This specification covers glass felt impregnated with coal tar intended to be used with coal tar pitch in the construction of built-up roofs and waterproofing systems. The felt shall be a thin, porous sheet of uniformly distributed glass fibers, with or without the addition of reinforcing stranded glass yarns, and bonded with a water-resistant resinous binder. Longitudinal and transverse breaking strength, pliability, width, area, net dry mass, parting agent and stabilizer content, moisture content, desaturated mass, bituminous saturant (coal tar) content, and ash content are among the property requirements to which the glass felts should conform to.

1.1 This specification covers glass felt impregnated with coal tar intended to be used with coal tar pitch conforming to the appropriate requirements of Specification D450 in construction of built-up roofs and in the construction waterproofing systems.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 The following safety hazards caveat pertains only to the test methods portion, Section 8, of this specification: 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.