During new construction, or when replacing an existing door, it is necessary to determine that there is (or will be) sufficient clearance for a new door of the desired size. It is particularly important to check clearances if you are replacing a "one-piece" door. The minimum clearance requirements for a one piece door is only about 2"; and because these doors are no longer available there can be complications if you need to replace one with a sectional door.
- Minimum headroom requirements above the door for "standard" track and "torsion" spring(s) is 12". (14" if an electric opener is desired).
- Minimum headroom requirements above the door for"low headroom" track and "torsion" spring(s) is 9". For "extension" springs 6" is necessary. (An additional 2" is required if an electric opener is desired).
- Minimum "side-room" requirements are 3" on each side of the door for standard track. (6" for "low headroom" track).
- Headroom is defined here as the distance between the top of the door and the lowest part of the ceiling, joists, ductwork or any obstructions above the door. This includes the portion of the ceiling above where the door will hang while in the full open position and *1-1/2 feet farther back than the height of the door to allow for the full length of the horizontal track. (*An additional 3 1/2 feet back is necessary to accomodate an electric door opener).
- Sideroom is defined here as the space available on each side of the door.
When headroom is not adequate to meet the above requirements it is usually necessary to "build-down" the opening and use a shorter door and/or "low-headroom" track.
- Minimum headroom requirements for standard track is 15". (always with a "torsion" spring)
- Headroom is defined above.
- More often than not commercial door have plenty of headroom for standard track, and in order to maximize available space inside of the warehouse or shop there is a need for special track. The two most common types of special track are "high-lift" and "vertical-lift" track.
- *High-lift track rolls the door up the wall above the door before it rolls backward.
- *Vertical lift track opens the door completely while keeping the door against the wall above the door. (never rolls back). Vertical lift track requires the space above the door to be twice the door height plus 12".