To install an interior door, check if floor is level, check the trimmers and walls, add shims, fit the door, check the reveal, anchor the door jamb, change the hinge screw, add the split jamb, and attach the lockset. You need a pre-hung door, a lockset, shims, a strike plate, 4D finish nails and 8D finish nails. You also need basic carpentry tools, including a 4-foot level and a 3/4-inch chisel. This project can be completed in 4 to 6 hours.Continue Reading
Place the 4-foot level in the doorway on the floor. The hinge side must be level or slightly higher than the latch side for the door to hang properly. If the latch side is higher, place shims under the level until the bubble is centered. Hammer a finishing nail into the shims to hold them in place.
With a plumb bob, check to ensure the trimmer studs and walls around the door are plumb. With the framing square, verify if the trimmers' faces are square with the wall. Make sure the trimmers are parallel to one another.
Measure from the bottom of the hinge jamb to the center of each hinge. Measure the same distances from the floor along the hinge-side trimmer and mark the locations of the hinges.Place the plumb bob at the top of the hinge-side trimmer. Drop the string and measure the distance between the string and the trimmer at the hinge marks. Tack overlapping shims with a finishing nail where the gap is the smallest. Place shims at the other hinge marks, and adjust the thickness so that the distance to the string is equal to that of the first. Cut the shims with a utility knife, so they do not stick out past the drywall.
Place the door into the opening, and push it up against the hinge-side shims. Three inches below the miter, tack an 8D finishing nail through the face of the hinge-side casing. Tack two more nails through the casing at the other hinge locations. If the wall is not plumb and the casing is not flush, additional adjustments must be made with shims.
The horizontal gap at the top of the door is known as the reveal. Measure it across the doorway. It should be a uniform 1/8 to 3/16 inch wide. At the top of the door, set the reveal with an 8D finishing nail through the face of casing into the trimmer on the latch side. The vertical reveal on the latch side should be the width of a nickel. To set the vertical reveal, nail 8D finishing nails every 16 inches along the latch side.
On the latch side, near the top of the door, slide shims between the jamb and the trimmer. When they are just touching the jamb, nail the shims to the trimmer with 8D finishing nails. Repeat just above the base of the jamb, as well as below and above the strike plate.
From the hinge jamb, replace the middle screw of the top hinge with a screw long enough to go through the trimmer.
Push the split jamb into the groove of the main jamb. With both hands, tap the two together. On both sides of the miter, drive nails into the casing every 18 inches. To secure the two jambs, add a nail at each hinge through the shims at the top and bottom of the latch-side jamb, as well as above and below the strike plate.
Screw the strike plate onto to the latch jamb. Slide the latch bolt into its hole in the door, and screw the plate onto the edge of the door. Fit the door knobs on either side of the door, and tighten the screws that connect them.