Overboarding lath and plaster ceiling - overhang issue

[tomnewcombe99]

Hi, I am plasterboarding a lath and plaster ceiling on a 1930s property. I’ve located all the joists so one side of the room the joist is right where the wall meets ceiling so perfect as can screw board in with no overhang - however on the other side the last joist sits about 5-6inches from the side of the wall so there will be an over hang on the 12.5mm board.

So not sure what to do. Is 6 inch overhang too much and assume I can’t screw into the laths?

I thought about a backing strip but the wall height ends where it meets the lath so nothing to screw that into. Any help appreciated

 

[JohnD]

I have seen the flapping end of plasterboard stuck to the side wall with pink expanding foam. Although that is good for sealing gaps, you would get better support from screwing a batten to the wall.

 

[endecotp]

I think you’ll get away with it.

 

[danfre]

Fix a 2x2 timber to the joist.
You will have less of a gap

 

[tomnewcombe99]

Thanks! But if just put a 2x2 to the joist it will alter the height of my ceiling?? Also the room is about 8ft long so I would need to remove all the ceiling to expose the joist to drill into or am I thinking of that wrong

 

[danfre]

Fix it to the side of the joist
Use 2 x4 foot sections.

 

[tomnewcombe99]

I mean it would mean having to expose all that section of the ceiling so proper messy job and then trimming all the laths so I can attach the 2 x 4 to the joist but I’ll have a go

 

[JohnD]

I think you would just whiz off the ends of the laths in a strip. Maybe using a small circular saw? With minimum pressure and vibration or more of the plaster will fall off, which is filthy. Leaving the old plaster up, if it is not sagging, will retain the very good noise blocking.

I was thinking more of tilers batten screwed to the wall but 2x4 to support a few inches of plasterboard is overkill. You just want to stop it moving and cracking. Do you have access from above? That would be easier.

When I found something similar, there was an unexpected plaster crack along the edge of the ceiling. I went into the loft and found the unsupported edge, cleaned out the gap and ran pink foam into it.

 

[danfre]

2 inch square timber, in 4 foot lengths.
Not 4x2 timber