Install a prehung interior door
Set a complete door and jamb square, shim it securely and tune the reveal.
Home · 4–6 hr · Medium
Before you start
Use a helper to handle the unit. Before disturbing older trim or paint, resolve lead hazards. Keep shims clear of hidden services and follow the unit’s fastening schedule; do not cut structural framing to make it fit.
Tools and materials
- Correct-size prehung unit, shims, specified fasteners, casing and finish materials
- Long level, square, tape, drill, hand screwdriver, hammer, nail set, hand saw, clamps and eye protection
Check the problem
Confirm size and swing
Check slab size, handing, wall thickness, opening dimensions and finished-floor clearance against the unit’s instructions before removing the old jamb.
Check the opening
Check sill level and both framing sides for plumb, damage or twist. An unstable or badly out-of-square opening must be corrected before this installation.
Steps
Prepare the opening
Remove old casing and jamb carefully after hazard checks. Remove projecting fasteners, clean the opening and protect the finished floor.
Set the unit with a helper
Place the prehung assembly in the opening following its transport-brace instructions. Support jamb legs at the finished-floor height; do not let the unit tip.
Plumb the hinge jamb
Insert opposing shims at the specified hinge and fastening locations. Use a long level on both faces so the jamb is plumb and untwisted.
Fasten through the shims
Use the unit’s specified fasteners into framing through shim locations. Recheck plumb as each is seated; do not bow the jamb by overtightening.
Set the head and latch-side reveal
Adjust the other shims until the head is level and the gap around the closed slab is even at the maker’s specified clearance. Keep the stop aligned with the slab.
Secure and test the bare assembly
Complete the fastening schedule, including specified hinge screws. Swing and latch before trimming; adjust shims if it rubs, drifts or binds.
Trim and finish
Trim shims flush without cutting the jamb. Fit casing, hardware and the specified finish on all required surfaces; do not fill operating clearances with paint or caulk.
Verify after finishing
Open, close and latch repeatedly. Confirm clearance above flooring, secure hinges and an even reveal with no sticking; correct defects before normal use.
Open, close and latch repeatedly. Confirm clearance above flooring, secure hinges and an even reveal with no sticking; correct defects before normal use.
Tips
Start at the hinge side
A twisted hinge jamb makes the rest difficult to tune.
Shims carry the load
Do not use screws to pull unsupported jamb sections toward framing.
Test before hiding the shims
Casing should cover a correct installation, not conceal binding.