PERFORMANCE REQUIREMENTS A. General: Install sheet metal flashing and trim to withstand wind loads, structural movement, thermally induced movement, and exposure to weather without failing, rattling, leaking, and fastener disengagement. B. Sheet Metal Standard for Flashing and Trim: Comply with NRCA's "The NRCA Roofing Manual and SMACNA's "Architectural Sheet Metal Manual" requirements for dimensions and profiles shown unless more stringent requirements are indicated. C. Thermal Movements: Provide sheet metal flashing and trim that allow for thermal movements resulting from the following maximum change (range) in ambient and surface temperatures by preventing buckling, opening of joints, hole elongation, overstressing of components, failure of joint sealants, failure of connections, and other detrimental effects. Provide clips that resist rotation and avoid shear stress as a result of sheet metal thermal movements. Base engineering calculation on surface temperatures of materials due to both solar heat gain and nighttime-sky heat loss. 1. Temperature Change (Range): 120 deg F, ambient; 180 deg F, material surfaces. D. Water Infiltration: Provide sheet metal flashing and trim that do not allow water infiltration to building interior. 2.02 SHEET METALS A. General: Protect mechanical and other finishes on exposed surfaces from damage by applying strippable, temporary protective film before shipping. B. Sheet Metal Thickness: The following table may be used to convert specified sheet metal thickness to gauges. Not all materials will be used on the Project. ACCESSORIES A. General: Provide materials and types of fasteners, solder, protective coatings, sealants, and other miscellaneous items as required for complete sheet metal flashing and trim installation and as recommended by manufacturer of primary sheet metal unless otherwise indicated. B. Fasteners: Wood screws, annular threaded nails, self-tapping screws, self-locking rivets and bolts, and other suitable fasteners designed to withstand design loads and recommended by manufacturer of primary sheet metal. 1. General: Blind fasteners or self-drilling screws, gasketed, with hex-washer head. a. Exposed Fasteners: Stainless steel bolts and stainless steel and neoprene washers. Neoprene isolator at washer if stainless steel bolts contact with galvanized steel. Heads matching color of sheet metal using plastic caps or factory-applied coating. b. Blind Fasteners: High-strength aluminum or stainless-steel rivets suitable for metal being fastened. 2. Fasteners for Stainless-Steel Sheet: Series 300 stainless steel. C. Primer: Zinc chromate type. D. Protective Backing Paint: Zinc molybdate alkyd. E. Elastomeric Sealant: ASTM C 920, elastomeric polymer sealant; of type, grade, class, and use classifications required to seal joints in sheet metal flashing and trim and remain watertight. Refer to Section 07 90 00 Joint Sealers. F. Plastic Cement: ASTM D4586, Type I.
