Door Won't Latch? Strike, Gap or Latch: How to Tell

A door that will not latch is usually a door whose latch bolt no longer lands in the strike opening. The door has dropped a little, the strike plate has shifted, or something such as new weatherstripping or a build-up of paint is holding the door away from the frame. Most of those are small adjustments: tightening screws, filing or moving the strike, scraping out paint. Only when the latch itself sticks or has a broken spring do you need new parts.

First, check the latch on its own

Before you look at the frame, find out whether the latch works. Open the door so it cannot touch anything.

Turn the knob or lever and let go. The latch bolt, the slanted tongue in the edge of the door, should snap all the way back out.
Press the latch in with a finger and release it. It should slide in easily and spring back fully, every time.
Look at the slant. The slanted side of the latch should face the way the door swings shut, so it meets the strike first and gets pushed in. A latch put in the wrong way round hits the strike flat-on and never clicks in.

If the latch is sluggish, only comes part of the way out, or stays in when you let go, the problem is in the door hardware, not the frame. Skip to the section on parts below.

Where the latch meets the strike

If the latch springs freely, the problem is where it meets the frame. Close the door slowly and watch the gap between the door edge and the jamb. You can often see the latch ride over the strike plate and miss the opening. Shiny scuff marks on the strike plate show where it has been rubbing.

There are three ways to miss.

Too high or too low. The latch hits the plate above or below the opening. Usually the door has sagged on loose hinge screws. Our post on a deadbolt that will not lock or turn explains how to read a sagging door and fix it at the top hinge, and the same fix brings a latch back into line.
Not far enough. The door closes against its stop, but the latch tip only just reaches the plate and never drops into the opening. The gap between door and jamb is too wide, often because the door has shrunk or the strike was set back too far.
Pushed back out. The latch drops in, then the door bounces back off something before it can hold. Thick new weatherstripping, a door stop set too tight, or a door that has swollen against the frame are the usual reasons.

Fixes you can do yourself

These are short jobs with a screwdriver and a file.

Tighten the strike plate screws. A loose strike can shift enough to block the latch.
Tighten the hinge screws. Start with the top hinge, then the others.
File the strike opening. If the latch misses by a small amount, filing the edge of the opening toward the latch is usually enough. File the plate, not the latch.
Clean out the paint. In older houses, layers of paint build up inside the strike recess and on the door edge until the latch can no longer drop in or the door no longer closes fully. Scrape it back to bare wood and metal.
Bend the strike tab, if yours has one. Some strike plates have a small tab or lip in the opening. Bending it slightly toward or away from the stop, a little at a time, changes how tightly the door holds once it latches.
Ease the weatherstripping. If a new seal is pushing the door back out, adjust it or swap it for a thinner one.

If the gap is too wide, a thin shim behind the strike plate can bring it closer to the latch. Shimming a strike well takes some patience, because the plate has to end up flat and the screws need to bite into solid wood.

When it needs parts

Some latch problems are not adjustments.

A latch that sticks in or comes out slowly. Dirt and old paint can be cleaned out and the latch given a little dry lubricant. If that does not do it, the spring inside is weak or broken, and the latch needs replacing.
A knob or lever that does not return. The spring in the handle mechanism has failed. On many locksets that means a new lockset.
A cracked or worn strike plate. Strike plates are cheap and easy to swap, as long as the new one fits the same recess.
A latch on an old mortise lock. In older doors, the latch is part of a mortise lock body set inside the door. Those often can be repaired rather than replaced, which keeps the original hardware on the door.
A door that has warped. If the door is twisted rather than dropped, no strike adjustment will fix it everywhere. The door may need planing or rehanging.

A latch is not a lock

A door that does not latch swings open in the wind and lets heat out, but the security point is bigger. A spring latch, even when it works, can often be slipped with a thin card, and it does not lock in place the way a deadbolt does. A latch that only half catches is easier still. Fix the latch so the door closes properly, and make sure the door also has a deadbolt. Our deadbolt installation guide covers grades, bolt throw and strike screws.

Harrison doors

The Town and Village of Harrison share the same borders and take in West Harrison and the hamlet of Purchase. Harrison is a short drive north of Larchmont, where two of our technicians live. If the latch needs more than a screwdriver, Larchmont Locksmith NY repairs and replaces door locks and latches as part of our residential lock work. Service starts at $125. See our Harrison locksmith page for more on the area.

Frequently asked questions

Why does my door only latch when I slam it?

The latch is reaching the strike opening only when the door is forced in past something. Usually that is weatherstripping or a door stop pushing back, or a strike set slightly too far from the latch. Filing the strike or easing the seal normally fixes it.

Can I fix a door latch without replacing it?

Often, yes. Tightening hinge and strike screws, filing the strike opening and scraping out old paint solve many latch problems. Replacement is for a latch that sticks, a broken spring or a cracked strike.

Should I lubricate a sticking door latch?

A little dry lubricant, such as graphite or a dry PTFE spray, on the latch bolt can help once it has been cleaned. Skip household oil, which collects dust. If the latch still sticks, its spring is likely worn.

Is a door that will not latch a security risk?

Yes. It may look closed when it is not, and a half-caught latch can be pushed open. Even a working spring latch is not enough on its own on an exterior door, which should also have a deadbolt.

Door still will not catch? Call Larchmont Locksmith NY at (914) 255-6611.