Step 2: Measure the height of the opening at the highest point. This is the distance between the floor and the top of the finished opening. Look for general irregularities, such as un-level floor.
Step 3 & 4: Measure the width of the areas beside the openings. Up to 5″ is required on each side for installation of the vertical track. If this is a 2-door installation, center post should be a min. of 10″ wide.
Step 5: Measure the area between the top of the door opening and the ceiling (or to the lowest obstruction at ceiling). See headroom requirements for track radius below.
Step 6: Measure the distance from the opening to the rear of the garage or nearest obstruction. For sectional type doors, the backroom requirement is the door height plus an additional 18″ for manual lift doors. If an electric opener is to be installed the door’s backroom requirement is the door height plus an additional 4’2″.