Airtight Tape and Compriband

[Barney12]

Sorry, having a thinking day today hence so many questions

Some window firms seem to include the cost of airtight tape and compriband in the install cost. Others suggest that its the timber frame co's cost?

So who's responsibility is it? We're intending to use MBC and their quote says:

"supply and fit of all airtight membrane and tapes round windows"

but is that the same as "compriband"?? 

I've said it before but "window quotes are SO confusing"! 

Edited June 28, 2016 by Barney12

[Jeremy Harris]

No, MBC will just fit the airtightness tape to seal between the frame and the windows on the inside.  Our window supplier offered to seal the gap around the windows (quite cheap, around £40 for the whole lot IIRC) bit I wanted to do it myself to be sure it was done as well as it could be.  I used low expansion foam, injected deeply into the narrow gap from both side, to try and get as good an insulation level, and prevent cold air from penetrating, as I could get.  It took time to do, but I think it was worth it to make sure the small gap was 100% filled.

[Barney12]

15 minutes ago, JSHarris said:

No, MBC will just fit the airtightness tape to seal between the frame and the windows on the inside.  Our window supplier offered to seal the gap around the windows (quite cheap, around £40 for the whole lot IIRC) bit I wanted to do it myself to be sure it was done as well as it could be.  I used low expansion foam, injected deeply into the narrow gap from both side, to try and get as good an insulation level, and prevent cold air from penetrating, as I could get.  It took time to do, but I think it was worth it to make sure the small gap was 100% filled.

OK, thanks. So the airtight tape is only on the inside? And the compriband is effectively a gasket/seal between the window and frame?

One supplier (of Internorm) has added close to a £1,000 for these two items. 

[TerryE]

Barbey, when are you putting your windows in?  Compriband is a special expansion tape. It would normally be used by your window installers as part of installation if you have a stone or brick skin which is in-place before the windows are installed.  In our case our windows are installed in the MBC frame and the skin is added later.  In this scenario, they can't use Compriband as it is gap filling mechanism, and there is no gap in front of the windows, just the wide outdoors. 

[Jeremy Harris]

51 minutes ago, Barney12 said:

OK, thanks. So the airtight tape is only on the inside? And the compriband is effectively a gasket/seal between the window and frame?

One supplier (of Internorm) has added close to a £1,000 for these two items. 

As Terry rightly says, but I'll add that I'm not a fan of compriband, particularly.  One thing you need to do is completely fill the tiny gap all around window and door frames (the gap is typically around 3mm all around, for the fitting straps).  This isn't just about weather tightness, it's about preventing air movement cooling the frame/window joint.  Hence the reason for me wanting to very carefully fill that thin gap with low expansion foam.  The foam isn't an air tightness seal, or a weather seal, it's solely to prevent air movement and provide an insulating gap filler, to reduce the risk of their being a local condensation locus.

[Barney12]

50 minutes ago, TerryE said:

Barbey, when are you putting your windows in?  Compriband is a special expansion tape. It would normally be used by your window installers as part of installation if you have a stone or brick skin which is in-place before the windows are installed.  In our case our windows are installed in the MBC frame and the skin is added later.  In this scenario, they can't use Compriband as it is gap filling mechanism, and there is no gap in front of the windows, just the wide outdoors. 

Thanks. Rather confirms the minefield that is window quotes as they knew that we were having a timber frame! 

[Barney12]

27 minutes ago, JSHarris said:

As Terry rightly says, but I'll add that I'm not a fan of compriband, particularly.  One thing you need to do is completely fill the tiny gap all around window and door frames (the gap is typically around 3mm all around, for the fitting straps).  This isn't just about weather tightness, it's about preventing air movement cooling the frame/window joint.  Hence the reason for me wanting to very carefully fill that thin gap with low expansion foam.  The foam isn't an air tightness seal, or a weather seal, it's solely to prevent air movement and provide an insulating gap filler, to reduce the risk of their being a local condensation locus.

Thank you. Understood. 

[Jeremy Harris]

Just now, Barney12 said:

Thanks. Rather confirms the minefield that is window quotes as they knew that we were having a timber frame! 

One thing I learned early on is that you have to expect all suppliers to be a bit less that well-informed when it comes to details about their products.  Some of the shortcomings in advice given by some suppliers was truly shocking, we found.

This isn't usually the manufacturer's fault, it seems that UK suppliers of products made elsewhere are often lacking in technical understanding, so it's best to assume the worst and question every single detail.

[ProDave]

3 hours ago, TerryE said:

Barbey, when are you putting your windows in?  Compriband is a special expansion tape. It would normally be used by your window installers as part of installation if you have a stone or brick skin which is in-place before the windows are installed.  In our case our windows are installed in the MBC frame and the skin is added later.  In this scenario, they can't use Compriband as it is gap filling mechanism, and there is no gap in front of the windows, just the wide outdoors. 

Exactly.

I am using compriband to seal the outer edge of the frame to my wood fibre cladding, applied as I fit the cladding. And like Jeremy, the small gap between the frame and the window is filled with foam.