I have notice recently that my sons bedroom walls are damp right at the top where the eves are and it is spreading into the next room I notice it after the prolong spell of frosty weather.What might be causing this and how do I fix it

[benjamin041152]

[milliezoe]

The felt under the tiles could have perished if you look at your fascia boards and they have a sort of grey staining this could be the problem

[milliezoe]

What I forgot to say is if the felt has perished you need to take of about six rows of tiles to renew the felt

[bookbinder]

This might have caused the dampness (I had this problem, but, fortunately for me, it didn't leave any lasting marks):
during the v. cold weather, ice built up in my guttering, and it was sizeable blocks. They stood about 2 to 3 inches above the edge of the guttering. They were caused by the snow on the roof melting a bit during the day and the melt water dribbling into the guttering. The flow was too weak for the water to run away down the fall pipes, so it froze in the guttering. This cycle was repeated until said blocks of ice had built up. Melt water still dribbled off the roof, but on to the ice blocks, which were now so tall that they directed the water back, towards the house and over the fascia board and into the roof space. My down pipes were also frozen solid, from top to bottom, so the water had no other escape.
My guess is that that is where your damp has come from, and it is probably still there.
As for how to fix it, I can only say either wait for warmer weather and hope that that cures it, or seek specialist advice, maybe from a firm that deals with damp rot and that kind of problem. A portable heater might be the answer to dry out your roof space.
Best of luck.

[Everhelpful]

Unfortunately you won't be covered by Insurance as it is "Wear and Tear".That is always their "get-out"!!