If your door won't latch, you don't have to rip the whole lock out in frustration. The culprit is usually the strike plate, the metal square attached to the door jamb that catches the latch.
Sometimes, the door weight and age can cause sagging; which knocks the strike out of place. You should be able to fix the strike plate without a professional. Here are tips to realign a door strike plate.
Prepare to Work
For this project, you need:
- work gloves
- safety goggles
- chalk or lipstick
- Phillips screwdriver
- metal file
- wood putty
- power drill with drill bit
The latch may just be stuck. Open the door, and pull the latch as far as it will go. If the latch moves further, it needs lubricating. Apply some spray lubricant or cooking oil to the latch, and try it again.
Retighten the screws using the Phillips screwdriver. Sometimes, loose screws cause sagging of the door strike. Proceed to trim the strike plate, if it still fails.
Trim the Strike Plate
See where the latch is missing. Dab some lipstick or chalk on the end of the latch, and close the door. This will determine if the latch strikes too high or too low. Older doors may have scratches to indicate where the latch strikes.
Use the Phillips screwdriver to remove the screws securing the strike plate. File the top or bottom edge of the strike plate with the metal file.
Reinstall the plate, and chisel any wood that protrudes from the edge of the plate. Retry the door latch. If it doesn't work, move the strike.
Move the Strike Plate
Measure how far the strike plate is from the opening. Trace the outline to mark where it needs to be; including the latch hole and screw holes.
Hold the chisel handle at a 30-degree angle on the door jamb, and chisel the outline. Sand the opening, if needed.
The outside plate face should be even with the jamb, and the bolt should hit the center of the plate. Tape the strike plate on the door, detach the bolt, and close the door to test the fit. If it still isn't in line, repeat the chalk or lipstick test, and adjust the mortise.
Attach a drill bit slightly smaller than the screw diameter. Drill new screw holes. Chisel extra wood from the latch hole to make it fit.
Insert the bottom screw and top screw, then tighten them. Cover old holes with wood putty. Let it dry, then sand.
Test the door again. If you don't trust your skill, or the latch still fails, contact a locksmith like Ability Lock & Key.