Gauge for metal studs (Construction of a darkroom)
I was wondering if anyone has a knowledge of construction, and could answer my question.
I am about to start building somewhat larger darkroom in my new building. This is a shared darkroom where we offer classes/workshops and rent out.
Temporarily, I have about 6-700 sq ft. space, and I am building about 13x20 ft room in the space. It is essentially a box in the space. It has its own ceiling at about 9ft high (ceiling height of the building is 14ft). This room is going to be divided into two separate darkrooms with 5 enlargers in each room.
My question is about the materials for framing. I have been using 2x4 metal studs for the outer walls so far (the building is built with bricks). They are light gauge like 25. I want to find out if I need to use a higher gauge studs for the room since it is going to be load-bearing with its own ceiling. I do not think there will be anything on top of the ceiling, but I would assume it has to carry itw own ceiling drywalls.
Does anyone do building for living and can answer my question? Let me know. Thanks in advance.
Good Afternoon, Tsuyoshi,
I don't have any particular expertise in this area, but I wonder if you might ever be wall-mounting any of the enlargers. In that case, I'd certainly want to be sure that the walls are beyond-the-normal sturdy.
Thank you for your suggestion.
Since this is a temporary space, I will not probably wall-mount the enlargers. This space will eventually come down...
My building is rather big (5500 sq ft), but I cannot finance all the construction right now. When I build the permanent darkroom spaces, I may consider wall-mounting though.
26 ga steel studs, placed vertically, will support a ceiling of drywall. The wall behind my enlarger is 12 feet, so I used the heavier 20 ga steel studs and placed 2 levels of cross bracing between those studs, for those concerns Konical mentioned. Still, there was too much vibration to wall mount the enlarger. The cost difference of 20 vs. 26 ga steel studs will not be that great, and the heavier studs will make a much nicer wall.
Originally Posted by Shinnya
Standard guage steel studs will work just fine. If I understand your description the ceiling studs are really not going to be load bearing, rather they will serve as ceiling joists on which you need to hang sheetrock, not bear the load on the building structure from above. If you can get 16 ft. steel 2x4s then you should have no concerns. You may need to attach stiffeners to the joist perpendicular to the direction of the joists. I would do this whether I was using steel or wood. For this, wood 1x4s will work fine.
OTOH, if you need to join shorter studs in the center of the ceiling span to reach the needed joist length you may want to use wood 2x6s instead. In any case I would build the walls and ceiling frame on 16 inch centers rather than 24 inch centers. Your structure should be plenty robust with good lateral support for sheet rocking. Using 24 inch centers tends to make the sheet rock wavy.
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That is correct that the ceiling of the room is there to carry sheetrock.
So as long as I frame 16" OC, I can use those light gauge metal studs provided that there is nothing on top of the room? Then, looks like I do not have to buy any more studs to build this room. That is great!
I will check if the cost of 20 ga is not that different or not. My assumption was that it will be somewhat different since I cannot buy them at HomeDepot readily. I will look into that regardless.
When people say a wall is load-bearing, it means that it assumes to carry the weight of structure above? What if I put a HVAC unit on top of the room? Now I have to use the higher gauge to support the weight, I suppose?
I have been a contractor by necessity for the last two years...
I would avoid placing an HVAC unit on the ceiling. This will induce vibrations into the structure which at the very least may cause enlargers to vibrate. You may want to suspend the unit from steel roof joists above or mount the unit on the floor. Whether or not the metal studs could reliably carry the load is unknown to me.
Originally Posted by Shinnya
To bear the weight of a HVAC unit may require the use of 18 guage steel. Also I would suggest the use of pressure treated wood on the concrete flooring for the plate of the steel partitions to sit on. This will reduce the possibility of rust damage to the steel bootom plate that would normally be touching the floor.
There is information online that covers good/approved construction practices with steel.
I thought of the vibration issue. I may have to hang the unit form the ceiling of the building. I am just trying to come up with the best possible solution to this right now.
I was going to place tarpaper underneath the bottom plate. I would think the moisture will rust the metal plate as the building has a concrete floor like you mention.
I still need to figure out the exhaust system and placement of lighting fixtures and switches... I will try to post the drawing of the space soon. Any suggestion is welcome.
Thank you again.
Originally Posted by donbga
I am an architect during days (many nights as well!) and thus cannot resist the temptation to make a few suggestions. First of all, since your walls will not have unbraced height* of more than 9 feet, the use of 3 5/8" x 25 gauge steel studs @ 16" o.c. is more than enough. Using 24" centers would also work IF you use 5/8" sheet rock.
*Assumes that the studs are continuous to the underside of the structure above and braced by the horizontal ceiling framing.
I agree that going to 20 gauge is better as it will give you a stiffer, flatter wall. Adding a layer of 3/4" plywood between the studs and sheet rock on the wall supporting the enlargers will go a long way towards eliminating flex and vibration. The lack of mass in normal steel stud construction is also a contributor to sound transmission problems so I suggest adding an additional layer of sheet rock to each side of the dividing wall and make certain to caulk the entire perimeter of the wall/floor junction as well. Sound behaves much like light, so if you can see a gap, sound will travel though it.
Assuming that the ceiling spans the 10 foot dimension of each of the two rooms you must use deeper horizontal members than in the walls. I'd say at least 6" deep. A way around this is to use the wall studs as horizontally framing that is spaced in exact alignment with the wall studs, and support them at mid-span with #10 wire attached to the underside of the structure above. This would give you very stiff and flat ceiling that also would easily support the weight of sheet rock, lights, exhaust fans, electrcial conduits and boxes, etc.. Alternatively the ceiling framing could be attached to the underside of the structure above using spare wall studs cut to length and used as "hangers". Not knowing the material of the floor underside above I can't say which would work best.
Some of the hanging work requires special tools so it might be best to use an experienced tradesman for the overhead work.
Good luck with your project!
Thanks for your expertise on this.
My concern right now is really to get it done in two months. Since this is a temporary darkroom as I move into the new building, it just needs to be functional for now. So, adding plywood or using higher gauge is not a quite option unless that is the only way I have to do it. Plus, I have loads of lighter gauge studs already...
And I have to say that this room will have to come down eventually as the permanent space is getting built. My question is always how eventual this is going to be...
Anyhow, I am trying to understand what you are saying here but it is a rather difficult language for me. The ceiling of the room spans the 10 ft dimension as you say (or at least that was what I was envisioning) as the divided room is 13'x10'. I would assume you are talking about how the ceiling should be framed. Is there any image I can take a look at of what you are describing?
By the way, floor joists of this building is 3x12 at 12" OC! (2 story building, and span is about 19') It was meant to carry some machinery, I suppose.
If you are interested, you can see 3D rendering by a link below. It is a heavy file by the way (15mb):
Originally Posted by RGyori