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Most people looking up how to adjust roller door tension have one of two doors: a curtain that has turned into a workout to lift, or one that creeps up off the floor and refuses to stay shut. Both usually trace back to the springs. Below is what tension is, how to tell which way yours is out, and where an owner check ends. We don't publish steps for winding or releasing the springs, because that is exactly where people get hurt.
How roller door tension works
A domestic roller door is one curtain of corrugated steel that coils around a drum above the opening. The drum rides on a steel axle resting in a bracket at each side, and the axle is clamped so it cannot turn. Inside the drum wheels sit coil springs, with one end fixed to the axle and the other to the wheel. As the curtain unrolls on its way down, the wheels rotate around the stationary axle and wind those springs tighter. That stored energy is what helps you, or the motor, lift the door back up.
Tension is simply how much wind the springs are holding. Set well, it cancels most of the curtain's weight through the whole travel, so the door feels light and stays wherever you leave it. Because the springs are anchored to the axle, the tension is altered by rotating the axle itself a controlled amount and clamping it again. For the parts that wear and how long springs tend to survive, read our complete guide to garage door springs.
Signs your roller door tension is off
Springs relax a little with every cycle, so tension drifts slowly and a door can feel much heavier years later without anything breaking. Watch for:
- Too little tension: the door is heavy to lift by hand, drops quickly once it passes halfway, or thumps onto the slab.
- Too much tension: the door fights you on the way down, lifts off the floor by itself, or shoots up through the last part of its travel.
- An opener that labours, slows near the top, or stops and reverses with nothing in the way. Motors are set up for a balanced door and struggle when it isn't.
- The curtain rolling on crooked or rubbing one guide harder than the other, which can point to uneven tension or a drum that has moved on the axle.
- A sudden change overnight, often after a loud bang. That isn't drift; a spring may have snapped, and the door shouldn't be used until it has been inspected.
The balance check you can safely do
Finding out whether the tension is right doesn't require touching a spring. If there is an opener, put it into manual mode with the release cord or lever first; our walkthrough on opening a garage door by hand shows how that works on the common motors. Start with the door fully closed so nothing can fall when the opener lets go.
- Close the door fully, then disengage the opener so the curtain moves freely by hand.
- Clear the doorway of cars, bikes, children and pets, and keep your fingers well away from the side guides and the point where the curtain feeds onto the roll.
- Lift the door by its handle or bottom rail to about waist height, then let go gently with your hands still close by.
- Watch it for a few seconds. A balanced door holds its place or moves only slightly. If it sinks, it is short of tension; if it rises, it is carrying too much.
- Raise it all the way and lower it again, noting any point where it suddenly gets heavier, catches or grinds.
- Close it fully and re-engage the opener before you reach for the remote.
Rule out drag before blaming the springs
A heavy door isn't always a tension fault. Sand packed into the side guides, a bottom rail bent by a nudge from the car, or dirty, dry guide channels all add resistance. Wipe the guides out and look for dents before deciding the springs have weakened.
Why adjusting the springs isn't a DIY job
The axle is loaded even when the door is still
The springs push against the axle clamps all the time. Loosen those clamps without the axle properly held and it can spin violently, whipping a wrench or bar around and letting the curtain run down. Leave the brackets, U-bolts and axle clamps alone.
Online videos make the adjustment look like a two-minute job. What they skip is how fast it goes wrong. The spring load arrives the instant the grip on the axle slips, not gradually, and a spinning bar at head height is how most roller door injuries happen. A curtain that drops can also crush fingers in the guides or land on the car beneath it. Worse, owners often add wind to a spring that is already cracked or fatigued, which loads a failing part even harder.
What a professional tension adjustment involves
On a visit where tension is the issue, the technician repeats the balance check, then inspects the springs, drum wheels, axle, brackets and guides for cracks, wear and rust before deciding whether an adjustment is even the right fix. If it is, the axle is secured with purpose-made tools, the tension is changed in small steps, and the door is retested by hand after each change until it holds mid-travel. The opener's limits and force are then checked against the newly balanced door, the guides are cleaned, and the door is run several times before we leave.
Sometimes more tension isn't the answer. A spring that has lost much of its strength only feels right for a little while after being wound up, and a door that keeps needing re-tensioning is telling you its springs are near the end. There, new springs are the fix that lasts.
Why does my roller door feel so heavy?
The usual reason is lost spring tension, either from age or from a spring that has broken. After that come sand-clogged guides and dented curtains that rub. Around the older estates in the northern and south-eastern suburbs, plenty of original doors are still on their first set of springs, and a gradual heaviness is often the first hint they are due. Homes near the coast have one more factor: salt air corrodes springs and brackets faster than it does further inland.
Roller door won't close, or goes back up?
When a motorised door won't close fully, or reverses on its way down, start with the simple causes: something in the doorway, safety beams that are dirty, knocked out of line or dazzled by low afternoon sun, and a remote with a tired battery. Our guide to checking and fixing garage door sensors covers the beams. If those are fine, the cause is usually the opener's close limit or force setting, or a door so overwound that the motor reads the springs pushing back as an obstruction.
Wanting the door to close tighter to the floor is almost always a travel-limit setting on the motor, not a spring job. Limits are set differently from one make and model to the next, so follow the manual for yours. If the door still stops short once the limit is reset, balance is the next suspect, and the door won't close troubleshooting page runs through the wider list.
Getting roller door tension sorted in Perth
If you're in Perth and your roller door still feels wrong after the balance check, book it in. We inspect the springs, axle and guides, set the tension properly and check the opener against the balanced door. There is no call-out fee, and the price is agreed with you before any work starts. Our roller door repair service covers homes across all of Perth, from Yanchep to Mandurah.
Product Safety Australia records injuries and recalls involving powered and spring-loaded doors, and roller door makers such as B&D publish the correct setup in their manual library.