Hi, Just after a bit of advice on the way forward and if it needs anyone to look at it. On the internal wall between us and our neighbour, there are damp marks. It's a mid-terrace from the early 1900s. There doesn't seem to be any particular pattern as to when it gets worse, but we first noticed after we had plastering done when we moved in two years ago. They're halfway up the wall, so doesn't look like rising damp, and run in a line along the wall and in the storage space under the stairs (pic 2). Does anyone have any suggestions as to what the problem may be? I'm suspecting as it's an old house there might be gaps in the brickwork, and don't really want to call a damp proofer out. Pic1 Pic 2 Thanks.