Plaster blowing over screws

Jeepers_Creepers

I was being deadly serious

Yes, I know PVA isn't gap-filling, but it shouldn't need to be - the p'board should be pulled tightly against the joists by the screws, so no gap to be filled. If thinned-down grab adhesive can be forced in there, PVA certainly can. And I think PVA will  be 'wetter' - ie flow into the fibres and paper better.

If you struggle to get the PVA squeezed in through the screw holes, then thin it.

stgermain

Thanks everyone for comments and apologies for the delayed response. So the consensus, such as it is, is to sink screws in around the affected areas and inject either pva or a grab adhesive into the hole left by the miscreant screws before putting them back in (by hand)? 
Any ideas if there's a better alternative to easy fill? I was thinking maybe toupret. 

NSG666

stgermain said:

Thanks everyone for comments and apologies for the delayed response. So the consensus, such as it is, is to sink screws in around the affected areas and inject either pva or a grab adhesive into the hole left by the miscreant screws before putting them back in (by hand)? 
Any ideas if there's a better alternative to easy fill? I was thinking maybe toupret. 

Not quite 'around' but either side of into the timber above - you need to establish which way they run..

I like Poyfilla Easy Sand as it is easy to work with - mix it using water and a bit of the ceiling paint to make a hard stop filler.

Never used Toupret.

Jeepers_Creepers

Yes, the filler isn't to blame here, so I'd also choose one that is easy to sand and blend in. 'Easy-sand' sounds as tho' it should be.

A too-'good' filler could be harder than the surrounding skim, so even when using a flat sanding block, you could see damage being caused to the area around the fill, before the filled bit is flattened smooth.

Happened to me once when filling holes on a tape-and-fill drywall - the surface paper was nicely raised and fluffy by the time I got the filled bits level. I hadn't realised it had no skim :-(