Hi there, newbie posting!
My house has a damp plaster issue I have been unable to solve, and am wondering if anyone can advise?
The rooms are well ventilated with bedroom windows opened each morning. There is an extractor fan and opening window in the bathroom. I have even tried a dehumidifier to no great effect. I have had a builder check the external window seals which he informs me are in good condition.
Yet, as per the photo, there is a definitive line of damp all around the upstairs windows. Can anyone advise if this is moisture from inside or outside, and best possible remedy?
Thanks in advance.