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Hi all,
I've just purchased a c1850's stone built cottage, with 1980's brick extension. There is extensive damp in the older stone part (low on walls, to 1ft up). No visible DPC. Although there are issues with guttering, high ground levels, stack etc. that I will fix, strangely the external walls in the same room are dry( suggests to me levels are not the main cause). The walls immediately around the fireplace is also dry (so stack may be OK).. There is also damp on an internal brick partition built inside the old stone part of the house (suggests water penetration from rain is not the main problem). It's been gypsum plastered over in a lot, although there seems to be some lime patches left (whiter colour) but these are still damp.
Since the usual causes seem ruled out, at least as prime causes, to me, this hints at another prime cause of the damp: the concrete floor poured into the old stone part of the house. The concrete floor itself seems bone dry. However, it may be preventing ground moisture escaping, except at one point - the join between the stone wall and the concrete.
My theory is that the moisture is being wicked up this join - and there is moisture in the ground under the concrete and there is nowhere else for it to go. Gypsum plaster / non breatheable paints have made things worse.
Obviously the main solution is ventilation / lime plaster + breathable paint. However, to my untrained eye the walls seem very wet and this alone may not solve things alone - it's a risk it won't work and I'd rather get it right first time.
I have 2 questions
1) Is my theory plausible, or am I talking *******s.
2) If I'm not talking *******s, is there a solution to stop water moving from under the concrete floor into the more porous stone, that doesn't involve removing the entire concrete slab. The less intrusive and expensive the better. I won't get a chemical DPC or concrete render to 'block' the damp. I don't want to damage the wall or cause the damp to reappear higher up at a later date. Anyone with any experience of this? Can you describe what the options are.
Edit: pics here:
https://www.diynot.com/diy/media/albums/a-damp-house.26913/
Thanks so much in advance!
Ian
EDIT: Turns out the party wall is brick, no visible DPC. Internal wall with most damp also brick. Stone walls to front and rear (external) both damp but dryer.
Humidity level in air was 75%. A day with the heating and dehumidifier took it down to 55%. Exposed bricks with plaster off visibly drying after a day.
It may have been empty for up to 3 years according to neighbour. Agent said 8 months... would explain it being a bit cold and damp.
I've just purchased a c1850's stone built cottage, with 1980's brick extension. There is extensive damp in the older stone part (low on walls, to 1ft up). No visible DPC. Although there are issues with guttering, high ground levels, stack etc. that I will fix, strangely the external walls in the same room are dry( suggests to me levels are not the main cause). The walls immediately around the fireplace is also dry (so stack may be OK).. There is also damp on an internal brick partition built inside the old stone part of the house (suggests water penetration from rain is not the main problem). It's been gypsum plastered over in a lot, although there seems to be some lime patches left (whiter colour) but these are still damp.
Since the usual causes seem ruled out, at least as prime causes, to me, this hints at another prime cause of the damp: the concrete floor poured into the old stone part of the house. The concrete floor itself seems bone dry. However, it may be preventing ground moisture escaping, except at one point - the join between the stone wall and the concrete.
My theory is that the moisture is being wicked up this join - and there is moisture in the ground under the concrete and there is nowhere else for it to go. Gypsum plaster / non breatheable paints have made things worse.
Obviously the main solution is ventilation / lime plaster + breathable paint. However, to my untrained eye the walls seem very wet and this alone may not solve things alone - it's a risk it won't work and I'd rather get it right first time.
I have 2 questions
1) Is my theory plausible, or am I talking *******s.
2) If I'm not talking *******s, is there a solution to stop water moving from under the concrete floor into the more porous stone, that doesn't involve removing the entire concrete slab. The less intrusive and expensive the better. I won't get a chemical DPC or concrete render to 'block' the damp. I don't want to damage the wall or cause the damp to reappear higher up at a later date. Anyone with any experience of this? Can you describe what the options are.
Edit: pics here:
https://www.diynot.com/diy/media/albums/a-damp-house.26913/
Thanks so much in advance!
Ian
EDIT: Turns out the party wall is brick, no visible DPC. Internal wall with most damp also brick. Stone walls to front and rear (external) both damp but dryer.
Humidity level in air was 75%. A day with the heating and dehumidifier took it down to 55%. Exposed bricks with plaster off visibly drying after a day.
It may have been empty for up to 3 years according to neighbour. Agent said 8 months... would explain it being a bit cold and damp.
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