DIY Network

How to Install a Deadbolt Lock

Don't rely on a spring-loaded doorknob to keep your home safe from intruders -- it's much better to install a deadbolt lock that can be opened only with a key from either side.

More in Windows Walls and Doors

installing a deadbolt lock

Step 1: Reference the Manufacturer's Template

Most deadbolt-lock manufacturers provide a template to help you install the lock. The template is designed to work with doors of different thicknesses and has reference points that may be marked on the door with an awl. The deadbolt should be at least 6" above your doorknob.

template helps to install deadbolt lock

Step 2: Cut a Hole for the Deadbolt

After you mark the reference points from the template, use a hole saw to begin cutting the hole for the deadbolt (Image 1). When the pilot bit on the hole saw comes through the other side of the door, stop cutting. Finish the hole from the other side of the door to prevent splinters. If your hole saw isn't deep enough to penetrate the exterior face of the door, use a standard bit to finish drilling the hole you'll use as a reference point (Image 2).

Step 3: Drill a Hole Through the Edge of the Door

Use a 1 1/2" spade bit to drill a hole through the edge of the door for the bolt.

use spade bit to drill hole through edge of door

Step 4: Mortise the Area Around the Faceplate

Dry-fit the bolt into the hole, and trace around the faceplate. Use a wood chisel to mortise the area around the faceplate so that it will be flush with the door. When using the chisel, keep the beveled side in toward the mortised area, and tap the tool deep enough to recess the faceplate. You may need a smaller chisel to mortise the rounded corners.

dry fit bolt into hole

Step 5: Secure the Bolt To the Door

Continue mortising until the faceplate fits properly. Drill pilot holes, and secure the bolt to the door with screws.

Step 6: Install the Cylinder And Thumb Lever

Dry-fit the cylinder and thumb-turn plate so you'll know how the pieces fit together. Fit the exterior side onto the door first, making sure the writing is upright. Then set the interior piece in place, and align the screw holes with the mounting holes inside the lock. Fasten the deadbolt in place with screws.

Step 7: Drill Holes and Secure the Strike Plate

Mark the end of the bolt with lipstick or paint. Close the door, and turn the deadbolt several times to mark the doorframe. Use a 7/8" spade bit to drill two overlapping holes in the doorframe for the deadbolt.

Mortise the area around the hole so the strike plate will fit flush with the doorframe. Drill pilot holes and secure the striker plate with screws.

drill two overlapping holes in doorframe