Hi, I live in a 30’s built house and a number of years back had a drive put on the front. A couple of years ago I noticed the plaster beginning to blow below the bay window (cavity wall) at the front so took up the first row of driveway blocks that were butted up against the exterior wall even though they looked to me to be below the dampcourse in the hope it would dry out a little before attempting to rectify the problem. About three months ago I removed chopped the plaster back to the brickwork and have had a dehumidifier going for 12 hours a day since then but I don’t seem to be getting any reduction in the amount of water being drawn into the dehumidifier which is about 4 pints per 12 hrs. Can someone advise me if this sounds right.
Also I have a moisture meter albeit for reading moisture in wood and the readings i’m getting are between 12 & 20 on different parts of the wall.
Any help would be appreciated, thanks in advance.