Engineering/Framing help! Will this work??
The building dimensions are 26×20′. The client wants to put on a shed roof(standalone). 20ft clear span, no purlins in the middle. They also want 2ft overhangs front and back. They want to insulate the roof with fiberglass batts and rock the lid. The structure itself is an 8×8 beam sitting on 4×8 posts 5 ft on center. Would you use I-joists (TGI), or 2x. I was thinking that by using 2×12 I would get the desired amount of insulation while still being able to span the 20ft easily. Wind and snow loads are not an issue where the building will be(Northern Cal). Am I reasoning correctly? Also, any suggestions for hardware to tie the roof to the frame on a structure like this?? It seems there could be a slide-off factor with a lean-to this large. Help would be appreciated! Trying to work up a design before approaching the officials…
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No one wants to touch this one? It's a simple shed with a large span, right? I know there are half a dozen ways to do it, I just thought I'd see what others have to say. Thanks to anyone willing to respond...
Jack,
2x12 should be fine. I only have pine span tables but they show #2 spanning 21'4" @30psf live 16OC.
Use some Simpson clips that the BI likes and you should be good to go.
KK
Most of the old crew is here. http://forums.delphiforums.com/breaktimeclass/messages
You're right ... simple. The TJIs will be light weight and easy to handle. But you'll have to do the eaves, so that's more work, but so is cutting 2x12s. Use the H clip from simpson, I think. Blocking at the beam/wall to keep joists from racking. You called it a freestanding shed AND a 'lean to' ... which is it? Lean to implies it is somehow connected to another structure. Semantics
Thanks for the reply...
You don't say what you are using to stop diagonal collapse and you don't say if the post and beam walls are stiffened in sheer. Both are important. Ply decking or strapping? What is the roof material?
Just thinking out loud. Local inspectors department will want to know.