DIY Fitting Interior Doors

Purchase a Pre-hung Door

Pre-hung doors come already hinged. Before purchasing one, measure the thickness of the wall so that the new door jamb is flush with existing wall surfaces. When you order the door, you will choose the height, width, which side of the door the hinges will be set on and whether to have the factory drill holes for the lockset.

Remove the old doorjamb and door by removing the hinge pins. Then remove any trim covering the doorjamb and the wall. Remove the jamb. Try prying the jamb away from the studs, beginning at the bottom or, if you own a reciprocating saw with a demolition blade, slip the blade between the studs and the jam and cut out the nails that secure the jamb. You should now have a rough opening.

Before fitting the new interior door, check that the lockset hole is drilled properly, the hinges are even and the doorjamb is square. Check that the door swings in the proper direction. Then, with the squaring supports intact, rough fit the new door into the roughed in opening. Tilt it with the bottom first and the top going in last. When you have it in the opening, take off the support straps. Then center the door to make sure it will open and close easily. Square the door with tapered wood shims. Push them into the space between the pre-hung jambs and the studs in the opening.

Install the door on the jamb's hinged side, working on the bottom section first. As you are mounting the door, keep checking that the doorjamb is square. Use 10d-finishing nails to secure the jamb into the studs. Allow the nails to protrude about 1 inch until you have finished nailing both sides of the interior door in place. Check that the door is square, and then repeat the process for the top hinges and then the middle hinges. Adjust the doorjamb on the other side, nailing as you did before except in the area where you will need to cut the door latch.

Check that there is at least a 1/8-to-1/16 inch space between the edges of the door and the jambs. If it does not appear even, take out the nails and adjust the door with the shims. Replace the nails and check it again. When the door is even, you can install the lockset. After the lockset is in, finish hammering in the nails and test that the door opens and closes easily. Nail in the trim with 6d-finishing nails.