Question
We are residential remodelers/installers and very seldom do commercial, but we have one coming up with a fair amount of high end cabinetry in conference rooms, etc. I'm not that familiar with commercial construction, but I will be screwing into both interior and exterior walls. The interior will be metal studs, but will the exterior be more structural/heavier gauge? What do you use for screws into regular steel studs and possibly heavier gauge?
Forum Responses
(Cabinet and Millwork Installation Forum)
From contributor J:
Do a search for "metal studs" and you'll find a lot of information and wisdom. I've been down this road myself in the last few months doing lots of work in hospitals. We screwed the cabinets to the wall with 2 1/2" fine thread drywall screws. I'm not crazy about using those because they're more brittle than installation screws, but they will hold in the metal. My regular installation screws with Type 17 tips wanted to strip out. I'm not sure what the answer is for the exterior walls. If the building has a maintenance supervisor, you'll want to ask them. In these hospitals I've been working in, the maintenance crews have been more than helpful.
Perhaps it was my inferior stud finder, but I had a hard time locating the studs behind the 5/8" drywall (sometimes double layered). Luckily, all the installations were in rooms that had suspended ceilings. I pushed up the ceiling tiles and could see where the studs were. The drywall only went a few inches above the ceiling so I could shine a light down into the wall cavity to see where wires, pipes, etc. were as well. That was nice. All of these walls, so far, have been on 24" or irregular centers. In a couple of situations, with smaller cabinets, there was nothing to screw into, so we used toggle bolts to secure the cabs. Those were rare and only with base cabinets. Had it been wall cabinets, I'd have added a good bead of Liquid Nails to make me sleep better.
Our typical box install on metal studs is to use 2 or 2 1/2 drywall screws and to double them up at top of the box. Sometimes we may use beauty washers and zinc screws, or if the box has a solid 3/4 back, we might countersink and putty or vinyl sticker the heads. Up to about 16 gauge we tend to use regular pointed screws and for the heavy stuff we go with the self-tappers. The tensile of the stud, skill of the installer and phase of the moon may actually dictate which screw to use. I can get a pointed screw to go most of the time and prefer them over self-tappers because it seems that self-tappers strip out faster. Yes, the screws do seem more brittle and will snap, but I also think that they are a smaller diameter than most wood screws.
If you are designing the boxes from the get go, allowing for furring strips behind them is the best route maybe, and then the stud layout is not as important. Adding glue does give peace of mind but is not the cure all. Toggles or one of their cousins are nice too, but again, not the cureall. Sometimes you would be better off opening up the wall and adding blocking.
Installing a $200 box on a wall over a $20,000 copier with 20 cents worth of screws knowing that the box will be stuffed with reams of copy paper, is risky business. Blocking is the right way to go, and whoever makes the call not to install it should be the one to accept the risk.
P.S. Sometimes if the boxes don't go to the ceiling, we add a continuous angle or cleat at the top back of the run.
For the Liquid Nails, I always insist that the walls be at least primed, because the glue doesn't stick to joint compound dust too well. Thinking about the box full of copy paper above the printer was a real life experience. A single 36" wide upper over a copier and two light gauge studs in the wall. You can believe I peppered the back of the box with screws and a tube of Liquid Nails and even considered adding some allthread through the ceiling to the bar joist for good measure. It's still there as far as I know.
