The walls in a room were replastered about five weeks ago and a couple of days ago, I started to paint them with watered-down emulsion. There are some patches of plaster that have been more difficult to paint than others, in that they haven't accepted the paint as readily as the majority of the surface. With successive coats, the hard-to-paint areas are becoming whiter, however, there is one patch in particular which has accepted next-to-no paint, and is pictured below.
How can I determine whether the wall is damp at this location? I will look outside tomorrow, to see if there is obvious damage to the wall at or above that location. Is there any other probably cause, other than damp?
In this thread, I raised the issue of slighlty darker patches of plaster in some areas and indeed, at least one particular darker area on the ceiling was more resistant to paint than surrounding areas, although I'm not sure if any correlation exists between darkness and preparedness to accept paint. You can see an area on the ceiling which is darker. Attempts to photograph after painting showed no difference, although it is clear enough the eye.
How can I determine whether the wall is damp at this location? I will look outside tomorrow, to see if there is obvious damage to the wall at or above that location. Is there any other probably cause, other than damp?
In this thread, I raised the issue of slighlty darker patches of plaster in some areas and indeed, at least one particular darker area on the ceiling was more resistant to paint than surrounding areas, although I'm not sure if any correlation exists between darkness and preparedness to accept paint. You can see an area on the ceiling which is darker. Attempts to photograph after painting showed no difference, although it is clear enough the eye.
