Paint not drying after one week

[baretto]

A bit of background info, I live in a terraced house with an alleyway that runs between my house and the neighbours. When I bought the house, 6 years ago, the survey showed damp problems so the walls in the alleyway were damp proof injected, and the interior walls plastered and painted.

One of the walls in the living room and one of the walls in the dining room back onto the alleyway.
Up until last week the walls in the dining room and living room were dry and had been since the damp proofing.

Last week I had the living room painted and dining room wallpapered. Everything is fine apart from the walls that back onto the alley (the walls which had the damp proofing six years ago).

In the living room, the wall that backs on to the alley is now damp at the bottom to the extent that the paint is still wet a week later.

In the dining room, the wall that backs on to the alley is OK at the top of the wall, but the bottom of the wall is absolutely soaking and the wallpaper is falling off.

I can't understand how the walls have been dry for six years but are now soaking after being painted / wallpapered especially seen as the walls affected have been damp proofed.
Can anybody help me?

 

[joe-90]

Sounds like condensation damp to me. Stop drying washing/towels in the house.

 

[blightymam]

I don't think it's as simple as condensation as condensation tends to be more wide spread than just the bottom of the wall. I would get some folk in to have a look - and the decorator that you hired back in too as he/she should've noticed excess damp. There could be a few things gone wrong, damp proofing failed before (and there are many mixed reviews about damp proof injections and if they actually work or it's a scam) and not been apparent until decorator came in, something leaking outside, gutters, roof tiles, breach of damp proof course, pipes leaking or whatever, am no expert but there will be a cause for the damp and that needs to be sorted.

 

[baretto]

I've spoke to the decorater today, he said the walls were dry before he started work.

I might add that the front window has had a lot of condensation as the living room radiator has been turned off and we have a real Christmas tree.

The wall where the damp is residing is part of a covered alley which is not exposed to the elements. The only way water could get through on that side of the house is from the roof tiles but I would have expected the top floor walls to be wet also, which they aren't.

 

[Grenage]

No radiator, Winter, Christmas tree, external wall.

Money's on Joe-90's suggestion.