"Andrew Gabriel" wrote:

Was the wall damp? The stripper will cause moisture
in the wall to boil, which might blow the plaster.

No, dry as a bone, the lowest areas are at knee height but most of the blown
areas are at chest, shoulders and head height (I am 6'2"), which I assume
would exclude rising damp. The affected walls are internal walls in the
ground floor stairwell and entrance hall which I doubt would be subject to
condensation, and I can't see any evidence of damp from any other source
such as a leaking pipe. The blown areas vary in size from a saucer to a
dinner plate, some larger areas are about the size of 3 or 4 saucers. I got
the impression that the lady who owns this house anticipated there might be
problems; she didn't seem surprised by what happened, and she wasn't in the
least curious as to why. Strange!