Birdair Inc.
New techniques are often greeted with a skeptical eye, and questions about whether new products and methods will have staying power are often answered with the phrase, “only time will tell.” Well, it’s been nearly 40 years since Birdair built the world’s first permanent tensile structure made from polytetrafluorethylene (PTFE), and with no serious maintenance issues in sight, it seems that time is on Birdair’s side.
“The base material used in tensile structures has proven itself well,” says Senior Vice President of Operations Tom Wuerch. “The life expectancy of the structures weren’t known when the industry first started; people thought maybe 20 years. But the first PTFE structure built was in 1972 – an athletic facility at the University of Laverne in California – and it is still in place today. We are still testing the membrane’s strength and it’s still at acceptable levels with no immediate replacements in sight while coming up on 40 years of existence.”
In the 1960s, NASA developed the base material, PTFE, a durable and weather resistant Teflon-coated woven fiberglass membrane. It was used in space suits as a strong but lightweight material with a fire-retardant membrane. It was good enough for NASA, and it was good enough for Birdair’s founder Walter Bird, who had the idea of using membrane for permanent structures when he was tasked with creating radomes and rapid deployment command shelters during the Cold War.
He translated the application into major sports and events complexes. With PTFE fiberglass membrane providing the industry’s solid foundation, Birdair, a subsidiary of Japanese-based Taiyo Kogyo since 1992, has led and partnered in many of the industry’s new innovations.
Leading the Way
“Along with Taiyo, Birdair has been able to maintain leadership and lead innovations,” Wuerch says. “We’re always looking for improvements to the membranes. We look at what we can do, where we can apply it and how we can improve it.”
In 2002, Taiyo introduced titanium dioxide coating, which, through a photocatalytic chemical reaction, allows the fabric to break down any organic materials that settle on the membrane, such as dirt. The membrane draws in UV rays, oxygen and water vapor present in the air, and through a process called oxidation reduction, renders the organic materials into harmless gases and natural components that are simply washed away by the rain – reducing the need for extensive cleaning.
A more recent innovation is Birdair’s patent-pending Tensotherm, which brings affordable insulation to the tensile structure industry. “One of the historical drawbacks to membrane structures is that membranes don’t have much in the way of energy or insulated value or sound absorption value,” Wuerch says. “[Tensotherm] allows us to insulate tensile structures, and this insulation has significant sound-absorption and transmission capabilities, too.”
The Tensotherm composite consists of an insulation blanket of Lumira™ aerogel, formerly knows as Nanogel® aerogel, a product developed by the Boston-based Cabot Corp.that is sandwiched between two layers of PTFE fiberglass membrane. With 95 percent air content, Lumira™ aerogel is the lightest solid material in the world but provides significant reductions in heat loss and heat gain achieving an R-12 insulation value with an overall composite thickness of nominally 1 inch. Despite the leap in thermal and acoustical performance, Tensotherm retains the sleek transparency and light-weight, free-form appearance so many architects like about tensile structures.
These innovations, mixed with PTFE’s passing grade on the test of time, have made these structures more acceptable in architectural and construction circles. In fact, the branded Birdair name is now synonymous with tensile structures just as Xerox is synonymous with paper copy machines. “It was first looked at as an unconventional building material,” Wuerch says. “Over the course of 30 or 40 years, membrane is now widely accepted as a primary building product just as steel or concrete or glass would be.”
Before There Was LEED
PTFE fiberglass membrane has seen even greater acceptance with the world’s hyper-focus on green living – a natural trait of Birdair’s tensile structures. Many LEED requirements such as use of less material and increased day lighting all come with the tensile territory.
The long-span panels reduce the amount of materials needed to construct tensile structures as the light weight nature of a tensile structure significantly reduces overall dead load of the entire roof structure. The results are not only less primary and secondary support structure, such as steel & cables, but also translates into less concrete needed for the foundations. When it comes to natural day lighting, the membranes transparency allows light to permeate the building while providing solar shading that glass does not.
“Membranes were a sustainable product before sustainability became a buzz word,” Wuerch says. “Many of the requirements associated with sustainability and LEED, the membrane has been doing for more than 50 years.” As the industry originator, it also means Birdair has been doing it for more than 50 years. Today, Birdair is a full-service contractor that designs, engineers, manufactures and builds structures for its clients with in-house project managers to see each project to completion and a support center for post-project assistance.
Its full-service capabilities have won it some of the largest projects in events and sports complexes. A few years ago, it completed the titanium dioxide-coated roof for the Dallas Cowboys in Birdair’s eighth NFL stadium. Early 2011, it completed the roof replacement of Canada Place in Vancouver, which served as the backdrop for the 2010 Winter Olympics. It also installed roofs on three of the four main, new-construction stadiums used for the 2010 South Africa World Cup.
Currently, the company is replacing the Minnesota Vikings’ Metrodome roof that collapsed last December amid severe snowstorms. Birdair was awarded the project in March, and as of May had fabricated and delivered 98 percent of the panels and installed 60 percent of the 700,000-square-foot roof and interior liner. It’s on track to complete the project in less than five months.
As it wraps up this project, Wuerch says Birdair is looking to Brazil, future host of the 2014 World Cup and the 2016 Summer Olympics. It also has received inquiries from Middle Eastern companies interested in Tensotherm’s weather-neutralizing benefits, further solidifying Birdair’s position as a global leader in tensile structures.
“From an experience standpoint, we still have a number of originators and engineers that have been in this industry for 30 and 35 years,” Wuerch says. “On the other side we have many young and gifted engineers and designers who are now being mentored by the people who created this industry who are training the next generation of leaders in tensile architecture.”
Leading Partners
As Birdair continues on its journey as the leading name in tensile structures, it continues to work with its parent company, innovative partners and key vendors who have all contributed to its success. “Working with companies such as Taiyo has allowed us to become a global organization,” Wuerch says. Other key partners include Weidlinger Associates Inc., Geiger Engineers and Hanes Supply Inc.