You may have to install appropriate column footings.Ģ) A W14 has a span-to-depth ratio of 30 (420" / 14"). Loads on supports at those locations will be noticeably higher than they would be for simple span supports. Added columns will be interior supports on a continuous beam. If you do add column(s), carefully look at loads on them.
The three continuous spans can be more or less arbitrary lengths as long as none of spans are "too" long. use two columns, maybe closer to LVL ends. a continuous beam is inherently "stiffer" than the same beam used for equivalent simple spans.Īlso, if near-mid span locations are not convenient. Another factor in favor of this solution. Spans of, say, 16' and 19' should be be fine.
The idea is to reduce the span, exact span lengths are not critical. Nice thing is that the column does not have to be at midspan. Probably W14 or greater.ġ) IMHO, that's best. RE: Long Span (35') LVL Beam Design Brobocop (Structural)ġ. because, for deflection, moment of inertia is more important than material properties. deflection > L/360, I'll bet?įWIW, span-to-depth ratios are a great first check for any beam, wood, steel or concrete. This floor will be even worse, because both ends of the floor joists will be supported by bouncy, low moment of inertia LVLs.ĭon't take my word for this, make the calcs using only known dead loads, and the 50 PSF floor live load (forget about wind load for now). This is not magic, it's about a beam's moment of inertia which is sensitive to beam depth. Any ratio over about 20 begins to act like a "flat spring" which will make the floor's serviceability seem "bouncy" to occupants. The reason, consider the LVL's span-to-depth ratio (420" / 16" ≈ 26). In all likelihood the floor will fail because of excessive deflection from even the most basic loads.
#Lvl beam span chart how to#
Save yourself time and "hand-wringing" over how to precisely apply the loads. I'm accurately calculating all loads before recommending a different solution. RE: Long Span (35') LVL Beam Design skeletron (Structural) 27 Dec 19 22:34įour 2x16 LVLs fastened together and 35 ft in length. Not many LVL manufacturers have spans listed that high in their literature. Looking at the roof framing, is the rafter bracing wall - that sits directly onto the beam - picking up much load? or does most of the roof load go to the exterior walls? I'm making sure I'm accurately calculating all loads before recommending a different solution (Being that the beam is currently installed).ģ5' is a heck of a span to begin with. My STAAD model results are currently showing Fail, and also a mid-point Deflection of about 3" (L/140). Rather than Model the entire building, I modeled just column/beam frame (diagram attached), and am wanting to put the distributed dead, live and wind load on the beam for my analysis. The rest of the ceiling is framed laterally with 2x10s 16" o.c. They are supported at the ends by two 5.5"x5.5"x0.25" Square HSS. There are two beams in question, each comprised of Four 2x16 LVLs fastened together and 35 ft in length. I was contacted by a building owner that wanted to build out his attic space into offices, and needed to ensure that 2 installed beams (Beam were never previously Engineered) are adequate to handle the additional live and dead loads.
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