What is the life expectancy of an extension spring on a garage door?

An extension spring on a garage door typically lasts 7 to 9 years, or about 10,000 cycles, where one cycle is one full open and one full close. Average households cycling the door three to four times a day will hit that range. Heavy users, often eight cycles or more per day, can wear them out in 4 to 5 years. Light use can stretch them to 12 years or more. Lifespan shortens in coastal or humid climates because rust attacks the coils, and shortens further when the door is out of balance, the safety cables are missing, or the rollers and pulleys are worn. When one extension spring fails, the other is close behind, so always replace both at the same time.