Garage door spring repairs almost always involve complete replacement of the springs. This is because the springs usually do their job just fine until the point that they completely fail; that is, when they break. The springs are part of the garage door itself, not the garage door opener. What springs do is make it much easier to raise and lower the door. They generally last a long time, but eventually all that lifting, through all those weather changes, tends to weaken the metal and leads to a break.
The process for replacing garage door springs depends on the type of springs and whether you will do the work yourself or hire it out. The following discussion will teach you how to deal with a broken spring, identify what type of springs you have, and determine who should do the work.
How To Know a Spring Has Broken
Most people don't realize their garage door spring has broken until they try to lift the door, or they notice their automatic door opener is making a lot more noise than usual or that it isn't working very smoothly. Garage doors can weigh several hundred pounds, and when just one of the two door springs breaks (usually only one breaks at time), the door suddenly feels as heavy as a truck. Springs usually break when they are fully loaded—stretched or twisted under tension—and can sound like a gunshot. If you're home when this happens, you'll probably hear it and won't know what it is. But there's no mistaking the heavy door.
If you have a garage door opener and you suspect a spring has broken, do not disconnect the opener from the door (by pulling the red emergency release handle) while the door is open. If you do, the door can come crashing down under its nearly full weight, with nothing to stop it. This is an extremely dangerous situation. It is never safe to leave the door open when a spring has broken because someone might try to close the door without realizing how heavy it is. Or, they might pull the emergency release handle on the opener.
If you want to leave the door open until you can make repairs, block the door track on both sides so the door can't move, and unplug the garage door opener (if you have one). If you want to close the door, you can try closing it with the opener, making sure there's nothing in the door's path, in case something goes wrong. However, this will put some strain on the opener. Alternatively, you can have a few strong helpers hold the door while you disconnect from the opener and carefully close the door manually; again, it will be very heavy.
Types of Garage Door Springs
Most residential garage doors have one of two types of springs: torsion and extension. Torsion springs are heavy-duty springs mounted to a metal rod that runs parallel to the door, directly above the door opening. These springs are loaded, or tensioned, with a twisting action. When the door closes, cables attached to the bottom corners of the door pull on pulleys attached to the ends of the metal rod the springs are mounted on. The pulleys turn the rod, which twists the springs and creates tension. When the door is opened, the springs unwind and help lift the door.
Extension springs are long, lighter-weight springs that run perpendicular to the door and are mounted above the horizontal portions of the door tracks. These springs are tensioned by stretching out, using cables and pulleys, as with the torsion system. Because extension springs are merely suspended between two brackets (they are not mounted to a rod, like torsion springs), they must have a safety cable running through each spring. This helps contain the spring in the event of a breakage. Without the safety cable, a spring breaking under tension is a serious safety hazard. If you have old springs that don't have safety cables, you should install safety cables even if you aren't replacing the springs.
To DIY or Not To DIY
In the home improvement world there's a common recommendation regarding garage door spring repair: always leave it to the pros. This is sound advice, but it's not as hard-and-fast as most sources claim. The fact is, a handy homeowner who's competent with tools and has a basic understanding of mechanical systems can replace either type of garage door spring. The procedures are pretty simple, but they involve many steps that must be done in the proper order, just like the pros do it. It's also critical that you get the proper size replacement spring. If you think you're up to the task, look at online tutorials by garage door pros to see what's involved. There are helpful videos explaining how to measure your old springs and order the correct replacement size as well as how to do the job from start to finish.
DIYers are generally steered away from working with torsion springs because installed springs are always under tension. To safely remove a torsion spring, you have to control the tension by holding the spring with a solid metal winding bar, then you loosen the spring from the rod and manually unwind the spring using two winding rods. The spring is potentially dangerous until it is fully unwound. By contrast, extension springs have little or no tension when the garage door is fully open.
In any case, working with big, heavy springs (not to mention big, heavy doors) is inherently dangerous. Always take precautions to prevent injury if a spring suddenly slips, come loose, or breaks, and always be aware of what is affected by a spring's tension: namely, pulleys, cables, and doors.