Help,
I am going to build an average 2 story 3100 sq ft house. My builder(who is also my Uncle) is determined to use 2×10’s when I would like to use I-beams(silent floor). It seems that other builders I talk to who build custom homes use I-beams and builders who build spec homes use 2×10’s. Please give me some ideas of the pros and cons for both.
Thanks,
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Replies
it depends on the spans... that 's the main thing
there is nothing cheap or wrong about 2x10's.. it really depends on how stiff the floor is being designed for..
ie: it is a design issue , not a quality issue
The I-beams are more reliably straight, and can be sized for longer spans. However, they are somewhat subject to weather damage if left exposed for a length of time, and they take some special (though minimal) knowledge/precautions that some oldtimers may not want to come up to speed on.
What Mike said.
I'm usually happy to use dimensional lumber and save the extra cost of the I joists if you don't need the longer spans. But doing my own house, hmmm. maybe I'd like the advantages of using I joists for mechanicals, and keeping the floors dead level, and having a "can't miss" drywall screwing situation. It's not a big deal though. In general, I'd use the money I saved to upgrade OSB to plywood wherever possible.
Dog
Another minor point is that the I-beams require a little more preplanning. If one is long a 2x10 or two then it can be cut up for headers or some such, and if one is short then a quick trip to the lumber yard will solve the problem. I-beams have little use outside of floor joists and, depending on where you are, may require special ordering for certain sizes.
Here's a point that the others haven't mentioned.
I-joists will go soft more quickly in a fire. To the best of my knowledge, this is not enough of an issue that it will affect your insurance rates.
But if you ask a firefighter which he'd prefer.......
Unless you're the lead dog, the view just never changes.
I always specify type x drywall for ceilings when using I-joists, for just that reason. I figure the additional fire protection more than compensates for increased tendency to collapse under fire.
TJC
i-joists will shrink less, something to consider if you are doing brick veneer, especially if there are several levels.
OK... Just my 2 cents worth here:
I've been in this business for most of 25 years. I spent many years as the guy who got to go back and investigate, diagnose, and fix floor squeaks. I have repaired over a hundred floor squeaks over the years. The only squeaks I have ever found that were caused by anything having to do with framing (most were due to plumbing or hvac) were because of the I-joists. Specifically those moronic "hang-over"joist hangers that they require when building anything with cantelevers or headering off joists. I have never, not even once encountered a floor squeak that was caused by framing when dimensional lumber was used for the joists. Now, let me just say that I am not opposed to the use of I-joists when all you have is straight runs, and no hangers are needed.
Another point about the I-joists that has always made me think. We are putting our complete trust in the adhesive and it's longevity to hold these houses up. What if we discover (too late) that some seemingly inocuous gas or agent in the air eventually causes that adhesive to break down after 20 years? Just remember how long everyone lived with the presence of Radon without being aware of it's existance, let alone it's potential risk.
Well, I have a home with 2x8 joists, and parts of the floor squeek big time. Also, if you walk too near the upstairs stereo set when a CD is playing, it'll skip, due to floor bounce. (Was really bad when we still played records.)My aunt has a small "patio home" with, I think, 2x8 joists. Squeeks to high heaven where a partition wall joins to the floor.
DanH, he did not say that houses with dimensional lumber don't squeek. He said do to framing. Nothing can stop a nail from squeeking, whether driven into a 2+- flange or a 2 by. Maybe you don't have a glued down subfloor. You would have to ask, but I believe his beef was with hangers which are typically used wiht the I-joists and not dimensional.
Jackofall:
You're sort of right. I said that I had not encountered any floor squeaks in houses that we built which were caused by factors related to framing when we used dimensional joists. Of course, I regard nails as part of framing , and I've never found a squeaky nail. We built hundreds of houses using ring-shank gun nails to nail the floor decking down. As long as the plywood is properly glued, the nails used to attatch the plywood can't move - therefore can't squeak, (in theory, I never say never!). And I'm sure that I will get Godsmacked by this and next week I'll encounter a floor squeak that makes a complete liar out of me.
Although, speaking of floor squeaks, The most interesting one I ever encountered happened about 2 months ago. It turned out that what was squeaking was the nails and screws on the drywall of the ceiling below! The homeowner called a friend of his who is a drywall contracter and he said flat out that I was a liar and there was no way that could be the case. We rescrewed the ceiling and the squeaks disappeared. Anyone else ever encounter this one?
Moltenmetal:
Well, I'm not exactly losing sleep over this issue. However, if it is the same adhesive that they use in plywood (I really don't know) I certainly have seen a lot of plywood delaminate after just a little bit of moisture infiltration. Although osb does certainly seem to be much more moisture resistant than plywood, I always just assumed it was because they were using a better adhesive.
I was just musing about the wisdom of placing our trust entirely upon an adhesive as a structural component in and of itself. A previous poster mentioned the fact that these joists basically "melt down" at a very (comparatively) low temperature and rapid rate during a house fire. I look for insurance companies to eventually start speaking up about issues like this when they figure out your rates. They already use factors such as whether you have deadbolts, or smoke detectors, or brick exterior.
It looks like, since most of the squeaks you deal with are in homes the you or your company built and that all the subfloor was indeed glued, that accounts for your statements, but older frame house do indeed suffer sqeaks from from solid lumber construction.In the case of the SR cieling squeaks, was there ample tim,e for framing to dry before rocking, or is it likely that the frame lumber shrank back from the sr to cause the squeaks?
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paul.... we've had squeaks.. but it was always associated with bridging of the subfloor due to warped sheets that couldn't be pulled close enough to close the gap for the glue...99% of teh squeaks would reveal themselves before finish flooring so we could correct them
our subfloor was always 3/4 T&G, P&TS, pretty strong unyielding stuff
since we've switched to advantech we've lost the bridging and the subfloor, glue , nails system works a lot better
before we starte using guns.... we never had a problem with nails & glue.. all of our nails were hot dipped galv... and the handnailing closed the gap..
when we switched to guns.. guns can shoot a nail without pulling the two surfaces together.. so one bridging nail helps to make the next nail bridge... and on and on
an awareness of the problem, and the improved flatness of Advantech , the ability to set the depth of the nails with shooting them below the surface, and the correct application of the subfloor glue has made the squeaks go bye-bye
aMike Smith Rhode Island : Design / Build / Repair / Restore
Awareness is key.
WEe nail down with hand nailing first as we apply the advantech, then snap laines and go back to nail off with guns, then double check here and there, tightening with hammer. We leave job at night with all glue in contact, regardless of whether solid lumber or I-joists.
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Something you miss, in blaming it on the nail, is that the reason mosty nails sqeak is that when the subfgloor was not glued, or the glue did not take due to moisture, ice or other reasons, the frame lumber shrunk back from the subflooring and left the nail loose enough to squeak. Thios does not happen with I-joists.
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Mark:
You must have had pretty narrow range of experience if you haven't come across squeaky solid framed floors. Plenty of old houses with nailed subfloor into solid joists got squeaks. Joist shrinks, nail pops slightly, movement of subfloor along nail shank: squeaky floor.
I joist hangers don't squeak if they are installed according to manufacturer spec: glue on hanger saddle and a single screw up from below. Definitely no toe nails into top chord. Not sure about the 'hang-over' type, I've never seen that spec'd for cantilevers but it does sound like a good recipe for squeaks.
Upstatenet:
Glueing and screwing subfloor is a must whether solid joists or I joists are used.
I joist pros:
integrated engineered system without cost of hiring individual engineer
higher load capacity means longer spans possible
lighter weight --> easier handling --> reduced labour cost
fewer pieces in floor system as they can be run continuous over bearing walls
do not shrink or warp
dimensionally consistent
produces a flat, consistent, silent floor system when correctly installed
wider chord stock makes it simple to line up subfloor over bearing
mid-web knockouts make it simple to install mech or electrical runs through joists - no drilling
made from wood fibre that would otherwise be wasted in logging process: more environmentally friendly than cutting premium trees for long 2x10s.
value added product that results in more forest sector employment
I joist cons:
higher cost than solid lumber (20-30%)
handling procedures different to solid lumber
engineered, pre-packaged concept means any deviation from original design is more difficult
crowning still occurs in longer lengths
hard-core traditional framers don't like 'em
WallyLignum est bonum.
With regard to my "narrow range of experience", in this case you're basically right. I'm refering specifically to houses that we built. Not talking about old houses that were built before they had glue. I was just trying to give a real world comparison in new construction between 2x10 or 2x12 joists and I-joists.
The hangers I spoke of were installed to manufacturer specs. They are just a pathetic design.
Which glue are you worried about? Granted, a TJI has a substantial amount of glue in it- but isn't this the same thermoset phenol-formaldehyde glue that's held plywood together for the past 60+ years? Heck- in Canada we were building Mosquito fighter-bombers out of the stuff during WWII...
There's lots to be concerned about with new construction techniques. We've been bitten in the arse on a few things for sure. I'm just not convinced that a time-tested glue like that is one you should be overly concerned about.
haven't seen too many older houises, have you?Either that, or you lay off the diagnosed 'reason' to something else that is still associated with solid wood framing.
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You've gotten a lot of info to digest here on this subject and I'm going to throw my two cents in.
I've framed with all sorts of floor systems. Not all are equal. What area are you in? For some time in N.J. and Pennsylvania I've seen otherwise Quality builders use Wet, I mean soaking pi$$ wet 2X10's or 12"s for the floor system. The shrinkage is amazing as are the problems thta come with it.
I know of on architect who specifies 2X12's for every floor he designs. Not cheap houses either. In the millions. But he never specifies dry or not.
A Floor system made of Kiln Dried 2X10's or 12's that are properly stored and installed can be evry bit as strong and squeek free as I Joists.
A floor system of off brand I Joists can be every bit as much trouble as the worst framed wet 2X10 or 12 floor you have ever seen.
Floor squeeks come from a number of things. on dimensional lumber floors the three big ones are: Bridging that touches and rubs as the load changes or shifts, Nails that skipped of the side of the joist and Plywood that was not properly seated and secured(Nailed) in the glue.
I joists have their own set of problems. If you go with them make sure the company that supplies them provides you with a layout and that the framer follows it. I joist require items like crush blocks and special hangers. If the supplier can't or won't provide a layout, find one that will.
Just like a 2X10 floor make sure no nials skip off the side of joists. Make sure every block and such is nailed tightly. Make sure I joists are securely fastened at connections. All too often guys put on hangers and then slide the end of the joist in it but never really fasten it. The joist then moves around in the hanger as well as against the beam.
Last, make sure you use a name brand. I have on two seperate occasions been provided with off brand I joists and the outcome is ugly. The size was inconsistant. The ends were weak and frayed and they had been improperly stored.
Either floor will work well as long as you install it correctly.