Torsion vs Extension Springs: Which Does Your Door Have?
Torsion springs mount on a horizontal shaft above the door opening. Extension springs stretch along the horizontal tracks on each side. Torsion is safer, lasts longer, balances the door better and is now standard on new installations. Converting extension to torsion costs roughly $300 to $600 including the springs.
Which do you have
Stand inside the garage with the door closed and look up.
A metal shaft running horizontally across the wall above the door opening, with one or two springs wound around it: torsion.
Long springs stretched along the horizontal tracks on each side, parallel to the ceiling: extension.
That is the whole test.
How each one works
Torsion. The spring is wound around a shaft. Opening the door unwinds it, and that unwinding turns drums that wind up the lift cables. The force is applied centrally and evenly across the door.
Extension. The springs stretch as the door closes and contract as it opens, pulling through a pulley system. The force is applied at the two sides.
Why torsion is better
Safety. When a torsion spring breaks, it is contained on the shaft. When an extension spring breaks, the stored energy sends the pieces across the garage unless a safety containment cable is threaded through it. That containment cable is why extension spring installations have them, and it is the first thing to check on an older extension door.
Balance. Central force distribution means a torsion door hangs more evenly and is smoother through its travel.
Life. Torsion springs are typically rated for about 10,000 cycles against roughly 7,000 to 10,000 for extension, and they hold their tension more consistently as they age.
Headroom. Torsion needs clearance above the door; extension needs side room. Which one you have often comes down to what the garage allowed when the door was fitted.
Opener options. A wall-mounted jackshaft opener drives the torsion bar directly and cannot be fitted to an extension spring system at all. In a low headroom garage that is a real constraint.
The costs
| Price | |
|---|---|
| Torsion spring, one, installed | $170 to $400 |
| Torsion springs, both together | $320 to $700 |
| Extension springs, pair | $150 to $300 |
| Conversion, extension to torsion | $300 to $600 |
| High-cycle torsion, per spring | $250 to $500 |
When conversion makes sense
Convert if you plan to keep the door for years, if you want a wall-mounted jackshaft opener, if your extension springs have no safety containment cables, or if the door has never hung evenly.
Do not convert if the door itself is near the end of its life. Put the money towards the replacement instead, and specify torsion on the new one, which is what it will come with anyway.
Conversion needs sufficient headroom above the opening. In a low headroom garage a low-clearance torsion kit exists, and it costs more.
What neither of them is
Neither is a DIY job. Both store enough energy to cause serious injury and both release it instantly if handled wrong. Extension springs are not the safer option just because they look less dramatic.
Related questions
Do extension springs need safety cables?
Yes, and this is not optional. A safety containment cable runs through the middle of each extension spring so that if it breaks, the pieces stay on the cable instead of flying across the garage. If your door has extension springs with no cables through them, get them fitted.
Is converting to torsion worth it?
On a door you plan to keep, usually yes. Torsion springs last longer, balance the door more accurately, and are required if you ever want a wall-mounted jackshaft opener. On a door that is close to replacement anyway, put the money towards the new door.
Which is cheaper to replace?
Extension springs are cheaper per pair, roughly $150 to $300 against $170 to $400 per torsion spring. Torsion lasts longer and balances better, so the cost over the life of the door is comparable.