Knowing garage door clearance requirements will help you avoid ordering the wrong garage door set-up for your needs. Garage doors use either torsion springs or extension springs to raise and lower the door. Torsion springs mount on a bar above the door, while extension springs stretch down the side of the upper tracks. Each has their own minimum door clearance requirements to allow for a trouble-free installation.
Standard Headroom Clearance
Headroom clearance is the distance between the top of the door opening and the ceiling. When a garage door opens, it rolls back on horizontal tracks. The top of the door requires some room to make that turn. Most standard garage doors with extension springs require a minimum of 10 inches of headroom. Doors that use torsion springs require at least 12 inches of headroom. The reason for the additional clearance for torsion spring doors is due to the brackets that hold each end of the torsion bar.
Clearance Minimums for Low Headroom
Some garages do not have the minimum headroom requirements for a standard garage door. This situation requires double low-headroom tracks. The top roller runs down the upper horizontal track, while the remaining rollers go down the lower horizontal track. The top section makes the turn quicker while opening. Garage doors operating with torsion springs require a minimum of 9-1/2 inches of headroom, while doors using extension springs require a minimum of 4-1/2 inches of headroom.
It is possible to mount torsion springs in a garage with only 5 inches of headroom. However, this requires mounting the torsion spring on the rear of the horizontal tracks. Although this is an option, it is not a user friendly way of hanging a garage door for the do-it-yourself homeowner.
Clearance Minimums for Sideroom
Sideroom is the space between the side of the garage door opening and the adjacent wall. Sideroom must be taken into account because this is where the brackets for the horizontal tracks connect to the opening. Torsion spring doors also require room for the ends of the torsion bar. The minimum sideroom requirement for a standard extension spring door and torsion spring doors is 3-3/4 inches.
Low-headroom installations require more sideroom than a standard door. Garage doors with torsion springs require room for the cables and cable drums to mount to the outside of the tracks rather than the inside. It is necessary to have at least 6 inches of sideroom for low-headroom applications.
Clearance Minimums for Depth
A final consideration for door clearance is the depth of the garage. This is the distance between the top of the door and the nearest obstruction toward the rear of the garage. The garage door needs room to roll completely up when opening. The standard rule of thumb is the door height plus an additional 18 inches. This allows room for the door, plus the hardware necessary to secure the rear of the horizontal tracks.