I live in a 'Coronation Street' type terraced house with a small kitchen added on to the back room. I have lived here a year and over the past four or five months I have notice great big damp patcehs across the back corner wall. I think the wall is just stone built with a plaster board attached on the internal side as the room is very cold with no form of heating. How do I get rid of these damp patches without having to replace the pasterboard?
Without stopping the moisture from getting to the plasterboard drying up the patches won't happen. The water maybe coming from condensation. This would require insulation and a vapor barrier to solve. If it is a seepage or leak threw the wall it could possibly be waterproofed from the exterior. Also don't forget to check up higher and make sure you have no leaks coming from above.