Plasterboard Ceiling Cuts

c1j2w3f4 · 25 Oct 2025

Good evening all!

We are in the process of carry out an extension, and I’m just about to plasterboard the ceiling. Annoyingly I have a room 3700mm wide, with space each side of the lantern of 1350mm. Obviously this means a 1200mm board won’t quite get to the edge of the lantern. The red dimension line on the attached image shows where a 1200mm board would get to.

My question is, would you install a 1200mm board from the wall, followed by a strip to cover the tripled timbers, or would you split two boards (say a 600mm and a 750mm) to equally cover?

Any advice would be much appreciated!

Thanks

endecotp · 25 Oct 2025

The boards must ends on timbers. Does a 1200 mm board land on the first of the tripled timbers? If it does, do that and then fit a strip. You can’t use 600+750 as you suggest without fitting an additional noggin for them to join on. Note 1200x2700 boards are available; 2 x 1350 = 2700.

23vc · 25 Oct 2025

Ceiling boarding long edge doesn’t have to land on a joist. But yeah, 1220 plus strip gives more supported edges than 2 other random sized pieces.

noseall · 26 Oct 2025

c1j2w3f4 said:
Good evening all!

We are in the process of carry out an extension, and I’m just about to plasterboard the ceiling. Annoyingly I have a room 3700mm wide, with space each side of the lantern of 1350mm. Obviously this means a 1200mm board won’t quite get to the edge of the lantern. The red dimension line on the attached image shows where a 1200mm board would get to.

My question is, would you install a 1200mm board from the wall, followed by a strip to cover the tripled timbers, or would you split two boards (say a 600mm and a 750mm) to equally cover?

Any advice would be much appreciated!

Thanks
View attachment 397022

Put an end catcher in - a piece of say 100mm x 50mm laid flat, so that you have decent meat catching both boards. We ignore the lantern and let the boards fly past, then trim them in place (as each board is fitted).

c1j2w3f4 · 26 Oct 2025

My worry now thinking about it is the small strip on the trimmers might have a noticeable difference in level / height due to the hangers? Or am I just overthinking this and the plasterer will sort ultimately? Just thought larger boards would help spread any hanger-related discrepancies!

Thanks all for your advice so far!

23vc · 26 Oct 2025

I’d knock it back with a wood chisel, if it’s quite bad you’ll risk the board breaking/bulging at that point. Not the end of the world tho either way.

Or if you’re on about the metal hanger itself, not much you can do other than a couple of whacks with lump hammer to flatten it up a bit

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Plasterboard Ceiling Cuts

c1j2w3f4

endecotp

23vc

noseall

c1j2w3f4

23vc

DIYnot Local

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