Putty over damp basement wall?

[Gusten_Gnuk]

I have a wall in a basement storage room in a house from 1930. The paint and plaster have come off in several places. The plaster easily comes off in several places. If you knock on the wall, it also sounds hollow in parts.

Can you fill the holes? What should be used then? Gypsum filler? Or something else? How do you avoid the problems? Apply something that breathes better?

 

[Stefan N]

You have quite significant moisture problems, and you should address the cause instead of just plastering over it.

 

[Gusten_Gnuk]

Thank you for the reply! It's an apartment building where I rent a basement space (I'm responsible for the surface layer). I don't know if there are many causes I can do much about.

I don't know if the previous tenant painted with some non-breathable paint that made the situation worse.

You have quite significant moisture problems and should address the cause instead of just plastering over it.

 

[neo11]

One should never use any form of plaster products in a damp environment. Patch up anything larger than 2mm with mortar, brush away all loose paint with a large wire brush or scrubbing brush. If anything sticks out (metal or old hard mortar), chip it away with a hammer. Possibly do some filling, but there is no filler suitable for that environment. Roll on with cheap white plastic paint, preferably for plaster, should work for a couple of years.

 

[Viktor.J]

Fixing that surface is like casting pearls before swine. The homeowner should be keen to drain and insulate the basement.