On Nov 13, 6:39*pm, "Phil L" wrote:
The Nomad wrote:
Evening all,

The room is an extension, single story with a flat roof (yes I know!)
approx size is 6.6m * 5.3m (with a corner cut out) the joists run
across the short edge (there is a RSJ from the corner of the cut out
to the short wall to which the joists 'join'). *There was no
insulation at all hence it was so hot/cold, I've almost put that
right.

The question si as the joists are 15" centres - not a divisor of
standard board sizes, which way to run the boards and should I/ do I
need to nog the joins/edges of the boards?

My feeling is I need to put quite a bit of wood in there to support
board ends/edges to prevent sagging.

As a follow up question 9.5 or 12.5mm board?

TIA

Have a good week-end

Nick

Firstly, if you've never plated a ceiling before, you aren't going to be
able to get it good enough to just tape the joints, it will need plastering.

its not that hard, if youre decent with filler.


NT