Colin Swan wrote in message ...
Although you can get interior damp-proofing treatments (or gloss
paint) that stop residual dampness affecting decoration, if the source
of the damp has not been fixed, then you will just seal the problem
into the plaster, which could make it worse.
SBR latex polymer is probably a more efficient sealer than gloss paint.
Unless the water is entering at one specific point I reckon it can get out
the way it came in, throiugh the masonry. In my case I think the mortar and
plaster are acting as a wick, and lining paper is just an extension of that.
Shorten the wick and, hopefully, you reduce the amount of water. Sealing the
inside is always a bit of a gamble but attending to it from the outside may
not be possible.
I'm doing some experiments on my gable end wall at the moment so we'll see
how the latex stands up to the next lot of driving rain.