How to Frame a Rough Doorway

Measure the wood and cut it all at once using the skill saw. The two king studs don’t need cutting if you purchased precut studs at 92 5/8 inches. Cut two trimmers from 2-by-4 inch studs to 81 1/8 inches long, then cut the 2-by-8 inch headers to 33 3/4 inches long and two 2-by-4 inch cripple studs to 3 1/2 inches long. Measure the sheet of plywood and mark it for cutting. Cut one piece 8 inches wide by 33 3/4 inches long. Cut the floor and top plates the length of the wall, whatever that may be. Frame in the rough door opening first, then frame the rest of the wall.

Sandwich the plywood sheet between the two header boards and nail these together to create one header. Place two nails 1 inch in from the end, top and bottom of the 8-inch tall header on one side. Repeat on the other end of the header. Nail between these two positions following the dot pattern on the face of a No. 5 domino: four nails in each corner with one nail in the middle. Repeat this at 8-inch intervals across the header to secure the pieces together.

Mark the location of the king studs on the top plate. For a 30-inch-wide door, add 3 3/4 inches for the trimmers and the jamb. The king studs will sit on the outside edge of this mark. Mark the location of the cripple studs both on the top plate and on the header. These studs are equally spaced over the width of the header, roughly 11 1/4 inches in from each edge.

Connect the header to the king studs. The header spans the distance between the king studs. Place the header flat on its 8-inch side. Measure and mark the king stud 3 1/2 inches down from the top of the board. Turn the king stud sideways and abut its wider edge to the end of the header. Because you sandwiched the 1/2 inch plywood between the 2-by-8 inch header boards, the width of the header matches the longer side of the king stud. Position the header so its top starts at the 3 1/2-inch mark. This leaves a 3 1/2-inch tail of wood from the king stud on either side of the header. Nail the king stud to the header using the No. 5 domino dot pattern described in Step 2.

Nail the first top plate in the position marked for the door using the five-nail pattern from Step 2. Set the cripple studs between the header and the top plate and secure them with two nails through the top plate, 1/2 inch in from each of its edges. The top plate nails to the king stud horizontally with its longer side flat to match the width of the king stud. Toe-nail the cripples into the header with two nails on one side and a single nail on the other.

Secure the floor plate to the king studs following the same procedure for nailing the top plate. Confirm you have left enough room on the top plate to secure the trimmers in place. The floor plate should extend 1 1/2 inches past the king stud on either side; this is the exact width of the trimmer. (You may notice that your 2-by-4 studs do not measure exactly 2 by 4 inches, which is the measurement when the boards are cut at the sawmill green. After drying, they shrink to 1 1/2 inches by 3 1/2 inches.)

Set the trimmers underneath the header and next to the king studs. The trimmers will support the header once the wall is lifted. Secure the trimmers to the king studs with nails, again using the No. 5 domino pattern at 16-inch intervals along the length of the trimmer. Alternate the No. 5 pattern with a single nail between groups of five. Secure the trimmers to the floor plate by adding two nails to the bottom of the trimmer through the floor plate. Finish framing the rest of the wall.