Constructed of 18-gauge galvanized steel with continuous welded seams
Wide base plate (flashing) to insure watertight bond to roof
Top ledge covered with 3⁄16″ polystyrene gasket for weather seal and
to reduce metal-to-metal conducted noise
Lined with 11⁄2″ fiberglass fire-resistant, sound-absorbing insulation
Damper shelf
Options: Aluminum (16-gauge) construction, Burglar security bars,
Metal liner (galvanized or aluminum), Special heights up to 24″, Wood
nailer (11⁄2″) secured to top ledge in lieu of polystyrene gasket, Single
or double pitched curbs for sloping roofs