Sealing our windows. But how?

[ToughButterCup]

We have an issue with how our windows are to be sealed into the window frame.

 

Today I got round to reading the instructions on how to seal our windows in and was surprised to read the following;

The instructions (highlighted in yellow translated above) show that Compriband should have been used between the window and the frame. It wasn't. The installers simply foamed them in, like this;

 

 

The point made by the installer is that Durisol isn't air-tight enough - and importantly smooth enough - to make a proper seal between the window and the wall with Compriband. The fact that this should have been picked up before is no longer relevant. Shit happens.

 

I have asked for help from Durisol: none forthcoming yet.... This can't be the first time someone has faced this issue.

Which  products would be likely to compensate for the leakiness and roughness of the Durisol / window interface?

 

I don't want to get to to air-tightness testing to find that the windows are allowing a gale through..... I will have paid for them by then - and nobody will be interested in helping solve the issue at that stage. 

 

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[PS . Craig from Ecowin the Gaulhofer agent)  has just rung to say  that if there is any air leakage round the windows, then Ecowin would would indeed be responsible, he also suggests that I get a company rep to observe the air tests. That would mean they'd sort any problems out on the spot.

Can't say fairer than that now can he? ]

[Declan52]

Trim the foam back. 

Seal with a good Quality mastic/silicone suitable for outside.

Use air tightness tape with the spilt so half sticks to your window a few mm and the other side can be glued to the block work. 

Inside the plaster/plasterboard will cover it and your cladding?? Will cover the tape on the outside.

Treat it like sealing up a normal blockwork window.

You could run a skin tight skim down the revels to give the tape something better to stick to. Although the glue I used was really really sticky and mine have been draught free 4 years now.

[ToughButterCup]

12 minutes ago, Declan52 said:

Trim the foam back. 

Seal with a good Quality mastic/silicone suitable for outside.

Use air tightness tape with the spilt so half sticks to your window a few mm and the other side can be glued to the block work. 

[...]

Thanks Declan.

Air tightness tape : in or outside?

Product trade names?

[Declan52]

What are you putting on the out side of the house, cladding???

 

https://passivehousesystems.co.uk/product/winflex-airtight-window-tape/

 

https://passivehousesystems.co.uk/product/gerband-fortax-6400-airtight-sealant/

That's the tape and adhesive I used for my inside walls.

If you are sealing the inside with tape maybe just silicone the outside.

[ToughButterCup]

?

[Mr Punter]

@recoveringacademic what is the external wall finish?  It may be that this needs to be installed before sealing the windows, which can be done with Compriband or mastic.   Compriband is vapour permeable so I understand that this reduces the risk of condensation forming between the window frame and the wall.  An airtightness tape sealing the window to the wall structure on the inside reduces the risk further.