- Bayside and South East Melbourne
- Victoria Police Security Registration No. 72185491
- Mon to Fri 7:00 am to 6:00 pm, Sat 7:00 am to 1:00 pm
- 0421 767 767
November 5, 2026
The key goes in, but turning it takes a shoulder behind it, and a few months later the same door rattles in its frame, and the latch barely catches. The lock has not aged that quickly. A timber door and its frame take up and give up moisture as the surrounding air changes, and the lock sits at the point where that small movement is most apparent. The table below sorts the common symptoms by what is moving.
| Symptom | What is moving | Quick separator |
|---|---|---|
| Key stiff only when the door is shut | Door or frame has shifted against the bolt | Key turns freely with the door open |
| Latch rattles, door shuts but wobbles | Gap between door and frame has opened | Door shifts in its frame when pushed |
| Door bounces back, latch misses the keeper | Latch has dropped or lifted off the strike opening | Latch lands off-centre in the opening |
| Key stiff even with the door open | Cylinder wear or a damaged key | Same feel in every season |
How Timber Takes Up and Gives Up Moisture
Wood fibres swell as they absorb moisture and shrink as they lose it. The movement runs across the grain and only along the length of a board, so a door gets wider and thicker with changes in moisture but hardly any taller. For a front door, that means the gap between the latch edge and the frame is where the change shows up.
In damp, cool spells, a door and frame take up moisture and swell, and the latch edge presses closer to the jamb. In dry, hot spells they release it and shrink, and the gap opens. Both directions move the same bolt relative to the same strike plate, which is why one door can be stiff during one stretch of the year and loose during another. Neither direction belongs to one season for every house: a door sealed on all faces, a frame in a sheltered porch and a door facing a hot western wall can each behave differently from the neighbour's.
The edges matter as much as the faces. The top and bottom edges of a timber door expose open grain, and bare or thinly painted end grain readily takes up moisture. A door with a well-painted face and a bare top edge can still swell.
Where the Bolt Meets the Strike
A front door lock has two jobs at the frame. The latch or deadbolt must slide cleanly into the strike plate opening, and the door must sit snugly against the stop so it does not rattle. Both depend on the door being set where it was when the hardware was fitted.
A bolt that enters the strike opening has only a small margin above and below. A door that swells even slightly pushes the latch edge harder towards the jamb, so the bolt drags against the face of the strike as it enters, and if the frame has also shifted, it catches on the lip of the opening. The key then has to push the bolt against the strike plate and turn the cam, and that extra load is what you feel in your wrist. A door that has shrunk does the opposite: the latch sits further from the strike, the door shifts in the frame, and a latch with a short throw can fail to reach its seat.
The pattern shows in the key. When the door is open and the key turns freely, the cylinder and the lock body are working. The resistance comes from the bolt meeting the frame.
Telling Door Movement From a Worn Cylinder
The door-open test separates the two main causes. Open the door, stand clear of the latch edge, and turn the key several times, then operate the handle. If the bolt throws smoothly and the key feels light, the cylinder is not the problem. If the key still grinds with nothing to push against, the fault sits inside the lock.
Wear inside a cylinder feels the same in every month. The key drags at the same point in the turn, may need a wiggle, and can be rough on insertion. A worn or bent key produces the same symptoms. Seasonal movement feels different: the stiffness comes and goes with the weather, and it appears only when the door is shut.
Both faults can sit in the same door. A cylinder with worn pins can tolerate an easy-moving door for years, then protest when the timber swells and adds load. Checking the door-open feel first stops a cylinder being replaced when the frame is the real source.
Rub a little chalk on the tip of the extended latch or bolt, close the door and open it again. The chalk transfers to the strike plate and shows whether the bolt lands high, low or on the edge of the opening.
Why Lubricant Does Not Fix a Moving Door
Spraying the lock feels like the obvious response to a stiff key, and it can temporarily ease a dry cylinder. It cannot move a bolt that is sitting against the edge of a strike opening. The resistance is the bolt pushing on timber or metal, and nothing inside the cylinder changes that.
The same reasoning applies when the lock is loose in dry weather. Lubricant does nothing for a latch that sits too far from the keeper. The gap is a measurement, and the fix is a change to where the strike or the door sits.
Strike Plate and Hinge Adjustment
Hinge screws are the first thing to check, because a door that has dropped slightly on its hinges puts the latch below the strike opening whatever the weather. Loose screws in the frame timber let the door sag, and swelling then makes the misalignment worse. Bringing the door back to where it was set is part of a locksmith's check, and a screw that spins without biting calls for a different fix in the hole.
If the door sits properly in the frame and the bolt still lands on the edge of the opening, the strike plate is the next adjustment to make. A locksmith can move the strike opening up or down, enlarge it slightly, or reposition the plate so the bolt enters the middle of the opening with clearance on both sides. That change fixes the alignment and leaves the door untouched. When the door has swollen so much that it binds along the entire latch edge, the door itself may need to be eased, and that is a carpenter's job.
An adjustment made at the swollen end of the cycle can leave the latch loose when the timber dries. Setting the strike so the bolt enters the opening with room at both ends gives it tolerance in either direction.
Pushing hard on a stiff key bends it, and a key that snaps in the barrel turns a simple adjustment into a lock repair.
What a Locksmith Checks First
A locksmith starts with the door, not the cylinder. The checks run in order: the door-open key feel, hinge tightness, the gap around the latch edge, where the bolt lands in the strike, and then the cylinder itself. Skipping to a new lock on a door that is out of line moves the problem onto the new hardware.
The findings decide the work. A bolt that lands on the lip of the strike causes the strike to be moved or opened out. A door that has dropped gets the hinges tightened or packed. A cylinder that is stiff with the door open gets cleaned, rekeyed, or replaced, and a mortice lock body that has worn gets assessed on its own.
A lock works only as well as the door holding it. Check the frame before blaming the mechanism, and the lock settles into working properly through the damp spells and the dry ones alike.
Frequently Asked Questions
Planing is a carpenter's job, and the timing matters: a door planed during a damp spell can end up too small once the timber dries, leaving a gap at the latch edge that rattles. Easing it in a dry spell, taking off only what the rub marks show, and sealing the bare edge afterwards avoids that.
Sealing the top and bottom edges with primer and paint slows moisture getting into open grain. Heavy paint buildup on the latch edge and jamb is also a source of sticking, because each coat adds thickness to the gap the door must clear.
On some locks, cold can stiffen the grease in the mechanism, making the first few turns slow, then easing as the day warms. A stiffness that clears within minutes and returns every cold morning sits in the lock body. A stiffness that lasts all day with the door shut sits in the door.
The latch and the deadbolt sit at different heights on the door edge and enter separate openings, so a door that has moved can leave one clear and the other rubbing. Note which one drags, because the opening for that bolt is the one to adjust.
It can leave the home held only by the latch. If everyone is about to leave, securing the entry comes first, and the alignment work follows once the door is safe. A door that cannot be closed at all is a reason to ring a locksmith at once rather than wait for the weather to change.
Yes. Where the plate moves only a short way, part of the old recess is left open beside it, and that strip is filled with a glued timber insert and finished before the plate is screwed in its new place.
Have the door checked before the cylinder is replaced — a door-open test and a look at where the bolt lands show whether the frame or the lock is causing the stiff key. True Locksmith serves Bayside and South East Melbourne. Call 0421-767-767.
