I've have chipped and scraped the layers of crap off my bathroom ceiling, paint,artex, paper, paint in that order... The surface is a tad patchy to say the least. Some bits are paint, sone plaster some plasterboard. I gave it a coat of pva (diluted) but for some reason the test area of skim coat (practising - I'm no plaster yet). ;-) was a bit uneven.
Went on ok but was very rippled - like a beach where the waves have ridged the sand. I've patched walls elsewhere and made a pretty reasonable job of the skim coat so have to put it down to the surface.
It looks like some areas have dried as they would on plaster etc. but the patches of paint were "wet" so weren't drying at the same rate.
This is strictly a practise ceiling but I didn't want to faff about removing the plasterboard, moving the loft insulation and all the messing about that involves.
Would a neat coat of pva be better to cover/prepare the patchiness or give up and stick up a new layer of thinner plasterboard over the top and skim that etc. ?
Mark S.