Garage door glossary

Counterbalance system is the collective name for the springs, cables, and drums that offset the door's weight. Torsion springs mount on a shaft above the opening; extension springs run along the horizontal tracks and should include safety containment cables. Cycle rating is how many open-and-close cycles a spring is designed to survive — one cycle is one open plus one close.

Headroom is the vertical space between the top of the opening and the ceiling; side room is the space beside the opening. Both determine which track configuration and opener will fit. A jackshaft or wall-mount opener sits beside the torsion shaft rather than on a ceiling rail, which is how low-headroom garages get automated.

Entrapment protection refers to the UL 325 requirements that residential openers reverse on contact with an obstruction and, in nearly all cases, include photo-electric eyes mounted low on each side of the opening — requirements that took effect for openers manufactured on or after January 1, 1993.

R-value measures insulation. Insulated doors typically fall between R-6 and R-18; a non-insulated door is effectively R-0. DASMA is the Door & Access Systems Manufacturers Association, which publishes the technical data sheets and standards this industry references, including ANSI/DASMA 103 for counterbalance systems on residential sectional doors.

How to choose

Ask for cycle rating, not 'heavy duty'

Cycle rating is a number you can compare. Marketing adjectives are not.

R-value beats 'insulated'

Insulated covers everything from R-6 to R-18. Get the number on the quote.

Headroom decides your opener options

Measure it before you shop. It is what determines whether a jackshaft opener is needed.

Entrapment protection is not optional

It is the UL 325 feature set that keeps the door from closing on someone. Never treat it as a nuisance.