For many decades, silicone has been the material of choice for the sealing of windows and doors in the UK. It comes in many colours, it’s easy to apply providing the guy holding the gun knows what he’s doing, and it’s convenient. Yet silicone is easily one of the most inefficient products in the whole window and door installation process.
The industry has been doing a sterling job of making the window frames and the units that go into them much more efficient than previous models. U-Values have dramatically reduced and WER’s (if you believe in those) are massive right now too. Yet, an area which seems to have been ignored is the opening new windows and doors go into.
We’ve focused so long on product, that we have ignored what the product actually goes into. Traditionally, a window is fixed to it’s opening through screws, then foam, then silicone sealed. Yet all of those materials are incredibly inefficient when it comes to insulating, and the U-Values are ridiculously high when you compare it to an A rated window.
As far as other European nations go, namely Germany, Austria and Scandinavian countries, we’re very backwards int he way we seal windows and doors. The idea of silicone is old fashioned by decades and sloppy. So what is the solution?
Expanding sealing tape
What seems to be gaining traction, albeit slowly, is expanding perimeter sealing tape. This is a compressed foam based material that is applied to the outer edge of the window and door, with a tape. When the tape is removed, the foam tape then expands. Once the window and door is fitted, the foam expands to compress against the outer edge of the brickwork, filling the gaps, giving a weatherproof seal and a much warmer, energy efficient seal.
It’s easy to fit too. Check out this promo video from Iso Chemie: