Hartsfield-Jackson Atlanta International Airport expansion pushes requirements for an air barrier system

Atlanta, GA

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. 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 an additional sealant over the fasteners was met with ExoAir 230’s nail-sealability testing.  

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. 

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.