Hi All,

I know this thread has been covered before but I am going to throw up a suggestion on how to fix it and to hopefully get you ideas on if you think it mafbe a viable option...

I have a sagging gyprock ceiling that was a little water damaged after intalling some roof battons to for a built in wardrobe i noticed the gaps and now I have had a good look at it underneath it is quite evident... I have got underneath and pushed the sheet and it moves about 15mm over a 2 mtr area x about 500 wide i tried to nail and screw but the sheet just pulls straight through

My Solution idea do you think putting a cut a blade length wide in the sheet length ways in the middle where the sheet is sagging to aleviate some of the stress in the sheet and get in the roof glue prop it up from underneath then fix either side of the sheet and tape join the cut!!

Just an idea any ideas Rod please please

Hi patty.

From what you have described you have a fairly bad sagging problem cased by water. The problem is when plasterboard gets wet, sags and then dries in a buckled position it is very difficult to get it flat again if not impossible.

Your best bet is to cut out and replace the damaged section of if feasable the entire ceiling. It is not that difficult to do.

Old fibrous plaster ceilings straighten up agian much better than plasterboard.

Even if you were to prop the ceiling you would need to fix every 150mm or so to get the buckle out where it is fixed to a joist or batten. The problem is it likely that it will still be buckled between the joist where you have no method of nailing or screwing to hold it in place.

If really had to straighten a buckled ceiling, I would wet it again from the back and let it soak in for a while, then the board will be flexible enough to be propped back into position. I would use quite a few props and cross members to get if nice and flat. Then let it dry in that position. Once it was dry I would then screw it off along the joists, before removing the props.

Scrimming from the back if possible would not be a bad idea either.

Cheers Rod.

__________________

This might work for you, I've done it the past with good results. Jack up the ceiling from below (using a car jack a 4x2 post and a board to spread the load at the ceiling) until it's flat against the joists. You will be able to see if the ceiling buckles out some where else. If all is good then fix it to the joists with screws at least every 120mm-150mm, don't miss any joists out. The more screws that you have the less weight each screw carries and so the less likely the ceiling is to pull through the screws.