Prefabricated roof curb to be manufactured of prime galvanized steel construction, 20 , 18, 16 or 14 gauge as required, meeting ASTM A653/653M, with welded corners and with seams joined by continuous water and air tight welds. Roof curb shall be internally reinforced with angles 48" on center and factory installed wood nailer. Internally insulated with 1 1/2” thick 3 lbs. density rigid insulation. Heights to be 8" above finished roof deck or as detailed. Top of all roof curbs shall be level, with pitch built into curb when deck slopes.