Hi all-hope someone can point me in the right direction.
I have my spare room replastered about 5 weeks ago. The guy who did it said there was a small damp patch and the plaster had blown where it was. He put a solution on it and filled a couple of holes and then plastered. He said it might come back and to watch it to see. He could not see any gutters or pipes near it on the external wall and there is no window there either. Now the plaster has dried, I have painted the room but in 2 spots (2 inches each) the paint has flaked but does not feel damp but in another there is a 2 inch darker patch which feels damp. It's a tiny spot, halfway up the wall and there is no chimney breast etc on the wall.
I can't understand what could be causing it! Is it the rendering outside, which looks a little cracked in places. I don't want to get someone in if it's something I can identify myself. If I had the external wall re-rendered and painted with waterproof paint would that help? Is it likely to be costly??
Any help gratefully received.