The function of garage door springs is to counterbalance the weight of the garage door and thereby make it easy to open and close. For example, if a garage door weighs 150kg, the springs need to provide a force of 150kg to pull against the weight of the door. This is achieved by using springs that either turn or stretch certain parts and thereby balance the door.
There are two different types of garage door spring mechanisms that are used on sectional doors:
Garage Door Springs: Torsion Springs
These are coiled springs which are tightly wound together – even a piece of paper cannot be inserted between the coils. If you pull the ends of a torsion garage door spring away from each other, the coils will separate, but then, as soon as you let go, they will snap together. This is a spring that works by torsion or twisting; that is, it is a flexible elastic object that stores mechanical energy when twisted. When un-twisted it exerts a force in the opposite direction, proportional to the amount it is twisted. A Torsion Spring system consists of tightly wound up springs mounted on a steel shaft (the torsion pipe) with cable drums at both ends. At each end of the torsion spring there is a cone. On one end is the winding cone (which often shows the spring diameter) while on the other side, there is a stationary cone. The stationary cone is mounted on a bracket
which is then attached above the top centre of the garage door frame (also called the “centre bearing plate”). The springs extend along the torsion pipe, which is mounted on the header wall above the garage door. It has three supports: the centre bearing plate and two end bearing plate at both ends. Cables attached to the garage’s lowest door panel are used to open and close the garage as the torsion springs twist. The cables wind around cable drums
. It is because of the tension that it is easier to lift the garage door from its closed position. The winding cone consists of holes every 90 degrees for winding the springs and two set screws to secure the spring to the shaft. Steel counterbalance cables run from the roller brackets at the bottom corners of the door to a notch in the cable drums. When the door is raised, the springs unwind and the stored tension lifts the door by turning the shaft, thus turning the cables drums, wrapping the cables around grooves on the cable drums. When the door is lowered, the cables unwrap from the drums and the springs are rewound to full tension. The garage door torsion spring system can be used to lift garage doors weighing from 45kg to 210kg. This means that they can be used for either double or single garage doors. The most common grade of torsion springs have an expected life of about 10,000 cycles wich are estimated to last between 3-7 years. It is important to remember that if the weight of the garage door is increased by adding glass or insulation, the life of the spring may be reduced. The hardened and tempered steel experiences tremendous forces each time the door opens and closes.
Gradually, the steel fatigues with each cycle, and eventually cracks and breaks, usually with a horrific noise or bang. It will then be that your garage door repairs
will include replacing the springs. CAUTION! Replacing garage door torsion springs is dangerous because the springs are under tension. If you do not use the right tools and follow safe procedures, you could lose hands, limbs or even your life. You could also damage property. We recommend that you use a reputable garage door repair company such as Mr Gate Mr Garage to do the repairs.
Garage Door Springs: Extension Springs
These are garage door springs That are mounted on each side of the upper garage door track. Most of the time there will be one spring on either side of the garage door; however, sometimes there can be more. Through the use of pulley wheels
, they perform the same function as the torsion springs. They come under tension when the garage door is closed to make lifting the door easier. The main factor in choosing the correct extension spring is that it must be the correct weight. It is also important that the spring be correct for the door height. When the spring stretches it is must be long enough to handle the garage door. Often, when we are repairing a garage door
, we find that the springs have broken because the incorrect size springs were installed previously.
The system uses stationary pulleys which are attached to the springs with cables that run over them. As the door lifts, the cables
move from the stationary pulleys to the second pulleys and wrap around them. Garage door extension springs are not as strong as torsion springs. The garage door extension spring system can lift garage doors weighing up to 75kg. Therefore they can only be used for single garage doors. CAUTION! Replacing garage door torsion springs is dangerous because the springs are under tension. If you do not use the right tools and follow safe procedures, you could lose hands, limbs or even your life. You could also damage property. We recommend that you use a reputable garage door repair company such as Mr Gate Mr Garage for the work.
Garage Door Springs: Safety Cables
These are cables which prevent damage and injury should a spring break. Garage door springs are under a large amount of tension; when they break, there are huge forces and parts can hit items or people who may be in the way. Garage door safety cables run through the springs and are fixed to the ceiling or wall. Their function is to help control the spring if it breaks.
Garage Door Spring Replacement
Over time, your garage door springs will become worn. Their lifespan generally depends on how many times the garage door is opened and closed, but if there are problems with your door, this lifespan could be reduced. Garage door springs need to be checked regularly and replaced when they have reached end-of-life, or when they break. They cannot be repaired. Read more about repairing garage doors
. See a case study where the incorrect springs were installed