Retrofitting cavity closers

[ChrisJLW]

Hi all,
Hopefully a quick question. Is it possible to fit cavity closers with the window in place?

The cavity is about 60mm wide and I can feel some lovely big blobs of filler foam round the edges of the window. So I imagine it could be quite difficult to get one in there.

As these are french doors I'm very reluctant to just fill the gap with foam as the dpc bridging properties of the stuff seems to be in question.

I'm tempted to leave it until the summer, remove the whole thing and then install the cavity closers.

Any other alternatives that y'all can suggest?

Ta muchly.

 

[noseall]

Any other alternatives that y'all can suggest?

I'd hack off the reveal plaster, to give slightly better access, hopefully leaving the corner bead in place. Get some100mm dpc, and carefully squirt polymer sealant down brickwork and stick the dpc onto the masonry. Then we'd wet the the dpc with a water spray and squirt plasterboard foam adhesive onto the dpc and feed in a slender piece of PIR (25mm?) onto the foam. Wait for that to cure then foam the gap this side.

Massive faff, but mask the door upright first.

 

[robinbanks]

I'm very reluctant to just fill the gap with foam

I recall reading that can based expanding foam is open cell, and hence can absorb some water, whereas board based stuff is closed and much more resilient to it; are you willing and able to remove the door and close the cavity off with a well fitted slice of kingspan?

 

[noseall]

are you willing and able to remove the door

I wouldn't go down that route, especially for a set of French and a combi frame - that's foamed and siliconed in. Not a prayer.

 

[noseall]

I recall reading that can based expanding foam is open cell, and hence can absorb some water, whereas board based stuff is closed and much more resilient to it; are you willing and able to remove the door and close the cavity off with a well fitted slice of kingspan?

Foaming would work. I'd still mask up though.

 

[Ivor Windybottom]

Take it out, do it properly... After waiting until the spring! Strip the sealant off, unbolt then run a hand saw round if it's foamed in.

Hack plaster back, put proper cavity closer in, refit the frame then plaster up to it. As good as a newbuild.

How did you end up here? Was a thicker wooden frame replaced with a thinner one? I'm guessing there was some plastic trim there, probably smothered in black mould.

 

[ChrisJLW]

Cheers all for the input.

Ivor, you're spot on. There was some plastic trim covering the cavity, which had a little bit of mould on it and had started to detach from the wall. So I pulled it off to see what was going on.

I'm not 100% what was there before this set of french doors as they were fitted around 2015, a few years before we bought the place. You'd think the window fitters would have done a better job of it.

The cavity insulation is pretty patchy too from the looks of it, white fluffy stuff that's been blown in badly, probably doesn't help with the damp. The whole extension is a bit of a 90s bodge, the builder owned the house but didn't seem to care much about the quality of work.

Will cover it up temporarily & revisit in the spring I think, along with possibly redoing the cavity insulation.

 

[Ivor Windybottom]

You might want to have a look at your other windows if they were done by the same fitters.

Trim is normally used over messed up decor, it's not intended to span a gaping hole.

 

[ChrisJLW]

I've had a few replaced here & there since we moved in. As far as I can see this is the only one with this issue, none of the others have trim like this one.

 

[robinbanks]

You'd think the window fitters would have done a better job of it

I wouldn't, but I've watched window fitters work

 

[ChrisJLW]

This is true, the whole house is a litany of bodges. The insulation & screed for the kitchen extension at the back had been laid over an open drain which they didn't bother closing, so we had an issue with unwelcome guests.

 

[noseall]

You'd think the window fitters would have done a better job of it.

Cavity closers are generally the builders job. Our fitters always ask..."is the scaffold down?" or "are the closers fitted"?.