Think about the last time you lifted your garage door by hand. A typical sectional or roller door can weigh well over a hundred kilograms, yet it rises smoothly with barely any effort. The hidden reason is the spring system, which stores and releases energy to offset that weight. When this counterbalance fails, the door becomes heavy, unpredictable and genuinely dangerous, which is why springs are one of the most common focuses of professional garage door repair Perth call-outs.
The counterbalance principle
Garage door springs do one essential job: they counterbalance the weight of the door. Without them, the full mass of the panels would rest on the opener or your arms every time you tried to lift it.
As the door closes, the springs wind up or stretch, storing mechanical energy. As the door opens, that energy releases and pulls the door upward. A well-tuned spring system balances the door so precisely that it almost feels weightless. This is why your motor can be relatively small and your door can pause halfway without crashing down.
In short, springs are the muscle of the system. The motor simply nudges a balanced door in the right direction; the springs do the heavy lifting.
Torsion springs vs extension springs
Two main types of springs are used on Perth garage doors, and they store energy in different ways.
Torsion springs sit on a metal shaft mounted horizontally above the door opening. When the door closes, the springs wind tightly around the shaft, building torque. As the door rises, they unwind and turn the shaft, which drives the lifting mechanism. Torsion springs tend to be more durable and offer smoother, more controlled movement, which is why many heavier and modern doors use them.
Extension springs run along the horizontal tracks on each side of the door. Instead of twisting, they stretch and contract. When the door is down, they are extended and under tension; as the door lifts, they pull back and contract. They are common on lighter doors and in older installations.
Both types rely on a network of connected components, including cables, to transfer their stored energy into smooth movement. We will look closely at those cables in a later article.
The lifecycle of a spring
No spring lasts forever. Springs are rated in cycles, where one cycle is a single open-and-close movement. Each cycle flexes the metal, and over thousands of repetitions the steel slowly fatigues.
Metal fatigue is gradual and largely invisible. Tiny stresses accumulate inside the spring until it can no longer hold the same tension. The door may start feeling slightly heavier or hesitating before it eventually fails outright.
Several factors speed up wear. Frequent daily use, Perth’s coastal humidity and salt air encouraging corrosion, poor lubrication and large temperature swings all shorten a spring’s working life. A household that opens the door many times a day will reach the end of its spring’s rated cycles far sooner than one that uses it occasionally.
Warning signs of a failing or broken spring
Springs usually give clues before and during failure. Learning these signs helps you act before the door becomes unsafe.
A loud bang from the garage, almost like a firecracker, is the classic sign of a spring snapping under tension. Many people hear it and assume something fell over, only to find the door won’t open afterwards.
Other warning signs include jerky or uneven movement, a door that suddenly feels much heavier by hand, a door that slams down rather than lowering gently, or one that opens only a few centimetres before stopping. You might also notice a visible gap in a torsion spring or a stretched, sagging extension spring.
If the door movement seems erratic, it is worth ruling out other system parts too. For example, problems can sometimes be confused with sensor faults, so it helps to understand how garage door safety sensors work when diagnosing strange behaviour.
Why spring tension makes DIY risky
Springs hold an enormous amount of stored energy, even when the door appears still. A torsion spring under full tension can release that force violently if it is unwound incorrectly or if a component slips.
This is what makes adjusting or replacing springs hazardous for untrained hands. The tools, technique and tension calculations are unforgiving, and a mistake can cause serious injury or damage. The risk is the same reason these jobs are best left to experienced technicians who carry the correct equipment.
It is also important to remember that springs do not work in isolation. They are linked to cables, drums, tracks and the opener, and a healthy spring system keeps the entire door balanced and safe. When springs weaken, every other part takes on extra strain, accelerating wear across the whole door.
Understanding springs is the first step toward appreciating the full lifting system. In our next article we will explore the next piece of the puzzle: Understanding Garage Door Cables and Tension Systems.