Quote Originally Posted by Tacoma John View Post
I am with Ordgen on this one, water is the problem. It is destroying the plaster. Concrete is porous, the water is coming in from the outside. By running the ac, the walls are cooler inside than out and the water is condensing on and in the concrete, thus destroying the plaster. If paint will not hold up to this problem, what makes you think wallpaper will?. Best way to handle the problem is to install a vapor barrier, attach wood strips and drywall over it. Any other fix will only be temporary. Sorry
Thanks for your advice.

There is no water condensation on wall. I have removed some peelings to check. It is quite easy. Touching them with a knife whole piece dropped down. Afterwards the old wall reappears, smooth and dry with little bid chalky.

Another idea comes to my mind. I'll start another posting.