We have moved into a house where the drywall walls were painted about 15 years ago.
When I paint over these walls, the existing paint develops patches of bubbles and peeling.
So, I don't know whether the cause is walls that were poorly primed in the first place, but I guess it doesn't matter so much as what I need to do now to repaint. Clearly I can patch the specific areas which have peeled but I would like to avoid this as much as possible.
Is the best thing to do to re-prime before painting? If so, should I use diluted PVA or is there a better alternative?