The only features that tension structures share with conventional sun canopies is that both are free standing (i.e. stand alone) and are permanent. Here are the advantages of cable-tensioned structures. (This comparison ignores temporary, “pop-up” canopies. which serve entirely-different market needs).
a. Cable-tensioned structures can have greater distances between columns (i.e. clearspan). This enables them to have fewer obstructions and cost less. For example, we did a hip-roof canopy project in Oakland, CA where a single fabric measures 67’x36′ for a total covering of 2,412 square feet. It has only (6) columns, which averages 402 square feet per column. This structure is 1/2 mile from the San Francisco Bay, where building code requires it withstand 85 MPH 3-second wind gusts.
b. Tensioned shade cloth structures don’t need horizontal beams, unless they’re cantilevered. Trusses are also unnecessary. This too enables them to cost less.
c. Tension structures can be cantilevered, whereas traditional canopies cannot because their aluminum poles and frames aren’t strong enough. Being structural steel, we routinely project tension structures 18′ out from their columns in parking lots. Greater distances are possible.
d. Conventional canopy roofs are typically impermeable fabric, metal, fiberglass or wood. These trap hot air inside the structure, whereas the mesh fabrics on tension structures lower air temperature as hot air rises between woven yarns.
e. The maintenance costs of tension structures are less because they don’t rot or mildew. HDPE yarns don’t absorb water.
f. Shade sails win the prize when it comes to aesthetic appeal. Dramatic height variations; fabric “warping” ; overlapping; multiple polygon shapes & colors; & the interesting curves (both fabrics and their shadows) are just some of the visual advantages that enhance landscape appeal.
Up to 97% of the sun’s UVA and UVB rays are blocked, depending upon shade cloth color. See sun safety for information about this importance.
Hot air rises out the top between the knitted yarns of High Density Polyethylene (HDPE). This draws outside air into the structure from the sides, which creates continuous air movement. That’s why cable-tensioned fabric shade canopies, shade sails, and permanent shade umbrellas reduce ambient air temperature up to 20 degrees. By contrast, hardened roofing materials (i.e. metal, wood, plastic, tile, stone, etc) and conventional awning fabric traps hot air inside the structure.
The purchase price of tension sun shade shelters is considerably less for same-size structures of comparable quality. Installation price is only a fraction and sites are disrupted for only a few days because structures arrive prefabricated. There are no maintenance costs, except for the occasional hosing to remove dirt and bird droppings.
The purchase price of tension sun shade shelters is considerably less for same-size structures of comparable quality. Installation price is only a fraction and sites are disrupted for only a few days because structures arrive prefabricated. There are no maintenance costs, except for the occasional hosing to remove dirt and bird droppings.
Steel columns and frames are warranted for 20 years. They’re factory-welded to be watertight and are protected with a powder coat finish. (See above photo). There’s a limited 10-year warranty on the HDPE fabrics. All are designed to withstand 3-second wind gusts of at least 85 MPH with the fabrics attached. Our structures meet California Building Code, which is the world’s toughest. They are approved by GSA for use by the U.S. Government. Finally, many of our shade canopy designs are pre-approved by DSA for use at California’s public schools.
Our shade canopies, shade sails and giant shade umbrellas are all permanent “tension sun shade shelters” a.k.a “tension fabric shade structures.” However, canopies have an upper steel frame, over which shade cloth is tensioned into various roof shapes. Shade sail structures don’t have upper frames. They only have columns, shade sails and the hardware to attach them and maintain proper tensioning.
There’s no structural reason for removing them unless snow is expected. A 2-man crew can remove each shade canopy and shade sail in less than one (1) hour and reattach them in less than two (2) hours.
None, except for an occasional hosing to remove dirt and bird droppings. Nothing rusts because our factory welds all structural steel to be water-tight. It then bakes on a UV-resistant powder coat finish. When constructing, we caulk all seams where steel members are field-bolted together. We also caulk behind all washers. Shade cloth yarns, being made of High Density Polyethylene, won’t rot or mildew because they don’t absorb water.
Shade canopies are “cantilevered” when horizontal beams extend beyond vertical columns to remove safety hazards (e.g. car parking lots or porte-cocheres) or visibility barriers (e.g. bleacher covers). See cantilever shade structure photos.
As large as can be imagined.
The distance between columns. For example, a basketball court requires “clear spanning” the entire court width.
A minimum of 85 MPH 3-second gusts. Most communities require less; but some require more. Regardless, we always comply with local code.
Most permanent shade canopies and all shade sail structures require concrete pier footings. But, we can bolt canopies to existing patios if the concrete is reinforced; at least 6″ thick; and the uncantilevered structure doesn’t exceed 400 square feet in size.