Decades ago, corrugated cement roofing sheets, more commonly called fibro or ‘Super Six’, were made with asbestos fibres to give the sheets strength and resistance to chemicals and the harsh environment.
Over time, lichen growing on the roof sheets commonly discolours them from the original light grey into a dark grey/grey black.
Unpainted Super Six roof with lichen on it
Lichen attaches itself to the smooth surface of the roof sheets, and its roots eventually damage the sheets’ integrity, creating small fractures on the surface.
A carport roof, unpainted and not maintained with moss ground in the guttering
Homeowners and roof painters used to clean these roof sheets with high-pressure water blasters. This was effective, but not safe for people or the environment. It is now illegal to clean a fibro roof with high-pressure water because it destroys the surface, causing cement and asbestos dust and debris to be sprayed into the air, contaminating your property and possibly neighboring properties.
ACD (asbestos containing dust and debris) which has settled on the grass and dandelion weeds, after a roof was cleaned by a high-pressure water blaster
If your asbestos roof is in poor condition, consider replacing it with a roof that requires no maintenance. However, if it’s still in good condition but just needs cleaning, it’s much safer to apply a fungicide, lightly wash it down (using a garden hose with no nozzle attached, at low pressure), then paint it to seal the surface. A well-maintained asbestos roof is not a risk to you and your family’s health.
Follow the below steps to prepare and maintain your corrugated asbestos cement roof. The same can be applied for asbestos containing awnings and fences.
As well as containing and controlling the risks associated with asbestos products, you will also need to control other safety risks such as:
Remember to always turn off the main power switches at the switchboard before going into ceiling spaces.
Ensure you have the following equipment:
Filter sock on downpipe with filter membrane beneath it
A painted Super Six roof
Worker wearing appropriate PPE and RPE to apply mould control on roof