The Space Frame in Action: SoFi Stadium

Architects have used space frames as an alternative to traditional truss supports in large spaces since the early 1900s. In recent years, however, they have evolved into support structures providing creative external looks for structures. They are about 30% lighter than conventional steel support systems, use less material and yet are more stable. That strength comes from their web-like structure that distributes weight evenly in all directions.

The SoFi Stadium Space Frame

Space frames are often the only solution for complex architectural designs. The SoFi Stadium in Inglewood, Calif., the first indoor-outdoor stadium to be constructed, was designed by HKS Architects Inc., Los Angeles, with a sweeping shape and open features that only a space frame could provide. The space frame was designed and engineered by DSI Spaceframes in collaboration with Crown Corr and manufactured by DSI, the nation’s leader in such systems and the only space frame manufacturer in the U.S. using all American-made steel components.

“Designing the space frame structure to support the outer perforated panel skin of this stadium was anything but a simple project,” says Josh Chambers, DSI president. “Each surface panel was unique in shape and pattern, playing its own strategic part in the structure’s final appearance.”

Behind the dramatic outer visible surface exists an equally remarkable substructure of engineering and design: a supporting ball and tube steel space frame that gives the finished skin its strength and rigidity. This skeleton substructure attaches to the stadium’s base structure and precisely positions the outer skin, while providing the strength that enables it to remain stable.

The SoFi Stadium space frame incorporates 55,000 forged nodes, each unique and weighing between 6 and 150 pounds, depending on its function and the number of holes to be drilled in it. Each node had a unique part number to ensure that it reached its proper location in the substructure. The steel tubes varied in length and diameter and also had unique part numbers.

The stadium's outer surface consists of 34,789 perforated anodized aluminum panels made by A. Zahner Co., Kansas City, Mo., and installed by Crown Corr Inc., Gary, Ind., working directly with DSI. In this surface area of 289,000 square feet, each of the nodes of the space frame was designed to hit a corner of each panel. Nodes were drilled and tapped at precise points to hold the panels in place and to accept the tubes that connected it to the rest of the web. Node holes were a slightly different size than standard to accept stainless steel bolts and were another reason that plating thickness was critical for proper engagement.

Zinc Plating

Like all substructures, it is critical that the space frame resist corrosion to ensure it retains its strength and stability. This becomes more of a challenge when the structure is a web of thousands of discrete parts interlocked to provide rigidity. In the SoFi Stadium substructure, each node is plated to rigorous standards. Experience has taught DSI that zinc plating serves as a good corrosion-resistant undercoat and protects the frame if the powder coat becomes damaged. After years of experience with multiple platers it now relies exclusively on Gatto Industrial Platers of Chicago for this critical work.

“The nodes were a challenge, due to both their spherical shape and holes on all sides of the parts,” says Gatto president George Gatto Jr. “We used a variety of plating techniques to prevent solution accumulation, air pockets and insufficient coating in the holes themselves.”

“The space frame components were not easily replaceable if lost or mixed with the wrong batch, which made order identification and tracking a critical part of the process.”

Final Stages

Following plating, individual parts were then powder coated in the custom colors specified in the architect’s design, and assembly began. At this point, collaboration between DSI and its suppliers became especially critical. For assembly to proceed efficiently and construction deadlines to be met, finished, plated, powder-coated parts had to arrive at the construction site on schedule. This is where DSI’s preferred suppliers earned their reputations.

For the SoFi Stadium project, construction proceeded as scheduled, and the stadium opened in September 2020 with its first NFL football game.

As the contributing author, Mike Weber is president of MLW Marketing, Lake Zurich, Ill. George Gatto Jr. is the president of Chicago-based Gatto Industrial Platers and can be reached at (773) 287-0100 or Josh Chambers is the president of DSI Spaceframes, Addison, Ill., and can be reached at (630) 607-0045 or

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