Repairs for Doors That Don't Latch Properly
My door closes OK, but it doesn't always latch securely. The dog is always pushing it open.
You should consider yourself lucky... I've had a few customers whose dogs ate or scratched right through the doors, locks be damned!!
Your problem can be one of two things- either the latch bolt doesn't engage properly with the strike plate on the door jamb, or your dog thinks she's Lassie and has developed an opposable thumb.
I can't do anything about the latter, but we can troubleshoot the former:
FIRST, be sure that the lock itself is working and that the latch bolt does not stick in the retracted position!
Turn the knob slowly and look for any sticking in the bolt. If it does not move smoothly, you can lubricate this without disassembly of the lockset with a silicone spray product. Spray a small amount on the bolt itself, being careful not to over spray and wipe off the excess. If the lock seems to be working smoothly, great! If not, you may want to disassemble the lockset to lubricate it internally. If you have a "mystery lock" without visible screws for disassembly, see our LOCKS article for more help.
Look at the strike plate...
That's the brass or chrome metal piece on the door jamb into which the latch bolt engages (graphic left). You may see wear marks on it, indicating the "route of travel" of the latch bolt. If the route of travel does not align with the opening in the striker plate, you have found the problem. Double check by standing on the hinge side of the door and close it until the latch bolt just hits the strike plate. Mark the positions of the top and bottom of the latch bolt on the strike plate with a pencil. Now, open the door and look at the alignment of your marks and the strike opening. If either mark falls outside the top or bottom of the strike opening, you must either:
If the route of travel aligns with the opening in the strike, but the wood from the jamb has not been completely cleared away from the strike opening (also know as sloppy installation), use a chisel or utility knife to remove the offending wood. You can do this with the strike on or off, but I prefer to leave the strike on as a guide for cutting.
If the route of travel aligns and there is no wood within the strike opening to inhibit locking, the remaining possibility is that the strike is set too close to the doorstop molding, so the door cannot close far enough for the latch to engage. In this case, you can either relocate the strike by moving it out away from the door stop molding, or use the following trick: