The "three stud corner" is a good choice for stability and the best choice for providing a nailing surface for interior wall covering, should you opt to use one. This corner is made up of three studs nailed together or two studs sandwiching blocking that acts as a spacer. Don't make the most common mistake: not nailing flush on all surfaces.
At the same end of the wall where you began your layout, three studs should be nailed together and installed into the wall. Secure all corners together with 16d nails every 16 inches. At the opposite end of the wall, where the plates are 3½ inches shy of the edge of the foundation (due to the over-lapping walls), place a single stud.
Walls with Doors or Windows
In many ways, laying out the walls with standard openings of doors and windows should be handled the same as walls without openings. Even when placing doors and windows you will need to continue with the 16" (or 24") spacing for the cripple studs.
Most Common Mistakes
Avoid the most common mistakes: boards cut to the wrong size, using warped or bowed stock around openings, headers not nailed flush with king studs, and building the opening with wrong dimensions. Check all measurements three times. This is by far the most common mistake in wall building.
After you have completed your normal layout as described in the previous pages, you will also need to mark the centerlines of all door and window openings onto the plates. When positioning a door or window opening in a wall, check your blueprints for the distance from the edge of the wall to the center of the door or window opening. Measure and mark that position on both plates.
The width of the "rough opening" is equal to the outside dimensions of the door or window opening. It includes the jamb plus ½ inch for margin of error. The rough opening widths and heights should be marked on your plans or in your window manufacturer's specification chart. Each manufacturer will specify these measurements for each window or door unit. Measure one half of the rough opening width in either direction from the center mark and draw a line across both plates. Check your measurements three times to be sure.
Example: If the center of a window is 54" from the edge of the wall, measure in that distance from the end of the wall and make your center line mark. If your rough opening is 3'4" (40"), measure 20 inches to each side of the center line mark. Draw a line across both plates.
Next, mark the positions of the trimmer and king studs, remembering that these fall to the outside of the marks, because the rough opening width is measured from the inside surface of one trimmer stud to the inside surface of the other trimmer stud. Place a T (for the trimmer) on the outside of each line. Place a K (for the king stud) on the outside of each T. This shows placement of the trimmer-king studs. The king and trimmer will both be full-sized studs if you are using metal header hangers. You will need to cut the trimmer to size if you are not using these metal fasteners. Both of these studs should be of the straightest stock possible.
Nail the trimmer to the king with 16d nails at a slight angle every 16 inches. Be sure the trimmer and the king are flush along all edges as well as flush with the plates at either end.
Over the door or window opening is placed a header. This can be made like a sandwich from two pieces of standard 2 inch stock with a filler of ½ inch plywood. This will create a 3 ½ inch thick header (1½" + ½ + 1½") to match the 3 and 1/2 inch thick wall. Also 3½" thick header stock is available in some areas. The size boards to use (2" x 6", 2" x 8", 2" x 12" etc.) will be determined by your local code. Often builders will use 2" x 12" which requires no cripple studs above it, thereby making the framing easier.
Headers can be attached to the trimmer and king studs in two ways. The simplest is to use metal header hangers that hang the header from the studs. In this case, both the trimmer and king studs are full-size studs. Measure and cut the header stock to the width of the rough opening. The alternative is sitting the header on top of the trimmer stud and nailing it into the king stud. The trimmer is cut so that the bottom of the header is at the required height of the opening. Here the header is cut to the rough opening width PLUS 3 inches, so that it sits on top of the trimmer studs.
Check your plans to determine the exact height of the headers. For most openings, the distance from the slab to the bottom of the header is 6' 9" (81 inches). This accommodates a standard 6'8" door plus one inch for the jamb and play.
Rough sills or sill supports for windows should be cut to the width of the rough opening. Check your blueprint for the distance of the sill from the floor, then measure and mark it on the trimmer studs. The sill supports can be easily attached with special metal fasteners called framing clips.
Cripple studs are standard 2" x 4"'s used above door and window openings between the header and the top plate (unless you have used a 2" x 12" header) and below window openings between the rough sill and the bottom plate. There should be one cripple stud for each original 16" layout mark X falling within the rough opening. Change these X's to C's. The cripple stud should be "toe nailed" (at an angle) into the header. Be sure all cripple studs above the opening are exactly in line with those below the opening.
Nail all framing pieces together with 16d nails or use the nails provided with the metal fasteners. The portion of the bottom plate which falls within the door opening will be cut out before installing the door.