SPECIFICATION 22

Curb mounted rooftop equipment shall be mounted on spring isolation curbs. The lower member shall consist of a sheet metal or structural steel sections containing adjustable and removable steel springs that support the upper floating section. The upper frame must provide continuous support for the equipment and must be captive so as to resiliently resist wind and seismic forces. All directional neoprene snubber bushings shall be a minimum of 1/4” (6mm) thick. Steel springs shall be laterally stable and rest on 1/4” (6mm) thick neoprene acoustical pads. Hardware must be plated and the springs provided with a rust-resistant finish. The curbs waterproofing shall consist of a continuous flexible flashing nailed over the lower curbs waterproofing. All spring locations shall have accessibility to adjust springs.  Lower curbs shall have provision for 2” (50mm) of insulation. The roof curbs shall be built to seismically contain the rooftop unit. The unit must be solidly fastened to the top floating rail, and the lower section anchored to the roof structure. Curb shall have anchorage pre-approval “OPA” from OSHPD in the state of California attesting to the maximum certified horizontal and vertical load ratings. Curb shall be type SRSC as manufactured by Mason Industries, Inc.