Coal Tar Pitch Roof System
Each roof system was created with the materials available at the time.
Coal tar pitch roof system. Built up roofing in which coal tar pitch forms the waterproofing component of the roof membrane. Even though modern roof technology was limited or next to none these roofs in the past sometimes lasted for up to 40 years. New coal tar pitch roof installations however are extremely rare. As coal tar declines in use most built up roofs today are comprised from the asphalt which is produced from crude oil.
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. 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. Asphalt a by product of processing petroleum to make gasoline fuel oil and various hydrocarbon polymers was also popular. It is solid for all practical purposes at room temperature.
The traditional coal tar built up roof is one of the most reliable and longest lasting low slope commercial flat roofing systems available. 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. For years a coal tar pitch roof was regarded as the best roof system in the market due to the fact that coal tar is impervious to ponding water and the material has a low melting point. 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.
Coal tar pitch is melted on site in an industrial kettle and applied to the roof as a hot liquid. History of coal tar roof systems. Coal tar is considered the product of choice for roofs which have ponding water due to its superior ability to withstand extended exposure to water. Construction definition coal tar pitch roofing.
Beginning with coal tar elastometric membranes ctem that were developed in europe as a low sloped roofing thru wall flashing and waterproofing product our systems are known for their years of superior performance. 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 coal tar roofing system represents the industry s premier built up roof membrane assembly. Application tools such as melting kettles mops and mop carts needed to be dedicated to either pitch or asphalt.
Because of the different properties of asphalt and coal tar pitch roofers were careful not to mix the two materials on the same project. Coal tar pitch was the roof system of the era and little was known about anything else.