This specification covers the requirements for two types and two classes of asbestos-containing asphalt roof cement consisting of an asphalt base, volatile petroleum solvents, and mineral stabilizers including asbestos fiber, mixed to a smooth, uniform consistency suitable for trowel application to roofing and flashing. Type I is made from asphalts characterized as self-healing, adhesive, and ductile, while Type II is made from asphalt characterized by high softening point and relatively low ductility. Class I is used for application to essentially dry surfaces, while Class II is used for application to damp, wet, or underwater surfaces. The cements shall meet specified composition limits of water, nonvolatile matter, asbestos and other mineral stabilizers, asphalt, and mineral matter based on original mass of insoluble residue. They shall also conform to physical requirements such as uniformity, workability, pliability and behavior at given temperatures, and adhesion to damp, wet, or underwater surfaces.