Can steel studs hold a ceiling?

I'm considering steel studs but am curious if they will hold a ceiling up. Walls will be double 5/8" with GG and same for the ceiling. My spans will not exceed 12'. I'd planned to use wood 2x6 for ceiling joists. Will that hold a double 5/8" ceiling? Thanks, ashley

bassman wrote:

I'm considering steel studs but am curious if they will hold a ceiling up. Walls will be double 5/8" with GG and same for the ceiling. My spans will not exceed 12'. I'd planned to use wood 2x6 for ceiling joists. Will that hold a double 5/8" ceiling? Thanks, ashley

With cold formed steel framing - at a 12' span designed for L/360 - 16" o.c. - a 4" 20ga. SS section with a 1 1/4" flange will be capable of carrying the mandatory 10psf dead load and no live load. This is based on subject properties as designed by Steeler Inc. although other manufacturer's materials with similar properties should be acceptable. With a 2x6 joist, any # 2 construction grade material should be fine for a 12' span at 24" oc - at L/360 Rod

Thanks for the info, Rod. Sounds like 2x6 is the way to go. However, I should have rephrased my question: Will the vertical steel studs support a ceiling comprised of 2x6 joists and double 5/8" drywall? Also, if 24 OC, the wall studs should also be 24OC as well, correct? That way, each joist has a direct load to the floor, if I understand correctly. Another factoid: the drywall needs to meet firecode for a partition between commercial and residential use. I believe this means Type X gyp and that weighs a bit more. -ashley

If you do double 5/8, that's probably way more fire protection than a single layer of "type x." Check with your local building department. Then again, I recall it was difficult/impossible for me to find 5/8" that was not Type X locally. I don't think Type X is heavier than non Type X. In fact, I think the opposite may true, slightly. --Keith :mrgreen:

According to the city inspector, I need two layers of 5/8" Type X to meet the fire partition requirements. If they weigh almost the same, shouldn't be an issue. -ashley

Type X is slightly lighter in weight, and (from IR-761 document) results in a SLIGHTLY lower TL at most frequencies, but not enough to worry... Steve Oops - for steel WALL studs, there are light gauge for NON-structural (won't hold up a ceiling) that are 25 gauge, and heavier ones for structural (usually 20 gauge) - the reported TL improvement for steel studs is ONLY for the light, NON-structural ones and is caused by FLEX. Placing wallboard on BOTH sides of the 25 gauge studs gives nearly the same result as using resilient channel on a wood stud frame, because the steel flexes (therefore decoupling the two sides a bit) No such advantage in TL for the structural ones, but they definitely WILL support a ceiling if properly sized... Steve

I'm currently looking into something like this for my forthcoming construction: (sorry, link is only in german, but it should give you an idea) Richter System Steel Building System Basically, the principle here is to have separate studs for the structural stuff (load bearing), while the walls itself can be built with standard steel studs (i.e. flexible ones). See the picture at the bottom of the page... You can build ceilings with bearing capabilities of up to 500 kg/m2 with this system, which should be more than enough... I hope I'm still getting the advantage of the flexible steel studs here... (just discovered this system some days ago, need to investigate more about prices etc...) cheers :P

This might help---It's working great for me---this steel grid will hold up to 2 layers of 5/8" rock in a ceiling formation... http://www.bpb-na.com/us/english/ceilin ... rygrid.php

...With cold formed steel framing - at a 12' span designed for L/360 - 16" o.c. - a 4" 20ga. SS section with a 1 1/4" flange will be capable of carrying the mandatory 10psf dead load and no live load. This is based on subject properties as designed by Steeler Inc. although other manufacturer's materials with similar properties should be acceptable. With a 2x6 joist, any # 2 construction grade material should be fine for a 12' span at 24" oc - at L/360 Rod...

When you say 20 gauge, does that mean structural or drywall gauge? See below: Thickness Mil In. Gauge 18 0.0188 25 27 0.0283 22 30 0.0312 20 - Drywall 33 0.0346 20 - Structural 43 0.0451 18 54 0.0566 16 68 0.0713 14 97 0.1017 12 thanx, K

I am just about ready to order steel joists (s-section studs) and corresponding track (or perhaps boxing, or back-to-back-ing 2 single studs to create 'header' joists). The studs would be: 400S162, 33 mil (20 gauge). This means 4" by 1.62".... According to appropriate span tables, with a mid-span lateral support of the flange, L/360 deflection, and 13 psf load (no 'live' loads for ceiling joists), 16" OC, I could span 12' with only a SINGLE stud-joist without track. The actual span will only be 11' or even like 10' 6". Now, the 'load' would be the joists themselves, and 3 potential layers of 5/8 " sheetrock (I may opt for two layers of 1/2" cementboard, with a 1/32 " layer of layer of lead between them (?), doing this ONLY to save headroom... as I otherwise would be approaching the 7 foot code miniumum height). So... the joists weigh 0.94 pounds per linear foot; that would be about 3/4 x 0.94 = 0.71 psf added to the load (at 16" OC).... I would round that to 1 psf to include the weight of mid-span blocking and such. If I used a stud in a track, or boxed studs, the weight would be approximately doubled to 1.41 psf ..... I would round that to 2 psf to include the weight of and mid-span stabilization, etc. For the single joist system, that leaves 12 psf for the weight of the sheetrock, etc. For doubled joists, or nested joists, it would leave 11 psf remaining.... BUT of course the capacity of doubled joists would be significantly increased, leaving a very large safety buffer... 3 layers of sheetrock should weigh no more than 8 psf. Anyone please care to comment on this idea? Remember, my reasoning for using 4 inch steel ceiling joists is due to the lack of headroom, and the pre-existence of 2 x 8 above floor joists (that now have been sistered to accommodate the weight of between joist sheetrock of outer-leaf). (So, I can't really use 2 x 6 wooden ceiling joists; if I put them too high, I lose blocking height of the floor joists; if I put them too low, I lose headroom.) thanx, K

Hey K, I followed all your math (although I didn't double-check any of it or verify your assumptions ;-)), and it all seems very solid. It's good to see another example of that level of analysis. Everyone should be doing this! 8) I don't think I'm a fan of using cement board on the ceiling, especially such a large one. Not only would it be a lot more difficult to install, it's a lot more expensive than drywall. It just seems that's a lot of trouble and expense to go through to save a bit of thickness. Have you considered 2 layers of 5/8" with Green Glue between them? Green Glue is expensive, but it is very easy to use and seems like a great prescription for this challenge. --Keith :mrgreen:

sharward wrote:

.... I don't think I'm a fan of using cement board on the ceiling, especially such a large one. Not only would it be a lot more difficult to install, it's a lot more expensive than drywall. It just seems that's a lot of trouble and expense to go through to save a bit of thickness. Have you considered 2 layers of 5/8" with Green Glue between them? Green Glue is expensive, but it is very easy to use and seems like a great prescription for this challenge. .... --Keith :mrgreen:

Thanx Keith. Yeah, the cementboard concerns me too a bit (although one thing would be that it certainly wouldn't dent as easily as regular sheet-rock would -- good for all those 'high-hefting' guitar necks and such). I have to weigh the material expense and installation difficulty with any savings in having to add an additional layer, and also any other cons/pros.... also, there seems to be question on it's TL properties (but mainly because it specifically hasn't been tested for it, like sheet-rock has) Still a bit down the line to consider at this moment anyway, so I have time.... As for the steel, I would like to order soon because there is a quarterly price increase starting in June... and it's like 10 or 12 percent -- enough to add at least 50 bucks to the cost... (I know. It's ironic that I could spend more on cementboard, yet wanna save on the steel...) Anyway, thanx for the encouragement.... I think I covered the 'calcs' okay, but wanted another eye to check it out.... I think I'll order what I need for the ceiling joists now.... K

Luftweg A few technical observations that you may be aware of but are not addressed above in this thread. Perhaps you were intending to finish the cement board with some product but your weight calcs did not include it so I assume you were considering installing cement board and treating it in the same fashion as drywall..... Don't do it, you'll be sorry. Most (all) manufacturers of cement board recommend the use of latex modified thinset as joint treatment. I've personally witnessed hundreds of instances where the installer attempted to finish cement board with drywall mud only to have it fail. I'll spare you the techno-babble as to cause. Next most manufacturers require the use of their proprietary fasteners when installing their product to steel studs. These fasteners are made to latch onto the fibre mesh on the exterior of the cement board. Regular drywall screws will not do this. These proprietary fasteners are a pain in the butt to work with and to get flush. Countersinking them is not an option as you would loose all your fasteners pull strength. Ok, since I'm new and anything I say is questionable here's the link to USG's installation pdf for Durock. http://www.usg.com/USG_Marketing_Conten ... _Guide.pdf Hope this helps your decision making. Bryant

I actually may only use the cementboard in one relatively small area, and that is on the soffit around the centerbeam and main HVAC duct. The reason for this is that I don't want to lose even a inch of headroom here, as it will already be getting quite low.... I have to go back to the data sheets, but I think I can get the same amount of mass from two 1/2 inch layers of cementboard with a sandwich of 1/32 inch lead between, as I would get with three layers 5/8 inch sheetrock (so that's 1 inch versus 1 and 7/8 inches). I'm not quite there yet, so I will be pondering the exact treatment til then... thanx, K

Bryant wrote:

Luftweg A few technical observations that you may be aware of but are not addressed above in this thread. Perhaps you were intending to finish the cement board with some product but your weight calcs did not include it so I assume you were considering installing cement board and treating it in the same fashion as drywall..... Don't do it, you'll be sorry. Most (all) manufacturers of cement board recommend the use of latex modified thinset as joint treatment. I've personally witnessed hundreds of instances where the installer attempted to finish cement board with drywall mud only to have it fail. I'll spare you the techno-babble as to cause. Next most manufacturers require the use of their proprietary fasteners when installing their product to steel studs. These fasteners are made to latch onto the fibre mesh on the exterior of the cement board. Regular drywall screws will not do this. These proprietary fasteners are a pain in the butt to work with and to get flush. Countersinking them is not an option as you would loose all your fasteners pull strength. Ok, since I'm new and anything I say is questionable here's the link to USG's installation pdf for Durock. http://www.usg.com/USG_Marketing_Conten ... _Guide.pdf Hope this helps your decision making. Bryant