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Home > Can I use a large LVL with 22-23 ft span to stiffen existing floor if only supported at ends?

Can I use a large LVL with 22-23 ft span to stiffen existing floor if only supported at ends?

By unklegwar
Created 12/03/2012 - 08:58

By my quick calc, a single

by NateMckenzie in reply to unklegwar [1] [original] [2] on Mon, 12/03/2012 - 13:58

By my quick calc, a single 2 x 12" deep LVL spanning 23' in length direction and supporting 6' of the floor above (15lb/ft dead load and 40 lb/ft live) will see ~8,000 psi.  Most LVLs will max out at 3,000 psi limit so ballpark you're looking at least 3- 2x LVL's or a metal beam.  For an arrangement such as this, however, I wouldn't trust a ballpark estimate (beyond rough planning).  (For example, in my ballpark calc, 3 x 2E LVLs didn't quite pass my jurisdiction's deflection requirement)

 

In my opinion, nothing wrong with the concept though, as long is it's properly braced and you spread the load from the 2x4s (depending on your slab).  Especially if you're just trying to do some supplemental load carrying.

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Links:
[1] http://forums.finehomebuilding.com/members/unklegwar
[2] http://forums.finehomebuilding.com/breaktime/construction-techniques/can-i-use-large-lvl-22-23-ft-span-stiffen-existing-floor-if-only-s