Roughing-In an Opening
If you plan to install a door in your wall, find out the rough opening dimensions you’ll need. For a prehung door, measure the outside dimensions of the jamb and add 1/2 inch for shimming. With a slab door (one that is not prehung), measure the width of the door, add 2 1/2 inches for the side jambs and shims, and add 2 inches to the height for the head jamb, shims, and flooring. Standard door widths are 24, 26, 28, 30, 32, and 36 inches. Door heights usually are 80 inches. Jack studs are the vertical 2x4s on each side of the door opening. They are attached to a king stud or to another jack stud. This doubling of studs provides solid, unbending support for the door.
The header is made of two 2x6s with a 1/2-inch plywood spacer sandwiched in between. (The plywood is needed to make the header 3 1/2 inches thick, the same thickness as the wall framing.) The header rests on top of the jack studs and spans the top of the opening, supporting overhead loads. For openings that are less than 3 feet wide, you can use 2x4s instead of 2x6s. Cripples are the short 2x4s added between the header and the top plate. They maintain a 16-inch on-center stud spacing for nailing the drywall and help distribute the weight equally from above. A window opening is much like a door opening. You install a sill (much like a header) at the bottom height of the window and add more cripples between it and the wall’s bottom plate.
Frame around an I-beam. Use 2x2s to frame around a narrow obstruction, such as a beam. Fasten the frame together with screws rather than nails because the structure will be wobbly as you work. Drill pilot holes whenever you drive a screw near the end of a board. Make chalk lines on the joists, 1 5/8 inches out from either side of the beam. On every other joist, attach a vertical 2x2 to the joists, cutting them to extend 1 3/4 inches below the bottom of the beam. Fasten horizontal pieces to the bottom ends of the verticals, then fasten horizontal pieces at the top, driving screws into both the vertical supports and the joists. Finish the framing by installing short horizontal cross pieces about every 4 feet between the bottom horizontal frame members.
Frame around a pipe. You can cover a soil stack or other tall, narrow obstruction with a frame. Mark lines on the floor and measure for top and bottom plates as you would a regular wall. Draw plumb lines on the walls to use as guides. Build three narrow walls of 2x4s or 2x2s; raise them into position; and fasten them to the floor, ceiling, wall, and each other.
Working with Metal Studs
Metal framing costs a good deal less than wood 2x4s, and it is lighter. Metal is not susceptible to rot or insect damage, and the factory-made pieces are free from bows, twists, knots, and other imperfections that sometimes make wood hard to work with. Working with metal studs takes some adjustments. You can’t build walls on the floor then raise them up. Instead, you must install the top and floor runners, then insert the studs. Cut metal studs with tin snips or a circular saw and metal-cutting blade. Fasten the pieces together with self-tapping screws.
If you make a mistake, it usually is easier to move a metal stud than a wood one. Running electrical wiring and pipes for plumbing is easy because punchout holes are precut in the studs. On the downside, once walls are built, you can’t attach items to metal stud walls as easily as you can with wood walls. You can fasten items to a metal stud with a screw, but not a nail. If you plan to hang cabinets or shelves on the wall, cross-brace the wall with C-runners. Doorjambs and windows can be attached to steel framing, but it’s easier to shim and attach the units if you use wood framing, fastened to the metal studs, around these openings.
Caution! Watch Out for Metal
The ends of metal studs, especially those that you cut, often are very sharp. When working with metal, wear gloves. If you're cutting with a circular saw and metal cutting blade, wear long sleeves that are not loose or floppy.
Cutting metal also can be dangerous because small pieces of metal fly through the air. Be sure to wear eye protection whenever you cut metal studs.
If you run electrical wiring through metal framing, use sections of plastic foam pipe insulation or specially made plastic grommets to protect wires from damage.
1. Cut the studs. Lay out framing as you would for a wood wall. Cut the runners to be used for top and bottom plates to length with tin snips. Or, use a metal-cutting blade on a circular saw. Using a circular saw is faster, but make sure no one is in the area as you cut, and wear protective eye wear and clothing as you work.
2. Attach the ceiling runner. Position the ceiling runner and attach it to each joist with a drywall screw. If joists run parallel to the wall, install cross-bracing so there is something to which you can attach the runner. Position the floor runner directly below the ceiling runner, using a plumb bob. Attach it to the floor with screws or masonry nails.
3. Cut and insert the studs. Cut the studs to length with tin snips. Insert them into the runners, starting at a slight angle and twisting them into place. For easier plumbing or electrical installation, make sure all the stud legs are pointed in the same direction and all the predrilled punch outs line up.
4. Attach studs to the runners. Once studs are placed correctly, drive in 7/16-inch pan- or wafer-headed screws through the runners and into the studs. Hold the stud flange firmly against the runner as you work. Drive in four screws, one on either side of each runner at the top and bottom.
5. Attach headers. Where you need a door or window header, cut a stud piece 8 inches longer than the width of the opening. Cut the two sides of the stud 4 inches from each end so you can bend back a tab, as shown. Slip the tabs into place and attach with screws.
6. Install the drywall. Inspect the framing to make sure you have a fastening surface for drywall at all points. Attach the drywall with drywall screws placed 8 to 12 inches apart. Install corner beads with screws or staples. Tape and finish the walls.