Thanks for your reply. I'd love to believe that the damp meter is inaccurate, but the patch does still feel pretty cold and damp to the touch. I'm prepared and would love to believe it's slowly drying out, but to be honest it's an act of faith! I'll try what you suggested though. Thanks again.
Hi. I have a damp patch on the ceiling in our early 20th C cottage. It began to appear over a year ago, very gradually getting bigger, emanating from a corner between an exterior wall and an exposed beam. Readings from a digital damp meter are around 55-60% at the worst point and drop to about...