A sectional garage door is a door type that rises vertically in sections (usually 4) and then curves in its tracking to move horizontally into the garage.
Various manufacturers have different sideroom and headroom requirements for this gear type so please call to clarify dimensions. The sizes used for sectional doors are the actual opening sizes for the doors and as they are usually installed behind the opening they also refer to the nearest structural opening requirements.

Side mounted springs for a Hormann or Garador sectional door gear on all doors up to 10'0" wide (3048mm) and 8'6" high (2625mm) only require 100mm of headroom above the top of the door height ordered.
The springs are situated in the side legs of the framing system with no requirement on the head for a structural fixing as there is only a steel fascia to fix. (Called Z track arrangement in Hormann doors)

The picture below shows the traditional sectional garage door operating mechanism for large or heavier doors or where tracks are required to travel higher inside the garage. The torsion spring is mounted above the door panels and usually fitted to the inside face of the lintel. Headroom requirements vary but the usual requirement is around 230mm with or without a remote control operator. This is the headroom required above the order height of the door.



Automation
Sectional Garage Doors can be automated very easily with traditional boom type centre mounted operator or in the Novoferm a side mounted motor that moves with the top panel and drives in the door tracking.