Was skimming a ceiling today & noticed a patch started to bubble, trowel let the rest of the ceiling up, before leaving scraped the blown bit out (it had cracked a little), &pvad ready to skim tomorrow. I noticed the paint hadn't adhered to the ceiling & was dusty/chalky! Distemper? What's the best course of action here? It may be in ceilings & walls! The skim had adhered to the paint that they'd painted over it with, but the paint they'd painted over it with hadn't adhered to it! If that makes any sense! Lol, and just for the record there weren't any signs of bubbling or loose stuff before hand!