Prehung Interior Door Installation Print
Overall Skill Level: Intermediate
Installation instructions for prehung interior doors.
- Check opening dimensions
- Place door into the opening
- Install shims at the hinges
- Securing the unit
- Check for square and plumb
- Tack frame
- Shim the strike side of the door
- Verify measurements
- Shim the head jamb
- Fasten the head jamb
- Verify measurements and adjust shims
- Secure the unit with finishing nails
- Replace center screws on the hinges
- Apply casing
- Finish the door unit
- 6' Level
- Tape Measure
- Interior Door
- 2 1/2" Finishing Nails
- 2 1/2" Screws
- Stain, Paint, or Clear Coat
Prehung Interior Door Installation
Check opening dimensionsCheck your rough opening dimensions. The rough opening height should equal the door height plus 2 ½". Standard door height is 80". The rough opening width should equal the door width plus 2" (Figure 1)
Place door into the openingPosition the door unit in the rough opening; center the unit so that you have equal spacing between the unit and the wall on each side.
Install shims at the hingesPlace shims between the door unit and wall at each hinge location.
Securing the unitMake sure the door unit is flush with the edge of the sheet rock. Pre-drill a hole through the door stop in the location of the top hinge shim. Use one 2 ½" finishing nail to hold the door in place. (Figure 2)
Check for square and plumbPlace a 6' level along the hinge side jamb to make sure the jamb is square. Adjust the middle and lower shims until the bubble on the level is exactly in the center (Figure 2). After the jamb is square, check for plumb on the jamb. Rotate the level so it is sitting flat along the jamb (Figure 3).
Tack frameOnce the door jamb is square and plumb, pre-drill a hole through the stop in the location on the middle and bottom hinges. Use 2 ½" finishing nails to tack the frame in place (Figure 4).
Shim the strike side of the doorShim the strike side of the door unit placing shims at the top, center, and bottom. Plumb and square the strike side of the door unit and use 2 ½" finishing nails to tack the frame into place.
Verify measurementsMake sure the distance between the hinge jamb and strike jamb is the same at the top, center, and bottom.
Shim the head jambPlace shims in two locations across the top of the door unit, between the head jamb and wall (Figure 5). Adjust the shims until there is an even margin between the door and the frame across the top of the door.
Fasten the head jambFasten the head jamb. Pre-drill through the door stop in the location of each of the two shims (Figure 6). Nail the head into place using 2 ½" finishing nails.
Verify measurements and adjust shimsClose the door and check to make sure that you have equal spacing between the door and frame at the top and along both sides. If not, adjust shims until the spacing is equal.
Secure the unit with finishing nailsOnce the initial finishing nails are in place on the jambs, a second set of nails will be needed to help secure the frame. To do this, first begin by opening the door and placing a second nail through the narrower side of the jamb for each of the shim locations (Figure 7). This process should then be repeated on the other side of the door. When all the finishing nails have been installed, use a nail set to sink the heads of the finishing nails.
Replace center screws on the hingesOnce the second set of nails are in place, the center hinge screw should be removed from the top hinge on the frame (not the door side of the hinge) and replaced with a 2 ½" screw. Replace this center screw on all three hinges (Figure 8).
Finish the door unitA. Before finishing, a light final sanding is recommended over all surfaces of the door. Remove sanding residue before applying sealer or finish.
B. Stain, paint, or clear coat following the finishing manufacturer's recommendations.
C. To prevent delamination and warpage, all six sides of the door must be sealed. Door may not be cut or altered, or warranty is void.
Products, materials, techniques, tools, building codes and local regulations are subject to change; therefore, Midwest Manufacturing assumes no liability for omissions, errors or the outcome of any project. The reader must always exercise reasonable caution, follow current codes and regulations that may apply, and is urged to consult with a licensed professional before beginning any project.