I got a print today for a church to build the stage/platform. It will be 14 inches above the floor, and it calls out metal joists with fire treated plywood decking. I have used metal studs before, but not joists. Any ideas, pictures, or where can I get these things? Can I just use 2×8 studs on edge? I dont think they would be strong enough on edge like that. Let me know what you know.
Dennis
Replies
If they are genuwine prints, were they prepared by an arch or engineer? If so I'd assume they did the proper calculations and in any event changing the specs makes you liable for any issues. I'd imagine they spec'd metal for fire code issues...
PaulB
http://www.finecontracting.com
I would think you would not want to use metal studs on edge.
If someone spec'd them, they must know what they wanted. They would be the ones to ask.
Here is but one source:
http://www.dietrichindustries.com/TRADEREA.HTM
the code here addresses stages in public gathering places... if constructed out of wood they want the area under the stage sprinklered (if thats a word) and yes metal joist are just like metal studs... the nice thing about metal is that you can keep the size and just go up on the gauge to get the strength required..
self drilling pan head screws.. and PL makes a metal to wood glue that I'd use under the decking... for the decking you use a self drilling screw with "wing" that drills the wood then the wings break off when you hit the the metal joist... they are usually self countersinking also...
if you don't have one ... go to harbor freight and get one of their 7.25" carbide metal cutting blades for your skill saw... (not the fricton blade) this blade will cut metal like it's wood... $18 (i was cutting stacks of 20 sheets of metal roofing this week with one... like cutting wood no/very few sparks)
good luck
p
"...sprinklered (if thats a word)"Yes, it actually is, although it sounds really weird. I've sat at hearings where the architect himself used that word, and nobody laughed. You only want the space SPRINKLED if there's a fire.Last time I dealt with commercial stages and audience risers, we had to use Non-Com (non-combustible lumber and plywood) for all spaces over 12" in height. So when the inspector caught me using foam sill-sealer (to reduce sound transmission) under the first set of audience risers, he said, "Aha! Combustible materials!"Luckily, he had caught me on the first riser, so my reply was, "Good point, I missed that, but we're at less than 12"." So for the next sets of risers, we used old-style fiberglass sill-sealer, and were in compliance throughout.AitchKay
Used all the time. You have to use structural steel joists. Not what you think of for partition walls.
What do the plans spec? should have a size and guage
http://www.litesteelbeam.com
Can get from 84's and Gordon Lumber and Home Depot in my neck of the woods
Edited 11/27/2009 2:49 am ET by qtsam2
in the mid 90's, a local drywall supply place, that also sold a lot of steel studding, decided to get into the light steel framing (i think that's what its called) market.i had heard about it, and decided to use it on an upcoming project. the steel company did all the calcs, and the supply house delivered the package.it was a small balcony redo, so i think they were the equivalent of 2x8's, about 8 or 10' long. it was a great product, perfectly straight and dimensionally consistent. they hadn't sold a lot of it, so the steel company sent out a rep to see how it was going, and get some feedback. told him it was all good, except, as a carpenter, it was weird going home smelling like a mechanic.anyway, it never caught on, and the supply hose quit carrying the product.
Built them many times. Like Barry Said -- not the gauage you normally think of as wall studs. Check the specs, should be 16 or better 14 gauage ( 16 and heavier are structural ). It's best to build a knee wall at each side to carry the load, don't depend on the trac at each side to carry the load, and bridging at evey 6-8 ft ( we make them out of cut-offs, cut off flange ,and bend to 90 at ends, and put together with tek screws {the hex head,self tapers} ). Also use 2 layers of 3/4" or 1/2"ply for a really solid floor.
The most solid I've done was with 12" 14 gauage, with 16 ga. knee walls on each side, bridging at every 6', and 2 layers of 3/4" ply. you could have driven trucks over it with no bounce or deflection. P.S. - used std self tapers to screw down the ply, you don't need the screw with the snap off wood drillers as mentioned, although they do come in bigger ( gauage ) sizes.
I just got off a gig at Disney area attraction, on a walk way thru the attraction, where the contractor didn't build the knee walls or bridging and 1 layer of 3/4' ply. The floor had sqeeks and bounce everywhere. When we pulled the carpet and cut an access hole for ispection. It was a walk way 6 1/2 wide and 39" above the concrete floor, many of the screws holding down the ply had striped from the bouncing, and when my partner ( 6'7" 270 lb. ) walked over it, the trac flange was also flexing. Two of us spent a week and a half crawing around there building knee walls and shoreing it up, with a small access hole at one end of it . And removing the carpet an rescrewing all the ply. One of those gigs that sucks.
As an alturnative, you can get fire treaded lumber, in just about any size, but think special/ special order and $$$$, and make sure you wash your hands befor eating lunch or bitting your nails.
Roger
I work with steel studs regularly. We have built a few stages and lots of loft platforms with metal studs. Usually 16 gauge or heavier, 8" upunched and with a larger flange, 1-5/8", 2" or bigger. The major manufacturers have span tables, but something in a public building of course would have an engineers stamp.
Cemco does make a structural floor joist with holes for MEP penetrations.
http://www.cemcosteel.com/ca-4.aspx
Mike
Small wheel turn by the fire and rod, big wheel turn by the grace of god.
OK, I've read all your replies, a lot or good information. Where do i get this stuff? Ths architect has spec'd all the wall information, but nothing for the platforms. Since I can't get ahold of him until next week, can you give me any ideas of sources for this stuff. Drywall supply house maybe? Thanks, Dennis
Yes, commercial drywall supply house. See what manufacturer they deal with the most, and they should be able to set right up. Mike
Small wheel turn by the fire and rod, big wheel turn by the grace of god.