An exhaust fan sits atop a roof curb secured with one-quarter-inch-diameter lag screws with a minimum of two per side. Counter-flashing wraps the curb assembly above the surrounding roofing membrane. The roof curb is anchored to the concrete structure using three-eighths-inch-diameter Hilti Kwik Bolt TZ expansion anchors with a two-inch effective embedment at each corner. A backdraft damper is secured to the duct below using pop rivets with a minimum of two per side.
COUNTER-FLASHING ROOF CURB ROOFING SECURE FAN TO CURB W/ 1/4"Ø LAG SCREWS (MIN. 2 PER SIDE) POR-RIVET BACKDRAFT DAMPER TO DUCT (MIN 2 PER SIDE) NOTES 1. SEE ARCHITECTURAL PLANS FOR ROOFING DETAILS. SECURE CURB TO CONCRETE W/ 3/8"Ø HILTI KWIK BOLT TZ W/2" EFFECTIVE EMBEDMENT @EACH CORNER ROOF EXHAUST FAN BACKDRAFT DAMPER
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