by Samuel J. Armijos, AIA
An umbrella is defined as a canopy supported by a single mast designed to protect one from sun and precipitation. Umbrellas are engineered for a variety of environments and purposes and can be designed to be fixed or collapsible. The structures are usually steel, aluminum or wood and can be almost any size. The perimeter or edge may be scalloped or rigid, the top open or closed. Foundations are required to support most umbrellas however a ground sleeve which is a slightly larger pipe than the umbrella column can also be used.
Umbrellas normally have either four, six or eight sides which are supported by a series of cantilever arms of equal length coming off the center mast. They can also be designed with a circular frame supported by a series of cables or rods much like a bicycle wheel. They may be installed in groups, or close enough to be attached to each other. Umbrellas can comprise of multiple units with repetitive frame elements which support one large cover. They can also have the mast located on one side supporting the umbrella from above to provide a column-free space. The inverted umbrella has a membrane that slopes toward its center support rather than the perimeter. Inverted umbrellas are normally designed to allow water to drain into the center support to be discharged elsewhere.
With today’s computer patterning programs, one can easily create membrane tops for unique umbrellas with cantilever arms of varying lengths, heights and slopes.
Gotta have an umbrella