Hi,
We have an Airey House and have a problem with damp patches occurring in very cold weather conditions. This problem started about 15 months ago. The patches appear when it is snowy or frosty outside. They are only appearing in one of the upstairs bedrooms, which has two external walls (east and south). We live in quite an exposed position in the West Yorkshire Pennines. The patches are mainly appearing all down the corner of the room where the east and south facing external walls meet. There have also been some lines of damp patches on these walls, which I think are in line with the steel uprights inside the wall.
There is not a problem with water ingress generally: we get a lot of heavy driving rain up here but the problem only occurs when there is snow or heavy frost outside. We had a new roof about 12 months ago. Viewed externally, there is no obvious damage to the corner panels.
Strangely, the damp only affects the walls on the first floor and not the ground floor room underneath, even though this has the same exposed corner.
The only possible explanation we can think of is that extreme cold causes condensation to form on the steel uprights and this is seeping through the walls, but we're not sure if external wall insulation (which is quite expensive) would solve this. Would be very grateful to hear if anyone else has had a similar problem or can think of any solution/suggestion.
Thanks, Katherine