Most of Merewether sits within about a kilometre and a half of the surf. That puts the suburb inside the coastal band where airborne salt measurably accelerates corrosion of steel hardware, the zone Australian Standard AS 4312 exists to describe. On a garage door, the salt doesn't attack the panel first. It goes for the moving parts: the torsion spring wound over the opening, the lift cables at each side, the rollers in their tracks, the opener rail overhead.
The part that catches people out is how coastal hardware fails. A spring is rated in open-close cycles, roughly ten thousand on a standard unit, and salt pitting quietly eats into that budget. Nothing looks different from the driveway. Then one morning there's a bang, or the door is suddenly too heavy to lift, with the car on the wrong side of it.
That is why the honest advice in this suburb is a service rhythm, not a repair number. Catch the corrosion at a tune-up and you replace a part on your schedule, not the door's.
AS 4312 salt band
316 stainless
~10,000 spring cycles
Marine powder-coat
Read the full guide: how salt air kills a Merewether garage door