Replies

1. 
   jayzog | Jan 20, 2004 01:16am | #1

   It is a much more exspensive way to go, but you can achieve longer spans in the same amount of joist depth. On my current job we used them for floor joists  because the cieling and floor had to line up with existing 2x10, and the span of the room is to farge for 2x10.

2. 
   dIrishInMe | Jan 20, 2004 01:16am | #2

   Price out a simple floor system with LVLs vs 2x10 and then you tell us.
    

   Matt
1. 
   flat_top | Jan 20, 2004 01:45am | #3

   Actually, I was doing just that. But we all know that you never get 100% yield from solid lumber - lately many pieces have to be culled and used for short cuts. And then there's the time spent "orienting" them "bow-up" - and if your crew makes a mistake with one or two joists, the problem is magnified. Also the fact that the width of 2 x 10's can vary from 9 - 1/8" to 9-3/8" creating additional problems down the road if the application is critical - like in a kitchen. So the raw material differential is only one factor - the hidden labor in some cases might be surprising.

   But for the sake of argument, if price wasn't a factor, are there any negatives?

   Edited 1/19/2004 5:46:27 PM ET by Flat_top

1. 
   BossHog | Jan 20, 2004 03:40am | #4

   Actually I've sold a floor that was done in LVLs. But it was for an LDS church, and money is no object to them.

   If you're comparing LVLs to 2X10s, why not throw I-joists in there too? Got something against them?

   Just guessing, but I'd say prices will be roughly as follows per running foot of material:

   2X10s - $.90

   9 1/2" I-joists - $1.20

   9 1/2" LVL - $4.50

   So there's a HUGE difference in price. I can't see any reason to use them.

   You asked if there are downsides to LVLs. The only one I can think of is that they change dimensions a lot when they get wet. If one side dries out more than they other they can cup badly. And they're danged heavy to work with.

   After reading your thread, I also wondered if you're considering LVLs because you're after a stiff floor. If you are, check out the thread on Floor Vibration if you haven't already. There are better and cheaper ways to make a solid floor.Q: What's the difference between a blonde and an ironing board? A: It's often difficult to open the legs of an ironing board.

1. 
   flat_top | Jan 20, 2004 04:36pm | #7

   Yes, I am looking for a super-stiff floor structure - no bounce whatsoever. I joists would be an option (I had originally quoted this project with I-joists), but the owner of the house (this is to be a two-story, 900 sqiuare foot addition to his house) is a retired fireman. He HATES I- joists  as he claims they will burn quicker and therefore collapse faster in a structural fire. And he doesn't want anything resembling OSB anywhere near his house.

   Now he's an extreme case, I'll admit. But in this case he's considering the price differential strongly (roughly a $2,400-2,800 difference on this project). He is, after all the customer. Since he's after a stiffer floor, the other option I threw at him was to use two steel beams to break-up the 25' span.  

   Thanks a lot for the link, BTW. I appreciate it.

   Edited 1/20/2004 8:41:30 AM ET by Flat_top

1. 
   BossHog | Jan 20, 2004 04:56pm | #9

   Thanks for clearing up what you're looking for.

   If he wants a really stiff floor, breaking the 25' span in half with a beam and using 2X12 floor joists should do that. (Regardless of the spacing) And it should be a heck of a lot cheaper than using LVLs.

   Using LVLs instead of 2X lumber won't necessarilly make the floor stiffer. Stiffness comes primarily from DEPTH.

   If he's really hung up on the LVL idea, how about 11 7/8" LVLs on 2' centers instead of 9 1/2" LVLs on 16" centers?

   If he doesn't like I-joists, he probably won't like wood webbed floor trusses either. But they would be a good option if he'll go for it. They're especially nice in a 2 story for running mechanicals in the open space. If he's worried about their fire performance, you can always break up the floor into compartments with some draftstops.

   Keeping customers happy who have wierd ideas is always fun. I hope it works out for you.Girdle -The difference between facts and figures.

2. 
   rasconc | Jan 20, 2004 07:59pm | #15

   How about timberstrand?  I guess your fireman may consider it osb but I think it is much cheaper than lvl and straight as an arrow with almost no deflection.  Anyone know of any limitation for joist use?

   http://www.icbo.org/ICBO_ES/Evaluation_Reports/pdf/4979.pdf

3. 
   tenpenny | Jan 20, 2004 09:14pm | #16

   I always find it interesting what people do and don't like.  In this case, the guy doesn't like OSB (chips of wood glued together), but is ok with LVL (layers of wood glued together; and doesn't like I joists because they fail too quickly in a fire, but is ok with a wide flange beam which will fail faster than a solid wood beam in a fire.

   We all have our quirks and preferences, and mine are just as weird.

4. 
   BillHartmann | Jan 20, 2004 09:14pm | #17

   I have 24 ft wide span with an I-beam support in the middle. And the floor is only 6" (maybe 8 i have to check the prints) thick.

   And it is SOLID. In fact I part my car on it.

   Seriously what about a concrete floor?

5. 
   gdavis62 | Jan 20, 2004 10:53pm | #18

   I agree.  Use LiteDeck forms, reinforce properly, do temporary shoring underneath, and pour him a concrete floor.  He can have the whole firehouse gang over and have a clog dance on it.

6. 
   MisterT | Jan 21, 2004 02:42am | #19

   If he REALLY wants a stiff floor, then reduce the spacing to 12" o.c. and/or use 1-1/8" or 1-1/4" t&g ply for the sub floor.Mr T

   Do not try this at home!

   I am an Experienced Professional!

7. 
   flat_top | Jan 21, 2004 04:27pm | #20

   Good suggestion! I was definately going to use 1-1/8 T&G subfloor, but for some reason, I never considered 12" O.C. It's funny how the mind gets locked into old habits.

   Thanks to all for responding and for the links provided. I now feel pretty comfortable that I have enough alternatives to offer to this client that will keep him satisfied.

   But that response of the firehouse gang having a clog dance - I can't seem to get that image out of my head. 

8. 
   dIrishInMe | Jan 21, 2004 04:30pm | #21

   If you do a little research, I think that you may find that 12" O.C. isn't going to buy you that much. Matt

9. 
   VaTom | Jan 21, 2004 04:55pm | #22

   If you do a little research, I think that you may find that 12" O.C. isn't going to buy you that much.

   Matt, to avoid doing that research myself, are you saying that the depth of the joist is more important?  Like going to 12" or 16"? 

   That's the situation for steel bar joists, my primary experience.  A 12" bar joist doesn't make 25' in the K series, requires a 14" depth.  With 14", however, you can get a 334 psf total load over that 25'.  And the higher the rating, the stiffer it's gonna be with small load, with diminishing returns of course.PAHS Designer/Builder- Bury it!

10. 
    dIrishInMe | Jan 21, 2004 05:16pm | #23

    Yes, that's what I'm saying.  Deeper is substantially better than closer.  Closer only provides a floor that is a little more stiff.  I was hoping that Boss would jump on this one too... Matt

11. 
    BossHog | Jan 21, 2004 06:22pm | #24

    DIRISHINME is basically correct.

    Depth adds stiffness.

    Closer spacing add strength.

    Strength and stiffness are only loosely related. The floor vibration thread explains that in a little more depth.Q: What is a man's idea of safe sex?A: A padded headboard.

2. 
   ian | Jan 20, 2004 05:56pm | #13

   Boss

   thanx for the link to your earlier floor vibration post.  very interesting

1. 
   BossHog | Jan 20, 2004 06:06pm | #14

   No problem.

   I keep the link to the thread handy, and use it often. I'm sure some of the regulars here are sick of hearing about it.Bumpersticker: I'm just driving this way to tick you off.

2. 
   dIrishInMe | Jan 20, 2004 07:25am | #5

   But we all know that you never get 100% yield from solid lumber - lately many pieces have to be culled and used for short cuts.   You occaisionally have some "culls" with LVLs too.  And there will be some cut-offs with LVLs.  With the linear foot cost of LVLs, a 5% waste factor will end up matching a 15% or 20% waste with dimensional lumber.

   And then there's the time spent "orienting" them "bow-up" - carpenters crown the boards as they put them in place, so this is a minor consideration, and whatever time is lost crowning the dimensional lumber would be lost when handling LVLs simply based on their weight. 

   .if your crew makes a mistake with one or two joists, the problem is magnified.  And if your crew, cuts an LVL short you just burned $60.   

   Also the fact that the width of 2 x 10's can vary from 9 - 1/8" to 9-3/8"  Yea - this is a pain in the a$$, but don't think that LVLs are necessarily perfect.  It's not unusual for them to vary a 1/16th or so.

   So the raw material differential is only one factor - the hidden labor in some cases might be surprising.  I think your just trying to justify your idea here.  Not sure what you are building, but once you get your whole project priced out, I bet that you will be looking for places to save some $.  Or, if your budget is that loose, I suggest you install granite floors over your LVL floor system and go ahead and get a copper roof too. :-).  If you reason for using is LVLs is that you want a perfectly flat floor and/or want larger spans that can be comfortably delivered from 2x10s or 2x12s or I-joists, I'd say go for it.

   Do let us know what the you find out for a floor system price comparison.  A lot of people stop by here and want a lot of info, but don't seem to want to reciprocate.Matt

1. 
   james | Jan 20, 2004 07:55am | #6

   only thing i use lvl's for is stair stringers, it is nice having perfectly straight runs that are still strong after cutting out the notches, and as a bonus it is very difficult to blow out one of the keys, and having the square edge is nick also.

   now for floor joists.... 2x10 or I joist, lvl is just too mutch.

   james

2. 
   flat_top | Jan 20, 2004 04:40pm | #8

   Actually, the floor system for this application is Granite tile over Cement board.

   The customer was considering a copper roof too, but is "settling" for copper gutters and downspouts. This is going to be one very expensive addition - even without the copper roof.

   But you guys are basically saying what I was thinking - the "justification of "labor cost saving" was one from the customer (you'd think he was a salesman for G-P or something). I told him that maximum he'd "save" maybe a hundred dollars in labor and that on the material end, there isn't that much waste since culled 2 x 10's can be used for blocking and whatnot.

   But I've done other work for this customer before - he's solid. Maybe I should just give-in and let him make the choice.

   Edited 1/20/2004 8:46:01 AM ET by Flat_top

1. 
   dIrishInMe | Jan 20, 2004 04:56pm | #10

   OK - sounds like LVL is a good solution for your coustomer.  Boss would know more about this than most here including me, but a 25' span sounds pretty long, even for LVLs. 

   Good Luck,Matt

2. 
   flat_top | Jan 20, 2004 05:26pm | #12

   Ok, on the 25' span thing, I didn't make myself perfectly clear. The original plan was to break the span in half with one wide flange beam. The alternate I proposed was to break it into thirds using two beams. Each joist would then only be spanning 8-10 feet. This should be plenty stiff using 2 x 10's - and the width variation on shorter dimensional lumber is usually less pronounced than on longer pieces.  The price for two additional pieces of steel isn't that great compared to the extra cost for the LVL's.

   On that customer thing, yeah it keeps it interesting. I guess that I shouldn't complain as this is a customer that wants to spend MORE money for a better end product. Every client should have such a defect, eh? I've always said that business would be much easier if it weren't for customers and employees...

3. 
   BossHog | Jan 20, 2004 05:01pm | #11

   "the floor system for this application is Granite tile over Cement board."

   O.K. - Forget what I said about 11 7/8" LVL 2'O.C. I'm pretty sure that to use tile you have to have the floor joists on 16" centers.If your dog is barking at the back door and your wife is yelling at the front door, who do you let in first?The dog, of course, at least he'll shut up after you let him in