A door that will not latch is one of those problems people live with far longer than they should. You pull it, lift it, slam it, and eventually you just stop locking it. In Toronto’s climate that habit is expensive: an unlatched door leaks heat all winter, invites moisture into the frame, and is the single easiest entry point in the house. The good news is that in most cases the door itself is fine. The problem is almost always somewhere else.

Why doors stop latching in the first place

Doors do not fail on their own. They fail because the opening around them moves. Toronto homes go through roughly 60 degrees of temperature swing between February and July, and the framing, the foundation and the exterior cladding all move with it. A gap that was two millimetres in October becomes five in March.

The four causes that account for the overwhelming majority of latch failures:

• Seasonal frame movement. Wood swells with humidity and shrinks in dry cold, shifting the strike plate out of alignment with the latch.
• Worn hinges. Hinge screws back out over years of use and the door sags, dropping the latch below the strike opening.
• Foundation settling. Older homes settle unevenly. The rough opening racks slightly out of square and the door no longer sits parallel to the jamb.
• Failed hardware. The latch mechanism itself wears out, the spring weakens, and the bolt no longer extends fully.

How to tell which one you actually have

Read the paint line

Close the door slowly and look at where the latch hits the strike plate. If there is a shiny scrape mark above or below the opening, the door has dropped or risen. If the mark is centred but the door will not push closed, the issue is depth, not height.

Check the gap around the door

Run your eye down the gap between the door and the frame. An even gap top to bottom means the door is square and the problem is hardware. A gap that is wide at the top and tight at the bottom, or vice versa, means the door or the frame has moved.

Grab the door and lift

With the door open, lift the outer edge. If it moves more than a millimetre or two, your hinges are loose or worn and the sag is your answer.

Test the latch by itself

With the door open, turn the handle and watch the bolt. If it moves sluggishly, sticks halfway, or does not spring back fully, the mechanism has failed and no amount of alignment work will fix it.

What actually fixes it

The repair depends entirely on the diagnosis, and this is where most DIY attempts go wrong. People move the strike plate to solve a problem that is really a sagging hinge, and six months later the door is worse than before.

• Sagging door: replace short hinge screws with three-inch screws that reach the stud behind the jamb. This pulls the frame back and lifts the door in one step.
• Misaligned strike plate: the plate can be filed or repositioned, but only a few millimetres. Beyond that you are hiding a structural issue.
• Racked or rotted frame: this needs real door frame repair, not adjustment. A frame that is out of square will keep pushing every other fix out of alignment.
• Dead hardware: a worn latch or cylinder should be replaced outright. If the door has ever been shared with a previous owner, tenant or contractor, a lock change in Toronto is worth doing at the same time so you are not paying for two service calls.

Why “just slam it harder” is the expensive option

Forcing a misaligned door does measurable damage. Every hard close drives the latch into the edge of the strike plate, gouging the plate and the jamb. The hinge screws work looser with each impact. The weatherstripping compresses unevenly and stops sealing, which is where the heating bill comes in. And a door that is not fully latched can be pushed open with shoulder pressure alone — the deadbolt is doing nothing if the door is not seated.

A minor alignment issue caught in autumn is a short service call. The same door left through a Toronto winter often becomes a frame repair, new weatherstripping and new hardware in the spring.

When to call a professional

Handle it yourself if the fix is tightening hinge screws or swapping a handle set. Call someone if you see any of the following:

1. The gap around the door is visibly uneven from top to bottom.
2. There is soft or discoloured wood anywhere on the jamb or threshold.
3. The door has dropped enough to scrape the floor.
4. The deadbolt does not extend fully into the frame.
5. The door was forced or damaged in a break-in attempt.

Any of these means the opening itself has moved, and adjusting hardware will only buy a few weeks. Professional door repair in Toronto starts by squaring the opening and then aligns the hardware to it — the order matters, and doing it backwards is why so many doors get “fixed” twice.

Preventing the repeat

Two habits keep most doors out of trouble. Once a year, before winter, check every hinge screw and tighten what has backed out — this takes ten minutes and prevents most sagging. And replace worn weatherstripping when it stops springing back, because compressed stripping changes how far the door seats and quietly pushes the latch out of alignment.

Frequently asked questions

Why does my door only stick in summer?

Humidity swells the wood in the door and the frame. If it latches fine in January and fights you in July, that is seasonal movement, and it usually needs a small permanent adjustment rather than an annual sanding.

Can I just move the strike plate?

For a two or three millimetre misalignment, yes. Anything more and you are enlarging the hole in the jamb, which weakens exactly the part of the frame the deadbolt relies on.

Is a sticking door a security problem?

It becomes one. People stop deadbolting a door that fights them, and a latch that only partially engages offers very little resistance to force.

How long does the repair take?

Hinge and alignment work is usually well under an hour. Frame repair or hardware replacement typically finishes in a single visit.

Should I replace the whole door?

Rarely. Unless the slab itself is warped, rotted or damaged, repairing the frame and hardware costs a fraction of a replacement and lasts just as long.

The bottom line

A door that will not latch is a symptom, not the problem. Diagnose whether it is a sagging hinge, a shifted strike, a racked frame or dead hardware before you touch anything — and fix the opening before you adjust the hardware. Done in that order, the repair holds. Done backwards, you will be doing it again by spring.