This specification covers standard specification for steel sheet metallic coated by the hot-dip process and coil-coated with organic films for exterior exposed building products. The substrate shall conform to all requirements of the appropriate specification for the steel sheet product. Material classification includes zinc-coated (galvanized), aluminum-zinc alloy-coated, and aluminum coated steel sheets. The recommended minimum coating mass designations for use in exterior exposed building applications shall be indicated. The properties of the substrate and the organic coating system, combined with the method of forming, shall determine the life expectancy and general appearance of the final product.

1.1 This specification covers steel sheet metallic coated by the hot-dip process and coil-coated with organic films for exterior exposed building products. Sheet of this designation is furnished in coils, cut lengths, and formed cut lengths. Building products include corrugated and various types of roll and brake-formed configurations.

1.2 The substrate is available in several different metallic-coated steel sheet products as enumerated in 4.1, depending on the requirements of the purchaser.

1.3 Coating systems supplied under this specification consist of a primer coat covered by various types and thicknesses of top coats. The combination of primer and top coat is classed as either a two-coat thin-film system or as a two-coat (or more) thick-film system. Typical top-coating materials are: polyester, silicone polyester, acrylic, fluoropolymer, plastisol, or polyurethane.

1.4 This specification is applicable to orders in either inch-pound units (as A 755) or SI units [as A 755M]. Values in inch-pound units and SI units are not necessarily equivalent. Within the text, SI units are shown in brackets. Each system shall be used independently of each other.

1.5 Unless the order specifies the “M” designation (SI units) the product shall be furnished to inch-pound units.

1.6 The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables and figures, shall not be considered as requirements of this specification.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.