Hiya,
Firstly, don't worry, I'm not going to ask about rising damp. What I do have is a condensation/ lower wall crumbling plaster problem. The trouble is on limited sections of 2 cold exterior walls (exterior areas in permanent shadow), solid brick 1910s mid-terrace. The problem was exacerbated by a mix of poor central heating (fixed now) and badly placed heavy furniture...
In one area plaster has 'blistered' away from the base layer of rendering (sand and cement, I believe). Another problem is on a closed-off chimney breast on the shared wall. There's crumbling plaster where the chimney meets the wall - it looks to be gypsum, so is basically just flaking away with the slightest moisture. The previous owner had DPC injection over a decade ago and god knows what mix of plaster and rendering.
To cut to the chase, I've had an independent surveyor advise that the exterior walls need to be hacked back to brick in the affected areas only plus another 300mm above and replaced with limelite renovation plaster or similar and the areas kept free of heavy furniture.
A surveyor from a preservation/ damp-proofing company went one further and advised hacking back to brick the whole of both exterior walls and fixing thermal boards with an integral vapour barrier directly to the brickwork using brick plugs.
Both surveyors agreed that the closed off chimney needs cowling, then reopening and cleared out. The independent then advised just tanking and replastering, the other suggested 'cementitious slurry' (???) and more thermal boards on the chimney breast.
They also both suggested extractor fans.
Question - what would be best choice overall? I've no experience with thermal board but I've reservations with a number of things:
Ideally I'd want to keep all walls as breathable as possible so moisture isn't trapped - I've already had problems from previous owners and next door tanking both sides of a shared extension wall. The brickwork was still damp and it rusted away a power socket housing and blew a fuse (but that's another story).
Thanks
Firstly, don't worry, I'm not going to ask about rising damp. What I do have is a condensation/ lower wall crumbling plaster problem. The trouble is on limited sections of 2 cold exterior walls (exterior areas in permanent shadow), solid brick 1910s mid-terrace. The problem was exacerbated by a mix of poor central heating (fixed now) and badly placed heavy furniture...
In one area plaster has 'blistered' away from the base layer of rendering (sand and cement, I believe). Another problem is on a closed-off chimney breast on the shared wall. There's crumbling plaster where the chimney meets the wall - it looks to be gypsum, so is basically just flaking away with the slightest moisture. The previous owner had DPC injection over a decade ago and god knows what mix of plaster and rendering.
To cut to the chase, I've had an independent surveyor advise that the exterior walls need to be hacked back to brick in the affected areas only plus another 300mm above and replaced with limelite renovation plaster or similar and the areas kept free of heavy furniture.
A surveyor from a preservation/ damp-proofing company went one further and advised hacking back to brick the whole of both exterior walls and fixing thermal boards with an integral vapour barrier directly to the brickwork using brick plugs.
Both surveyors agreed that the closed off chimney needs cowling, then reopening and cleared out. The independent then advised just tanking and replastering, the other suggested 'cementitious slurry' (???) and more thermal boards on the chimney breast.
They also both suggested extractor fans.
Question - what would be best choice overall? I've no experience with thermal board but I've reservations with a number of things:
- I've got to mount a radiator back onto the wall being boarded, plus there are cables and sockets - wouldn't these just breach any vapour barrier?
- If the cold exterior wall is still cold and damp, would this risk damaging the board?
- What about if in future I wanted to mount things on the walls?
- I understand boards on the exterior walls, but is there really any point in thermo boarding a chimney breast on a shared wall?
Ideally I'd want to keep all walls as breathable as possible so moisture isn't trapped - I've already had problems from previous owners and next door tanking both sides of a shared extension wall. The brickwork was still damp and it rusted away a power socket housing and blew a fuse (but that's another story).
Thanks