How to Hang an Interior Door Using an Existing Jamb

Measure the door opening's length and width. Subtract 1/4-inch from these measurements to determine the door slab's size. Transfer these measurements to the door. If the door is larger than necessary, run a strip of painter's tape along the door edge which needs to be cut. Mark a straight line on the tape and cut along the line with a circular saw.

Place the door in the opening. Put wooden shims along all four sides to center the door in the opening. Make sure all the gaps between the door and the jamb are even. Use a pencil to lightly mark all three hinges' tops and bottoms onto the door. Mark the latch hole's location in the strike plate as well.

Remove the door from the opening and set it on the ground with the hinge edge facing up. Align a hinge butt gauge stamp's top and bottom edges with the top hinge's two marks. Hit the stamp with a hammer. The stamp outlines the hinge as well as indicates how deep to mortise. Repeat with the remaining two hinges' marks.

Place a 1/2-inch wood chisel in one of the hinge outlines. Hold the chisel so it is almost flat on the door edge's surface. Tap the chisel's end with a hammer to drive it through the wood. Remove the wood in the hinge outline to the depth indicated by the hinge butt gauge stamp. Repeat with the two remaining hinge outlines.

Drill the doorknob's hole using a hole-saw kit. Position the kit so the doorknob hole is centered over the mark you made indicating the latch hole. Drill through both the large doorknob hole and the smaller latch hole. Install the doorknob onto the door.

Lift the door up to the opening. Position the door so that each hinge lines up with its mortised area. Set each the hinge leaves into the mortised areas. Install a Phillips-head drill bit in your drill and secure the hinges in place with their supplied screws.