Shirley this is exactly what cavity insulation does? I was lead to believe that damp issues with this were based in the exacerbation of existing damp problems, by stopping the wicking and drying effect of air flow over areas of damp, rather than by the insulation creating damp bridges?
two different types of damp innit.
Penetrating damp - rain hits wall - soaks through brick, bridges cavity, soaks though inner leaf and plaster, damp wall, wall paper falls off.
Condensate damp - you boil pasta for twenty minutes whilst having a shower just before you hang the washing on the radiator then make yourself a brew. Litres of Steam/water vapour hang around thinking where shall I go cause you forgot to turn the bathroom extract on and your cooker hood is one of those recycling ones rather than a direct extract. It finds a nice cold wall bit of wall cause you aint got no cavity insulation and forms condensation = damp wall, black spot mould and your wall paper falls off.
Its gotta go somewhere. (single glazed windows are actually quite a good 'sink' for water vapour if your looking on the bright side).
plus Rising damp - actually quite rare due to most houses having damp proof courses, where the damp is sucked up your wall leafs from the ground.
I'd say, off the top of my head + a bit that i've read online + a chat with a couple of damp proof course sales men, that condensate damp is by far the biggest problem. I know that its an issue in our house and I'm looking into various MVHR extract options.
Its a minefield.
