The Naval Hospital Replacement Project at Camp Pendleton, the largest military training facility on the West Coast, is a 500,000-square-foot, five-story hospital funded by the American Recovery and Reinvestment Act. The facility will accommodate inpatient medical facilities with 54 patient rooms and up to 60 beds, ancillary departments, emergency care, primary care, specialty care clinics, support spaces and facilities for non-ambulatory patients who require stays in excess of 24 hours. The project also includes a 1,500-space, multi-level parking structure.
Being a medical facility, control of air and moisture infiltration to prevent environments prone to mold and mildew and protect fragile immune systems was imperative.
The facility design incorporated a rainscreen system. Tremco’s ExoAir 110 Self-Adhered Air & Vapor Barrier Membrane was selected for use on the wall. With a stand-off out to the exterior system of stone, terra cotta and metal panels, the air barrier membrane had to be self-gasketing around fasteners. The “pop-out” windows created a 90 degree angle from the wall. The ExoAir 110 was wrapped into the opening at each floor at the top of the windows.
A 3/4" deflection joint was positioned over the head of each window opening to accommodate a 3/8" movement at each floor level. To accommodate extra movement, Proglaze ETA ribbed silicone extrusions were connected around each opening using 3-dimensional molded corners with Spectrem 1 Silicone Sealant forming a silicone “boot” where the window is set forward from the plane of the weather-barrier surface. A filet bead of Spectrem 1 was placed on the outside of the windows at the corners. The Proglaze ETA extrusions are adhered to the air barrier membrane with Spectrem 1, providing clear proof through the translucent, ribbed sheet of a secure bond and durable connection across the seismic drift joints.
To ensure performance of this design, a mockup was built 50 ft in length and 30 ft tall. Rigorous testing was then conducted to determine air leakage under dynamic pressure conditions and its ability to withstand structural wind loads. A series of ten tests were conducted with racking. The mockup was also tested in accordance with ASTM E331– Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors and Curtain Walls by Uniform Static Air Pressure Difference at 720 Pa (15 psf) Pressure. The mockup passed all tests.
To provide the compatible continuity required on the replacement hospital, Tremco’s TREMproof 6100 Hot Rubberized Asphalt with PowerPly modified bitumen membrane heavy-duty protection course and TREMDrain drainage board used on the roof deck was tied into the parapet wall with ExoAir HTF High Heat Membrane, which would lap over the membrane and be protected with a metal flashing. Thorough testing was also conducted on the roofing systems to ensure watertight integrity and performance.