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The garage is often the weakest door on a house, and the reason is rarely the lock itself. It is a lock whose bars no longer reach the guides, a release cord that can be hooked from outside, or a remote sitting in a car parked on the verge. This guide covers the locks fitted to Australian roller, sectional and tilt doors, what changes once a motor is on the door, and a checklist for the weeks the house sits empty, a familiar situation for the holiday homes around Mandurah.
How garage door locks work
A manual roller door has a keyed lock set into the curtain about waist height, usually in the centre. Turning the key, or the snib on the inside, pushes two flat steel bars outwards so their ends sit inside the vertical guides, and with the bars out the curtain cannot be lifted. The lock is only as strong as the bars reaching the guides: bars worn short, or a curtain that has crept sideways on the drum, leave the door lifting freely with the key turned. Sectional doors use a slide bolt inside on a lower panel that pushes a bar through a hole in the track so the rollers cannot travel. Tilt doors use an outside T-handle with rods that shoot into keepers at each side. Some newer sectional doors come with no lock at all, because they are sold with a motor and the maker expects the motor to hold the door.
Motorised doors: the motor is the lock
On a door with an opener, the drive holds the door shut. A sectional door is pinned to the trolley on the rail and a roller door curtain is held by the gearbox on the axle; neither lifts from outside without breaking something. That is why installers remove or disable the mechanical lock when a motor goes on: a slide bolt thrown one evening means the opener drives against a locked door the next morning, and the result is a stripped gear, a bent bar or a curtain pulled out of its guides. The motors we install go on with the lock disabled as part of the job. The weak point on a motorised door is the manual release instead. A thin tool slipped over the top of the door can hook the release cord and the door then lifts by hand, so shorten the cord, tie the handle back from the top panel, and fit a release shield if the opener has one. The manual release guide shows where the release sits on each door type.
Never padlock or bolt a motorised door shut
Add a padbolt, an anchor lock or a padlock to a door that has an opener and the motor can start against it. On a roller door that can tear the curtain out of the drum; on a sectional door it can strip the opener and drop a panel. Secure a motorised door through the opener and the release, not with hardware that fights the motor.
How to lock a garage door from the inside
- Manual roller door: close the curtain fully, turn the snib on the back of the lock until both bars slide out, then lift the door a few centimetres to confirm it is held.
- Manual sectional door: slide the bolt on the inside of the panel through the hole in the track, and check it has passed through rather than stopped against the track face.
- Manual tilt door: turn the inside handle until the rods seat in the keepers at both sides, then push the door to confirm neither side gives.
- Motorised door: leave every mechanical lock open. Use the opener's lock or holiday mode from the wall control if it has one, and secure the release cord as above.
- Any door: deadbolt the internal door between the garage and the house. It is the last line, and the one most people leave on the latch.
This question usually comes from someone who has lost the key or whose outside barrel has seized. On most roller door locks the inside snib still works without the key, so you can lock the door from inside and leave through the house. If the barrel has corroded solid so neither side turns, the lock is replaced rather than repaired, a short job covered further down.
How to secure a roller door
The roller door security check, from outside in
- With the door locked, try to lift it. Movement of more than a couple of centimetres means the bars are not reaching the guides.
- Check the bottom rail sits flat on the floor across its width; a gap at one corner is where a bar goes in.
- Confirm the guides are fixed firmly to the wall and the curtain sits inside them along its full height.
- On a manual door, fit a padbolt or anchor lock at each bottom corner, so the curtain cannot be forced up if the centre lock fails.
- On a motorised door, skip the padbolts, secure the release, and use the opener's lock mode instead.
- Fit a sensor light over the driveway, and keep the remote out of any car parked outside.
Roller doors on older homes in central Mandurah and the estuary suburbs are the ones that most often fail the first item on that list, because the curtain has crept along the drum over the years and the bars only reach one guide. That is a door adjustment, not a lock problem, and re-centring the curtain fixes it. Where the curtain is corroded through along the bottom, the honest fix is a new roller door supplied and installed with a lock or motor chosen at the same time.
Leaving for weeks: holiday-home security
Before you leave the house for a month
- Motorised door: put the opener into lock or holiday mode, or unplug it and tie the release handle back so it cannot be hooked.
- Take every remote out of any car or boat that stays behind, and delete any keypad code you have given to a tradesperson.
- Manual door: lock the centre lock, throw the corner padbolts, and take the key with you.
- Spray the lock barrel and bars with a dry lubricant so salt does not seize them while you are away.
- Ask whoever checks the house to run a motorised door once a fortnight, or turn the key on a manual one, so nothing seizes shut.
The seized lock is the one that catches part-time residents. A roller door lock barrel that sits unused near the water for three months can corrode enough that the key will not turn on your return, and the door is then locked against you rather than against a thief. A minute with a dry lubricant before leaving, and a fortnightly turn of the key by whoever checks the house, avoids that entirely.
Burglar-proofing: what actually works
Most forced garage doors are not forced at all. They are opened with a remote taken from an unlocked car, lifted because the lock bars never reached the guides, or released with a hooked cord. Fix those three and you have dealt with the bulk of the risk. After that, the upgrades that earn their money are a sensor light over the door, a shield over the release, a deadbolt on the internal door, and an opener with a lock mode and alerts. A smart garage door opener that tells your phone when the door opens, and lets you close it from wherever you are, is worth more than any second lock on the curtain. If you are not sure your lock is doing its job, book a repair visit for a door that does not lock properly and it is checked along with the rest of the door.
Replacing a roller door lock
- Measure the old lock: the diameter of the hole in the curtain, the distance from the lock to each guide, and the length and shape of the bars.
- Buy a lock whose bars will sit inside both guides with the curtain centred; most Australian roller door locks come with bars that are cut to length.
- Remove the old lock: undo the retaining nut or clip on the inside, slide the bars out of their keepers and lift the barrel out of the curtain.
- Fit the new barrel from outside, secure it from inside, and hook the bars into the cam so they move together when the snib turns.
- Cut the bars so each end sits well inside its guide when locked and clears it when unlocked, then fit the bar keepers to the curtain.
- Test from both sides: key from outside, snib from inside, and a firm lift with the door locked.
A lock swap on a manual roller door is one of the shorter jobs on a garage door, and the parts are standard. We carry the common lock sets, so a seized or broken lock is generally replaced on the first visit. Most repairs are finished the day they are booked. If the door has a motor there is no lock to replace, and the security check turns to the release and the opener settings instead.
