They form a film by evaporation of the solvent and solvents can dissolve the film.
Coal tar pitch roofing details.
History of coal tar roof systems 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.
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.
The dry film is damaged by direct exposure to sunlight which causes rapid severe cracking.
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.
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.
Bituminous roofing hits the market back in the pre world war ii years there were two bituminous substances bitumens that dominated the roofing industry.
Built up roofing in which coal tar pitch forms the waterproofing component of the roof membrane.
Coal tar pitch is melted on site in an industrial kettle and applied to the roof as a hot liquid.
Construction definition coal tar pitch roofing.
Coal tar films provide very good corrosion protection.
Coal tar coatings are made from processed coal tar pitch dissolved in suitable petroleum solvents.