Damp Proofing

Damp patch on upstairs wall & ceiling

Anonymous user 03/03/2024 - 3.34 PM

Hi there, We've recently moved into an old house (1880s) which has a damp patch at the top of the wall and ceiling of the bedroom upstairs. The damp is in the middle of the house, on the chimney breast. The damp patch is large - the wall is dark and looks more like a dull shadow on the wall rather than a discolouration. The ceiling patch is smaller - after heavy rain it can feel wet to the touch (but not dripping), and after a few days of dry weather it feels slippery and slightly sticky rather than wet. It can also feel a little wet in the mornings, presumably due to condensation during sleep. The ceiling is old lath and when we poked a few holes with a screwdriver no water was released. The second bedroom which backs onto the main bedroom has a few damp shadows also around the chimney breast, but not a large patch. The chimney breast itself is shared with our neighbours, and has two active flues and five disused capped flues. As best as I can tell, the damp patch spans across both a disused and active flue. The chimney breast brickwork in the attic appears dark, but there are no obvious signs of water running across the beams or dripping leaks that we can see. The loft is boarded and we have as yet been unable to see what the state of the insulation is beneath the boards. In our building survey, the damp patch wasn't highlighted and this is perhaps due to the survey taking place in summer. However, the surveyor did recommend that the pointing on the chimney should be redone. When we first noticed that the damp worsened after rainfall, and the ceiling patch became wet to the touch, we arranged some work on the roof to repoint the chimney, repair the flashing, and sort out the valleys where old mortar had washed away. This work has been done in the last week. We know that these things can take a long while to dry out, and so it could be some time before we are able to tell if the work to the chimney has sorted the issue. So our question, really, is whether it sounds from that description if we are missing something that could be causing damp on the chimney breast at the top of the house. Is there a common culprit for this type of thing or something else we should be looking at? We appreciate that these things can be difficult without seeing the issue but any thoughts or instincts for what should prepare to do next would be hugely welcome. Many thanks for any advice!