I suppose if condensation collects there it's possible that's the cause. In which case you need a paint that's waterproof as rodabod suggested. Although I'm not sure an acrylic eggshell would be. It's also possible that a moisture Vapor permeable paint would be better as the moisture can travel through the paint, that will only help if the layer underneath is stable.
I suppose if condensation collects there it's possible that's the cause. In which case you need a paint that's waterproof as rodabod suggested. Although I'm not sure an acrylic eggshell would be. It's also possible that a moisture Vapor permeable paint would be better as the moisture can travel through the paint, that will only help if the layer underneath is stable.