The name fibro is short for "fibrous (or fibre) cement sheet", more commonly called "asbestos cement sheet" or "AC sheet". It is a building material in which asbestos fibres are used to reinforce thin rigid cement sheets.
Although fibro was used in a number of countries, it was in Australia where its use was the 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 involved were almost always asbestos.
The use of fibro that contains asbestos has been banned in several countries, including Australia. As recently as 2016, the material has been discovered in new components sold for construction projects.
Asbestos is directly related to a number of life-threatening diseases including, asbestosis, pleural mesothelioma (lung) and peritoneal mesothelioma (abdomen). Fibre cement sheet is still readily available, but the reinforcing fibres are now cellulose rather than asbestos. However the name "fibro" is still applied to it for traditional reasons.
Some Australian states, such as Queensland, prohibit the cleaning of fibro with pressure washers, because it can spread the embedded asbestos fibres over a wide area. Safer cleaning methods involve using a fungicide and a sealant.
In the James Blundell & James Reyne song Way Out West, there was a reference to a fibro cement house, with the original Dingoes version of the song having a reference to a house of fibre cement. Also mentioned several times on the Australian TV show "Housos".