Garage door springs come in two styles: torsion (see above), which mounts on the header above the door, and extension (Photo 1), which floats above the upper roller track. In the past, extension springs were safer to install but didn’t have containment cables running through the center of the spring. Without cable, these springs become dangerous, heavy whips when they break. They also tend to be noisier than torsion springs, and we recommend you use them only if you don’t have the 12 in. of headroom above the door that a torsion spring requires.
Measure the various areas where the door will be installed: door-opening height and width, headroom (from top of opening to ceiling), and back room (length of garage). For the headroom, you should have about 10" to 12" of space, depending on the spring system you're installing. For the back room, you should have the door height, plus another 18" or more of space.
Insulation, which increases energy efficiency and can help to lower utility bills, is crucial when a garage door is attached to the home. In this case, doors with high R-values are preferred. This means it has insulation that can keep the heat in. The higher the R-value, the better insulated your garage will be against outside noise and cold and hot air.
Safe automatic door openers. All automatic openers must now have an auto-reversing mechanism and photoelectric eyes located near the floor on both sides of the door (see photo). If the door is closing and the beam between the eyes is interrupted, the door will automatically reverse. If the eyes aren’t connected, the door won’t operate. For instructions on how to install a new garage door opener, see How to Install a Garage Door Opener.