If your garage door has extension springs (the springs stretch out as the door closes and retract as the door opens) the garage door industry has released a standard color chart for the strength (pull) for these springs as seen in the table below. Many of the older extension springs may not have visible paint color on either end of the spring. If you are trying to replace extension springs you can follow our instruction sheet located here and be sure to install the safety containment system to help prevent the spring from becoming a flying projectile in your garage. We have seen these springs destroy the sides of a car, land on the opposite side of the garage, and even go through a concrete block wall and land in the back yard.
In most cases the stretch of the extension spring should be half of the door height. This means for a 7 foot high door (84 inches) the spring stretch would be 42 inches. Most extension springs for 7 foot high doors are 25 inches long with a 42 inch stretch. For an 8 foot high door the spring would be 28 inches long with a 48 inch stretch. Once you know the total weight of your garage door (using a bathroom scale for doors under 300 pounds) you can use the chart below to see the color extension spring you need. If your door is 210 pounds you would need a pair (on for each side) of the 210 pound white springs. You could also use 4 springs consisting of 2 at 100 pounds tan and 2 at 110 pounds white. It should be noted that since the cable loops around a pulley the lifting force of a 210 pound spring is only 105 pounds as seen by the garage door. Therefore you need a pair of 210 pound springs even though your total door weight is 210 pounds.
Garage doors which have extension springs are considered by many (including us) to be unsafe and inferior to torsion springs. Even when adjusted properly many doors with extension springs go up and down uneven (tilted) especially on uninsulated metal doors.
Garage Door Corporation ALWAYS recommends that extension springs be converted to torsion springs by a trained professional. If you are in the Chicago, IL area (our local service area) please use the contact links above for personal assistance in replacing your extension springs. This conversion can be done in most cases without changing the track, garage door sections or the garage door opener. Contact us for pricing and details.
Extension spring chart with strength and identification color
|Stength (lbs)||Color (DASMA)|