Plaster issue against double glazing.

[lancs_lad]

Any ideas what would cause this? Its not damp, just appears to have blistered. I'd like to be sure before i sort it.

 

[RandomGrinch]

If it is definitely not damp and water ingress, could it be cold bridging causing condensation, that is then disturbing the plaster/filler?

I think I would chisel out any bad areas, fill gaps with foam and cover the lot with uPVC cloaking profile.

Others may have better ideas!

 

[lancs_lad]

If I inject expanding foam in the gap for better insulation am I likely to cause further issues?

 

[HawkEye244]

If I inject expanding foam in the gap for better insulation am I likely to cause further issues?

It should be ok.

Out of interest, do you have solid external walls or is there a cavity ?

 

[lancs_lad]

It's a cavity wall. Just 3.4% moisture. Plaster skim has bubbled down where the double glazing is fitted. Less obvious lower down.

 

[foxhole]

Rake out and see, no point guessing , could be poor filling around frame just crumbling .