How to Install a Deadbolt Lock in an Exterior Door
When heading out to buy a deadbolt lock, be prepared to make a choice. Single-cylinder deadbolt locks are equipped with a thumb latch for easy opening from the inside. Double-cylinder deadbolt locks require a key from either side. Single-cylinder locks work great for most doors, but a door with a window is more secure with a double-cylinder lock. Someone breaking in would still need a key to get the door open. The downside is that you'll still need a key to get out of the house in an emergency.
Tape the template, supplied by the manufacturer, to the door.
Mark the location for the latch bolt on the edge of the door, using a nail. Mark the location for the center of the cylinder on the face of the door.
Drill through one side of the door with a hole saw and drill until the hole saw starts to come out the other side of the door. Remove the saw and continue drilling the hole from the other side of the door. Drilling the hole this way keeps the door from splintering.
Drill a hole, using the spade bit, for the latch bolt hole.
Place the bolt in its hole. Screw the plate on the door. Trace around the plate, using the utility knife. Remove the plate from the door.
Hold a chisel with the beveled side facing up. Tap the end of the chisel a mallet until the cut is as deep as the thickness of the plate.
Make deep, parallel cuts 1/4 inch apart by holding the chisel at a 45-degree angle and tap the end of the chisel with a mallet.
Cut out the waste by holding the chisel at a low angle with the bevel side toward the door. Push the chisel downward by hand to make the cut.
Install the plate. Insert the latch bolt and secure the deadbolt in place with the screws provided.
Screw the strike plate on the door frame. Drill the latch bolt hole, using the spade bit. Trace around the strike plate with the utility knife.
Remove the strike plate. Chisel out the recess for the strike plate. Reinstall the strike plate.