How to tell which spring system you have, why cycle ratings matter more than price, and why neither type is a DIY repair.
Codes are amended locally. Where a city adopts an amendment that changes the answer, the section below says so — and the permit counter, not this page, is the final word.
Look above the door. A torsion system is one or two springs wound on a steel shaft mounted on the header, driving cable drums at each end. An extension system is a pair of long springs running horizontally above the two side tracks, stretching as the door closes. Torsion is the standard on modern and heavier doors; extension is common on older and lighter single-car doors.
Torsion springs lift more smoothly, balance the door more accurately across its travel, last longer, and fail more predictably. Extension springs stretch and relax through a wider range and are harder to keep matched. When an extension system fails, the spring can travel — which is why safety containment cables through the spring interior are essential on every extension door and are the first thing a technician checks.
Springs are engineered to a cycle count, one cycle being one open plus one close, and a standard residential spring is commonly rated around 10,000 cycles. For a household that opens the door four times a day that is roughly seven years; at twelve times a day it is under three. A high-cycle spring costs modestly more and can double or triple that life. Ask what rating you are being quoted, because two quotes for 'a spring' are frequently quotes for very different springs.
DASMA's TDS #190 sets out the factors: how the spring was handled before installation, how it was installed, how the door is used, and the conditions it lives in. In California, corrosion is the big one — a coastal spring whose coils bind against each other never reaches its rated count — and thermal cycling in the Central Valley and desert adds to it. Light annual lubrication is one of the highest-return maintenance actions on a garage door.
On a two-spring door, springs installed together have consumed the same cycles. Replacing one leaves a mismatched pair, an unbalanced door and a second service call within about a year. Any technician who quotes one spring on a two-spring door should be asked why.
A wound torsion spring holds enough stored energy to break bones or kill, released through winding bars that have to be handled correctly, in sequence, at height. An extension spring under load is no safer. This is the single most dangerous routine repair in residential construction and there is no version of it that a homeowner should attempt with hand tools and a video.
Need this fixed today?
Pick your city and you land on the spring crew that covers it — with its own dispatch number, its own hours and its own price band. Or skip the reading and call now.
Not listed, or the box does not suggest anything? Every market below is a link.
Permits, inspections, HOA packets and code amendments — we deal with them every week in every California county we cover.
CA-GARAGEDOOR California — California contractor licence CSLB #1098234. Licensed, bonded and insured. 1-year parts & labor.