I don't know if you can help me but here goes, I've a problem with an interior surface on a gable end wall, some time in the past
there must have been a dampness problem caused by condensation, it had since been remedied by installing cavity wall insulation and central heating.
The wall surface is a wet plaster finish straight on to brick.
This surface was treated with a material supposedly to help prevent dampness problems as I think they assumed it was as a result of moisture penetration.
Now this material is black a has a slightly tackiness to it and is not stable, it had been covered with several coats of paint in the past but has been exposed during
redecoration in places. This is where it is causing me problems, the last I wall papered this wall 4-5 months later brown stains started to come through and of course has
ruined the finish. I'm now about to redecorate and need to seal this wall to stop this happening again, can you suggest any product that will do the job for me?
If not, you might be better placed to pass this on to someone who can answer my question.