Damp stone cottage and plasterboard

[Padraig Clarke]

I am renovating a 100 year old stone cottage in Ireland. The property has not been lived in for about 5 years so there was a big condensation/damp problem. The roof also has its issues, but at least I know where water has been penetrating. There is a big damp smell, so doing my best to work out the issues.

In regards to the plasterboarding: I removed the bottom sections on a few walls as it was clear the bottom sections were damp (mould present). The wood framing at the base was rotten. I removed to a clear separation about half way up the wall and the wood frame seems dry higher up. There is a gap inbetween the remaining plasterboard and the stone wall. Then behind the board it feels cold but only very 'slightly' damp.

1. Can this dry out?

I have another internal plasterboard wall which I have not investigated as there is no mould etc. However it does feel cold and I can see the nail heads coming through (like a stain). I have been told 'cold' boards are actually damp and should also be replaced.

2. Does this mean this board also is damp because it is cold to the touch? Is that a true fact?

3. Overall: Can plasterboard eventually dry out or is it better to just replace it?

 

[Doggit]

Plasterboard can dry out, but only time will tell however, if the plasterboard is crumbling, then it needs replacing.

If the house has been empty for 5 years, then the boards will be cold, so unless you use a damp meter on the boards, you won't know if they're just cold, or wet. The nail staining is more of a worry, and suggest they are rusting, so either the wall is wet, or they haven't used galvanised nails.

Look at the Dryzone website, and see if you then feel that the wall needs treating to stop the damp coming through on the lower part of the wall, that then may the upper part of the plasterboard damp. I suspect you'll end up taking the boards down, and doing the job properly.

 

[vinn]

Padraig, Here's the thing with old stone cottages:
Nothing can be done halfway, the roof for instance should be replaced if leaks have been appearing here and there.
The first rule is to keep water out of a property, and the roof is the first barrier.
So the roof should be the first job with first claim on the monies.

If the walls have been dot & dabbed then its best practice to remove the lot and see what you have behind the plaster board. Think why have the walls been dot and dabbed?

The exterior is probably rendered and painted, and nine times out of ten the render needs knocking off back to masonry.
There's also the condition of the floors: if moisture is coming through then they should be lifted and replaced with modern floor installations.
The interior FFL should be higher than the outside ground level.

I say all the above without seeing your cottage (or photos of it).