Help - insulation advice

newbuild25

Hi,made this account to ask for any advice on what ye would do in this situation? This isn't the only window like this.. some have chunks gone out of them! Would ye use insulating foam to fill gaps or take out the plasterboard altogether and replace? Thanks 👍

Exiled Rebel

why was there a gap in the first place? I would have thought it should have been a single sheet of full fill insulation in the first place.

Personally I'd remove all loose insulation and use expanded foam. Be careful not to get any on the window frame or glass as it's pain to try and remove (especially from the frame).

karltimber

Use expanding foam, let it harden, cut flush and then use air-tightness tape and seal up the window to the wall. Goodwins have this tape.

keno-daytrader

Did the block layer do this or the window lads?

Is this a self build or do you have a main contractor?

The insulated boards should be flush with the inner leaf.

Not something I would expect to see in a new build and would have serious questions about the insulated boards thru the whole cavity.

10-10-20

https://www.boards.ie/discussion/comment/123139641#Comment_123139641

I think it's just a really bad cavity closer job rather than the vertical boards being out of place. Can't be sure.

OP, I'd remove that silly piece across the cavity in the first photo. I'd then check that the insulation is up against the internal leaf and that there is a cavity remaining at the internal face of the external blockwork (needs to be 25mm or whatever was spec'd). Then I'd fill that cill cavity with a fresh-cut piece of insulation held in with foam all around. I'd trim back any of the foam snots and make the insulation elsewhere flush with the blockwork; then I'd tape up the window, cavity-closer and blockwork with air-tight tape making sure that the cavity is covered right into the blockwork. Just like this example from my window here now:

That's the 125mm segmented air-tight tape. Method for installing is available on Brook's site as well as others.

https://brooksonline.ie/phs-fusion-variable-plus-window-tape-135-15-150mm-up0834

Should sort it for ya.

newbuild25

@10-10-20 can you still use cavity closer when windows are installed?

10-10-20

https://www.boards.ie/discussion/comment/123141896#Comment_123141896

By use you mean install...? You can cut up sections of 20 or 25mm PIR board and fit it around the window brackets, then use adhesive foam to fill any gaps. It doesn't need to be airtight as the membrane will sort that out. Make sense?