Up until about 10 years ago, if you decided to render your property, the builder would most likely have used a sand and cement render. Sand and cement render is made by mixing 4 parts sand with 1 part cement and is applied to a depth of about 10mm – 15mm. The problem with it is that it has no give. Over the course of a year, your home will expand and contract as the weather changes – in cold weather the house will actually shrink and the opposite is true during the summer months.
Sand and Cement renders Crack
The problem with the older sand and cement renders is that as the building changes in size, the sand and cement render won’t move with it. The result is that the old sand and cement render will begin cracking. At first you will begin to see hairline cracks but as time goes on and water begins to get behind the render, it may begin coming off the walls.
One of the ways of limiting the cracking that occurs when sand and cement render is used is the addition of lime to render. When you mix lime in with sand and cement, the finished render coat will have greater flexibility. It is not completely flexible so will still be liable to cracking, but it should be a significant improvement on sand and cement alone. The presence of lime in the render also improves its workability, making it easier to spread.
K-Rend also cracks eventually!
To be honest, any thick render system is liable to cracking; it is not just sand and cement render. K-rend and other scratch renders are also more likely to crack than more modern thin-coat renders. It’s not that they are bad products – in fact K-rend is probably the UK’s best selling render – but the unavoidable fact is that any render applied that thickly is more likely to crack.
Thin coat renders are virtually crack proof!
As time has gone on, people have been seeking ‘crack proof’ render finishes. Our thin coat render is just that. It has a flexible fibreglass mesh embedded within the basecoat adhesive and this gives it flexibility. The top coat render is also very flexible. If you put the render as a test on a piece of EPS, you can then flex the EPS and the render will still not crack.
When you consider the overall thickness of the EWI Pro render system then it is much much thinner than K-rend and other scratch coat renders. The basecoat adhesive is just 6mm thick, and the render topcoat can be as thin as 1mm, this takes the whole system up to a thickness of just 7mm. The flexibility of the components and the fact they are applied very thinly means the system will genuinely move with the building so the render system will stretch during the warmer summer months and when it gets cold in the winter, the render system will shrink.
Crack proof and maintenance free render!
The beauty of this system is that once installed on your property it will genuinely last, with no cracking and no maintenance required. You can install the system your home and then rest assured knowing the system will last decades!
We do recommend you get qualified installers to install the system though. The reason for this is that since the system is so thin, it is fairly unforgiving to install. Qualified installers will be able to get a lovely finish – one that you will be able to admire for years to come!