As I get ready to make sub-beams with 2×12’s (2 & 3 wide), someone plopped a SelectTem LVL pamphlet on my desk. I’ve never used LVL’s and don’t really know anything about them other than they cost more than regular lumber.
Without wading through the numbers, is there a typical LVL equivalent to a 2×12? Two 2×12’s? Three 2×12’s?
My spans are around 10′.
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There's not really an easy answer. LVLs and 2X12s are different sizes, for starters. There many different species and grades of 2X12. And different brands of LVL have different strength characteristics.
Boss I remember last time I was looking at LVL's and PSL's and the like they all had different "strenght" numbres attached to them like 1.5 1.7 or 1.9.
Can you explain the difference between them and what they mean?
How much time have ya got ??? Having trouble sleeping? Read this post just before going to bed for best results.(-:There are several different values assigned to lumber and beams. Here are some examples:The number you mentioned, like "1.9" is the "modulus of elasticity". That tells how much a beam will deflect when a given amount of weight is put on it. There's also a vale called "Fb" - Some people call it "flexural stress", others call it "Extreme fiber bending". That tells how much bending stress a beam can handle before it breaks. These 2 values are different - One is the strength, and on is for the elasticity. They're loosely related, but not the same. The value for modulus of elacticity is generally what they advertise, which makes no sense to me.Then there are other values, like tension, compression PARALLEL to the grain, comperssion PERPENDICULAR to the grain, and shear. But they don't come into play much in residential LVL design. In all cases, the higher the number the better.Safety factors are already built into the design values. So if you load a beam up to it's maximun design value that doesn't mean it's on the verge of breaking. Does that sorta answer the question?
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yes... and it makes me think I need to learn more about it.
The rep at the lumber yard asked me if I wanted a 1.5 1.7 or 1.9 "rated" LVL...
I said... ah... I dunno..... I guess if the 1.9 is the strongest I'll take that one!
If ya wanna learn more about beams and beam design, there's a fairly good tutorial at beamcheck.com:http://beamcheck.com/publications.htmlYou can read it online or download it in PDF form. .GP has some info about their beam design values here:http://www.gp.com/build/PageViewer.aspx?repository=bp&elementid=3928If I ain't put you to sleep yet, those things ought to.
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John,
Th closet to a 2x12 is an LVL that's 1-3/4" x 11-7/8".
Two of them together are stronger than 2-2x12's together.
They make them 3-1/2" x 11-7/8", 5-1/2" x 11-7/8" and bigger.
It all depends on spans and loads and heights.
I've had 2-2x12's specked for openings before but the 2x12 was to high, so the Architect replaced them with a 3-1/2" x 9-1/2" LVL that would carry the same load.
I've had 2-2x12's specked for openings before but the 2x12 was to high, so the Architect replaced them with a 3-1/2" x 9-1/2" LVL that would carry the same load.
Joe, thanks for the info. I think the reason it was nagging at me was that I was wondering if I went with LVL's if they would be shorter than the just over 11" of the 2x12's. About an inch shorter and I could use baby lally posts instead of creating posts with concrete block. Trade $$ for saved time. A 9.5" would probably do the trick.
The engineer's report put the main beam as a built up beam with 3 2x10's (nearly 16' span on joists, 1-story ranch house on crawl). That was assuming no sub-beams. The sub-beams are my own addition to the over-kill/over-budget (I like a solid floor). They cut the main beam's span in half.
Might be worth pricing a 3-1/2"x 9-1/2".
jt8
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Edited 9/25/2006 1:36 pm by JohnT8
R.P. in Chatham stocks LVLs, if ya wanna check on prices.We stock them at the Springfield plant too. But since we only sell through lumber dealers that means I can't sell ya any directly. You may be able to get pricing and/or order them through one of the big boxes if you know exactly what you want.
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R.P. in Chatham stocks LVLs, if ya wanna check on prices.
They're my current favorite. Good service, fast delivery, reasonable prices. Less than 1.5 mi from the project house.
I've already got the 2x12's for the back 3 pads, but I sure am thinking about LVL for the front 5. The spans are around 10', so I was just going to get 12'ers (with the 2x12's).
jt8
"Success is not the key to happiness. Happiness is the key to success." --Albert Schweitzer
Went by Lowes and called RP. The Lowes dude quoted me $5.46/ft, but while he was saying it was 3.5x9.5, I suspect it was really 1-3/4", because he had trouble looking the price up and kept going back to the book. RP dude said 1-3/4"x9-1/2" for $4.50/ft.
So regular lumber 2x12x12' = $12.68 (Lowes)
LVL = $54- 65.52.
Now unless I've got my numbers sideways somewhere, that looks like the LVL is around 4.5 times more expensive than the regular lumber. I might be able to justify up to twice as much, but 4.5 times?! I think this means I'm back to the 2x12's and block pillars.
jt8
"Success is not the key to happiness. Happiness is the key to success." --Albert Schweitzer
I don't have access to our pricing. But the $4.50 per foot sounds like about what I would have expected.
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For what it's worth, we're paying $4.76 a foot for 9 1/2" and $6.11 for 11 7/8"
Going back to the original post, my understanding that engineered wood is much more expensive, however, the payoff is that you have to use less material than dimensional lumber. For instance if you were initially using 2 x 12, you could drop down to a 9 1/2 LVL which saves in framing material. If you are looking for something 3 1/2" wide, such as a header, then you make want to look into LSL's which are usually a little bit cheaper but don't have quite the strength of an LVL. Another added benefit of LVL's is that they can come in almost unlimited lengths. which come into play when stick framing roofs. Most architects call for double 2 x 10's or 12's for the hip rafter, but you can replace that double with a single LVL. Also, on long hips over 30', there is no need for a scarf joint in the rafter because the LVL can be manufactured to run the entire lenght. I think that LVL's are probably useless to a DIYer, but to contractor, they are irreplacable. Balloon walls here I come!
Our Menards has 9.5" LVL on sale this week for $2.99/ft, but i didn't see what kind it was.
The Lowes was 1.8E.
jt8
"Success is not the key to happiness. Happiness is the key to success." --Albert Schweitzer
I ran across some moer stuf about loads and designs that you may be niteresetd in. I don't relly have any idea how much you know about the subject, so I'm kinda guessing. But even if you already nkow all this stuff, there may be someone else following the thread who doesn't.Here they are:Calculating Loads on Headers and Beamshttp://www.umass.edu/bmatwt/publications/articles/calculating_loads_on_headers_and_beams.html.Sizing Engineered Beams and Headershttp://www.umass.edu/bmatwt/publications/articles/sizing_engineered_beams_headers.html.Understanding Loads and Using Span Tableshttp://www.umass.edu/bmatwt/publications/articles/understanding_loads_using_span_tables.html
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Thanks for the links, Just printed them out.
We pay $4.03/LF for 9-1/2" 1.9e and $4.99/LF for 11-7/8" 1.9e.I think you're underestimating the strength/value of LVL's. I'm sure they are 4x more expensive because they are 4x stronger.Just to illustrate, we recently framed an addition that was 24'x32'. The usage was a mixture of sleeping and living areas so the loading was 40LL/10DL. We used a two ply 1-3/4"x9-1/2" 1.9e LVL with only two posts so the max span was about 10'8". Even spanning this much, the beams had a total load defletion of L/528. I doubt you could even do that span with a four ply 2x12.It's kind of like using trusses. You can clear span 32' no problem with just a 2x4 truss, but if you were to stick frame your lumber would be huge, if it was even possible.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I use LVL's quite a bit. I use the Boise Cascade version, which is most commonly available in this area and common sizes are stocked in the local yard.
After I saw this thread when I got home, I dug out my BC specifiers guide where there are span tables for for all sizes (which I suspected....). So your yard should be able to supply you with the spec guide (free).
In addition, Boise Cascade and, I believe weyerhaeuser offer free engineering CD's for their engineered projects.
Because of the expense of LVL's I usually limit their use. One thing to keep in mind is that they're a dry, very stable product intended for indoor use only. And if you mix them with sawn lumber for, say floor joists you might have some uneven shrinkage, especially if the sawn wood joists are green or air dried.
But as someone else mentioned, their strength is consistently superior to sawn wood and I find them pretty decent to work with. (and they make great stair jacks!).