This week we are taking a look at our top of the line, through-coloured, silicone render in order to offer a little bit more technical info about why you would want to choose coloured silicone render, and what it can do for you and your home!

To start with, and to state the obvious, silicone render contains silicone. If you’re not aware of exactly what silicone is, it’s basically a polymer which is rubbery and heat resistant – it has a molecular structure built up by a large number of similar molecules which are bonded together. Silicone is typically used in adhesives, lubricants, medicine, make up, cooking utensils and thermal and electrical insulation. A great thing about Silicone is that it has a low thermal conductivity – so it’s perfect when used as part of an external wall insulation system!

Silicone rubber is widely used in the construction industry because it is known for its tensile strength, reliability and longevity. That’s why silicone is great for use in renders, because it provides an incredible level of flexibility which will help to prevent cracking in the long run.

Not only is silicone flexible but it also offers a high level of water resistance, but importantly at the same time it is vapour permeable. What this means is that your render won’t absorb any water, but it will allow water vapour from the inside to escape through it (water vapour moves from warm areas e.g. inside to cool areas e.g. outside). This will contribute towards the prevention of damp within your home by letting the moisture escape rather than building up within your insulation system and your walls. Moisture and condensation can hugely affect the thermal performance of insulating materials, so it’s a pretty important factor to consider.  

Because of its breathability, we recommend that silicone render is great for use in mineral wool systems – Rockwool insulation boards offers unsurpassed levels of breathability, so if you live in a humid, damp area then this is the perfect system!

We have found that silicone render works really well if you’re installing it in a place where algae and moss or organic growth are likely to occur, such as near water or plant life. This is because it is highly resistant to organic growth. What this means is that in the long run you are much less likely to have to clean your render, and even less likely to have to re-render before the end of its lifespan.

How to apply Coloured Render

Silicone render comes as a ready-to-use mix so you don’t need to add anything to it before use. It is advisable that you give it a bit of a stir first to ensure that all the colour pigments are evenly distributed throughout (if you’ve gone for a coloured render).

To apply the silicone render, you need to first install the basecoat mesh layer (EPS Basecoat Adhesive and fibreglass mesh embedded within it). This will create a smooth, even surface for you to render onto – you wouldn’t be able to apply the thin coat coloured render directly to the substrate because it is such a thin texture that you would be able to see brickwork etc underneath.

Once the basecoat layer has dried, you can use a stainless steel trowel to apply the coloured render to the substrate. To create an even, textured finish you will then need to rub up the surface of the of the render using circular motions with a plastic render float.

You will need to ensure that you have enough people on site to be able to apply the render to an entire wall at once. If you attempt to apply the coloured render section by section, then you will find that when it dries there will be a scarring effect where the different render sections meet.

To apply silicone render, you will also need the right weather conditions. Rain, wind or too hot/cold temperatures can have a negative impact upon the finished result. Make sure that it is not due to rain during installation and drying time.

Silicone Render vs Silicone Silicate Render

Silicone render and silicone silicate render are the twin siblings of the EWI Store render group. Both renders are well matched in terms of performance, the only real difference between them is that silicone silicate contains sand granules which makes it slightly less resistant to organic growth.

Silicone silicate is one of our most popular renders. It’s also the slightly cheaper than silicone render because of the addition of sand, which is a less expensive material. However, for the performance of the render you aren’t losing out by paying less.