Damp

paulj2021

There was a damp problem in one of the rooms of the house I’m selling, I had what appeared to be the cause fixed (damaged flat roof, cracks in exterior render) in April/May this year, and had the internal plaster redone shortly after. However a very small damp stain has reappeared, I was wondering, how long does it take for a wall to fully dry out after repairs like this? Is there any easy way to see if the damp is still penetrating or if it’s just the last of the old damp? Ps this damp spot is against a bricked up former chimney breast, if that makes any difference. 

dimbo61

How is the pointing and lead flashing around the chimney breast. 
Does the damp patch get worse after heavy rain.
Can you get into the loft next time it rains heavy ?

paulj2021

dimbo61 said:

How is the pointing and lead flashing around the chimney breast. 
Does the damp patch get worse after heavy rain.
Can you get into the loft next time it rains heavy ?

There is no actual chimney on top, it was demolished years ago, just a void inside the loft (which is almost impossible to get to as the roof is very low there) however the tiles above the void are apparently in good condition according to the people who fixed the flat roof. I didn’t see any changes to the damp spot after the recent bad weather

FreeBear

Usual rule of thump is one month for each 25mm of wall thickness to dry out. So a 100mm wall (assuming cavity) will take 4 months to dry fully. May was pretty cold and damp, so that may well have slowed things down a bit. You'll probably have a bit of residual staining to cover up.