Joists for a storage space

[Chris French]

Hi,

We have an old stable, brickbuilt, with a pitched slate roof, basically used as a big shed.

Plenty of height, so I'd like to put some joists across part of it to form a storage area - probably board part of it with chipboard flooring and part left open for things like the scaffold tower sections, length of pipe etc. It will probably be the lighter, bulkier stuff stored up there, heavier stuff will stay down below

But umming and ahhing on the on the joist size, as it's not something I really have experience of. The span is about 4.4m - 4x2 sounds a bit flimsy for that. 6x2's at 600mm centres with 22mm chipboard flooring?

[Tim Watts]

You want to have a look for Superbeam and run a trial copy - that'll help you be sure.

But for a finger in the air:

600mm spacing is too big from experience - will be a bouncy as hell. 400mm is the norm and 500mm will be "just about get away with it". 4x2 over 3.3m is passable for light loads. Very light loads, like a loft floor. 8x2 would be pretty passable for medium loads. 6x2 might be passable for again light loads.

Any reason not to go up to 8x2?

[Bob Minchin]

Domestic floor rule of thumb is divide span in feet x 2 and add 1 to give joist depth in inches. this is for 16" or 400mm spacing and 2" wide joists

So that is about 8" x 2" for a full domestic floor.

6x2 would be too weak but 8 x2 on 500mm would possibly do but a pain for sheet flooring with 8 x 4 sheets.

Up to you where you draw the compromise.

[Chris French]

Thanks

Not really, other than not wanting to spend more than necessary.

I don't really expect to walk on the area - just go up and down a ladder to store stuff. Initial plan is to put joists over about half the useable area across one end of the building - basically to take a 2 .4m long length of flooring - and then maybe board half of it - so about 6 m2 of boarded area

[tabbypurr]

2x6 is fine over 4.4m for a house floor, at 16" spacing. Lighter than typical, but no problem with heavy loads. If you were using it as industrial duty storage I would definitely go bigger, but with normal domestic goods floor to ceiling its enough.

If you want to pinch the pennies, an upright halfway can really help.

For real penny pinching you can get away with scrap half inch chip as flooring. Use 2 layers staggered & glued for passable strength, avoid small pieces and spread heavy loads over joists.

NT