A Contest of Wills: The Georgia Dome’s Fabric Membrane Roof vs. 100-mph Tornado Winds

As the cleanup continues in Atlanta from the mid-March tornado that ripped through the city—leaving collapsed buildings and much rubble in its wake—inspections reveal that the Georgia Dome survived relatively unscathed after undergoing what the facility’s manager called a “focused Herculean team effort” by Birdair Inc., the specialty roofing contractor for lightweight long-span roofing systems and other tensile structures that that constructed the original roof on the Georgia Dome.

During a Southeastern Conference (SEC) basketball game on the night of Friday, March 14, the Georgia Dome felt the effects of the 100-plus MPH winds that struck Atlanta. The scoreboard swayed from the force exerted on the building, but none of the fans packed inside was injured—and Birdair’s PTFE fiberglass fabric membrane enveloping the structure proved to be the perfect match for the ferocious winds. Designed to be flexible, the fabric roof rippled and bellowed with the wind but, unlike other structures in the same section of the city, sustained only minor damage.

The storm, initially classified as a thunderstorm with winds in excess of 60 mph, was later upgraded. “The storm that hit Atlanta was a tornado,” said AccuWeather’s Ed Adams, Manager of Forensic Services. “Its classification as an EF2 tornado means that winds in excess of 100 mph swept through the region.”

CNN, which itself sustained heavy damage at its Atlanta headquarters, reported that The National Weather Service’s Peachtree City office rated the storm an EF-2 on the Enhanced Fujita scale, meaning it packed top winds of 135 miles per hour. Both the Georgia’s governor and Atlanta’s mayor declared the city in a state of emergency.

Birdair officials noted that, on the west side of the building, only a diamond panel, a small sub-panel and some cabling needed replacement.

“The remainder of the roof is in very good condition, as we’ve established this through a thorough inspection of the membranes and attachments,” said Dave Ricci, Director of Customer Service and Warranty at Birdair, Inc. “All involved at the Dome are very impressed with its performance. Buildings and other facilities around the dome suffered far greater damage, and the two panels that were damaged on the Georgia Dome were in the direct path of the tornado.”

“The fact that this is a tensile structure really helped to ensure that nobody was hurt,” said Kevin Mayer, Vice President of Business Development for Birdair, Inc. “Had this been a traditionally roofed structure, the heavier components used for support, such as metal beams and concrete, could have come loose and injured, potentially significantly, patrons of the facility. The lightweight nature of the materials used on roofs of this nature reduces the potential of injury, as is the case here.”

The game, seen on TV and before a live audience of more than 18,000, was briefly delayed when the tornado struck at 9:40 p.m. The Washington Post later quoted SEC associate commissioner Charles Bloom as saying there were no injuries inside the arena among the fans, players and media attending the game between Alabama and Mississippi State. Within an hour the building was reported to be structurally sound and the teams finished the game with Mississippi State defeating Alabama 69 – 67 in overtime.

Birdair has been praised for its quick response. Less than twelve hours after the storm hit, crew members were on-site to evaluate the extent of the damage. Workers immediately removed damaged material and cabling and temporarily patched the diamond panels back together in an effort to dry the building’s interior. The necessary replacement panels were installed in a timely fashion and all repairs were completed within several weeks.

Birdair’s immediate response has been hailed by officials at the Georgia Dome as a “focused Herculean team effort,” according to Carl Atkins, General Manager of the Georgia Dome. “It took a variety of skill sets and talents working closely together to address the many immediate and longer term issues via a methodical and measured approach to get us on the road to recovery,” noted Atkins. “I can see the fruits of that labor in both the temporary repairs as well as the clear, defined path for the permanent repairs. This is directly attributable to Birdair’s immediate response, attention, focus, and commitment to the project.”

The Georgia Dome did not get hit directly, as tests indicate that the tornado itself passed about 100 yards north of the Georgia Dome. However, “the structure was definitely affected by the 100 mph winds,” Adams clarified.

The tornado is the first to strike downtown Atlanta on record.

Other Birdair structures, too, have been tested by brutal weather conditions. Florida Hospital Waterman, located in Tavares, Florida, has survived numerous hurricanes, including Hurricane Charley in 2004, which hit the building with winds traveling 140 mph. “The stability and exceptional durability of Birdair structures is clearly seen through their performances in the face of inclement weather,” explained Mayer. “Birdair gives clients a tested, proven, out-of-the-box system for achieving the building structures they design, no matter what the weather may bring.”