Remove the wall covering (paneling or drywall) where the new door frame is to be installed with the proper tools: pry bar for paneling or utility knife for drywall. Remove the necessary wall studs for the door frame with the reciprocating saw. Do not cut out the bottom plate yet.
Cut two pieces of 2-by-6 3 inches wider than the door's rough opening with the electric miter saw. For example, a 36-inch door calls for a rough opening of 38 inches. This means the 2-by-6 pieces need to be 41 inches long.
Place the half-inch plywood between the two 2-by-6 pieces you cut in Step 2 and secure them with the 16-penny nails. This is the header for the door frame.
Mark the bottom plate and cut out the section where the new door frame will be installed (2 inches wider than the door). Cut two studs to 80 1/2 inches with the electric miter saw and secure them to full-length studs so they are even on one end.
Install the stud assembly to the bottom and top wall plate with the 16-penny nails. Next, place the header on top of the 80 1/2-inch studs and secure it with the 16-penny nails through the wall studs on each side of it.
Measure the distance between the top of the header and the top plate and cut two 2-by-4 pieces to this length with the electric miter saw. Install them with the 16-penny nails.
Things You Will Need
- Pry bar (if walls are paneling)
- Utility knife (if walls are drywall)
- Reciprocating saw
- 2-by-6 lumber
- Electric miter saw
- 1/2-inch plywood
- 16-penny nails
- 2 by 4 studs
- When cutting drywall, center the cut on a stud to make replacing the wall easier. When cutting the bottom plate, keep in mind it is the same as the rough opening, which is 2 inches larger than the door measurement. The short 2-by-4 pieces over the header can be installed with 1 1/2-inch drywall screws if needed.