Types of Asbestos
Asbestos has been included in many materials in the last 150 years. Three common types of asbestos can be found in buildings: Crocidolite (blue asbestos), typically found in sprayed coatings, pipe insulation and cement based products was banned in 1985. Amosite (brown asbestos), is usually found in asbestos insulating board (AIB) and was banned in 1985. Chrysotile (white asbestos), was legal until 1999 and banned thereafter. Often found in cement based products, artex and floor tiles, Chrysotile can be found in insulation materials and insulating board (AIB). Asbestos, in loose or contained form, can be found within: Cement items such as roofing,insulation Boards, thermal Insulation, Rope Insulation, Lagging and Yarns, sprayed Coatings, floor Tiles, textiles and composite products, textured Coatings, loose in cavities, floors and ceilings.
Generally containing 10-15% asbestos fibres which are bound in portland cement or calcium silicate. Uncoated sheets, widely used in the past as a building material can be identified as light grey in colour. Whilst they were banned in 1999, asbestos cement products are the most common types of asbestos. Many houses, especially if built between the 1940s and the mid 1970’s will have asbestos cement garages and other asbestos cement products within and around the property. Often found in: Garages, Sheds, Industrial Units, Dutch Barns, Nissan Huts, Domestic & Commercial properties, Schools, Hospitals, Churches
Vinyl, thermoplastic tiles and bitumen can contain asbestos. Floor screed typically contains about 2% asbestos. These screeds were often used in areas of high occupancy such as stairwells and entrance halls. Often used for: Floor Coverings, mastic, adhesive, roof felt, sink pads
Asbestos Lagging, Ropes and Yarns
Where used for lagging or packing material ropes and yarns can contain 40 – 100% asbestos depending on its functional requirements. Often used for: Pipe lagging, insulation, jointing pipes, heat resisting situations.
May contain asbestos and if well bonded, fibres are not often easily released. However, because of the asbestos content it is to be worked with safely.
Asbestos Insulating Board
This is a compressed board that contains asbestos fibre and Portland cement or calcium silicate with other materials.
Millboards that were manufactured between 1896 and 1965 can contain chrysotile asbestos (up to 97%). Often found: Pipe runs, electrical gear, vaults, storage.
Asbestos Sprayed coatings
Are contained within products that can generate very high fibre levels if disturbed. Often found in: Roof underlining (especially on asbestos cement roofs), service risers, floor voids, ceiling voids and around firebreaks.