Temporarily repair Rigips ceiling - plastic sheeting? Alternatives?

Don't think that it will run down

It also sticks to walls, so why not also to the ceiling

Quick and easy solution compared to "sanding everything down and then repainting"

A stupid question: Are you tenants there?

Sort of, the house is family-owned and will probably be sold after we move out. Whoever buys the place will have to do various things anyway. The bathrooms are from the 1970s, and due to the water damage in the intermediate ceiling, it will have to be properly done later anyway, so we're just making it "passable" for a few months now.

Don't think it will run down

It sticks to walls too, so why not to the ceiling

Quick and easy solution compared to "sanding everything down then repainting"

Sorry, but you can't just paint over something that's already coming off on you. That won't work!

Sorry, but you can't paint over something that's already coming at you. That's not going to work!

From the way it looks in pictures, that's not a normal paint but something thicker. If what is currently coming down sticks up there, that would be enough for me.

The problem is more likely to be that it is something heavy that can only stick to the paint which does what? Crumbles off. So everything will come at you soon after. So either screw on another drywall panel (with 25mm long drywall screws, then they go exactly through two panels without drilling through). Or sand off the paint and paint again.

I would simply staple a vapor barrier foil over it…