We have just purchased our first house (hooray) and uncovered a few gremlins the home buyers report failed to pick-up.
There was some damp on the wall behind a sofa in one room (which failed to get noticed by surveyor) and in the corner of the same room.
We had a damp expert visit and hack-away at the plaster, apply DPC, lay a water-proof paste (bitchumin). Wait 1 week to dry then plaster over.
However the problem lies in the corner of the room (external wall) where moisture is still visible, almost forming where the DPC injections were placed. Now i'm not sure whether this is the silicone of the DPC seeping through onto the painted surface, or whether damp/rainwater is slowly still seeping in from the corner (the damp in the corner was mild before).
Any advice is appreciated!