Hi,
The very top section of a bay in our c1850 town house has had a damp problem for a number of years . We had both the bay flat roof and parapet replaced, this is the time line of the works
1. Flat roof replaced
2. Room plastered and decorated
3. Damp appeared
4. Parapet replaced
5 Damp problem better but still there
I am very happy with the work done on the roof and parapet and I am sure that the water is not coming from there now and is probably penetrating (or condensation?).
I have finally decided to bite the bullet and try and fix it. Obviously one issue is that the plaster has been subjected to damp and needs to be replaced. As you can see from the picture I have cut a small hole in the ceiling and hacked away the plaster to see what is underneath. Most of the wall has a cement render which is showing completely dry on my damp meter.
The render however stops about 10cm from the ceiling and above that is just normal plaster which is showing a reading of 15% on my meter. This backs on to a wooden beam providing support for the joists. This is showing a reading of about 4% on my meter.
My original plan was to render with waterproof cement and then re skim. I did this a couple of years ago with a damp patch in the basement and it has worked a treat. I know with old houses though that render can also trap damp in causing wood to rot so I am wondering if this is the best course of action now (It may also be why the render stopped before reaching the beam).
It may just be that replacing the damp plaster will be enough. I was also thinking that I could fit some coving and leave an air gap over the wood which would help air circulation.
Any thoughts or advice?
Jasper.
The very top section of a bay in our c1850 town house has had a damp problem for a number of years . We had both the bay flat roof and parapet replaced, this is the time line of the works
1. Flat roof replaced
2. Room plastered and decorated
3. Damp appeared
4. Parapet replaced
5 Damp problem better but still there
I am very happy with the work done on the roof and parapet and I am sure that the water is not coming from there now and is probably penetrating (or condensation?).
I have finally decided to bite the bullet and try and fix it. Obviously one issue is that the plaster has been subjected to damp and needs to be replaced. As you can see from the picture I have cut a small hole in the ceiling and hacked away the plaster to see what is underneath. Most of the wall has a cement render which is showing completely dry on my damp meter.
The render however stops about 10cm from the ceiling and above that is just normal plaster which is showing a reading of 15% on my meter. This backs on to a wooden beam providing support for the joists. This is showing a reading of about 4% on my meter.
My original plan was to render with waterproof cement and then re skim. I did this a couple of years ago with a damp patch in the basement and it has worked a treat. I know with old houses though that render can also trap damp in causing wood to rot so I am wondering if this is the best course of action now (It may also be why the render stopped before reaching the beam).
It may just be that replacing the damp plaster will be enough. I was also thinking that I could fit some coving and leave an air gap over the wood which would help air circulation.
Any thoughts or advice?
Jasper.
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