Hi, new member here looking for a bit of clear advice
I've got a post-war bungalow with cavity walls and lime/cement plaster.
It's got no cavity insulation and was thinking about adding 50mm PIR on the
inside. Just over what seems an age ago now, I bought a load of 25m foil backed
Celotex.
Ok so the dilemma now is that I seem to have at least 4 options !!!!!!
As this is the first room of the entire property, I want to get this right first time, so
advice on the right config would be much appreciated.
So options are:
Remove all plaster, add a concrete slurry (if needed)
1. Add 2x 25mm in opposing layers, then plasterboard on top fixing all the way through to brick.
2. Add 25mm, then Batten on top and infill voids with 25mm, then plasterboard on top.
3. Fix battens to wall, infill with 25mm, then 25mm over the lot then plasterboard on top.
VPC where? Some websites say under PB others say against wall, some not needed at all. - confused.
And then
Options 1, 2 & 3, but on top of the plaster as is.
My preference is to batten the wall (easier to deal with levels) with plaster remaining, fill the voids with
25mm and seal. Then add another layer of 25mm over the top again sealing the wall, which should mean
no need for another VPC. Finally fix the PB through the 25mm to the battens.
I've been dithering on this for a week now and itching to start this weekend, so any advice very appreciated.
Ed