Garage Door Spring Types: Torsion, Extension and Roller Door Springs

Question 01

What are the different types of garage door springs?

Garage door springs come in two main types: torsion springs, which twist on a bar above the door, and extension springs, which stretch along the sides. Steel-Line says most Australian homes have one or the other. Roller doors are a third case, because their springs sit inside the drum the curtain rolls around.

Steel-Line puts it plainly: the spring type is set by the design of the door, not by what the owner prefers. So the quickest way to know your spring type is to know your door type. If you're not sure what kind of door you have, roller vs sectional vs tilt doors explains how to tell them apart.

Steel-Line uses torsion springs on its sectional doors and extension springs on its tilt doors. B&D says extension springs are found on older doors and tilt doors, and that torsion springs are most common on sectional doors.

Question 02

How do I tell what type of garage door spring I have?

Stand inside the garage with the door shut, keep your distance and look up. A thick coil on a bar across the top of the opening is a torsion spring. Long coils running beside the tracks are extension springs. A roller door with no spring in sight has its springs inside the drum. Just look, never touch.

1. 01Close the door first. Do this check with the door fully down, so nothing is moving and nothing can drop.
2. 02Stay out from under the door. Stand back inside the garage where you can see the top of the opening and both sides.
3. 03Look above the opening. A steel bar running across the top with one or two big coils on it is a torsion setup. B&D describes torsion springs as sitting horizontally above the door.
4. 04Look along the sides. Long coils running beside the tracks are extension springs. B&D says they run along the sides of the horizontal tracks.
5. 05Check for a roll. If the door is a single curtain wound onto a roll at the top and there's no coil on show, it's a roller door with its springs inside the drum.
6. 06Take a photo from where you stand. It helps when you ring, and you don't need to get any closer to take it.

Question 03

What is a garage door torsion spring?

A torsion spring is a heavy coil that sits on a steel bar above the garage door opening. B&D says it coils tighter as the door closes, storing energy, then unwinds to help lift the door as it opens. Torsion springs are most common on sectional doors, either as one spring or a pair.

Steel-Line says torsion springs can be installed as a single or dual system, depending on the size and weight of the door. So a bigger, heavier door may have two springs on the bar rather than one.

On a torsion door the springs don't lift the door directly. They work through two steel cables, one on each side, which wind onto drums on the spring shaft. That's why a cable problem can look a lot like a spring problem from the ground, and why the two are checked together on a spring repair callout.

Question 04

What is a garage door extension spring?

An extension spring is a long coil that stretches along the side of the door as it closes, then pulls back as it opens. Steel-Line says they're installed in pairs, one on each side, and that safety cables are essential to stop a broken spring flying loose. Steel-Line uses them on its tilt doors.

Steel-Line says extension springs suit lighter, non-insulated doors, and garages with little headroom above the door. B&D lists them on older doors and tilt-door systems.

The safety cable matters. Steel-Line says it stops a spring snapping loose if it breaks, and B&D lists a higher risk if they snap without safety cables among the downsides of extension springs. If you can't see a safety cable with each extension spring, mention that when you ring.

Question 05

What kind of spring does a roller door have?

A roller door has its springs inside the drum at the top of the opening, where the curtain rolls up, out of sight. They wind up as the door comes down and help lift it as it rolls up. The tension is held on the axle, so the brackets and U-bolts at each end are part of the spring system.

B&D's Roll-A-Door instructions warn that the axle must be securely clamped, otherwise the door will lose spring tension. Steel-Line says loosening the U-bolts can release spring tension and bring the door down forcefully. Steel-Line's roller door manual tells owners not to loosen any fastener on the spring assemblies, including where the shaft is fixed to the brackets, because the door can approach or exceed 150 kg.

So on a roller door, treat the brackets at each end of the roll as part of the spring. Steel-Line also tells owners not to attempt to tension a roller door, at risk of serious injury or death. A roller door that has gone heavy, drops or creeps up is covered in roller door spring tension, including the safe balance check.

Question 06

What are the disadvantages of torsion springs?

Steel-Line lists three downsides of torsion springs: a higher upfront cost, a more complex install, and the need for enough headroom above the door. Extension springs work in tighter garages but need more parts, tend to be noisier and are generally rated for fewer cycles. On an existing door, the door's design has already made the choice.

A cycle is one full open and close. The ratings vary with the grade of spring and between the makers' guides, which is why more than one figure is shown. What the spring type means for the price of a replacement is covered in garage door spring replacement cost.

Question 07

What does a failing spring look like on each type of door?

A broken torsion spring often shows a clear gap in the coil above the door, and many people hear a loud bang. Either type can show a clean break, a stretched-out section or loose, uneven coils, and a two-spring door may lift crooked. A tired roller door spring makes the door feel heavy or stop staying where you leave it.

B&D describes a visible gap of about two inches (about 5 cm) in a torsion spring as a clear sign it has broken. The first four rows come from B&D's guides to garage door springs and broken spring safety. If yours has already gone, what to do about a broken spring covers the next few minutes, including what not to touch.

Question 08

Can a heavier or different spring go on my garage door?

Not as a guess. Each spring is matched to the door, and Steel-Line says choosing the right torsion spring depends on the door's weight, height, width and cycle rating, with professional guidance. B&D warns that springs that aren't properly chosen can make a door noisy, slow or dangerous to run. A heavier spring isn't an upgrade.

The wrong spring leaves the door heavy or makes it fly up. Swapping one spring type for the other isn't a simple change either, because Steel-Line says the spring system follows the door's design.

This is why the spring type is worth knowing before you ring. Thom replaces torsion and extension springs across the Sunshine Coast, from Mooloolaba to Buderim. Tell him the door type when you ring, so he brings the right spring. Call 0402 882 653 or book a callout.