How to secure plasterboard in place on ceiling to apply filler

[Steve111111]

Electrician moved a light switch for me. He had to cut out the slabs in a few places to fish the cable around to the new location.

The cutouts on the wall are fine but there's one on the ceiling that I'm struggling to fill in.

There's empty space above it so when I apply the filler it pushes the piece of slab up. I can lower the piece of slab to be fairly flush with the ceiling but as soon as I apply the filler it moves up.

I did try to just do the edges bit by bit, to have the filler sort of act like glue to hold it in place before doing the rest. That sort of worked but as soon as I tried to sand it the slab pushed back up.

There's nothing above the cutout so there's nothing that I can screw the slab to. Any suggestions?

 

[Harry Bloomfield]

Screw a screw into the centre of the piece, apply the filler to the edges, pull it down into place, and let it set. Once set, remove the screw, and fill to level.

 

[23vc]

Or cut a bit of batten a couple of inches longer than the hole, fix it across the top of the hole either by glueing or a couple of screws up into it, then screw the piece onto it

 

[Steve111111]

Screw a screw into the centre of the piece, apply the filler to the edges, pull it down into place, and let it set. Once set, remove the screw, and fill to level.

I kind of tried this already, but without the screw. When I tried sanding it the piecejust pushed up. The filler wasn't strong enough to hold it in place. I did use a strong filler (ready made one) though hoping that it would hold it in place better but unfortunately it was harder to sand, so maybe I just applied too much pressure.

Or cut a bit of batten a couple of inches longer than the hole, fix it across the top of the hole either by glueing or a couple of screws up into it, then screw the piece onto it

I'll try this batten approach. Seems logical. Thanks