This specification covers clay roof tiles with such durability and appearance that can provide a weather-resistant surface of a specified design. Each tile should be manufactured from clay, shale, or similar naturally occurring earthy substances and subjected to high-temperature firing. The heat treatment should develop a fired bond between material particles that provides the required strength and durability. The tiles should be shaped by molding, pressing, or extrusion during manufacture. Generally, the tiles are planar or undulating rectangular and are classified into three grades according to the degree of resistance to weathering. Materials are also grouped into three types according to profile and rise-to-width ratio. Colors and textures produced by application of inorganic coatings are allowed except when the coloring is done by flashing or the texturing by sanding where the sand does not form a continuous coating. Each tile should conform to the specified values of durability, freezing and thawing, transverse breaking strength, efflorescence, reactive particulates, and permeability.

1.1 This specification covers clay tiles intended for use as roof covering where durability and appearance are required to provide a weather-resistant surface of specified design.

1.2 Tiles are manufactured from clay, shale, or similar naturally occurring earthy substances and subjected to heat treatment at elevated temperatures (firing). The heat treatment must develop a fired bond between the particulate constituents to provide the strength and durability requirements of this specification (see firing and fired bond in Terminology C 43).

1.3 Tiles are shaped during manufacture by molding, pressing, or extrusion and it is permitted to use the shaping method to describe the tiles.

1.4 Tiles are generally planar or undulating rectangular shapes available in a variety of cross-sectional profiles, shapes, sizes, surface textures, and colors.

1.5 Three grades of tile having various degrees of resistance to weathering are covered in this specification. Three types of tile are defined to cover the features that influence appearance.

1.6 The values stated in inch-pound units are to be regarded as the standard.