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Cleaning asbestos cement roofs

Guidance for employers about the risks associated with cleaning asbestos cement roofs with high pressure water blasters.

Date: 2014-04-01
Keycode: 0173/01/04.14
Publication type: alert
Industries: Electricity, Gas, Water and Waste Services


This safety alert shares guidance for employers about the risks associated with cleaning asbestos cement roofs with high pressure water blasters.

The cleaning of asbestos roofs should be avoided and replacement considered but if cleaning is necessary a fungicide or sealant may be applied.


There have been several incidents where workers have been exposed to asbestos while using high pressure water cleaners to clean roof surfaces containing asbestos.

Cleaning an asbestos cement roof in this way damages the roof surface, causing cement debris and asbestos fibres to be sprayed into the air. This can cause widespread contamination and puts the worker, the occupier and any neighbours' health at risk.

Your legal obligations

Under the Occupational Health and Safety Regulations 2007 (Vic), use of high pressure water cleaners on asbestos is prohibited, unless use of the cleaning instrument is controlled in the manner specified in the Regulations. Under the Regulations, use of the cleaning instrument is controlled if while it is in use, it is enclosed and/or engineering controls are used, to ensure that a person is not likely to be exposed to more than half of the asbestos exposure standard.

In most cases, it is unlikely that use of a high pressure water cleaner on an asbestos roof will be able to be controlled as required under the Regulations. Consequently, you may be prosecuted for water blasting an asbestos cement roof. Note that the Regulations also require you to eliminate, so far as is reasonably practicable, the exposure of people at your workplace to airborne asbestos fibres. Where this is not reasonably practicable, you must reduce exposure so far as is reasonably practicable.

How to tell if a roof contains asbestos

Some cement sheet roofs (such as those referred to as 'Super Six') contain asbestos. As a general rule, if the building was constructed before 1990 and has a cement roof, you should assume it contains asbestos. If you are unsure when the building was constructed, it is best practice to assume the roof contains asbestos.

Handling and removing asbestos roofing

Asbestos cement roofs that are in good condition are not a risk to human health unless they are physically disturbed or damaged, which may occur during maintenance or renovation works.

Where practicable, you should avoid cleaning an asbestos roof and instead consider replacement. If you do need to clean an asbestos roof, you may be able to apply a fungicide or sealant. You can find out more about sealants and fungicides from your local roof restoration company, paint supplier or hardware store.

If a roof containing asbestos shows signs of crumbling or deterioration, it must be removed and replaced with alternative roofing materials. In almost all circumstances, this work must be done by an asbestos removalist licensed by WorkSafe Victoria.

Further information

For more information about asbestos in the workplace or to find a licensed removalist, contact WorkSafe Victoria on 1800 136 089 or, or go to or

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Disclaimer:This Alert contains information following the Victorian WorkCover Authority’s inquiries into the incident at the date of this report. The information contained in this report does not necessarily reflect the final outcome of the Victorian WorkCover Authority’s action with respect to this incident. The Victorian WorkCover Authority does not warrant the information in this report is complete or up-to-date, and does not accept any liability to any person for the information in this report, or its use