The south-easter, and the door built for it
The West Coast from Milnerton up to Melkbosstrand gets the wind harder and more often than anywhere else in the city, and a garage door that faces it is a door under load for months of the year. That is why the coast is full of roll-up doors: a curtain in guides carries the wind into the wall, where a sectional's panels rattle and stress their hinges and a tip-up catches the wind on its swing. A roll-up was the right choice for Table View and Bloubergstrand, and it still is.
Its weakness is the other West Coast element. Sand gets into the guides the curtain runs in, and a roll-up that has never had its guides cleared is a door that starts sticking on a windy week and straining its motor. Clearing and lubricating the guides — with a lubricant that does not attract more sand — is the maintenance a West Coast roll-up needs, and it is done on every visit.
The new estates, and the developer motor
Parklands, Sunningdale and Big Bay have been built almost entirely in the last twenty years, and their garages have the same handover problems as the Northern Suburbs: motors chosen for price on doors they were never rated for, beams never aligned, remotes never properly paired. The year-three motor failure is the commonest call in these suburbs, and the honest answer is a motor sized for the door, not a repair to one that was never right.
The dense complexes add a second problem: a dozen garages sharing a wall, on receivers sharing a frequency, and a remote that works for one door and opens the neighbour's. Moving to a receiver on a different frequency is a small job that ends it.
Salt, and the bottom panel
The seafront suburbs — Blouberg, Sunset Beach, Melkbos — get the Atlantic Seaboard's salt as well as the wind, and a steel sectional facing the sea loses its bottom panel from the edge up inside a decade. Panel replacement with stainless hinges and a coated seal is the fix, and specifying the door for the coast in the first place is the prevention. Century City, Royal Ascot and Montague Gardens further in are wind without the salt, and their doors last accordingly.
All of it is worked from the same routes, and the vans carry the tubular motors, slats and guide hardware the coast's roll-ups keep needing.