Why has my up-and-over garage door become heavy to lift?
How the counterbalance works, what a heavy door is telling you, and the checks you can safely make before calling an engineer.
- Difficulty
- intermediate
- Time
- 1 hr
- Read
- 6 min
- Safety
- restricted
Short answer
The door is heavy because the counterbalance has weakened or failed — a broken or fatigued spring, a stretched or snapped cable, or a seized pivot. You can safely check the tracks, rollers, hinges and pivot points and lubricate them. You must not touch the springs or cables. A door that will not stay open halfway, or that drops when released, is unsafe to use until it is fixed.
An up-and-over door weighs a great deal — the counterbalance springs are what make it feel light. When the door becomes heavy, the counterbalance has lost some of its force or the mechanism has become stiff. Both are worth diagnosing, and the diagnosis is entirely a matter of looking and listening, because the components carrying the force are the ones that hurt people.
Safety
What you'll need
- Torch
- Step ladder
- Silicone or PTFE lubricant for tracks and rollers
- Light machine oil for pivots and hinges
- Garage door engineer's phone number (optional)
Step by step
- Take the immediate safety decision first.Open the door partway and let go, from a safe position to the side. A properly balanced door stays roughly where it is put. If it falls, or slams down, or will not stay open, stop using it and get it looked at. A door that drops is capable of causing a serious injury.
- Look at the springs without touching them.Torch on the spring assembly. On a canopy door there are usually springs at the sides connected to the lifting arms; on a retractable door they are on the horizontal tracks. Look for a spring that is visibly broken, one that is noticeably longer or more open than its pair, or a coil that has gone. A single broken spring on a two-spring door leaves the door roughly twice as heavy.
- Look at the cables.The lifting cables run from the spring assembly to the bottom of the door. Look for fraying, kinking, a cable off its drum or pulley, or one cable slack while the other is tight. A cable off its drum makes the door heavy on one side and it will bind.
- Check whether it is heavy or just stiff.A door that is heavy throughout its travel points at the counterbalance. A door that is light in some positions and jams in others points at the tracks, rollers or a bent panel — a mechanical obstruction rather than a spring problem.
- Inspect the tracks and rollers.Look along the tracks for dents, twists and debris. Check each roller turns freely. A flat-spotted roller or a bent track makes a door dramatically harder to move, and both are things you can see.
- Check the pivots, hinges and the frame.Every pivot point should move freely. A seized pivot on a canopy door's lifting arm can make it feel like a spring problem. Check the timber frame the door is fixed to as well — a rotten or moving frame throws the whole geometry out.
- Lubricate what is safe to lubricate.Rollers, hinges, pivot points and the tracks — a light machine oil on pivots and a silicone or PTFE spray on tracks. Do not use a heavy grease on tracks, which collects grit. Do not spray lubricant onto springs and cables as a fix; it does nothing for a fatigued spring.
- Check the door has not simply got heavier.Insulation panels, boarding, a new skin or a coat of paint added over the years all add weight the springs were never balanced for. If the door was modified, that is the cause and it needs re-balancing by an engineer, not more force.
- Call an engineer for anything spring or cable related.Springs and cables are replaced with specialist tools, in pairs, by someone who does it routinely. It is inexpensive relative to the risk, and it is the clear boundary on this job.
Tips
- Test the balance every few months: lift the door halfway and let go. Ten seconds, and it is the single most useful check on a garage door.
- Springs have a rated cycle life. On a door used several times a day, ten to fifteen years is a normal life and replacement is a maintenance item rather than a failure.
- Always have both springs replaced together. Replacing one leaves a new spring working against an old one, and the old one fails soon after.
- If you have an electric opener, know where the manual release cord is and check it works. You will want it during a power cut.
- Keep the tracks clean and dry rather than greasy. Grease holds grit and makes rollers wear faster.
Common mistakes
- Adjusting or removing a spring — The stored energy is enough to cause severe or fatal injury. Purpose-made tools and technique exist for a reason, and this is the clearest DIY boundary in the whole cluster.
- Turning up an electric opener's force setting — The force limit is a safety device — it is what makes the door stop when it meets an obstruction, including a person. Turning it up to mask a balance problem defeats it.
- Continuing to use a door that drops — A door with a failed counterbalance can come down fast and it is heavy enough to cause serious injury. It is not something to live with until it is convenient.
- Adding insulation or cladding without re-balancing — The springs are matched to the door's weight. Adding weight leaves the door permanently out of balance and shortens the springs' life dramatically.
If it doesn't work
The door became heavy suddenly, with a bang
Cause: A spring has broken. The bang is the failure. — Fix: Stop using the door and call an engineer. Springs are always replaced in pairs, because the second is the same age and will follow.
The door has become heavy gradually over years
Cause: Spring fatigue — springs lose force over tens of thousands of cycles — often combined with dry pivots and worn rollers. — Fix: Service the mechanical parts yourself, and have the springs assessed. Gradual weight increase usually means the springs are near the end of their life.
The door is heavy and lifts crooked
Cause: A cable off its drum or pulley, or one spring failed on a two-spring door. — Fix: Engineer. A crooked door binds in the tracks and can jam completely, and forcing it damages the frame.
The door is stiff at one point in its travel only
Cause: A dented track, a flat-spotted roller, or an obstruction. — Fix: This part is safely fixable. Clear the track, straighten a minor dent, replace the roller. If a track is badly bent it needs replacing.
An electric opener struggles or reverses
Cause: The opener is compensating for a door that is out of balance — the motor is doing the springs' job. — Fix: Never turn the opener's force setting up to compensate. Disconnect the opener, test the door by hand as above, and fix the balance. Increasing the force removes the safety feature that stops the door closing on something.
Questions people ask
How long do garage door springs last?
They are rated in cycles rather than years — commonly in the region of ten thousand to twenty-five thousand open-and-close cycles depending on the spring. On a door used twice a day that is a decade or more; on a door used ten times a day it is far less.
Can I just fit a new opener to lift a heavy door?
No. An opener is designed to move a balanced door, not to lift an unbalanced one. Using one that way overloads the motor, wears the mechanism and removes the margin the safety reversal depends on. Fix the balance first.
Is a canopy or a retractable door easier to fix?
Neither is a DIY spring job. The mechanical checks — tracks, rollers, pivots, cables visible from the ground — apply to both. Retractable doors have their springs on the horizontal tracks and canopy doors on the frame at the sides, which changes what an engineer does but not where your boundary sits.