Garage door springs play a crucial role in facilitating the lifting and control of garage doors. Given that garage doors typically weigh over 150lbs, it can be challenging to manually lift them or operate them with an opener without some extra assistance. To address this, two types of springs are commonly used: torsion springs and extension springs.

Torsion springs are pre-wound or coiled by certified garage door technicians, storing a certain amount of force within them. These springs naturally tend to unwind, but the weight of the door prevents them from doing so. When an upward force is applied to a closed door, the energy stored in the spring, combined with the applied force, enables the door to open with minimal effort.

Similarly, extension springs fulfill the same purpose, but instead of winding and unwinding, they stretch and compress akin to a slinky toy. When the door is closed, the spring is stretched out and desires to compress, but the weight of the door maintains its balance. By applying a small force in addition to the stored energy in the stretched spring, the door can be opened.

In both cases, as the door is opened, the weight of the door is shifted to the horizontal tracks, resulting in reduced downward force. Conversely, as the door closes, more weight is transferred vertically, while the springs progressively provide increased upward force. This mechanism prevents the door from abruptly crashing down.

In summary, the primary function of garage door springs is to supply supplementary force, ensuring a delicate equilibrium between the door’s weight and the energy stored within the springs.