Given a floor deck design with a lot of different span conditions, not just a simple rectangle, 2200 sf footprint, how much time savings might you figure the job using I-joists versus sawn lumber?
In sawn lumber we would be lapping over intermediate beams, using lengths at 8, 12, 14, and 16, or cutting and butting. By lapping we would be adding some blocking where our subfloor decking layout would be shifting 1-1/2″. Cutting, butting, and blocking, we would avoid the shifts.
Of course, in I-joists, everything is a home run; we’ll have no laps or butts.
#2 SPF 2x10s will do all spans.
Replies
Advantages with I-joists -
No crowning.
No culls. (generally)
Lighter in weight.
Less laps over interior walls.
.
Downsides:
Fire concerns
More expensive material cost (Sometimes not much)
Takes longer to get them if not stocked locally
.
.
Advantages with conventional 2X lumber:
More readily available - Every lumberyard stock 2X10s
Downsides:
More chances of splits and squeaks
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At least that's my perspective. But us suppliers are always suspect. (-:
I've never personally framed a floor with I-joists yet. So it's hard to guess how the labor runs.
They sure are popular around here. I'd venture to guess that 90% of new homes in this area have them.
The difference between Rush Limbaugh and The Hindenburg is that one is a flaming #### gasbag, and one was a dirigible. [Doonesbury]
100% of the floors framed in Fairbanks use I-joists. Flatter, quieter, stiffer, lighter.
With lumber, it takes time to cut and butt or nail the laps...I joists just need one end trimmed square and cut to length and you're ready to roll. One person can move a 30' joist easy enough. Make a saw jig for cutting and the stuff goes in fast. If you need info on a home made saw jig, let me know.
And All...
Personally, I don't see why everyone says that labor is or should be less with I_joists when compared to sticks. I do agree that they make for a better floor in the long run, but that's another ball of wax.
I've done a fair amount of work with I joists....probably 12 new homes. I find them to be pain in the arse. Both ends need to be cut square as they've been cut free hand with a chainsaw at the yard. Whereas sawn lumber is usually squared off. Squash blocks are a pain in the butt. Blocking can get difficult. Padding out webs for hardware is no fun. And top mount hangers are a royal pain when changes come down the pike LONG after the decking is installed. Not to mention that all but one of my circ saws are 7 1/4". So 90% of my saws are useless (with a saw guide) while framing the floor systems as we always see 2 1/2" or 3 1/2" flanges here. Plus, everyone cutting has to have a saw guide nearby. Unless we set up the slider.....and I like to keep my slider off the frames and save it for finish work. We use a 10" beater chop box for framing.
I agree they are a superior floor system compared with today's sawn lumber. Not argueing that point one bit. I just don't agree that they are "easier" to install. And it scares me when I hear builders throwing around stuff like that based on what they hear.....cuz they expect their opinions to be reflected in my pricing. It doesn't work like that.
When I was a framer, we loved I-Joists. For one thing, when you power nail the floor deck on, you can't miss hitting the joists! They were a pain to cut though. It was easy to slide joists across the foundation once one was across--just tip it "sideways" (or two are better, less chance of the subsequent ones falling off) and slide the others sideways in the "trough" across to the other side. BTW--there was no "bounce" to floors done with I-joists.
Edited 9/2/2004 6:38 pm ET by Danno
" BTW--there was no "bounce" to floors done with I-joists. "
It ain't that simple.
With any kind of floor system, you can stay in the "comfort zone" or push the limits. Doesn't matter if it's I-joists, 2X12s, or floor trusses.Exciting minority teens? How, by aiming gamma rays at them until the spontaneously ejected a photon? [Rohit Khare]
From a plumbers (and hvac) point of view, open web trusses are the only way to go. I HATE I-beams.With the truss, virtually all the mechanical can be in the truss space, making a cleaner looking job.Goes quicker too.
The contractor I frame for likes doug fir 2x8's on 16 inch centers, pony wall every 8 ft. That is partly because we usually pour the footings/foundation and can reuse the 2x8's we poured the footers with. It is a more time consuming floor, no doubt, for all the reasons you mentioned. I prefer it to an I-joist floor myself because I think its stouter. We get select/struct 2x8's, 16 ft. long. Cull them hard and when you find the marginal one, cut it at the pony wall to take out the crown. I've seen too many I-joist floors built with 9 1/2's on 2 ft centers maybe a pony wall every 10 or 11 ft and then the contractor wants 3/4 osb for the subfloor. Yeah, it bounces real good. I'm starting my own house in the near future as my current one has sold. (finally) I'll be using the 2x8 floor I've described above. When I pour the center footers, I'll take a little extra care to get them level from one end to the other. By taking a little extra time, which I do for the contractor I work for anyway, I think I'll have a superior floor to an I joist floor. Not quicker or easier, but better quality. Thats just my opinion, though.
"I've seen too many I-joist floors built with 9 1/2's on 2 ft centers maybe a pony wall every 10 or 11 ft..."
I think that's one of the problems with I-joists - Some guys seem to think they can span a lot farther with them. Push the limits, and you start having problems.
"By taking a little extra time, which I do for the contractor I work for anyway, I think I'll have a superior floor to an I joist floor."
But wouldn't that be true REGARDLESS of the materials used? Take a little extra time, and ANY floor can be better.Did you hear about the Trojan and Pillsbury merger? They want to create a self-rising condom.