Novice - Plasterboarding ceiling at 600mm centers.

gjowens4

New Member
Hi all,

I'm working on a house with new posi joists at 600mm centers. We will be plasterboarding in the next few weeks. Would a 12.5mm sheet be ok or will it have to be 15mm? There are no noggins and the boards will be foil backed.

Cheers.
 
 
The board manufacturers will say 12.5 is ok, but there is still quite a bit of flex if there is no noggin. 15mm would be better to use. Some pozi-joist are 150mm so in essence, the unsupported span is only 450mm
 
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