Hartsfield-Jackson Atlanta International Airport Expansion Pushes Requirements for Air Barrier System
Hartsfield-Jackson Atlanta International Airportis the busiest airport in the world. Projections for international passenger traffic by 2015 are estimating 13 million passengers will need to be accommodated, requiring expansion of the airport with the Maynard H. Jackson Jr. International Terminal.
NOW Specialties, Inc. was selected to design, fabricate and install the exterior composite wall system with strong, 4mm Metal Composite Materials that would reduce buckling and oil canning. Fluid applied weather barrier was specified behind the metal panel system, but the demanding requirements of the application went beyond the capabilities of standard products currently available. The most stringent requirements included:
- Temperatures up to and in excess of 180°F.
- Self-gasketing capability where fasteners penetrated through the membrane so additional detailing wasn’t required.
- The ability to withstand UV exposure for up to a year without degradation since the roadway for arrivals and departures, being done at the same time, meant a prolonged period before the panels could be installed.
A tested system with documented performance was required. Temperatures beyond 150°F pushed the limits of available products and manufacturers’ guidelines warned against prolonged exposure to ultraviolet rays. Penetrations in air barriers are the source of air and moisture infiltration, requiring detailing to ensure a continuous seal.
The new ExoAir® 230 Vapor-Permeable Air Barrier Membrane from Tremco Commercial Sealants & Waterproofing was just getting ready to make its debut when NOW Specialties was analyzing systems capable of meeting the specs and found that it was able to perform to requirements demanded for the project. It could also be used as part of a system in order to warrant the performance of the exterior wall cladding.
With the ability to withstand temperatures up to 240°F, ExoAir 230 surpassed NOW’s performance requirements with ease. One of the requirements of the membrane during formulation was the ability to withstand UV exposure for up to twice the highest levels currently achieved by existing weather barrier membranes so extensive documentation was readily available. The NOW requirement for a product that would self-gasket so additional labor wasn’t necessary to go back and apply additional sealant over the fasteners was met with ExoAir 230’s nail-sealability testing. Extensive testing for air leakage, water leakage and structural performance was also conducted at Architectural Testing, Inc. with the 4200 panel system installed and with penetrations.
Other components used during construction included ExoAir 110 Self-Adhered Air & Vapor Barrier Membrane around the windows, ExoAir Primer, Spectrem® 1 Silicone Sealant, Tremflex® 834 Acrylic Sealant and Proglaze® SSG Silicone Sealant is used on all the stiffeners installed on the metal panels at NOW’s shop. The stiffeners adhered to the aluminum composite materials are required to provide rigidity in the panel and ensure a uniform, consistent look when the panels are affixed to the façade. Being an airport, the system has to withstand winds of up to 100 mph which is greater than a hurricane. Therefore, NOW chose to go with a Tremco high performance sealant Proglaze SSG, which is rated at 40% stronger than other structural silicones typically used.
The airport expansion began in November of 2009. Phase I included 650 of the 20’ x 5’ NOW panels. Phase II included 760 of the panels. The company has developed a reputation for its work on large scope, high complexity and tight schedule projects such as DFW Airport Terminal D, Love Field Airport, Dallas and El Pasoconvention centers, US embassies and the Fluor headquarters. When the demands are high and the risk is great, only documented, tested performance will do.
