A damp patch has appeared at the foot of the wall between my kitchen and dining room. This is on the ground floor and nowhere near an outside wall. I originally thought it was condensation from the freezer being too near the wall as it appeared on the kitchen side - I moved the freezer away, but the damp is now showing on both sides. there is a radiator on the dining room side but no signs of it leaking. Water pipes run through that wall. What type of tradesperson do I need to diagnose and fix the problem?
