Coal Tar Pitch Roof
Construction definition coal tar pitch roofing.
Coal tar pitch roof. Coal tar pitch membranes using coal tar saturated organic felts is one of the oldest systems listed in table 2. Built up roofing in which coal tar pitch forms the waterproofing component of the roof membrane. A coal tar roofing system represents the industry s premier built up roof membrane assembly. Roofing systems originally consisted of alternate layers of hot bitumen and reinforcement.
Coal tar pitch roofing is particularly pungent and contains a slew of harmful chemical compounds asphalt roofing is relatively benign compared with pitch. They actually made a pitch modified but it didn t sell well from what i heard. History of coal tar roof systems. It is solid for all practical purposes at room temperature.
Koppers was one brand another one was allied signal. You can also get pitch base felt and membrane. Asphalt a by product of processing petroleum to make gasoline fuel oil and various hydrocarbon polymers was also popular. Coal tar pitch is produced by distilling or heat treating coal tar which is a by product of the production of coke or coal gas.
It is used as a base for coatings and paint in roofing and paving and as a binder in asphalt products. Coal tar pitch roofing in the processing of coal to make coke for steel making volatile compounds are collected from the coking ovens condensed and separated and become the base of hundreds of raw materials including dyes plastics and a byproduct called coal tar pitch. Coal tar s unique molecular structure provides a system that resists water and vapor penetration insect damage chemical attack uv exposure and most elements considered common enemies to other roof membrane systems. That make a coal tar based mastic.
Due to its resistance to ponded water oxidation chemical attack and its cold flow self healing properties coal tar pitch built up roofing systems typically require little maintenance. Coal tar pitch was a by product of processing coal to make coke which in turn was used in making carbon steel and electrodes for the aluminum industry. Historically coal tar pitch was used as a component on the first sealed roads has served as a heating element and was used to manufacture paints synthetic dyes and photographic materials. A waterproofing material used since the beginning of time coal tar pitch is a superior and sustainable raw material that is ideal for use within a roofing membrane system.
These systems perform very well historically but are limited to very low slope applications and must be gravel surfaced because of the low viscosity of coal tar pitch at normal rooftop temperatures. Both coal tar and coal tar pitch contain many chemical compounds including carcinogens such as benzene. 2 9 coal tar pitch built up roofing.