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bintopo
05-31-2010, 09:54 PM
Hi,

I'm planning on building a shed and I'm wondering what is sturdier, 2x6 every 12" or 2x8 every 16"?

Thanks
Brian

pushkins
05-31-2010, 10:03 PM
I'm assuming your talking about floor joists for your shed. What is the span your looking at ?

bintopo
05-31-2010, 10:26 PM
Yes, floor joists. Just 9x12. I'm planning on using four 8" concrete posts with laminated 2x8x12's for support beams.

Brian

manhattan42
06-01-2010, 07:06 AM
Hi,

I'm planning on building a shed and I'm wondering what is sturdier, 2x6 every 12" or 2x8 every 16"?

Thanks
Brian

2x6 #2 SPF lumber at 12" on center can span 10' 3" with a 40 psf live load and 10psf dead load.

2x8 #2 SPF lumber at 16" on center can span 12' 3" with the same loading.

This means than even at wider spacing, 2x8 lumber is 'sturdier' and will deflect less than 2x6 with narrower spacing.

In fact, you can use the 2x8 at 24" on center and achieve the same 10' 3" span that you can get using the 2x6s.

pushkins
06-01-2010, 07:08 AM
If it were me I'd be using the 2x8's treated as my floor joists. (2x8's can span up to a max. of 12'3", I like to keep mine at 9 (ish) feet).One thing I cannot stand is a bouncy floor, 3/4" treated ply flooring would be my option for the floor as well. Another thing to think about is adding blocking perpendicular to the joists to support the sheets of flooring at the joints, this really helps with the flooring flex especially if you have a lawn tractor that will be stored in there.

bintopo
06-01-2010, 09:04 AM
Thanks for the great advise.

Since the floor joists will only be 9' in length I should be able to do 2x8s with 16" centers. I will use 2 support beams of doubled 2x8s and 3/4" plywood and everything will be pressure treated.

I like the blocking advise in supporting the plywood sheeting. :)

Is there a web site where can I find the technical information that was listed?

Thanks
Brian

pushkins
06-01-2010, 08:30 PM
By technical info. I assume your referring to span calculations.
The link I've posted is a pretty good one for basic spans, use the drop down lists to enter data then click on calculate.
Remember these numbers are for "maximum" span.

Maximum Span Calculator for Joists & Rafters (http://www.awc.org/calculators/span/calc/timbercalcstyle.asp)