How to fix a sagging ceiling?

[ivanptr]

Hi,

We have a water-soaked insulation batt that caused the center of the ceiling plasterboard to sag.

We've already stopped the leak before the water managed to get through the batt and damage the ceiling board itself.

Since the sag is in the center of the plasterboard, and we're just rookies, we did some research.

It seems the first step is to use a plasterboard lifter (or T-brace) to push the board back into a flat position ? 

 

After that, we should use Zenith 8G x 50mm Gold Passivated Bugle Head Plasterboard Screws to secure the board back into the timber joists—does that sound right?

But what if there are already screws in the joist? Should we use a scraper to remove the surface layer to find and remove the old screws? 🫠

Then we’ll use self-adhesive reinforcement tape to cover the crack.

Is there a very strong tape you'd recommend for this?

[ivanptr]

@JacobZ @MitchellMc @EricL 

 

Making slow progress—hope that's alright 🫠

  

[JacobZ]

It's coming along nicely @ivanptr.

I'm excited to see it when you are done.

Jacob

[ivanptr]

Good morning @JacobZ @MitchellMc @EricL 

We’ve attached all the battens on the four edges.

The opening size is 177cm x 120.5cm.

Right now, we have one plasterboard panel:
Gyprock 1200 x 900 x 10mm Repair Panel

How should we arrange this?
Do we need to buy two more sheets?
And how much would we need to cut off?

How much space we need to reserve between two sheets ?

[MitchellMc]

Hi @ivanptr,

It would be better to use one 2400 x 1200mm sheet and cut it down to the exact size of the hole. That would minimise the number of joints. Though I understand that it will make installation more difficult. If you are to use multiple smaller sheets, you'll need to ensure, once again, that all their edges are supported by timbers behind them. 

For positioning, the 1200mm length matches your 1205mm opening, which would be the logical way to position it. You'll then need a second sheet cut down to 870 x 1200mm to fill the rest of the gap.

Mitchell