Half of my house is solid stone. The other half is a cavity-walled
extension, built in 1991. When the builder added the extension, he inserted
sheets of 1"-thick foam polystyrene into the cavities, as insulation. I
would have been better off if he had used *no*
insulation! The 1" of
polystyrene does little to prevent a cold draft from circulating within the
cavity, and it makes it harder to get additional insulation added. Although
I am eligible for a grant, the cavity insulating companies say the 1"
sheets already installed prevent them from adding extra insulation under
the grant scheme. I might be able to pay for it myself, but I'm told that I
would have difficulty finding a company who would guarantee the job. If the
work is not guaranteed, it means there is also no guarantee that they would
make a reasonable effort to do the job properly.
So I have two options, as far as I can see:
1) do it myself (following the "if you want a job done right, DIY!" axiom).
2) find a company who I can trust enough to do the job well, but without
any guarantee (not easy)!
Can anyone offer any advice on this?
If I do it myself, what materials should I use? beads, fibre or foam? My
guess is that foam injection would be the way to go (even though this
method seems to be rarely used these ddays for some reason. Anyone agree?
Does anyone have any idea how much it should cost to do it?