In article ,
"Andrew" - says...
Just had the exterior of a Victorian house repainted/re-rendered. The solid
walls
are about 450mm thick. There was penetrating damp on some of the inside
wall.
These walls are still damp but we assume that it will take some time for the
the
brickwork to dry out. (In fact some of the internal damp seems to have got
worse - probably because it is now less easy for trapped damp it to escape
externally).

The building is about 15m high. Damp occurs at all levels. How long is
reasonable
to wait before we can expect the inside to be dry, assuming the source of
damp
has now been eliminated? The building is well ventilated and it is not
condensation.

Unless you rendered with lime mortar and painted with a porous paint it
quite possibly won't go away at all.