DIY Doctor UK DIY Forums

hi there, I have an apartment (1880s building) with two disused chimneys. when the cold weather set in we noticed the paint starting to flake off the wall on one of the chimney breasts. I asked a builder to come and have a look thinking it might be damp but he said it was more likely condensation, but advised us to sand down and repaint using Zinsser paint. but now I'm confused as looking at all the descriptions on Zinsser paint they seem to be for damp rather than condensation?

we got the room where the other chimney breast is replastered but now there is a water stain on the plaster in this area, I'm thinking that must actually be damp - should I paint that with Zinsser and if so which one? thanks in advance!

Hi mcws,
Surface condensation will not generally blow paint off a wall but it may be damp in the chimney passing through the chimney walls. if the chimney is open, poorly capped or fireplaces have been sealed then this is the most likely cause.
If you want to try sealing in the stain use Zinnser Bin.
Regards stoneyboy

Thank you! I'll give it a try