Garage door springs counterbalance a sectional door and reduce the load on the opener. Most systems use either torsion springs or extension springs, which work differently and require different supporting hardware.
For your project, the right choice depends on the door weight, available installation space, track arrangement and operating frequency.
What Is a Garage Door Spring System?
The opener controls the movement of a sectional door, but the spring system carries most of its weight. When the counterbalance is correct, the door can move without placing the full load on the opener and hardware.
This is why you should not select the spring as an isolated component. Its performance depends on the door weight, track arrangement and the hardware used to transfer force to the door.
Types of Garage Door Springs
Before you choose a spring system, it helps to understand how each type works. The following sections introduce torsion and extension springs, including their installation positions, operating methods and common applications.
Torsion Garage Door Springs
In a torsion system, you will normally find the springs mounted on a steel shaft above the opening. As your door closes, the springs wind and store energy. When the door opens, they apply torque to the shaft, which turns the cable drums and winds the lift cables.
If you are specifying a heavier sectional door or a project with frequent operation, a torsion system is often the more practical starting point. You can configure it with one or more springs and match it to different track-lift arrangements.
However, specifying “torsion spring” is not enough. Before you confirm the system, check that the springs, shaft, drums and cables all suit your door weight and travel path. You should not automatically reuse a torsion system designed for standard lift on a high-lift or vertical-lift door.
Extension Garage Door Springs
In an extension spring system, you will normally find the springs alongside or above the horizontal tracks. They stretch when your door closes and contract as it opens.
The system usually operates with cables and pulleys on both sides of the door. If one side of your system is incorrectly matched or adjusted, the door may not travel evenly.
If you are working with a lighter sectional door, extension springs may still be a suitable choice when the installation is designed around this arrangement. Do not dismiss them simply as a lower-cost alternative. You also need to check the available track space, pulley configuration and required safety components before making the final decision.
Torsion vs. Extension Garage Door Springs
Torsion and extension springs perform the same basic task, but they store energy, transfer force and connect to the door in different ways. Understanding these differences will help you recognize why the two systems require different hardware and installation conditions.
Difference in Operating Method
A torsion spring stores energy by winding around a shaft. As it unwinds, it applies torque to the shaft, which turns the cable drums and lifts the door through the cables.
An extension spring stores energy by stretching. As it contracts, it pulls through a cable-and-pulley arrangement to help raise the door.
The main difference is therefore rotational force versus linear pulling force.
Difference in Installation Position
Torsion springs are normally installed on a shaft above the door opening. The system occupies space around the header and must provide room for the springs, shaft, drums and bearing hardware.
Extension springs are usually installed alongside or above the horizontal tracks. They use the space around the track area rather than a central shaft above the opening.
For your project, this difference affects where the counterbalance components can be positioned inside the building.
Difference in Supporting Components
A torsion spring system normally includes a shaft, cable drums, lift cables, bearing plates and spring anchor hardware.
An extension spring system normally uses pulleys, cables, brackets and suitable safety-containment components on both sides of the door.
Because the supporting components are different, torsion and extension springs cannot be exchanged without reviewing the rest of the counterbalance system.
Difference in Door Balance
A torsion system transfers force through a common shaft and cable drums positioned on both sides of the door.
An extension system uses separate springs and pulley arrangements on the left and right sides. If the two sides are not correctly matched, the door may lift unevenly.
In both systems, the spring force must match the completed door weight, but the method used to distribute that force is different.
Difference in Typical Application
Torsion springs are widely used on residential, commercial and heavier sectional doors. They can also be configured for standard lift, low headroom, high lift and vertical lift systems.
Extension springs are more commonly found on some residential and light-duty sectional doors designed around horizontal tracks and side-mounted spring hardware.
Operating life should not be judged from the spring type alone. Both systems must be specified according to the actual door weight, spring design and required cycle life.
How Do You Choose the Right Garage Door Spring Type
To choose the right spring type for your project, you need to look beyond the spring itself. Start with the complete door, then review the installation space, operating frequency and counterbalance arrangement.
Confirm Your Door’s Actual Weight
When you select a spring system, do not begin with the old spring number or the nearest catalogue size. Begin with your finished door.
Confirm your door’s actual or calculated weight, including insulation, windows, reinforcement and hardware attached to the moving sections. A 16-foot insulated door, for example, should not be treated as equivalent to every other door of the same width.
For your replacement project, the existing spring is useful reference information, but it is not proof that the original configuration was correct.
Check Your Installation Space
Next, look at where the spring system can be installed in your building. Check your available headroom, sideroom and backroom, as well as any beams or services close to the opening.
Review this information together with your garage door track configuration. Standard lift, low headroom, high lift and vertical lift systems do not all use the same drum, cable or spring arrangement.
A useful rule is to confirm your door path before finalizing the spring. If you change the track configuration later, you may also need to review the counterbalance system again.
Consider How Often Your Door Will Operate
If your door will operate only occasionally, it may have a different spring requirement from a workshop or commercial door operating throughout the day.
Define your required cycle life instead of asking only for a “heavy-duty spring.” One cycle means one complete opening and closing operation. Your expected daily use and required service period give the supplier a clearer basis for spring selection.
Avoid relying on a universal cycle-life claim. Springs that appear similar can have different wire sizes, lengths and working stresses.
Review Your Complete Counterbalance System
Finally, check your spring together with the shaft, drums, cables, pulleys and supporting brackets.
This is particularly important if you are:
- Changing from extension springs to torsion springs
- Changing the track-lift configuration
- Adding insulation, windows or reinforcement
- Increasing the required operating cycles
- Replacing only part of an existing counterbalance system
If you treat one component as a direct substitute, you may create a mismatch elsewhere in the system. It is usually easier to resolve that mismatch during your technical review than after the hardware reaches the site.
Frequently Asked Questions
What Are the Main Types of Garage Door Springs?
The two main types used on sectional garage doors are torsion springs and extension springs.
What Is the Difference Between Torsion and Extension Springs?
Torsion springs wind around a shaft and transfer force through drums and lift cables. Extension springs stretch and normally work with cables and pulleys along the tracks.
Which Spring Type Is Used for Commercial Garage Doors?
Torsion springs are frequently used on commercial sectional doors, especially where the door is heavier or operates more often. You should still confirm the door weight, lift arrangement and required cycle life before making the final choice.
Can the Same Door Use Either Spring Type?
A conversion may be possible, but the two systems are not directly interchangeable. You may also need different tracks, cables, pulleys, drums, brackets or shaft components.
Can a Spring Be Selected from the Door Size Alone?
No. Door size is only the starting point. You also need the door weight, construction, track arrangement and operating requirement.
Final Thoughts
When you compare torsion and extension springs, focus on how the complete door will operate rather than which spring sounds better on paper. Submit the door dimensions, weight, track arrangement and operating requirements to Gemax for spring-system review and quotation.
Gemax also supplies roll-up door spring solutions, which will be covered in a separate guide.
