5-ply LVL beams
5-ply LVL beams
(OP)
I was wondering if anyone has used 5-ply LVL beams for previous projects. I have a project where I recommended a 5-ply 1.75"x16" LVL beam. The beam is 23' long and loaded mostly from the top and a little side loaded. I have specified the beam to be bolted with 2 rows of 5/8" bolts.
The contractor told me that the manufacturer does not recommend this and that the warranty would not be valid.
Any thoughts?
The contractor told me that the manufacturer does not recommend this and that the warranty would not be valid.
Any thoughts?






RE: 5-ply LVL beams
RE: 5-ply LVL beams
BA
RE: 5-ply LVL beams
Mike McCann, PE, SE (WA)
RE: 5-ply LVL beams
But i have done that on several occasions, as previous posters i would not do this for heavily side loaded members. For mostly top loaded it is a non issue as long as the boltIng is sufficient for the 5 plies to act as a unit.
Pmt
RE: 5-ply LVL beams
Maine Professional and Structural Engineer.
(Just passed the 16-hour SE exam, woohoo!)
RE: 5-ply LVL beams
You do mean 5 members, 1.75"x16" LVL’s bolted side by side, right? That’s an 8.75"wide by 16" deep beam, right? Must be pretty heavily loaded. Is this a new beam, or a couple side LVL’s added to an existing 3 ply beam? And, don’t forget the applicable adjustment factors, long term creep for example. The primary issue probably is how effectively you transmit/distribute the total load, equally, to all five members making up the beam. And, the LVL manuf’er. probably has some doubts that that gets done properly or adequately in many cases. Take a look at the NDS or any good Wood/Timber Design text book for how to design a doweled/bolted connection, and their different modes of failure. We have a fairly good understanding of two and three member connections, but it get a little fuzzier when connecting five members. And remember, that the member must deflect/move a bit to really bring the bolts into bearing in the holes. Also, driving a bolt through a nice tight hole 8.75" long is a trick too. Do you really load all five members essentially equally? If most of your load is from the top and you truly do apply that to all five members, that’s good. But, remember that two joists spanning from opposite sides will tend to overload the outer ply by the very nature of their own deflection and curvature. Side loads from joist hangers and the like really must intentionally be carried into the inner plys by the design and implementation of your bolted connection. In trying to finesse this detail a bit, I’ve actually held the outer plys 1/8" to 1/4" lower than the inner three plys. This causes the first inner plys to be loaded and then the bolts are forced to distribute loads through fewer plys, but both inward and outward. This sorta replicates the three member failure mode. Another reason for this detail was that I didn’t want to shift the bearing area out from under the end verts. on existing 2x4 wood trusses.
RE: 5-ply LVL beams
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: 5-ply LVL beams
In all cases, they claimed they were put up wet.
RE: 5-ply LVL beams
RE: 5-ply LVL beams
RE: 5-ply LVL beams
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.