#LVL SUPPORT BEAM SPAN TABLE CODE#

and it bites when you know it'll work.Įxactly, the solution on those floors is to add mass to dampen them and it still is a poor floor. I'd start with codebook, move to WSDD, Ilevel, then if he won't budge decide whether to spend the money on lvl's or an engineer to say SYP will squeek by. I'd call it prescriptive but have had that thrown back in my face before.

#LVL SUPPORT BEAM SPAN TABLE CODE#

wood structural design data, I think it's on the AWC site has some beam span data that might help, free DL from the folks who write the code referenced nat'l design standard for wood construction (AF&PA's NDS). I can guarantee you he'll be impressed if you show him mine, it has been checked by several engineers, has shown up on their forums, but he don't know that and you could enter something wrong. Ilevel Forte free on the net does calcs for lvl's and some dimensional lumber. I know but people have more stuff than that, and thump in unison at parties. Yup the ol heeldrop test is qualitative in some ways but you are designing for 40psf uniformly distributed, pack everyone in there that'll fit and then start pushing a few more in. Double the span and the span doubled and so did the load, bending moment just quadrupled. Increasing a span does a whole lot more than most folks realize. LVL's are a good bit stronger (Fb ~2800 vs 1600) and stiffer (E2.1 million psi vs 1.6) than SYP. My head is still way too swimmy for higher math, y'all are making it spin I don't know who didn't wash his hands but I got strong suspicions. Sorry guys, had a little setback this week. To get the splice at the right spot outside of over a post gets to more complicated engineering, so for ease, code is alway over a post.ĭon_P might be able to run you through some better numbers. Don_P frequently cites the code citation, I don't know it off the top of my head. Code requires all splices to be supported by a stud or post. You would be trying to support those 20-2x12s with only 4-2x12s spanning a greater distance than the 20 (13'-6' vs 11'). You can think about it logically that you the beam will be supporting 20-2x12s (10, 16'o/c, 2 sides) in that 13'-6'. Since you have a 13'-6' between your posts you will need to cut down the span (more posts) or use an LVL. For widths between those shown, spans are permitted to be interpolated.Ĥ-2x12's can span 9'-1' in a 36 foot wide building and 10'-2' in a 28 foot building, so to interpolate (split the difference), 4-2x12s should be able to span 9'-7' according to code. Building width is measured perpendicular to the ridge. Your building is 32 ft wide, which is right in between the 28 and 36 foot columns of the chart. It sounds like the girders under the joists will be an 'interior bearing wall' span supporting 'one floor only.' They have charts for girders and headers in the ICC. Hopefully Don_P will be along sometime soon and see if I have messed up or not. Perhaps you need some engineered wood, or steel. That still FAILS the fiberstress in bending test. Using three columns across the length reduces the span for each to approximately 120' (10 ft) The calculator tells me that 4 layers of 2x12 (actual beam width of 6' and depth of 11.25' will FAIL the Fiberstress in bending test and the deflection test. (the calc is fixed to use a value of L/360 on floors)īut let's see what happens when we use. Using Don_P's simple beam calculator and the following data for SYP. Half of that will rest on the center beam and a quarter on each side wall.Ģ4750 / 2 = 12375 on the center beam for each segment.

If we call the LL to be 40 PSF, let's call the DL out at 15 PSF. Let's call that a 32 x 42 building that = 1344 sq ft.ĭivide that into three parts = 448 sq ft per section

I always though it was better to stagger the joints to minimize a hinge effect over the column, but he says his way is correct. My contractor (NOT an engineer) says a beam built up out of 3 or 4 2X12's will be 'plenty', but of course, the inspector has to believe that, too.Īs an aside, my contractor builds such beams with all of the joints over the column. Materials available locally are #2 southern yellow pine- strong stuff. Design load should be 40 psf minimum live load, and I want a L/480 stiffness. I don't have enough room to put them on top of the carrier beam, so they will be attached with hangers. They will be hung from ledgers at the edges, and the carrier beam in the middle. Specs- The floor joists will be 2X12's on 16' centers. The lumber yard said I would need an LVL, but what did they do before those were around? I show two evenly spaced support posts, but could go with three if it would help. I'm attaching a drawing with the dimensions. I'm wondering if there's a way to prescriptively calculate the carrier beam I need for my main floor.

Lvl support beam span table