I have recently been looking at metal stud framing in loft units going up in the Chicago area where the demising walls are 12′, but the partitions are only 8′ with runs exceeding 14′.Any ideas as to how or what keeps these walls from moving?Gauge?Glueing tracks to the floor?Framework is post and beam with t&g decking, 3/4 plywood and 3″ of lightweight
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Edited 12/5/2002 8:06:40 PM ET by JONRUZ
Replies
"demising walls"...." Now that's a new phrase for me. I take it that demise is the existing outside walls; which you say are 12 ft high. You say the metal stud partitions are only 8 ft high, but run as long as 14 ft; unbroken by intersecting walls?
Well, like any partition wall; be it wood or metal stud, the strength of the wall is determined by how well it is solidly constructed, braced, and attached to other walls, floors, and or ceilings.
If a non load bearing, metal stud wall is simply screwed down along the floor, and solidly attached at both end points to existing walls, this partition is not going anyplace. If the partition is a "stand-alone" wall that is not attached to any other wall, then the floor attachment becomes most critical. BTW, glue is not the answer.
One way to help strengthen the wall is to cut through the existing floor and have a stud extend down through this floor/subfloor and be bolted to an underlying floor joist. This technique can be done along the length of the wall at several locations. If using metal studs, I would be more inclined to sister in a wood stud to it and bolt the wood stud to the floor joists. Sistering in wood with metal studs is common practice for use as "backers" for trim around door and window locations.
Yes, metal studs can be had in different guages and this does make a huge difference in strength. Different types of sheathing also helps give the wall more ridgidty. A layer of plywood before attaching the drywall always helps in these circumstances.
As for your particular case, I'm not from Chicago, so I don't know what exactly is being built or the techniques they are using. I was amused by the fact that you thought glue might be the reason for holding the walls in place and therefore decided to respond back to you.
Perhaps someone from the Windy City can give you a better response.
LOL.
Davo
Davo-
In this case, running a stud through the floor is not an option. The building is post and beam with the t/g decking making up the ceiling for the floor below it. As for glueing, it seems to be common practice in the city for freestanding walls. Supposedly glueing the bottom track to the floor alleviates some of the horizontal movement not allowing the track to rock back or forth. Any other ideas?
thanks for the response
Usually when I have put in metal stud walls, the adhesive used on the bottom track is for sound control, to seal the small space between the (concrete) floor and the track. You'd be surprised the amount of noise that can get through the crack. I suppose it helps a bit with hold down power, but the track usually is screwed down enough that it would not add much.
You could run a full stud or a metal strap to the ceiling every 4 feet or more to strengthen it, or depend on abutting walls, if there are enough . . .
are there no floor joists..as per davo's suggestion?
JeffBuck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
No, there aren't any floor joists. Beams and purlins with exposed decking which would make coming through the floor unsightly.
thanks for all the ideas everyone
Edited 12/7/2002 3:48:36 PM ET by JONRUZ
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Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Just for clarification, a demising wall is the required fire-resistant wall between living units. It hopefully keeps your partying neighbor from burning your unit down.
there is a u-channel made to lie flat in the knock out hole in the metal studs available from where you get the studs. in commercial it is sometimes a requirement to add this if your walls get high or long. we framed metal studs wall with a 30 foot long stud length and that stiffner does help.
bye
don't forget that the lever arm on that wall grows longer exponentially for every inch you add to the height . why not go through the floor anyway, and make the brace going through decorative as it is fastened to the beam below. you could shape the end of it with an ogee or chamfer, with routed edges, or with copper wrapping, or with whatever other style you care to design into it. there is always a way, unless the client really doesn't want to pay for it, or unless you want to add another miracle to your portfolio.
Never saw a 14' long free standing 8' high wall. I guess it might work with 8" 16 ga. studs. While Chicago doesn't use UBC, UBC requires partitions to withstand 5 psf. Most cases that I have seen there are corner returns or intersecting tee's that break the wall into smaller lengths. I would want to run a post up to the structure at the end of a 14' long wall. With low railing walls (3'-4' high) I spec. steel tubes anchored to the floor (anchoring depends on the floor system) at 6' o.c. and 18ga metal studs (2 1/2" or 3 5/8") at 16" o.c..
Archy-thanks for the information. I've been a framer for the past 10 years only ever having worked with wood. Started a new business last year and am trying to land some larger jobs whereas most of the multi-unit dwellings in the area have been using metal. Up til this point have been doing rehabs and conversions of 3&4 flat buildings. If I get some time maybe I'll post the drawings (if I can figure out how to do that).
Don't know about the code requirements, but I've seen this done (I believe in FHB), where the bottom two feet or so of the wall is sheathed with cement board and then filled with concrete. Gravity then takes over. This was done for a tile wall, but could also work for sheetrock (second layer above the CB).
I'm sorry I can't remember the name, but there is a reinforcing "u" shaped steel bar stock that goes through the holes in the studs. Keeping the holes in the same line is critical. On the keyhole shaped hole, the bottom squared of opening is where the bar is locked in. You slide it through and then turn down and lock it firmly in position. I believe the bar comes 14-16 ft. If using in a longer wall, you lap the ends a stud space and tie wire them together. It does stabilize a wall quite good. We would use these in the lower portion of the wall, the top plates being fastened to the deck above. I would think there would be a spec on the ga. of metal used. The heavier track at the top would be more rigid than the lighter ga.
__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/