Has damp gone?

Probably due to using PVA, which is not a good thing to use under paint as it stops it sticking. There are proper paint on stain blocks to use underneath paint.

Oil based undercoat should cure the problem if it's just salts residue

seldom a good solution

not a good idea

is it falling off? is it exuding crusts of salt?

Bodge jobs like this often make things worse.

NT

Dear Brad If the wall is wet from outside and is say 9" solid it will take the best part of a year to dry out not two weeks PVA is re-emulsifiable and blockers would be best to paint on once the wall had dried and you know it is not gone hygrosopic on you I suggest scrape off what you have put on down to bare plaster and for a distance around that is damp using a damp meter wait till it dries (if you have to one coat of light emulsion) and check with regular montioring using a meter and mapping the damp drying with a measured location recording When dry decorate if it varies with the RH it is hygoscopic and you will need to get shot of it It is likely this will have happened with gypsum plaster but if it is lime you have a better chance of it drying out

Chris

heck of a lot quicker to paint it with distemper now and forget it. Distemper wont stop it drying.

NT