Freeze-thaw cycles are hard on a garage door. Panels expand and contract, seals stiffen, and springs work against colder, denser air every morning. A door chosen for looks alone tends to show it by the third winter.
Insulation is the first thing to look at. An insulated steel door holds its shape better through temperature swings and keeps the garage closer to the temperature of the house, which matters most when the garage shares a wall with a living space.
The second is hardware. Springs, rollers and hinges are the parts that fail, and they fail sooner on a door that is cycled several times a day. Heavier-gauge hardware costs more at installation and less over the life of the door.
The third is the seal. A bottom seal that stays flexible below freezing keeps drifting snow out; one that hardens lets it in and ices the threshold.
