Hi, I'm looking for some help. I recently had a stippled ceiling plasterboarded over, however, there are a number of areas where joists weren't available to screw the boards into, apparently, and they are not level with adjacent boards. Can anyone suggest a solution to this? Would plasterboard fixing screws work to pull the two (existing ceiling/new boards) together and stop the sagging/pull these in line. I can't get hold of the guy who did it so I'm at a bit of a lost end in that respect. Any help is really appreciated. Thanks.