Should this 3 ply LVL bear on a single 2×4

beamload-bearingsupport

My engineer has designed a 6'6" beam to carry my load and this would consist of 3 LVL glued and screwed together. 7 1/2" LVL. Like most LVL, a single ply is 1 3/4" deep. So, as he has it specified 3 of those will be put together and that'll be 5 1/4" deep. However he has specified this will go inside / span the bearing wall, which is a 2×4 wall. In this case, he has also specified that each end of the beam will bear on only one 2×4. I don't doubt his design necessarily but would like more explanation on how/why it is legitimate to bear the 5 1/4" beam on a 2×4 ( 3 1/2" actual depth). I've attached a sketch below for clarity looking at the side of the 2×4

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link to engineer doc https://drive.google.com/file/d/1vlIXbt2FQ_YYJN9PjOkHpAx7pcumKWch/view?usp=sharing

Best Answer

None of us can really answer this with confidence, not having all necessary information (or, in my case, an engineering degree). I will offer a few assumptions and suggestions based on the engineer's drawing:

  • A tripled, relatively squat beam is probably being used to maximize head clearance. More typically this would be a doubled 9-7/8" beam, which rests more comfortably on a single trimmer stud and fits within a 2x4 wall. You might consider whether that's a more desirable option than having a beam that exceeds the width of the current wall.
  • A single trimmer stud is apparently adequate for the load on the beam (though it wouldn't hurt to ask the engineer rather than us), and the attached full-height (king) stud provides the stiffness that I was concerned about in my comment above.
  • On second thought, this looks like a "flush beam" situation, whereby the beam is at and above ceiling line. Concerns about beam width in relation to wall width are probably moot, and the beam will rest on doubled studs per spec.
  • Otherwise, you could always double the trimmer studs to alleviate concern. This is a low-cost solution that may bring peace of mind.
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