Transite is a composite fireproof material that is used in the building trades and has been used in the building trades since the late 1920s. Until the mid 1980s, transite included 12 to 50 percent asbestos, mixed with Portland cement. Transite was used to make roofing shingles, siding shingles and boards, furnace flues and cement siding, especially where fireproof material is desired.

This page assists in the recognition of transite pipe used for chimneys or heating flues and discusses potential hazards of this material when it is found in buildings. Transite pipe is an asbestos-cement product which was used for both HVAC ducts and for chimney or flue material to vent gas-fired appliances. In use as a gas-fired appliance chimney/vent transite pipe may have been classed as a type "B" flue vent which required 1" clearance from combustibles.