Metal Framing Basics
Steel stud facts
I've heard that houses can be framed with steel studs instead of wood studs, but I haven't found much information about this topic. Specifically, I would like to know how the framing elements are fastened together and how wiring and plumbing are routed through the walls.
— Nick, Waipahu, HI
Tom Silva replies: I've installed a lot of metal studs in remodeling projects, though I've never built a whole house out of them. But I can tell you that light-gauge steel framing is different in several respects from wood framing.
For example, the horizontal plates at the top and bottom of walls are U-shaped tracks that the C-shaped studs fit into. The edges of the track are then simply fastened to the edges of the studs with self-tapping screws, which cut their way into the metal without pilot holes. Not surprisingly, your main tool in this work is a screwgun instead of a nailer or a hammer. A cut-off saw, basically a chop saw with a 14-inch abrasive blade, takes the place of a miter saw for trimming studs to length.
I think it's easier to run wiring and plumbing supply lines through light-gauge framing than through wood because metal studs have holes, called knockouts, already punched in them. If you're using an electrical cable like Romex, however, you have to snap in a plastic grommet to protect the cable's soft plastic sheathing from the holes' sharp edges. For armored or BX cable, which has flexible metal sheathing, there's no need for grommets.