3x3" on 7foot span ceiling ?

I have a lot of 3x3s from old pallets, 70mmx70mm, and spans of upto 2.2w1 meters for my bedroom ceiling.

On top I plan to put a layer of kingspan, and then Ply or OSB, then use it for storage.

Tony Brier wrote: Our old rule of thumb when I was a BCO which matched the tables pretty well was that for floor joists is double the depth in inches and subtract two to get the permissible span in feet; Which would give 2"x4 1/2 " for a room floor

Does the panel think the 3x3s will be OK, how close to each other should I put them/ The loft will never be converted into a room. [george]

Reply to
george - dicegeorge
Loading thread data ...

It'll work. I wouldn't though, I'd glue & screw them to make 2x6s.

If for some reason you do it with 3x3s, 3 rows of noggings supported at the ends would help. Its easier to precut all the 13" noggings.

NT

Reply to
meow2222

e:

he ends would help. Its easier to precut all the 13" noggings.

Or put them in @ closer spacing than normal if you have plenty of them. eg @ 300mm centres.

Reply to
harry

That is for floor joists carrying a normal floor though, not for joists just carrying a ceiling.

Remember floors have to be designed to allow for the parties when there are 20 people in the room, or the bedroom with a row of heavy wardrobes all say on a pair of joists down one side, or the 250kg hot water cylinder or bath etc,

400mm c2c...

What you going to store on them?

at 0.4kN/m load (half what you would allow for on a real floor) you will only get about 5mm deflection on a 3x3 at that spacing used in that way at that span.

Reply to
John Rumm

Thanks but plans changed tonight when talking it over with a carpenter freind and I realised that if I double up the 3x3s with glue and screws then I'd be able to use the loft for storing slates etc when I come to repairing the roof and valley.

[george]
Reply to
george - dicegeorge

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.