I was asked to look at some damp in a first-floor flat today because one of the tenants has been complaining that it was damp. I took along my moisture meter and showed him how it worked so he could test the wall for himself. I knew it would be dry, because the window, a double hung sash window was streaming with condensation. He did, and he found no real damp but he argued and argued and argued that the wall was damp. I tried to explain that he, and indeed you and I give off an awful lot of water vapour throughout the day and for some unknown reason, particularly at night time. This water vapour has to go somewhere and it condenses on the window and on the wall which was becoming contaminated with condensation that is shown up by a black mould growth. I told him to sleep with the windows OPEN, to reposition his bed and to turn the heating off at night. He still did not believe me, so he will just have to suffer until he realises he does need to OPEN the window. Upon leaving I saw condensation elsewhere when I made enquiries it seems that for blokes live in the flat and don't open windows and keep the heating on full. Enough said…   more »