Damp Proofing

Fixing insulated plasterboard to a (formerly) damp wall?

Anonymous user 23/02/2024 - 3.01 PM

Hi there We have an outbuilding (3.5 external walls) which we're trying to turn into an office. It's about 150 years old, solid walls and when we moved in there was major damp. We have got rid of all the sources of penetrating damp (overflowing waterbutt, blocked drain, attached brick wall with no DPC). Then we realised the building itself had no DPC after spotting some damp rising up in the corner so we did DryZone injections. 2 months on the problem seems to be gone. We did notice some condensation on the walls the other day, but put it down to the fact that the weather very suddenly heated up (over 10 degrees increase overnight!) and that was not a problem the next time we went into the room. So hopefully we've got rid of the major damp sources but we're still a bit concerned about penetrating damp just because the room is very to the elements with empty land on one side of it that the wind and rain howls accross. Anyway, now we want to plaster, and, because it's a solid-wall construction with no insulation, we want to plaster using Celotex insulated plasterboard (has a VPC integrated). However, we've seen really conflicting suggestions about how to fix this plasterboard to the wall...it seems we can either: a) Dot and dab - risks damp coming through the adhesive but quicker and easier, some people say definitely never D&D, others say it's fine. Our plasterer suggested D&D nad he seems good although we're going to do this ourselves. b) dot and dab using very expensive waterproof dryzone adhesive - will cost more and have read some very mixed reviews - some say it's great (lots of room for air to circulate as you don't form a solid barrier with it), others say it's not (you end up with bouncy walls!). c) batten with wood battens - but a risk of interstitial condensation which could also rot the wood as well as causing plasterboard problems d) batten with metal battens - still the condensation risk. And expensvie/more complicated. Does anyone have any advice about how best to fix our plasterboard to the wall? Thanks so much...!