Garage door springs offset the weight of a garage door and allow the door to be opened and closed easily, either by hand or by an automatic garage door opener. The high-tension steel in the springs has a limited lifespan, and over time, the springs lose their effectiveness. Garage door springs come in levels of quality—they may be described as "10,000-use" or "20,000-use" springs, for example. This may sound like a very large number, but when you consider that a garage door might be opened four or five times a day, every day, every year, it becomes clear that there is a limited lifespan for these critical garage door parts.
Types of Garage Door Springs
Most residential garage doors have one of two types of springs: torsion or 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 very serious safety hazard. If you have old springs that don't have safety cables, you should install them even if you aren't replacing the springs.
Symptoms of Failing Springs
Aging garage door springs cause the door to effectively "weigh" more as the steel loses its resiliency. With new springs, a heavy garage door should take no more than about 10 pounds of force to lift into an open position. With springs nearing the end of their lifespan, the force required to lift the door can be considerably more, since a garage door may weigh 200 pounds or more.
A garage door with aging springs puts an enormous load on a garage door opener, so another sign of failing springs is when you hear the electric door opener begin to strain as it attempts to lift the door. At this point, it is time to consider replacing the springs. Aging door springs can also break suddenly, a situation that can cause the door to slam shut violently. If you happen to be present when a spring breaks, you will hear a very loud sound like a gunshot, because the break usually occurs when the spring is fully loaded—stretched or twisted to its full tension. When one spring breaks, the door will suddenly feel very heavy when you try to open it by hand, and an automatic garage door opener may no longer be able to lift the door at all.
Garage door springs cannot be repaired. Maintenance involves full replacement of both springs at the same time.
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 need 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 it from the opener and carefully close the door manually—again, it will be very heavy.
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.
Professionals can replace garage door springs in an hour or two. When you hire a pro, make sure to ask about the quality of the springs they will install. They may well offer several grades of springs to choose from, at a range of costs. Top of the line springs may be guaranteed for life, while economy springs can be expected to last perhaps five years under normal use.
Consider the Garage Door Opener
Because your automatic garage door opener has been under some strain as the springs have become more worn and less effective, this is also a good time to evaluate the opener. The same technician who replaces the springs can also replace the opener if it is nearing the end of its life.