In short:
- Most roller shutters are locked in one of three ways: a centre lock in the bottom rail, slide bolts into the side guides with padlocks, or bolts into the floor.
- Many "lock" problems start with the door: grit in the guides, a curtain that sits lower than it used to, or impact damage that stops a bolt lining up.
- Never adjust or release the springs yourself. Roller door makers warn that the spring stores enough energy to cause serious injury.
- Lubricants are not interchangeable. Door and lock makers recommend different products, and some warn against the ones people reach for first.
- We work on the whole shutter: the locks and padlocks, and the springs, curtain, guides and motor.
How a roller shutter is locked
Roller shutters are everywhere in Kempton Park's industrial areas. Warehouse listings in Isando and Chloorkop advertise roller shutter doors for loading. They're also common on shops, garages and storerooms. The way a shutter is locked decides what can go wrong with it.
| Lock type | How it works | Typical problems |
|---|---|---|
| Centre lock | A keyed lock in the middle of the bottom rail, often with a handle that doubles as the lifting point. Bars or bolts shoot sideways into the guides. | Key won't turn; handle loose; bars don't reach the guides or won't withdraw |
| Slide bolts with padlocks | A bolt on each end of the bottom rail slides into a hole in the guide channel and is padlocked. | Bolt won't line up with the hole; padlock seized by rust or dust; hasp bent |
| Floor or ground bolt | A bolt drops into a socket in the floor, usually padlocked or keyed. | Socket blocked with dirt; bolt bent by a vehicle; floor socket damaged |
| Inside bolts | Bolts or a bar operated from inside the building only. | Can't be reached if there's no other way in; see our warehouse lockout guide |
Symptoms and their likely causes
- The key turns but the bars or bolt won't move. The lock's internal parts may be worn or broken, or the bolt is binding against the guide because the curtain has shifted.
- The bolt won't slide into the hole in the guide. The door isn't coming down to the same position as before. Often the curtain has dropped slightly, the guides are bent, or debris on the floor stops the bottom rail seating.
- The padlock won't open or close. Dust and rust on a padlock exposed to the weather, or a shackle bent by someone forcing it.
- The door got harder to lift, then the lock started playing up. That points to the door itself: springs losing tension over the years, or grit in the guide channels. B&D, a roller door maker, notes that springs lose tension through normal metal fatigue.
- A motorised door strains or stops when you press the button. Check whether a manual lock is still engaged. Door makers take this seriously: Novoferm's manual requires a lock used with an electric drive to have a switch that stops the motor running while the door is locked.
Safe checks you can do
You can learn a lot by looking, without taking anything apart:
- With the door closed, look at whether the bolt lines up with the hole in the guide. If it sits above or below, the problem is the door's position, not the lock.
- Look along the guide channels for stones, packaging, rust flakes or a bent section.
- Check the floor under the bottom rail for debris that stops the door closing fully.
- Check that every lock is fully open before lifting, and that a motorised door's manual locks are released before you run it.
- Lift a manual door with both hands on the handle or lifting points. One-handed lifting can twist the lock mechanism sideways.
- Look for impact damage at forklift or vehicle height.
Don't touch the springs, the barrel or the cones that hold spring tension. Roller door makers warn that the torsion springs store enough energy to cause severe injury or death if mishandled. Leave spring work to the technician.
What makes it worse
- Forcing the curtain up against a lock that's still engaged. It can bend slats or push them out of the guide channels, and a curtain forced back into its guides is often damaged for good.
- Hammering a bolt into a hole it no longer lines up with. The bolt, hasp or guide bends, and the next fault is worse.
- Cutting off a seized padlock with a grinder. Sparks near stock and dust, and often a damaged hasp that then needs replacing too.
- Spraying any lubricant you have into the lock and the guides. See the next section.
- Ignoring a door that's getting heavier. The lock is often the first thing to show that the door has a problem.
Lubrication: follow the door and lock makers
There's no single product that's right for every part of a roller shutter, and makers disagree:
- B&D recommends a silicone-based spray made for garage doors on the inside of the guide tracks, applied sparingly, and warns against petroleum-based products such as WD-40, which attract dust and form an abrasive sludge.
- Trellidor recommends its own lubricating spray on the slats and inside the guide channels of its roller shutters, and says never to spray lubricant into the shutter's motor.
- ASSA ABLOY recommends graphite powder for cylinders, lever locks and padlocks, and warns against silicone-based lubricants on exposed mechanisms because they go tacky.
So a product that suits the guides may be wrong for the lock. Use what the maker of your door, and the maker of the lock or padlock, specify. If you don't know who made them, ask before spraying anything. Our article on a key that won't turn or a stiff lock explains why the wrong lubricant can make a lock worse.
What we check and fix
| Problem | What we do |
|---|---|
| Centre lock, slide bolt, floor bolt, padlock or hasp faulty, or key lost | Repair or replace the faulty part: see our commercial locksmith service |
| Locked out because the only key is missing | Open the door, trying non-destructive methods first |
| Door heavy, drops on its own, or springs damaged | Check the springs and barrel, then adjust or replace the springs |
| Curtain out of the guides, slats bent, guides damaged | Refit the curtain, replace bent slats, and straighten or replace the guides |
| Motor, remote or control fault | Find the fault, then repair or replace the part |
| Bolt won't line up because the door sits wrong | Correct the door first, then adjust the lock |
If you're not sure whether it's the lock or the door, send us photos. The technician checks both on site and quotes before any work starts.
What to send before a visit
- A photo of the whole door, closed, showing both guides and the bottom rail.
- Close-ups of each lock: centre lock, bolts and padlocks.
- A photo showing where the bolt sits relative to the hole in the guide.
- Whether the door is manual or motorised, and the make if there's a label.
- Whether you're locked out, or the door is open and won't lock.
A shutter that won't lock at closing time is an urgent security problem; we're open 24/7. The R250 call-out brings the technician to you, the work is quoted on site before it starts, and payment is by EFT, cash or card. If the padlocks themselves are the weak point, read choosing padlocks for warehouses, yards and containers. For everything else we do, see our mobile locksmith in Kempton Park homepage.
Questions
Can I just put a padlock through the bolt holes instead of fixing the centre lock?
As a short-term measure it may be better than nothing, but a padlock is only as strong as the bolt and hasp it's on. Have the centre lock looked at; it may need a part rather than a whole new lock.
Our roller shutter was hit by a truck and now won't lock. Who do we call?
Call us. Bent guides or slats are usually the cause, so the technician checks the door first, then the lock, bolt and hasp, and quotes for both on site before any work starts.
Will you cut off a padlock if the key is lost?
Non-destructive opening is tried first. If a particular padlock can't be opened without damage, the technician explains why and quotes for removing and replacing it before doing anything.
Need a locksmith to look at it?
If this hasn't solved the problem, our commercial locksmith service covers it. We're a mobile locksmith in Kempton Park, so we come to your door. Areas where this comes up often include Isando, Chloorkop.
Sources and further reading
- B&D Doors: Rollmasta roller garage door manual operation — Centre-mounted lock as the lifting point; one-handed lifting can twist the lock; springs lose tension; torsion springs can cause severe injury or death; forcing can pop slats out of the guides; silicone spray on tracks and avoid WD-40.
- Novoferm door manual (Novoferm 45-1), section 5.2 Outside lock, on ManualsLib — A lock used with an electric drive must have a switch that prevents the motor switching on while the door is locked.
- Trellidor: Roller shutters care guide — Wipe down side guide channels; Trellidor lubricating spray on slats and guide channels; never spray lubricant into the motor; maintenance per the maker's instructions.
- ASSA ABLOY South Africa: Product Care and Maintenance (PDF) — Graphite powder for cylinders, lever locks and padlocks; no silicone-based lubricant on exposed mechanisms.
- ASSA ABLOY Ireland: Roller shutter door maintenance — Regular inspection catches wear, corrosion and mechanical issues early and keeps safety mechanisms intact.
- Anvil Property: warehouse listing, 14 Diesel Road, Isando — Isando warehouse unit listed with roller shutter doors.
- Anvil Property: A-grade warehouse, Proton Industrial Park, Chloorkop — Chloorkop warehouse with multiple roller shutter doors.