I have a damp / condensation problem on a party wall. I live in a single story bungalow - my roof is higher than next doors where it joins and there was a visible crack / gap where rain was getting in between the two properties (the same wall where the original damp could be seen).
We have had the roofing repaired so no rain should now be coming in.
I have removed some of the plaster from the party wall and have observed that the signs of damp have now 'spread' to areas that were previously unaffected (the white areas on the attached pic). This 'spread' has happened over the period of a couple of weeks.
I am guessing this is a sign of a significant condensation problem (the room in question is a spare bedroom which is heated but has no furniture and is unoccupied)
Any suggestions most welcome!