How to Replace Full Mortise Door Hardware

Ask This Old House carpenter Nathan Gilbert helps a homeowner to replace his traditional mortise hardware with hardware that locks.

By Nathan Gilbert

Photo by Makayla Townsend

Replacing a full mortise lockset:

Start by removing the old hardware. This can usually be done by removing a few screws in the door knobs, around the face plate, and the lockset.
Fit the new lock body into the old mortise. If it’s a tight fit, try loosening the opening with a chisel to ensure the door doesn’t split during the installation.
To ensure the lock body cover also fits in the old mortise, it may be necessary to chisel out some depth into the door. Secure the lock body into the door with a screw, trace the opening with a utility knife, then remove the lock body and chisel it out.
If the holes for the lock body no longer line up with the holes on the face of the door, trace out the new holes using a pencil.
Cut away the excess wood in the door using a rasp.
Install the new hardware with the provided screws.
Make any adjustments to the striker as needed to ensure a nice, tight fit.

Nathan used reproduction door hardware, provided by Rejuvenation. In order to match the existing hardware, he purchased individual components that included Plain 2-in Door Knob, Colonial Revival Plate, Colonial Revival Plate with Thumbscrew, Replacement Privacy Strike Box Kit in Burnished Antique, 3-1/12 Inch Doorknob Spindle, and Privacy Mortise Lock, all in Burnished Antique finish.