Yes, we share walls. It structured that 4 units make a square, and meet in the middle. So I share 2 walls with 2 other units. Does that make sense? No units above or below, its a 3 floor town house.
It seems to be wet a few days after it rains, and not while it rains, but sometimes, it can stay damp for many days.
I hope I explain this right, but the stairwell is the area with the wet walls. We have 3 floors. The top floor has the most wet spots, and the half way down the stairs landing has a wet spot thats growing very slowly. There is a full bath on the top floor.
The contractor is stumped. He doesn't think its plumbing, and has a suspicion that its a siding issue? I'm going to have a roofer come look and get a second opinion. Replacing the siding would be a very expensive experiment.
We have shingles for the roof. I will look into what kind. I'm not 100% sure. The roof are going to be replaced in 2012-2013 as a part of our HOA contract.