How can I tell the difference between penetrating damp and condensation?
I'm in an end of terrace house and my bedroom has stains on the corner of the two outer walls at ceiling level. I have felt it and it doesn't feel wet and it doesn't look like mould, it's more orangey than black. How can I tell for sure if it is penetrating damp or condensation and what's the best way to deal with it?
Thanx!