Duncan Lees duncan-at-snsys-dot-com wrote in message ...
Good idea about the insulation, I'd not considered that. Might as well
do it since the wall will need replastering anyway. Any idea why the
plaster in the rest of the house isn't doing the same though?

At a guess I would say because they have had less time to weather. Day
and night temperatures for them will have been pretty constant and
there will have been no damp on the other side of the wall. Lime
plaster is ok for decades only because it was breathing the damp away.

After the insulation all that ability to breathe will end as the
internal air will no longer be so warm. Your house was keeping dry by
heating the atmosphere. I don't know if this means you will need to
vent or polythene. Or both.

Or not.