My external wall has never showed any signs of staining or damp until I painted the wallpaper. (looks like watermarks) The anaglypta has been in place for 4 years without showing any stains until paint was applied recently. The house originally had damp in the walls until it was re-rendered, but has been dry for several years now. Is it possible that there is something in the wall that can bleed through from the plaster once it is painted? (I think that Black ash mortar has been used in the construction)
If I re-plaster the walls, what type of sealer will stop this from happening again?
If I re-plaster the walls, what type of sealer will stop this from happening again?
