Non load bearing ceilig joists

[Bogg]

Hi, I am framing a toilet in a shed and am using 90x35 timber for this.
Question - What size timber do I use for the ceiling joists?
I have put up some 40x35 timbers and the length of the joists are 1820mm.
Are these suitable or too thin? My ceiling is non load bearing as there is no roof on it as its in a shed.
Do I need a support beam above the joists I have put in or not?
Dimensions of the toilet frame is 1820mm wide by 2400 long.
Thanks, any advice would be appreciated as I have not done this before and I am using knowledge solely obtained from the internet.
Below is a picture so you can see what I have done and see if its suitable.
Cheers, B
86210

[The Roofer]

Hi Bogg,

The span tables provided here in the Library - say a 120x35 MGP12 Pine at 450mm centres - will allow for you to put on sheet of ply etc for a bit of storage later plus you can hang the ceiling sheets off this too! By the way - on edge - not flat!

Library index is here: http://www.renovateforum.com/f220/index-90136/ and then select TDA Pine Span tables.
86211

[Bogg]

Hi Roofer, thanks for that. I have some timber in that size so I will remove the battens I put up and replace them with the 120x35 on edge.
Cheers, Bogg

[Bloss]

But this is just a frame in a shed so you could use 90x35 and don't put anything on it too heavy - or use the 120. Depending on the thickness of the ply you use for the 'roof' the batten would be enough.

But bugger all cost difference anyway.