The properties of asbestos initially determine the range of asbestos materials – fire and corrosion resistance, thermal insulation qualities and the ability to add great strength to weak materials provide good clues as to where asbestos materials can be found. Of course, for many years asbestos was also very cheap, so it was also used in building materials which did not necessarily have any of the above qualities.
Its strength as a fibrous addition to the asbestos materials used in construction accounts for the vast majority of asbestos use. Corrugated cement roofs are exactly that – very weak cement becomes much stronger simply by adding up to 15% of asbestos. Vinyl floor tiles, simulated slate roof tiles, ceiling tiles, roofing felt and textured paint finishes also contained small quantities of asbestos for many years.
Most asbestos materials also have good fire resistance, and so they are used in the form of fire blankets, and within fire doors and other barriers to resist the spread of fire and provide additional time for escape.
The insulation value of asbestos materials is utilised in many products. They can exist as a “spray”, applied often to steel beams and the concrete ceilings of underground car parks, for example, and as lagging applied to heating and steam pipes and as boiler insulation. Compressed in to boarding, known products have been used extensively for wall insulation in industrial units, but also for partition boarding in offices and houses, and even for acoustic purposes in cinemas and theatres.
All asbestos materials are hazardous, but the risk varies according to the type of product in question. Those in which the asbestos fibres are bound by some other material (cement, plastic etc) do not shed fibres as easily as those products which contain asbestos simply compressed into a board, or applied to a surface as an insulating layer.
