The weight of your garage door is a major factor in determining what type of torsion springs or extension springs you need. Door weight, along with other information like door height, track radius and drum size are used to calculate a spring that will balance out your door. In order to properly weigh the door, you will need an analog bathroom scale. Always use one or more analog bathroom scales to weigh your overhead door. Using a digital scale will make the process difficult since they register a reading within a narrow time frame and don’t account for changes in door weight. Analog scales adjust door weight in real time and can be purchased cheaply.
The process of weighing your overhead garage door is different based on the type of garage door springs you have installed. The two types of springs commonly used are called torsion springs and extension springs. Before attempting to weigh your garage door you need to identify what type you have.
Weigh a Garage Door for Extension Springs
Extension springs are color coated according to weight based on DASMA standards. Each color represents a different weight rating from 10 lbs to 300 lbs. If your spring is old enough and near the end of its life cycle, there is a good chance the color labeling has rusted off.
Step One: If you have a garage door opener installed, you will need to disconnect the operator arm from the garage door. Disengage the pin from your operator attachment bracket. Pulling the red emergency release cord alone could result in an inaccurate reading.
Step Two: Remove all spring tension or uninstall both extension springs while the door is in the open position. Always use vice grips on each side of the door under the bottom rollers to prevent the door from slamming to the floor.
Step Three: Lower the door to the floor by hand and slide the analog bathroom scale under the center of the door. If you have a heavy door or double wide door you will need two people to safely lower the door down. Come alongs may be required to lower heavy doors down. It is best to use a 2×4 block of wood aligned with the bottom of your door positioned on top of your scale.
Never rely on old figures or notes when calculating door weight. Garage doors often absorb moisture over time which adds a significant amount of weight – this is especially true with wood garage doors.
Step Four: Take multiple door scale readings to rule out any possible errors. If your readings fluctuate you will need to make sure the scale isn’t set on a pitch or un-level surface.