2-3cm slivers of plasterboard possible?

[jfsoar]

I've installed velux windows between roof trusses and plan to box them in and get a plasterer to skim them while bonding/ skimming over the artex on the rest of the ceiling.

However I've messed up slightly and cut the ceiling plasterboard right flush to the joists. The rebates on the windows for plasterboard are about 2cm - 3cm in from the rafters give or take, and not equal on each side. I was hoping to box in with vertical side walls, but this will leave a ~2cm gap on each side of the light shaft between the vertical plasterboard and the existing artexed ceiling.

Is it possible to cut a 2cm strip of plasterboard and use it in the gap? (I'm assuming it would crush to bits when screwing it in, but I suppose I could glue it?). Any way I can dress it for plastering without having to replace the whole ceiling board or having the plasterer insist I overboard it?

The alternative is to have slightly flared side walls, but as the windows sit slightly differently between the trusses and not directly in the middle, it might look a bit "off." It's 2cm over about 1m at the high end and probably about 40cm at the low end, so I reckon it's enough to be noticeable.

 

[SFK]

Don't screw - Cut 2cm strips and no more nails it in place.
SFK

 

[jfsoar]

Thanks -- will go for it then.