There are 3 main types of render within our EWI Pro Insulation System range of BBA approved products – we offer a Mineral Render, Acrylic Render, Silicone Silicate Render. As you might expect we get asked a lot what the difference is between the types of render? Well in this blog we thought we would try and explain the differences so you can pick the right render for your next job!
Our EWI Pro 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.
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 cheapest 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 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 1mm render. This means that within the render, it has Silicate granules just 1mm 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.