Term Description
Coal tar

A dark brown to black cementitious material produced by the destructive distillation of coal.

Coal-tar pitch is further refined to conform to the following roofing grade specifications:

coal-tar pitch: A coal tar used as the waterproofing agent in dead-level or low-slope built-up roof membranes and membrane waterproofing systems, conforming to ASTM D450, Type I. coal-tar waterproofing pitch: A coal tar used as the dampproofing or waterproofing agent in below-grade structures, conforming to ASTM D450, Type II.

coal-tar roof cement: A trowelable mixture of processed coal-tar base, solvents, mineral fillers and/or fibers; classified by ASTM D5643, "Coal Tar Roof Cement, Asbestos Free."

Equiviscous temperature (EVT) for coal tar

The recommended EVT for roofing coal tar (ASTM D450, Type I or III) is the temperature at which the coal tar’s apparent viscosity is 25 centipoise.