Extension Spring Replacement: comparing quotes

A safety or containment cable is threaded down the inside of each extension spring and fixed at the hanger behind and the bracket in front. It carries no load in normal use. If a spring snaps, the cable keeps the broken halves in place beside the track. Every extension-spring door should have one each side, and the industry's inspection checklist asks for it. Doors installed decades ago often have none; they are added with the new springs.

Door weight and size

Spring rating follows the door's weight, and a wide insulated door or a wood door takes heavier springs than a light single. Weight and height together set the parts on the quote.

Weight added since the door went in

Insulation panels, windows or a wood overlay fitted after the original springs mean a heavier rating than the old pair. The door is weighed and the quote reflects the door as it is now.

Working room around the springs

Shelving, a stored canoe or a car parked under the tracks slows the work along the horizontal run. Clearing the sides of the garage beforehand keeps the time on the quote short.