9mm plasterboard

[GaryinAshby]

Where is it suitable? I'm boarding & skimming both block and stud walls. I've always used 12mm but a friend uses 9mm. Is there any real difference (apart from 3mm and the cost).

Also, the ceiling joists are on 400mm centres. If using 2.4 x 1.2 x 12mm boards, and the edges don't meet on a joist (ie. there is a 2.4 long length, with the edge 200mm away from a joist) is it okay to have the join between this board and the next not supported by a joist if scrim tape is used?

 

[noseall]

we rarely use 9.5mm plasterboards unless depth restrictions mean 12.5mm are impractical. out of a hundred boards i will maybe use two at 9.5mm.

i would not join plasterboards unsupported. this is not to say you can not join them without a joist, just that the join needs a reinforcement.

you can use either fix a noggin or a 'floating' bridge plate. this involves using a piece of ply as a link between the boards, by screwing through the fixed board into the ply allowing the ply to overlap the join and catch the next board. the next board is then be screwed into the ply.

it merely stiffens the join.

 

[PaulJR]

if your joists are at 400mm crs, your joints should all be on joists, that's why they are 400crs and not 450.

 

[gday2uk]

Where is it suitable? I'm boarding & skimming both block and stud walls. I've always used 12mm but a friend uses 9mm. Is there any real difference (apart from 3mm and the cost).

Handy overboarding ceilings as sheets are lighter.