can i use 2x6's for floor joices on a 2nd floor of a barn?

Question

the barn is 16x32 and the large 15" square beams span the width of the barn at about 10.5' oc intervals....can i run 2x6's to the beams as floor joices?

Answer 1

With a standard residential live load of 40 pounds/square foot, a #2 doug fir 2x6 is rated for a span of 9'-11" at 16"oc, and 10'-11" at 12"oc.

That's sufficient for a standard residential-space type of use. But if you'll be storing hay or feed there, you could only go 3 bales high of green alfalfa, or 2 sacks high of 100 pound feed sacks without exceeding the 40psf spec.

To handle a stack of 100lbs feed sacks stacked 6 bags high, you're looking at about 100psf live load, and you'd need either 2x8s@12oc, or 2x10's@16oc. For hay, 100psf would handle a stack about 6 bales high.

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editorial-
Sorry, but I just gotta say it -- there's a lot of people here who are simply talking out their a$$e$. This is physics -- either look up the tensile strength and modulus of elasticity for the wood you're using and do it the hard way (Dad's a rocket scientist - this is his idea of fun), or look it up in a joist load schedule (again, specific to the wood you're using - there's a big difference between, say, white pine and doug fir). There's a fair amount of safety margin in the load schedules - but you said it's a barn, so I'd plan on *somebody* putting a heavy load up there - if not you, then the next guy -- unless access to that area is such that you couldn't get anything heavy up there. That's why I gave you numbers for both a standard residential load and the 100psf load.

Answer 2

A tough question without knowing the weight the floor is expected to carry and what type of flooring you intend to use. The average floor joist used in housing is roughly a 2 X 10, generally spaced 16 inches on centre. However, since you are only spanning a distance of roughly 10 feet, that would definitely be overkill. I would suggest using 2 X 8s or a similar dimension in a manufactured joist, which every is cheaper. Better safe than sorry.

Answer 3

All valid answers so far. They Keyword was/is "CAN".

Certainly, to directly answer that Q, "YES". Is it wise to do so? Probably not. Is it a code issue at all? Perhaps even if not adding 2 or 4 inches just for the peace of mind factor might be prudent. Most suggest what weight will it have to support? beyond whatever flooring you add to the beams/joists/rafters.

I don't do physics, but it seems at least one answerer does, and perhaps in the end the minimal extra cost for the added beam depth, will just be a comfort/safety thing, as opposed to weighing everything you put on that level.

Steven Wolf

Answer 4

This is a local code issue. Check with the building inspector office.

Otherwise yes it would work for a no payload condition, however if you intend to put an office with furiture or bails of hay stacked in dense areas do not do it. You will at the least end up with floor sagging. Run either 2x8 or 2x10 depends on what your load plan is.

Answer 5

since it is a barn it is probably not a code issue due to being away from city limits.
it depends upon the weight you are planning to put on it and how closely spaced they are.
be sure existing structure can also support the load and is in good shape.

Answer 6

Check with a Building Inspector. Depends on what you gonna pout up there too. You could use 2x8

Answer 7

No...Use something stronger, like a 2x8's or 2x10's Better having an overkill then to be sorry later. It will cost you more, but how would you feel if it collapsed . Think about it.

Answer 8

it depends on what you are going to put on the floor.