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Custom canopy scores big at Kansas City’s new soccer stadium.
Kansas City’s Livestrong Sporting Park opened in June as the city’s first soccer-centric stadium and the new home of the Sporting Kansas City, the soccer team formerly known as the Kansas City Wizards. To make the arena both athlete- and fan-friendly, architect Populous envisioned a soaring roof canopy designed to evoke the arc of a soccer ball flying across the field. The team considered building the canopy with ETFE (ethylene tetrafluoroethylene) pillows, but desired a look more in line with glass panels. The weight of glass would have significantly increased the amount of steel substructure, in turn raising the canopy’s price. Working with Michigan-based architectural canopy design, engineering, and fabrication company Duo-Gard, the team began instead to develop a high-performance polycarbonate glazing system that minimized weight and maximized light transmission onto the field.
In addition to its impact-resistance and long-span structural requirements, the canopy had to meet several programmatic demands. The architects wanted to create an intimate environment that would amplify the crowd’s noise, so the canopy had to cover every seat. While it would provide some shade for the audience, the structure also had to have enough light transmittance to maintain the natural grass preferred by Major League Soccer. The polycarbonate canopy would curve around the more than 1,800-foot stadium circumference, ranging from 25 to 70 feet in depth with a 1/12 pitch and 12-foot spans between structural members.
“This kind of span hadn’t been done before by anyone with polycarbonate at a slight slope,” said Duo-Gard president David Miller. “Our engineers broke ground with this.”
More than 100 feet above the ground, the stadium’s steel structure cantilevers 95 feet and supports a metal deck that transitions to the two-tiered clear polycarbonate deck, which is built with a 36-inch step-down to form a cavity for lighting and sound equipment. The 25mm triple-wall polycarbonate glazing allows 80 percent light transmission and integrates Duo-Gard’s 3 ½-inch aluminum profile at 32 inches on center to minimize shading. The framing system incorporates a custom engineered base plate, pressure plate, and curved cap that conceals canopy fasteners.
According to Frank Kosciolek, Duo-Gard’s engineering manager, typical canopy systems have a 7-inch profile at 24 inches on center, creating more shadows and requiring an additional steel purlin. The team estimated that elimination of the extra purlin resulted in a 35 percent reduction in the amount of metal used. The system also met one and a half times of its structural loading requirements during testing. As home to the largest polycarbonate stadium canopy in North America, Kansas City’s sports scene is enjoying its moment in the sun.