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How To Fix A Door That Won’t Lock

If your door isn’t locking, chances are that the problem is with the latch instead of the locking mechanism. If a strike fails to penetrate a door jamb, either the door has become warped or the screws have loosened and the plate has shifted. When the door closes, the strike doesn't slide past its plate into the jamb's receiving hole, or it goes in but doesn't reach bottom, preventing the door from locking properly.

Locking problems are common issues but they need to be addressed. Whether a door is meant to be locked for security or privacy reasons, failure to do so can mean embarrassment at best (think a bathroom door that won’t latch) or a security issue at worst. In this article, the team at Access Residential Hardware explains how to fix a door that won’t lock.


Depending on the source of the locking issue, you may need the following tools for this project:

  • Dry-erase marker
  • Masking tape
  • Phillips screwdriver
  • Chisel
  • Hammer
  • Diagonal pliers
  • Metal file
  • Abrasive

Step #1: Identify the Source of the Misalignment

Test where the latch contacts the door by applying a dry-erase marker or a similar marking material. Tape a strip of masking or painters tape to the strike plate, close the door, and re-open it. If the latch had been in contact with the strike plate hole, a mark should have been left by the dry-erase ink. If the mark lies below the strike plate hole, sagging hinges may be to blame. In contrast, if contact is made above the strike hole, then the strike plate's position is more likely to be at fault. (If this is the case, skip to Step #7.)

Step #2: Tighten the Hinges

Sagging can occur at the hinges of older and frequently used doors as gravity pulls them down. The door may swing in a different direction as a result, leading to a misaligned latch that contacts below the strike plate hole. If sagging appears to be the source of the locking issue, ensure that the door is properly supported by the door frame by tightening the screws in the hinges.

If tightening the screws doesn't fix the problem, consider drilling a longer 3” screw into the jamb side of the hinge so that it grabs the wall framing and pulls back the entire frame. In cases where the latch contacts below the strike plate hole, drive a 3” screw into the top hinge to help lift the door into place. If the latch contacts above the strike plate hole, drive a screw into the bottom hole to help pull the door down.

Step #3: Check the Strike Plate

If sagging hinges aren’t the issue, check the strike plate. Place the plate back in the mortise if it has slipped out, and tighten the screws with a Phillips screwdriver if it is loose. If this doesn’t solve the locking problem, try adjusting the door stop (steps are outlined below).

Step #4: Reposition the Door Stop

On the strike side of the jamb, tap the end of a chisel under the door stop. Remove it by prying up on it until it comes loose. Remove the door stop on top too. Then use diagonal pliers to remove the nails from the door stop. (The nails can be reused.) Reinstall the door stop on the jamb, placing it 1/4 inch away from its original position. Reattach the side and top pieces of the door stop. Now you should be able to shut the door and lock it normally.

Step #5: Sand Down or Shim Under Hinges

If the problem persists, the door frame may need to be sanded or shimmed.

Locking issues are often caused by hinge mortises that are too shallow or too small for the hinge's size. In this case, sand the hinge mortise down to the correct depth and sand the edges to accommodate the hinge. Replace the hinges and verify that they are flush with the door frame and that the door is balanced properly.

In order to shim the hinges, remove them from the door frame and cut a small piece of cardboard (or similar material) to fit into the mortise of the hinge. Replace the hinge after the cardboard has been inserted and check the door. When the problem is caused by sunken hinges, shimming usually corrects the alignment of the door. This cushion of extra material supports the hinge and balances the door.

Step #6: Enlarge the Strike Plate Hole

If the door adjustments did not solve the problem, the strike plate hole may be the cause. You should check whether the latch is located above or below the hole, as well as how much the latch is misaligned. The strike plate hole may need to be moved if it's out of alignment by more than ⅛”. Try enlarging the hole if the misalignment is only ⅛” or less.

To enlarge the strike plate hole, remove the strike plate from the door frame and use a metal file. The best tool for widening is a half-round file, which matches the curvature of the latch hole. In this case, the latch should slide into the strike plate hole with no lifting, forcing, or other manipulation outside of normal door operation.

Step #7: Move the Strike Plate Hole

When you check the contact position of the latch in relation to the strike plate hole using the dry marker test, you may find that it is over ⅛’ inches out of alignment. Even if the strike plate hole were larger, the door would still not latch. If the hinges are tight and the door is balanced, the next step is to move the strike plate so that it is properly aligned with the latch.

The first step is to remove the strike plate from the door frame. Using a sharp chisel and a hammer, enlarge the strike plate mortise, so that the strike plate can be moved up or down depending on the latch alignment. Ensure that the new position for the strike plate is aligned with the latch so that the door will close smoothly. As soon as the latch and new strike plate position are aligned, drill two small holes and secure the strike plate. Make sure the door closes and latches properly.

Is It Time to Replace Your Lockset?

Although these steps can help solve locking issues related to components like the strike plate or door jamb, different measures are needed if the door knob’s mechanism has failed. If this is the case, you’ll need to replace the entire lockset.

At Access Residential Hardware, we sell a premium range of interior and exterior door hardware in a variety of styles, from traditional door knobs and levers to advanced keyless entry solutions. Whatever your practical or aesthetic needs, we have a lockset that will both work well and blend seamlessly with its surroundings. To learn more or place an order, call 866.752.9002 or use this contact form and we’ll get right back to you.