I have a damp patch one meter diameter from a leak through a party wall (from pipes in the floor of a flat one up and one across) The damp starts about 6inch below ceiling level. My patch is repeated in the adjacient flat.
The plaster is one coat, dark grey half inch thick onto red brick, then painted. It seems to be soft on a trial area. Will it ever be okay to dry out, clean up and over paint, or should it be hacked off and replastered for a lasting job?