Got a small question regarding rising dampness (currently ~2ft high)
on an internal ground floor wall...
The wall itself is around 100 years old, and was ~2 years ago covered
by 10-20mm plaster and then two layers of plasterboard, with the
first plasterboard foil backed (no idea why):
|------------old brick--------|-plaster-|#-p. board-|-p.board-|
The '#' denoted the foil backing.
Oddly enough we have started getting dampness on the wall, with a
dampness meter (when poked into the plasterboard) reading >90%. But
more oddly the old brick wall behind the plasterboards is virtually
dry! If this was rising damp from the ground shouldn't the brick be
wet and the outside plaster/plasterboard progressively get drier??
One dampness expert says "we believe that it is contaminated wall
plaster in these areas" (no further explanation) and recommends a
£600 treatment for less than 2 linear metres of wall...
Another explanation was that the plaster is drying out and expelling
water, and due to the foil backing the moisture has nowhere to go
except to the edge and then out/up. But shouldn't the brick wall
then be equally wet as the plaster?
I first suspected my plumbing but that seems to be all in order...