Between the 1950's and the 1980's, asbestos ceilings were used because of their fireproofing and heat resistant properties, which is why asbestos ceilings are most commonly found in bathrooms, laundries and garages; rooms considered as those where a fire may start unattended. Used to reduce the risk of fire spreading through the ceiling, asbestos was also used on verandah ceilings and eaves to reduce the risk of fire spreading to adjoining properties.
There are several types of common asbestos ceilings including:
- asbestos cement sheet
- asbestos insulating board (AIB)
- asbestos ceiling tiles; and
- sprayed insulation (vermiculite or popcorn asbestos ceiling).
When sampling asbestos ceilings, fibres will fall within the breathing zone which poses a health risk. Correct sampling techniques for asbestos ceilings include wetting the surface down, using drop sheets, wearing protective respiratory equipment and disposable overalls.
The risk of asbestos related health issues will depend on whether the asbestos ceiling comprises bonded or friable asbestos, the condition of the material, and the use and occupancy of the area. Bonded asbestos ceilings made of cement sheet and corrugated asbestos are generally quite stable when they are in good condition and are only cause for concern during renovations or major refurbishment.
Friable asbestos ceilings such as popcorn asbestos ceilings, however, are potentially quite hazardous due to fibres that may be released from small amounts of disturbance. Other issues can arise with asbestos ceiling tiles in commercial buildings where contractors may be moving the asbestos panels to gain access to the ceiling. The edges of the panels can rub on the frames that hold them in place creating dust. This can increase over the years creating a significant hazard. Special precautions are required when accessing asbestos ceiling tiles and panels.