Almost every day I get a call from a customer who can not open their garage door, and nine out of ten times the cause is a broken torsion spring. The torsion spring on a sectional roll up door is the muscle of the door system. It is what physically opens and closes the door. Generally on a single car garage there is only one spring, but on a double car garage there should be two. Sometimes there is only one on a double car system but a two spring system is ideal. That way, in case one of the two springs breaks the customer still has some time to get a professional out to replace the springs before the second spring breaks and the door is unmovable. Also, if the door is in the up position and the spring or springs break the door will have nothing holding it up. It can crash down causing damage to other parts of the garage, and can also cause damage to anything that could be underneath it.
On a sectional garage door the springs are located directly above the door, wound around a long tube. If the door is struggling to go up or will not raise at all that is the first place I have a customer look. If the spring or springs are broken there is a distinct and obvious break in the coils that should be continuous. Even if the motor is able to lift the door with a broken spring customers should avoid doing that if possible. Raising the door with a broken spring causes a lot of stress to the motor and can damage internal parts. This damage can lead to more cost in repairs. Lastly, customers should never prop the door up or stand under it to help the door raise. This can be extremely dangerous. Instead, they should call the garage door man as soon as they notice a broken torsion spring or the door acting differently to diagnose and solve the problem.