As with anything you leave outdoors permanently, sun, wind, and rain, impact on the integrity of the product over time. To combat this a good commercial umbrella will not only be constructed of corrosion resistant, all weather materials, but if it’s built to last, it will have a properly tensioned canopy.
Tensioning systems help preserve the structural integrity of the canopy via a series of taut cables that
run the perimeter seams and arms of the canopy, secured in place with anti-creep fixings.
A properly tensioned umbrella will reinforce your canopy, helping it to retain it’s shape and continue to withstand the weather.
A true commercial umbrella will always incorporate tensioning in some form, but internalised tensioning is optimal, as it is protected from the weather and has the added advantage of delivering a cleaner design, eliminating the visible support cables under the canopy.