Door Knob Lock Replacement and Deadbolt Installation: What the Job Actually Involves
Replacing a door knob lock sounds straightforward, but the details matter. Bore-hole diameter, backset measurement, door thickness, and the condition of the existing strike plate all affect which hardware will fit and how it needs to be prepared. On older Santa Monica homes — particularly the 1920s and 1930s Spanish Colonial and craftsman stock common in the Sunset Park and Ocean Park neighborhoods — doors were often built for mortise lock hardware rather than the cylindrical bores standard today. A mortise lock sits inside a deep rectangular pocket routed into the door edge and handles both the latch and the deadbolt in one integrated unit. Our technicians assess whether your door is a candidate for a direct-swap cylindrical installation or whether it is better served by a quality mortise lock set, which offers superior pick resistance and a cleaner look on period doors.
For newer construction, multi-family buildings along Lincoln Boulevard, or standard tract homes, a keyed entry knob paired with a single-cylinder deadbolt above it is the most common and cost-effective upgrade path. We prep the strike plate, reinforce the door jamb where needed, align the bolt throw, and test every function before we leave. If you are adding a deadbolt to a door that currently has only a lock door knob, we core a new bore and install the deadbolt in the same visit — no return trips, no subcontractors.