I’m building a shed sized 10′ x 24′ with a wood post on embedded concrete pier foundation, 4 posts per side so approximately 8′ between posts. I’ve sized the the floor joists as 2×8 for the 10′ span. My original plan was to have (2) 2×8 built up beam around the perimeter, flush with the floor joists, to transfer the loads to the posts and foundation. When I submitted the plans for permit they were approved but the permit reviewer changed all the (2)2×8 to (3)2×10 based on the girder/header chart in the residential code (R602.7). My problem is that the lowest that chart goes is for 20′ wide buildings, and this just seems like overkill.
So I went to Forte Web to assess the loads on the beam and I get a pass with SYP No. 2 (2)2×8 floor girder. See the attached load report. Am I missing something? The only thing I could think of is if this is not accounting for the weight of the wall that will be on top of this beam, but I thought that’s what the dead load was supposed to cover.
Has anyone had experience submitting the results from Forte Web to code official without having a structural engineer’s stamped drawings? I know they will accept structural calculations, but this seems much more intuitive. I sent the permit reviewer the Forte report on the beam but he hasn’t acknowledged the results in my conversations with him.
Any help is greatly appreciated.
Fine Homebuilding Recommended Products
Spyder Stinger Spade Bit
Insulation Knife
Bluetooth Earmuffs
Nitrile Work Gloves
A Field Guide to American Houses
Replies
To answer your question... yes, I've successfully used Forte to have a structural plan approved. It depends on the building official. There's certainly guys out there that say either demonstrate compliance with a code-approved chart or it needs engineer/architect review.
Is this a battle worth fighting tho? If your plans were approved and this change in the beam size was a condition, I think I'd just say thank you and do it.
The way you set up the Forte calc looks ok if you don't have any doors or windows in the long walls over the beam.
Mike - thanks for your reply. The code official had refused to review the forte calculations, so we struck an agreement - keeping the (2) 2x8 girders, but adding a post so that the post spacing is reduced to under 6'. This is much more efficient from a material standpoint than beefing up the girders. I guess the acceptance of the forte software calculations is up to the individual code official.
I think in the end you have two choices to be safe: get an engineer's stamp or over-design. Sounds like an extra post is by far the cheapest option.