat dilapidated look. As well as this, over time the pebbles can drop, which leaves the mortar exposed to the weather and therefore vulnerable to absorbing water and creating problems with damp. Due to its unpopularity, pebbledash can also 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 nice to look at. Our coloured renders are available in thousands of different colours and can be ordered online or by phone!

We’re not hating on pebbledash (much), but many people want to know how to remove it in order to replace it with a coloured render. For those who have recently moved into a new home, or who are looking to update the look of their property, re-rendering is a popular consideration. However, there is a definite gap in the public knowledge over whether you can apply the render on top of pebbledash, and this is something that we are frequently asked here at EWI Store. So, we thought we would tackle the question for all the pebbledash homeowners out there.

The short answer is that unfortunately, you cannot replace pebbledash with coloured render by applying coloured render directly on top of the pebbledash. However, not all hope is lost, because there are a few ways around this that you may want to consider, which we will elaborate on in this blog post…

Ways to replace pebbledash with coloured render

So, as you may have realised, pebbledash is incredibly difficult to get rid of. You basically have three options when considering how to remove pebbledash…

Option one: removing the pebbledash

The first option is to attempt to hack the pebbledash off, at risk of the brickwork underneath and with no guarantee that you will be able to achieve a smooth finish. If you do decide to go for this option be really careful about who you hire to do this and make sure they are experienced in removing pebbledash. If your pebbledash is forcibly removed by a builder, this can really damage the underlying substrate and can invalidate your house insurance. Even after all of this, you still wouldn’t be free to apply coloured render directly over 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 two: One Coat Dash Cover (OCDC) to cover up pebbledash

The second method is to use the 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, updated appearance. The good thing about the One Coat Dash Cover is that it is breathable, so it will help any trapped moisture within the underlying pebbledash to escape.  It can also be applied up to 20mm in one pass (up to a maximum of 50mm), so it’s gruaranteed to smooth over the pebbledash nicely!

Option three: insulate then render over pebbledash

A beneficial way of ridding yourself of the pebbledash look is by installing 20mm (or thicker, but the thicker you go the more expensive) external wall insulation boards over the top of your pebbledash. This is actually 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 over the 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 out there for replacing your pebbledash with coloured render that it can be quite overwhelming. We wanted to give you a clear idea of what each coloured render can offer you so that you can make the right choice to suit the needs of your property and your own personal tastes.

Thin Coat Coloured Renders to Replace Pebbledash:

Thin coat renders are a great option to go 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 because 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 box. (Read more about Silicone Render here).

  • Acrylic render: Acrylic Coloured 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 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 it’s 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 external solid wall insulation, 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…

We want to strike up a bit of a 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. Check out our blog ‘Pebbledashing: Dash Receiver or Cement Mix?’

We upload a new blog post every Tuesday so stay tuned for more external wall insulation installation advice, tips for homeowners and product information!


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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!

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.

Can You Apply Render In Hot Weather?

Render can create a beautiful Finnish for your home if done in the right conditions, but what if it isn’t, and what are those tiny holes ruining your texture?

We have a lot of people coming to us with complaints regarding how their render has dried. The complaints commonly include things like pin holes and the product drying too quickly. This is mostly caused by applying the render in the wrong weather conditions or in direct sunlight, as the product has specific temperature margins where the product will work at its best. The temperature margins tend to be around 5˚C – 25˚C but each render may vary so you should always check your product packaging to determine its specific temperature requirements.

This shows that it is not a problem with the quality of the product but through applying the product in inadequate conditions. Pin holes can happen from time to time but there is normally a reason for this, so it is important to follow the correct application techniques to reduce the chances as much as possible.

One contributor to pin holes in hot weather conditions may be not applying a render primerBase-coat is very dry and porous so will suck the moisture from the render very quickly which will massively increase the risk of getting pin holes. The render primer will help prevent this by creating a barrier between the render and base-coat preventing this from occurring.

One of the main causes of pin holes in hot weather conditions is due to the product drying too quickly, so by not applying a primer you are exacerbating this problem. A way to reduce this problem further is by applying two coats of primer instead of just one, because this will create a stronger barrier between the render and the base-coat, further preventing the base-coat from sucking the moisture from the render.

Pin holes are unsightly but are not the only aesthetic problems that may occur as a result of applying the render in poor weather conditions. The render will naturally dry much quicker in hotter temperatures and in direct sunlight, which may reduce the amount of time you have to correctly apply the product, which may lead to an unfinished or uneven texture.

It takes 4 men around 3 hours to render 200 square meters. By not having enough time to apply the render you may not be able to apply it using the correct technique so may result in a render with lines, and although there won’t be any real discolouration these lines and uneven textured finish can create the appearance of discolouration. The correct way to apply the render is in circular motions rather than in strips, because this will help create that uniform and smooth texture you are aiming to achieve.

The best way to reduce the chances, is of course, to apply the render in the correct temperatures. But, what do you do if you are in the middle of summer? The solution is to get up early and get going! We have many installers who will start the process at 5 in the morning, so they can get started before the sun is at its hottest! you should avoid applying the render in the middle of the day because this is when the sun is harshest.

Another technique, which may seem a little bizarre at first, is to work by avoiding the sun. What I mean by this is to follow the shadows and apply render on these sections, and as the angle of the sun changes, these shadows will move and so should you! This means you can keep applying your render while staying in the shadows and staying away from the glaring sun.

Do these problems affect different render types?

Yes, pin holes are a problem that can affect most types of render, this is a problem in silicone render, thin coat renders and acrylic render of all grain sizes. This means switching to a different product may not be an ideal solution, as not only will you still have the chance of getting pin holes, but you may not get the aesthetic look you were going for, because some renders look very different from each other. Another reason this is not an ideal solution is because you will not gain all the amazing other benefits that for example, a silicone render would provide you with. This means the only real solution to this problem is to be conscious of weather during application and using the above techniques to help minimise the chances of pin holes occurring.

If you are interested in Learning the correct process for applying render then consider attending one of our courses or watching our YouTube video ‘Applying Silicone Render In Hot Weather’.

Don’t let these small risks put you off, there are no long term side effects or damage to your property that can occur with pin holes, the problems are purely visual and there are so many advantages to rendering your property. Please check out our blog on ‘The Benefits of Using Silicone Render’.

What Is The Cost Of An External Wall Insulation System

calculating the cost of external wall insulation is not a simple task, there are many components that determine the price including the installation and labour costs, the choice of insulation material and the choice of decorative finish. Depending on what insulation material you choose, not only do they themselves vary in price but some materials required fixings and some require adhesive which also will alter the price. Therefore, trying to calculate exactly how much materials cost can be tricky, especially when the different materials cover different areas – for example, our reinforcement mesh comes in 50m rolls, while a bag of EWI-220 Adhesive will cover 3m2 of wall.

Calculating the cost of the External Wall Insulation Materials

At EWI Store, we are here to help! We have a great team who are on hand to help with any quote you may require. Simply give us a call with some rough measurements of the area that needs to be insulated using our EWI systems and we can quickly calculate exactly what you need.

Use our EWI Calculator to calculate the External Wall Insulation materials you require

If you have some experience of solid wall insulation, you might want to use our EWI materials calculator.

We have designed this to be a very easy-to-use tool which will accurately calculate the correct materials needed for a solid wall insulation install. To use this tool you will be asked a series of questions and measurements so we can help calculate the amount of materials you will need. The questions are as follows:

– Choice of Render

– You can choose between three options depending on what you are interested in, eco, premium and standard, this relates to the decorative finish you want on your walls. To find out more about these options then please visit our page ‘Welcome to the EWI-Pro solid wall materials calculator’.

 – Amount of meters squared needed

Enter amount of system needed , this needs to be the coverage in meters squared- this is calculated by multiplying the width by the height of each wall you are going to insulate. Do not subtract windows or doors as it will give you an incorrect result because our calculator builds in wastage into the final calculation.

 – Choice of insulation material

– Choice of mechanical Fixings


–  Amount of Corner beads

 – Insulation Thickness

– Amount of Stop Beads

 – Amount and choice of starter track

Trade installers get fantastic prices and warranties on the system

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

As an installer you may well be eligible for our trade discount prices too – so not only do you get a BBA Approved external wall insulation system delivered directly to site, you also get the materials at a great price. As a trade partner we are also able to offer system warranties – provided the installers have been on our free training course.

We also offer a huge range of brick slips!

We also now are delighted to say we have a huge range of brick slip finishes for those looking to recreate the brick feel of their property (i.e. don’t want to simply render a brick wall). These acrylic brick slips are not only incredibly realistic, but they are also extremely robust, so despite being flexible and easy to install, but they also look the part and will last!

So there you have it – if you need some help calculating the material requirements for an EWI job, give us a call – our team are on hand to help!

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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 Pebble-dash

How do I get rid of pebble-dash?  

Pebble dash became extremely popular in the 1920’s 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. In present this has resulted in a dated, and for many an unsightly look that many home owners are looking to remove. 

Re-rendering pebble-dash without removing pebble-dash can be difficult if the right materials aren’t accessible. Removing pebble-dash 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, pebble-dash 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, pebble-dash has taken a bit of a hit as of late, with pebble-dashed house prices falling to reflect a national dislike. Luckily, as long as the pebble-dash is in good condition, there is no reason this can’t be rectified without the expensive process of removing it.




How to re-render pebble-dash without removal

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

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

One of the best ways of re-rendering pebble-dash without removing pebble-dash 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 thick without compromising structural integrity. You wouldn’t want to put a non-breathable material on top of the pebble-dash 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 pebble-dash is to ensure that any loose stones are rubbed off.

The next step is to prime the pebble-dash using the 310 Universal Primer, this will limit the absorptive capacity of the pebble-dash render and will 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 mixing 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’.

  1. Externally insulating on top of the pebble-dash

Another method of re-rendering pebble-dash without removing pebble-dash render is by applying insulation boards to the existing pebble-dash. 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 pebble-dash.

Once the boards are set in place, you should have essentially created a new substrate for re-rendering pebble-dash without removing pebble-dash. 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 pebble-dash without removing the pebble-dash render.







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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.