Roll-up garage door repairs and motors

A roll-up door is a single curtain of thin, corrugated steel. At the top of the opening, it's screwed to drum wheels on a horizontal axle, and as the axle turns, the curtain winds onto the drums like a blind. A channel on each side of the opening, the guide, keeps the curtain straight, and a weight bar along the bottom edge keeps it from bowing out as it starts to come down.

The weight is carried by counterbalance springs on the axle. They're wound up as the door closes and give that energy back as it opens, which is why a healthy door lifts with one hand. When the springs tire, the door feels heavy; when they break, it can't be lifted at all.

A roll-up motor sits at one end of the axle and turns the drum wheel directly, unlike the ceiling-mounted motors on sectional and tip-up doors.

Centurion's installation manual for its RDO Digital motor gives a simple standard for a roll-up door in good order, and it's the one we work to:

• It takes the same effort to open as to close, and no more than about 15 kg of effort either way.
• It stays where you leave it. Let go of it at about waist to chest height, between 900 and 1,200 mm off the floor, and it shouldn't rise or fall more than about 100 mm.
• It runs freely, without binding or sticking in the side guides, and without rubbing on the walls or the frame.

A door that fails any of these needs work on the door, not the motor; the RDO Digital even warns when its door has gone out of balance.

• The door feels heavy or won't stay up. The springs have lost tension or one has broken. See garage door springs.
• It jams or drags partway. A guide has been bent, often by a car or a bin, or the curtain has a dent that catches in the channel. Dirt and leaves packed into the bottom of the guides do the same.
• It doesn't roll up tight. The curtain winds on loose or uneven when the springs are weak, when the weight bar is missing or bent, or when the curtain has started to come loose from the drum.
• The curtain has dropped at one side. Its screws into the drum wheel have pulled out, and the curtain has to be refixed before anything else.
• It's stiff in winter and fine in summer. Centurion notes that springs not greased between their coils rust, and that temperature changes then alter the friction enough to upset a motor.
• It won't open at all. The lock is engaged, a spring has broken, or, on a motorised door, the motor or its battery has failed.

The springs on a roll-up door hold a great deal of stored energy, even with the door closed. Releasing, winding or adjusting them, or loosening the drum wheels or axle brackets they're attached to, can let that energy go in an instant. Leave them alone, and don't use the motor on a door whose springs have gone: a motor isn't built to lift the door's full weight, and running it can damage its gears or the drum.

What you can do safely is look and listen: a gap in a coiled spring, a loud bang from the garage, or a door that has suddenly become very heavy all point to a broken spring.

Yes, you can put a motor on a roll-up door, provided the door is balanced and runs freely. Each motor has limits, set by its maker:

Both keep running from their batteries when the mains fails, and both stop and reverse when the door meets something. ET's control box isn't waterproof, so it goes on a dry wall. ET adds two rules: no motor on a door with a pedestrian door built in, unless opening that door switches the motor off, and safety beams whenever the door closes by itself. The older Centurion RDO II is covered on our Centurion RDO page, and ET's range on the DC Blue Advanced manual page.

1. The door first. We test its balance as above, and repair springs, guides or the curtain before any motor goes on.
2. Locks and ropes off. The manual lock and any pull rope are removed or disabled, so a remote can't drive the door against a locked bolt.
3. The curtain checked at the drum. It must be properly screwed to the drum wheel, with extra screws where it has worked loose.
4. The weight bar fitted or straightened, so the curtain starts down cleanly from fully open.
5. The motor on the axle, at the right-hand end as seen from inside unless the garage needs it on the left, and the control box on a dry wall.
6. Limits and force set, then a safety test with something solid on the floor under the door, which it must touch and reverse from.
7. The release cord within easy reach, no higher than 1.8 m off the floor, and everyone at home shown how to use it.

Choosing a motor and what the whole job involves is on garage door motor installation.

Roll-up doors are made to the opening. As one example, Hydro Doors builds its standard single roll-up door for an opening 2,440 mm wide (2,400 mm for its Econo door) and 2,130 mm high, and asks for 400 mm of headroom and ceiling space above the opening for the coiled curtain, with a 150 mm nib of wall on each side for the guides.

To quote a new door, a door supplier needs the opening's width and height, the headroom and ceiling space, whether there's power for a motor, and whether the garage has another way in. If it doesn't, Hydro Doors asks for an escape lock with the door. A wide double opening should also be checked against the motor's limits in the table above before anything is ordered.

On a motorised roll-up door, a cord hanging from the motor disconnects the drive from the drum so the door can be lifted by hand. On Centurion's RDO Digital, one pull on the red cord frees it with a click and a second pull engages it again. Centurion asks for the door to be fully closed when you release it, and never with people, pets or a car under or near it, because a door with weak springs can drop once it's free.

The cord is inside the garage, so from outside you depend on the motor's battery or another door into the garage. Our guide to opening a garage door manually covers each case.

• Wash it. Hydro Doors suggests every three months inland, with a microfibre cloth and warm water with a car soap and wax, then a rinse. No pressure washer, rough cloths, window cleaner, bleach or solvents.
• Keep the guides clear of leaves, grit and anything leaning against them.
• Have the springs greased between their coils on a service, as Centurion asks, rather than doing it yourself under tension.

Our installed kits are the Centurion RDO Digital roll-up kit at R3 899 and the ET DC Blue Advanced roll-up kit at R4 399, each with battery back-up and remotes, installed on a door that already runs freely, and with our 1-year guarantee on every motor kit we supply and install.

In South African shops, for comparison, before fitting:

• Centurion RDO Digital roll-up kit: about R2 900–R3 000 (Takealot)
• ET DC Blue Advanced roll-up motor head: about R1 870 (NeonSales)
• ET DC Blue Absolute roll-up kit: about R2 510 (Takealot)
• Gemini 24 V roll-up motor: about R3 970 (Takealot)

We don't price new doors here: a door is made to its opening, so its price depends on the size, the steel and the finish. Door repairs are priced once we've seen the door. Prices checked October 2026. Your exact price is set in a free quote before any work starts. No call-out fee when we do the work. If no work is done, a R650 call-out fee applies.

On the job card, tell us what the door is doing, whether it has a motor and which one, and whether you've heard a bang or seen a gap in a spring; a photo of the door from inside, showing the axle and the motor, helps us bring the right parts. Same-day repairs are offered when the day allows. All our spare parts are genuine, and every repair comes with our six-month guarantee on our repairs.