Peeling Ceiling Paint

Hi,
making a new bathroom. Rubbed down existing ceiling; patched holes etc; gave a watered down coat of PVA to seal; went to roll on water-resistant paint and sections of the old exisitng paint peeled off with the roller or have bubbled - not all of ceiling just 10 or so sections 3" x 3" ish. Any ideas to overcome this welcome !
Thanks
Dbleman

Probably down to the PVA as it is not regarded as the best sealer for painting over.

A coat of watered down paint (10-20% water) would have been better to seal the patches, especially in a bathroom.

It could be that the old paint wasn't adhered well enough, but more likely that the PVA was 're-activated' by the new paint which then peeled off the old. It may also be that there is moisture in the boards/plaster underneath.

Remove flaky paint, ensure surface is dry and do any necessary filling/feathering in. Rub down and apply mist coat (as above) over the patches and allow to dry completely. Your topcoats should then cause no more problems.

Thanks will give it a try.
Dbleman