How to deal with old PVA mist coat on bathroom plaster

[Cocora]

Before someone start yelling at me: NO, I didn't. But sadly the people I got my house from did, and now the bathroom paint is peeling off.

I was wondering what is best: applying zinsser base + paint on top, or I need to take a more drastic approach like sanding it/using other products to remove the PVA coat completely?

If it's Zinsser, seems like from the last time I used it, the family has grown like crazy! What would be best for a humid northern bathroom?

Options I'm thinking about are:

1 - Peel Stop + BIN Aqua
2 - Bulls Eye 1-2-3 + Normal Bathroom paint

I would really appreciate any help!

 

[Wayners]

If PVA was the good stuff and waterproof PVA it's fine to emulsion over. Well if it was thinned with water first.
In saying that I don't think you could apply without adding water tbh.

If PVA was the cheapest stuff that has been known to cause a problem. It's plastering PVA and will become sticky again if water or wet plaster is applied. If this type of PVA is emulsioned then it could cause problems.

Test with a damp sponge. See if it becomes sticky again.

If you want to prime it use gardz.