Think about how far our industry has come in the past decade or so. The energy efficiency of windows has gone through the roof. Doors are now a sexy purchase thanks to the composite door market and more creative PVCu offerings. General security standards are higher across the board. Homes are warmer and more secure because of it all.

Yet, when it comes to installation of said new windows and doors, we remain rooted in the past when it comes to what we use. I’m talking specifically of silicone. Given where society is headed, and the range of new and arguably better products out there, it might now be time to start thinking about ditching the silicone.

Cold spot

I have been reliably informed that the u-value of silicone is 2.6W/m2K or worse. Consider then that a high quality, energy efficient window will have a u-value of around 1.2W/m2K or better. Many are 1.4W/m2K. That makes the insulation value of silicone horrendous in comparison. I covered this topic back in 2016.

This creates a problem. As an industry we sell our new windows and doors to home owners on the merits of better energy efficiency. We have spent a huge deal of time and money to make sure our products get better each time. And thats great. But then we go ahead and ask installers to fit them with a product which has about as much insulating power as a flannel!

We have paid so much attention to improving the product, that we have forgotten about the installation of the product and where that can be improved upon. That being said, there are options out there, some of which I have covered on here previously. The main one being insulation tapes.

There are quite a few insulation tape manufacturers out there:

  • Iso-Chemie
  • illbruck
  • TruFit (Edgetech’s illbruck offering)
  • Sika
  • Vitaseal

There are others as well. But more and more are popping up and giving even more choice to installers. It’s not difficult to install either. This is an example video from Iso-Chemie:

A neat seal around the edge of the window. An easy way to get a tight seal around uneaven walls externally. Far better against the weather and far better insulation values than silicone.

These sorts of tapes come in different colours too. There was an argument that there were too few colour choices to compliment different window frame colours, but as with most things over time, choice of colour has widened and this has become less of an argument against it’s use.

Crucially, installation is simple. Roll out the tape and cut to size. Either fit it to the window frame or to the wall, start installation and watch it expand to fill the gap. I know some installers are already ahead of the curve on this one and are using it on their installations. Of the images I have seen where this has been used, they do look very tidy. You can be an artist with a silicone gun against a stone built house. But these tapes achieve a neater finish than silicone ever can. Does it help speed installation times on? Perhaps, but there is another point to not using silicone as we move forward.

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Old silicone is very rarely recycled because its difficult material to break down and recycle. Therefore, much of it will end up in landfill sites or the incinerators to get rid of it. At a time where our industry really needs to prove to the general public that we’re an industry that takes our climate and sustainability seriously, this is a pretty difficult truth to get around.

If you’re a fitter you know how messy silicone is. You all probably have at least one t-shirt that is now more silicone than fabric. It takes time to set, and curious home owners can easily stick a finger in it before it sets properly! It has to be done well, otherwise it will look like a dogs dinner. There’s even been shortages of the stuff recently. So taking just these points into consideration, insulation tapes is surely something we should all be looking at as a replacement for silicone?

The green thing is important here. Whilst insulation tapes are far better from an efficiency point of view, it’s our ability as an industry to demonstrate to the public that we understand we have to go about our business in better and more environmentally friendly ways which is just as important. These tapes could be a small but key way to show that by ditching silicones that will most likely be sent underground in the years to come, we are trying to change to be a better industry.

I am under no illusion that after decades of using silicones for sealing around windows and doors, most fitters won’t be keen to hang up the silicone gun immediately for expanding insulation tapes. Habits die hard. But there are plenty of reasons to consider stopping using silicones right now, and plenty of positives in looking at these tapes as an alternative.

If we are to take sustainability as seriously as we think we should, we need to be looking at all areas of fenestration, and not just the production of product, but installation, recycling and education too.

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