exterior deck, beam design
exterior deck, beam design
(OP)
I am designing a beam for an elevated exterior deck, the span is kind of long - 20' post to post. loading is 265 plf. at first i had spec'd lvl but do not want use that on an exterior application exposed to rain / moist. if i spec a built up beam w/ 1/2" x 11.25" A36 plate and (2) treated 2x12 SPF #2, does anyone have suggestions or details for thru bolt size / spacing? the plate would be primed and painted. thanks.






RE: exterior deck, beam design
RE: exterior deck, beam design
Dik
RE: exterior deck, beam design
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RE: exterior deck, beam design
RE: exterior deck, beam design
RE: exterior deck, beam design
If you use a steel beam, you will need it galvanized for contact with pressure-treated lumber or use a barrier to prevent corrosion.
RE: exterior deck, beam design
Regarding bolting details, I would check for transfer of shear from the steel to the wood (for bearing) such that you might have 1/2" diam. at 16 inch oc staggered over the length of the beam and probably 2 columns of 2 bolts (1/2", 5/8" or 3/4") near each end. (meaning a total of 4 bolts at each end in 2 columns. I've not run any numbers but that seems likely to be what you would find from analysis. (Civil Engineering mag from September 1989 had a nice artical about flitch plate beams. I'm guessing you could google and find more recent articles. Probably fine homebuilding or Journal of light Construction would have something technical too.)
On the subject of treated PSL beams, I have seen problems with availability or lead time and/or shipping cost issues. I think the product is not commonly stocked and so, one piece might be harder to get (either more time to wait or high shipping cost for one piece.
RE: exterior deck, beam design
I don't like the treated parallams because they are expensive, hard to get, and have reduced capcities.
RE: exterior deck, beam design
Where would you recommend locating salvaged beams?
Thanks,
rjgladish
RE: exterior deck, beam design
Dik