Clay roof tile shall comply with ASTM C 1167.
This code implies that clay tile shall comply with the material standards set forth in ASTM C 1167. Clay tiles are manufactured with clay, shale or other earthly substances and are heat treated at an elevated temperature. The process develops a fired bond between the particulate constituents to provide the strength and durability requirements of ASTM C 1167.
ASTM C 1167 specifies the material characteristics and physical properties of clay tiles that intended for use on the U.S. steep-slope roofing market. The standard provides performance requirements, including durability, freezing and thawing, strength, efflorescence, permeability and reactive particulates.
The tiles are classified into three grades based on their resistance to weathering.