Jus re skimmed a bungalow pva'd all walls a skimmed thru like a million times before, 2 weeks have passed an customer has started painting an I get a call about blown plaster I pop in an on 2 walls its like the paint has soaked in an the skim has blown in patches... I've never had this before.. Any ideas as to what may have caused this!? I've hacked the 2 walls off today an used febond blue grit an going to re skim them tomorrow.. Bit embarrassing