Timber for ceiling sizing

[BrianMa]

Hi,

I've had a good look at joist sizing tables but none seem to account for my, non-load bearing situation.

My garage is 6 x 7m and I'm building stud walls around the perimeter (I will insulate and cover in ply wood). Now I'm looking to spec a ceiling and need to size beams.

They will need to span 5.8m unsupported, and does not need to be load bearing except for the ply wood, fluorescent light fittings and some insulation.

I'm assuming C24 and 400mm centres.....but very much open to other suggestions!

Thanks in advance!

 

[freddiemercurystwin]

Why can't you use the roof structure?

 

[BrianMa]

Why can't you use the roof structure?

It's steel and metal profile sheet building. The roof it a very shallow angle and nearly collapsed in the snow of 2011. I've replaced the main structural metal beams as they bent at that time and put in a horizontal tie-rod as there was no horizontal tie before.

I don't think I want to put any weight on the roof structure, if possible.

 

[^woody^]

non-load bearing situation

You're not planning on supporting any snow or dealing with wind load then?

75 x 200 are at their limit @ 400 c/c so you may need to go with 75 x 220

 

[BrianMa]

non-load bearing situation

You're not planning on supporting any snow or dealing with wind load then?

75 x 200 are at their limit @ 400 c/c so you may need to go with 75 x 220

There will be no snow/wind. It will be totally free standing and independent from the roof.

Is the specs that you're quoting for non-load bearing?

 

[endecotp]

I'm building stud walls around the perimeter (I will insulate and cover in ply wood).

Wouldn't a non-combustible material, i.e. plasterboard, be a more conventional choice for a garage wall?

 

[BrianMa]

I'm building stud walls around the perimeter (I will insulate and cover in ply wood).

Wouldn't a non-combustible material, i.e. plasterboard, be a more conventional choice for a garage wall?

To be honest I had not considered combustibility in my material selection......I was more concerned with plasterboard getting wet at some point, you do make a good point though!

 

[foxhole]

For the walls osb over clad with plasterboard will give a good surface to fix to , shelving etc.

 

[BrianMa]

Does anyone else have a table that you can adjust the imposed load to zero? Or a formula of how to work it out?

Being a ceiling and with nothing above perhaps greater deflection is acceptable...as long as visually it does not sag?

Edit - Found this, page 27: -


C24 47x220 at 400cc = 5.93m max span (Imposed load and dead load <0.25kN/M^2 each)

Does anyone see any fault with this? Just need to find a supplier now, any online suggestions?

 

[BrianMa]

Any final input before I order the wood this week.

Thanks in advance