Asbestos cement

Asbestos cement, genericized as fibro, fibrolite (short for "fibrous (or fibre) cement sheet"; but different from the natural mineral fibrolite), or AC sheet, is a composite building material consisting of cement and asbestos fibres pressed into thin rigid sheets and other shapes.

Invented at the end of the 19th century,^[1] the material was adopted extensively during World War II to make easily-built, sturdy and inexpensive structures for military purposes. It continued to be used widely following the war as an affordable external cladding for buildings.^[2] Advertised as a fireproof alternative to other roofing materials such as asphalt, asbestos-cement roofs were popular, not only for safety but also for affordability.^[3] Due to asbestos cement's imitation of more expensive materials such as wood siding and shingles, brick, slate, and stone, the product was marketed as an affordable renovation material. Asbestos cement competed with aluminum alloy, available in large quantities after WWII, and the reemergence of wood clapboard and vinyl siding in the mid to late 20th century.

Asbestos cement is usually formed into flat or corrugated sheets or into pipes, but can be molded into any shape that can be formed using wet cement. In Europe, cement sheets came in a wide variety of shapes, while there was less variation in the US, due to labor and production costs. Although fibro was used in a number of countries, in Australia and New Zealand its use was most widespread. Predominantly manufactured and sold by James Hardie until the mid-1980s, fibro in all its forms was a popular building material, largely due to its durability. The reinforcing fibres used in the product were almost always asbestos.

The use of fibro that contains asbestos has been banned in several countries, including Australia, but as recently as 2016,^[update] the material was discovered in new components sold for construction projects.^[4]