Overboarding in landing

[Jupiter01]

I am planning to overboard my landing ceiling.
The section that curves around has a joist running parallel to the wall but around 25 cm away from the wall. I’ve tried to indicate it with a yellow line in the pic. There is no joist next to the wall and hence no fixings can be put in at the end of the plasterboard. I hope this explanation makes sense.

How can I deal with this?

 

[23vc]

Assuming you’re not boarding the walls, you could try and fit more support from within the loft.
But if it was me, I’d probably just crack on, and give that side some foam/adhesive on the existing ceiling to help it stay up.
Scrim the corner if you’re also skimming the wall. Be prepared to caulk it after if not

 

[Jupiter01]

Assuming you’re not boarding the walls, you could try and fit more support from within the loft.

A few timbers going across the joists that I can screw the plasterboard into?

I think without this, the plasterboard will sag over time.

 

[23vc]

Yes, just span few battens across from that joist to the next, or on top of the wall

 

[Jupiter01]

Ah, can I just rest the batten on top of that wall with one end screwed to the joist?

 

[23vc]

I’d fix both ends

 

[Jupiter01]

I’d fix both ends

I was thinking that if I could rest one end of the batten on the wall, I can do this from below using a multi cutter. Access from the loft will be tricky as it’s boarded…

 

[23vc]

Do that, plus the foam/adhesive along the margin to stick to existing ceiling and it’s not going to go anywhere