Gauge Overview
Comparing gauge values can be tricky, because these numbers are counterintuitive. The lower the gauge, the thicker and stronger the steel, and the higher the gauge, the thinner and weaker the steel. For example, a 24-gauge steel door is thicker, stronger and more dent resistant than a 26-gauge steel door.
Recommended Gauge
Garage door gauges generally range from 24 to 28, though you may be able to find specialized or cut-rate products outside of this range. "This Old House" recommends choosing 24-gauge doors due to their strength. The National Association of Realtors also recommends sticking with 24- or 25-gauge garage doors, as they reduce the risk of dents and damage compared to 27- or 28-gauge units.
Nominal Gauge
When shopping for garage doors, you should understand the difference between nominal and true gauge. Each gauge number corresponds to a specific industry-standard thickness. For example, a 24-gauge door should be 0.0209 inches thick, according to the Door and Access Systems Manufacturers Association International. Nominal gauge typically means that the total thickness of the garage door, including galvanizing and other coatings, equals the industry-standard thickness for that gauge. While the total thickness of the steel with all its coatings may measure 0.0209 inches, the steel itself is much thinner. While galvanizing and other coatings increase the weight and thickness of a door, they do little to add strength, according to Coplay Building Products Company. To avoid confusion, ignore nominal gauge ratings and ask about the decimal thickness of the steel for each door, not including the coatings.
Considerations
Doors used in hurricane zones typically feature a 24-gauge rating. Doors designed to withstand the wind in hurricane-prone regions like Florida rely on 24-gauge steel but use special reinforcements to increase strength without increasing the thickness of the steel, according to the website of home improvement expert Bob Vila. They may use features like 14-gauge tracks, heavy-duty brackets and reinforced framework to increase wind resistance, but the 24-gauge steel is capable of withstanding not only the wind itself but also the force of objects and debris blown into the door.