I have a 22’x28′ garage with storage loft above. At 22 ft the SPF 2×8 joists are overspanned and deflect badly when I’m up there…and, it looks like they’re starting to sag.
I’m thinking a site built box beam would be easier to hoist into place than a steel beam or gluelam. Are there any tailgate engineers ou there who would care to take a stab at sizing a 28 ft box beam? And – do you think it should be cambered at all?
Thanks…..
Replies
Old info.....
I haven't been there in a long time but the A.P.A. { american plywood assocation} had some great info on box beams.
Sizing Box Beam
Easy to say but not easy to do. They can be complex to design and build and require much care in their constructon and I doubt no easier to install. A multiple LVL beam installed with individual LVL's and laminated in place should a simple straight forward way of doing it..
If the joist are running across on top of the beam, individual LVL's can raised in place and be simply nailed together. If the joist are to be hung with joist hangers, on one or both sides, the laminating is a little more involved.
The AHJ may want and engineers seal and supervision during construction.
If you sister on LVL planks, you might look at GRK RSS screws
GRK makes a screw they call the RSS which has rated strength ratings. They are available in a few lengths from the big orange but (probably) from your local lumber yard in a lot of different lengths (like 5 1/8" to go into but not through 3 pieces of LVL). T-25 drive plus impact driver equals decent overhead driving. Plus you can preset them in the LVL beam.
I have no idea if your engineer will sign off on them but here is the product page
http://www.grkfasteners.com/index.php/en/products/rss
No this isn't spam. I love these things for assembling headers etc.
Thanks to all
Thank you to everyone who responded to my post. It was all useful info......