One of the most frequent questions we get asked is how everything goes through winter and whether we can continue to work in cold/wet conditions, this mainly effects our external work - External Wall Insulation & Rendering. The answer to that question is yes, however it's much more of a challenge. The first thing we do and recommend anyone to do in this line of work is to change your materials to winter stock. Not all suppliers manufacturer such materials however ours does - EWIPRO.
The main differences are the temperatures you can work with them in. Normal materials have a temperature limit of between 5 and 25 degrees Celsius, winter stock let's us work down to zero which is an absolute game changer! The curing time of winter stock is also a great deal quicker. There are two alternatives for our winter stock, the base coat & adhesive changes to Winter Adhesive which is supplied by EWIPRO. We can also move over to a Mineral Render opposed to a through coloured finish, its takes a bit longer as you have to paint the finish once complete. It dries quicker just like the winter adhesive as it is a dry-mix render, meaning it dries quicker naturally.
There are still other issues to consider though, render cannot be applied in wet conditions for obvious reasons. Another factor is whether the render will freeze or frost overnight so you need to keep a real close eye on the weather forecast, we recommend met office! If there is any chance that you think it may happen then don't do it as you will end up having to strip & redo if it effects the render. If the render has mostly dried you can protect the front of it using large hessian sheets which will help protect if it is going to frost overnight.
The reason for render failing through winter (in cold & wet conditions) is because the render takes longer to dry, a Render Accelerator reduces all of these risk substantially. there are additives which can go both in the top coat and in the base coats of the render. The additive used is different for the two types of render, it speeds up the curing process. In turn this speeds up our completion time on all of the rendering work to be carried out, a definite must have if you plan on working through winter!
Let's not forget about fitting the insulation to the wall, it's the most important part if the system! We generally don't have much issues when fitting the boards as the adhesive used to stick the boards to the wall are not directly exposed to the elements, don't forget we are using winter stock at this point as well. Wet weather and snow cause the same problems however, this is because the system isn't yet sealed which would allow potential rain and snow to get behind the insulation boards which would cause a moisture trap.
That's all from us on this topic, be sure to keep an eye out for our next blog where we will be talking about Maintaining EWI & Render.