A door that opened fine in April and now needs a shoulder to close it is one of the most common service calls we hear about across Toronto and the GTA every July and August. Almost every homeowner reaches the same conclusion: the door is warped and needs replacing. Almost every homeowner is wrong.

Humidity Is Only Half the Story

Wood is hygroscopic. It pulls moisture out of humid air and pushes it back out when the air dries. In southern Ontario the swing between a dry February and a humid August is large enough to change a solid wood door by roughly 1 to 3 millimetres across its width. That is real, but it is small.

Here is the part that matters: a properly hung door sits inside a 3mm gap on each side. Seasonal swelling alone should not close that gap. When a door binds in summer, humidity is usually just the last millimetre on top of a problem that was already there.

The three problems humidity exposes

• Loose or worn hinges. Screws back out slowly over years. The door drops on the latch side, and the top corner on the hinge side starts kissing the frame.
• A frame that has moved. Freeze and thaw cycles, foundation settlement and a wet spring all push door frames out of square. The door never changed. The opening did.
• Paint and finish build-up. Three coats of paint on the door edge plus two on the jamb can eat 2mm on its own before a single drop of humidity gets involved.

Diagnose It in Five Minutes

Read the rub marks

Open the door and look at the edges and the jamb in good light. Binding leaves a burnished, shiny stripe exactly where the contact happens. Where that mark sits tells you the cause:

• Top corner, hinge side: the top hinge is pulling loose.
• Top corner, latch side: the door has sagged; bottom hinge or frame issue.
• Along the whole latch edge, evenly: genuine swelling or paint build-up.
• Bottom, dragging on the threshold: sagging hinges or a lifted sill.

Check the gap, corner to corner

Close the door and slide a business card around the perimeter. On a healthy door it slips through everywhere with the same resistance. If the card sails through at the bottom and jams at the top, the door is out of square with the frame and no amount of sanding will fix it properly.

Grab the door and pull

With the door open about 45 degrees, take the latch edge and lift. Any play, any clunk, any movement at the hinge barrels means the hinges are your problem, not the weather.

Fixes That Work, in Order of Cost

1. Tighten and re-anchor the hinges

Start here every time. Replace the short factory screws in the top hinge with 75mm screws that reach through the jamb into the framing stud behind it. This single step pulls a sagging door back into position and solves a surprising share of summer binding for the price of a handful of screws.

If the screw holes are stripped, glue in wooden golf tees or hardwood dowels, let them cure, then re-drill. Do not just go up a screw gauge; it splits the jamb.

2. Move the strike plate before you touch the door

If the door closes but will not latch, the fix is almost always a 2mm adjustment to the strike plate, not surgery on the door. Chisel the mortise slightly, move the plate, done. Ten minutes.

3. Seal the edges — the step nearly everyone skips

A door only absorbs moisture through unfinished surfaces, and the top and bottom edges of an exterior door are unfinished on a shocking number of Toronto homes. Take the door off, sand the edges lightly, and seal all six surfaces including top and bottom. This is the difference between a door that swells every summer and one that does not.

4. Plane it — last, and carefully

Planing is permanent. A door you plane in August will have a visible gap in January that leaks heat and lets in drafts. Only plane after you have ruled out hinges, strike plate and frame, and take off the minimum. If you have to remove more than 3mm, the real problem is elsewhere.

When It Is the Frame, Not the Door

Some binding cannot be adjusted away. If the jamb is visibly bowed, if the mitre joints at the top corners have opened, if there is rot at the base of the jamb where water sits, or if the reveal changes by more than 3mm from top to bottom, the opening itself needs work. That is a job for professional door frame repair in Toronto, where the frame is re-shimmed, squared and re-anchored to the rough opening rather than the door being shaved to match a crooked hole.

Frame problems also show up as a door that locks fine in one season and not the other, or a deadbolt that needs the door pulled toward you to throw. Those are alignment symptoms, not lock symptoms.

Steel and Fibreglass Doors Do Not Swell. So Why Is Yours Sticking?

Steel and fibreglass slabs barely move with humidity, so when they bind the cause is mechanical every single time. The usual suspects are a sagged hinge, a compressed weatherstrip, a frame pushed out of square, or a skin that has dented and bowed near the lock. Steel doors also expand slightly in direct afternoon sun, which is why a south or west facing entry can rub at 4pm and close perfectly at 9pm.

Because the skin is thin over a foam core, steel doors cannot be planed. They have to be realigned or, where the skin is creased, properly repaired — which is why steel door repair is a different trade from carpentry on a wood slab.

What This Costs Around the GTA

• Hinge re-anchoring and strike adjustment: usually a single short service visit.
• Full realignment plus new weatherstripping: a half-day job on most entry doors.
• Frame repair or jamb replacement: priced by the extent of rot and whether the brickmould has to come off.
• Slab replacement: the expensive option, and the one that is genuinely necessary far less often than people assume.

The economics matter here. Homeowners routinely spend four figures replacing a door that needed forty dollars of screws and twenty minutes of alignment. Get it diagnosed before you get it quoted.

Do Not Wait for October

A binding door is not just annoying. Forcing it every day accelerates hinge wear, cracks the jamb around the strike, and damages the weatherstrip that keeps your heating bill down. A door that sticks in August is a door that leaks in January.

If the five-minute checks above point at hinges or a frame rather than the weather, get eyes on it while it is still a small repair. You can book a free on-site estimate and have the alignment sorted before the season turns.

Frequently Asked Questions

Will my door go back to normal on its own in the fall?

If the cause is purely seasonal swelling, yes — it will ease off as humidity drops. But if it binds worse each summer, or does not fully release in winter, the underlying problem is mechanical and it will keep getting worse.

Can I just sand the edge where it rubs?

You can, and it will work today. The risk is that you have permanently removed material to compensate for a temporary condition, leaving a gap and a draft for the other nine months of the year. Sand only after hinges and strike plate are ruled out.

My door sticks only when it is raining. Is that the same thing?

Related, but that pattern points more strongly at an unsealed bottom edge or a threshold that is holding water. Sealing the edges usually fixes it.

Is a sticking door a security problem?

It can be. If the deadbolt does not throw fully into the strike because of misalignment, you may only be engaging a few millimetres of bolt. That is a real vulnerability, and it is one of the more common things found during a service call.

How long does a professional realignment take?

Most straightforward hinge and strike realignments are done within an hour. Frame work takes longer, and rot repair depends on how far the damage has travelled up the jamb.