Asbestos cement, genericized as fibro, fibrolite (short for "fibrous (or fibre) cement sheet") or AC sheet, is a building material in which asbestos fibres are used to reinforce thin rigid cement sheets. Although invented at the end of the 19th century, the material was adopted extensively during World War II to make easily-built, sturdy and inexpensive structures for military purposes, and it continued to be used widely following the war as an affordable external cladding for buildings. 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. 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 faced competition with the aluminum alloy, available in large quantities after WWII, and the reemergence of wood clapboard and vinyl siding in the mid to late twentieth 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, it was in Australia and New Zealand that its use was most widespread. Predominantly manufactured and sold by James Hardie & Co. until the mid-1980s, fibro in all its forms was a very 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, the material was discovered in new components sold for construction projects.
