High-pressure cleaning of an asbestos cement roof is, in WA Health’s words, a highly contaminating activity prohibited under the Health (Asbestos) Regulations 1992. Cleaning by any method can release fibres, painting is now often too late to help, and for most roofs of this age HealthyWA’s view is that removal and replacement is best.
General informationGeneral information from WA Health, HealthyWA and WA’s regulations, not advice about any roof. HealthyWA points to the environmental health services at the local government for advice on asbestos removal.
Asbestos safety
The national Asbestos and Silica Safety and Eradication Agency says it is “not recommended that you handle or remove asbestos yourself”, and in Western Australia the law sets a limit: WorkSafe WA says a homeowner may take out up to 10 square metres of non-friable material from their own home, and must follow strict safety steps in doing it. The national agency adds that a professional makes the job easier, safer and often cheaper. Its rule for the waste: it goes only to a landfill site licensed to take it, and a household rubbish bin can bring a fine.
No safe level of exposure to asbestos exists, WorkSafe WA says. It reserves friable asbestos in any amount, and non-friable asbestos over 10 m², for a licensed asbestos removalist only, and tells homeowners in WA that the waste has to be handled safely, moved properly and delivered to a licensed asbestos disposal facility.
WA’s health advice and the national agency warn against some methods. HealthyWA says high-pressure water and air cannot be used on asbestos products. The national agency warns against cleaning an asbestos cement roof, or any asbestos material, with high-pressure water or anything abrasive, scrubbing and sanding included. For its own state’s homeowners, Queensland’s government asbestos site lists “Saw, sand, scrape or drill holes in asbestos materials” among things not to do.
The pressure cleaner, and why it reaches next door
WA Health says the people who usually commit pressure-cleaning offences are property owners or roof painters who do not know the rules, and that they can contaminate several properties badly enough to need specialised remediation. It says that clean-up should be done by an unrestricted asbestos removalist, because of how friable the material becomes. In WA, the Class A removal licence is also called “unrestricted”, and Class A is the licence for removing friable asbestos.
The Regulations themselves, in the copy published as at 29 September 2020, put the rule a little differently. Regulation 7(4)(d) lists, among the reasonable measures against releasing fibres, not using a high pressure water jet or compressed air unless it is used in a way that adequately prevents fibres entering the air and that the Chief Health Officer has approved in writing.
Four roof jobs, as WA’s health sources describe them
| The job | What the WA source says | Whose words |
|---|---|---|
| Cleaning | Cleaning can release fibres. Any method has to be non-abrasive, and whatever washes off the roof has to be caught and disposed of as asbestos waste. | HealthyWA |
| Painting or sealing | A good coating was once recommended to lengthen a roof’s life and improve its look, but many roofs are now too worn for that to work. Paint that does not penetrate, or is poor quality, can peel or flake and spread contamination. | HealthyWA |
| Keeping up a sealed roof | Only a structure that has been kept well maintained and sealed or painted can be cleaned, resealed or repainted without releasing fibres. | Department of Health |
| Walking on it | Among the points the Department suggests councils give homeowners: aged sheeting is brittle, so walking on an asbestos cement roof is a serious fall risk. | Department of Health |
Why HealthyWA puts the roof first
HealthyWA recommends making removal of the roof a priority, and gives five reasons.
- Moss and algae growing on the surface stop it being cleaned safely.
- A high-pressure hose cannot be used on the sheeting, because it would release fibres and spread them.
- The sheets grow brittle with age, damage more easily and become unsafe to walk on.
- A roof in poor condition costs more to remove, because licensed removalists have to take more care with it.
- A roof damaged by fire or wind spreads contamination widely, raising the risk of breathing airborne fibres, and its clean-up is extremely costly.
The Department’s suggested messages to homeowners make the same case: complete removal is strongly preferred to maintaining and repairing an ageing asbestos structure, and replacing a roof that is still fairly intact is safer and usually much less expensive. WorkSafe WA adds that removal is generally cheaper and safer while the material is still in good condition, and suggests an inspection for asbestos before any work starts, to help plan the cost.
If the roof stays for now
For an owner who keeps asbestos products that are in good condition, HealthyWA’s list runs as follows.
- Do not break or damage them.
- Keep plants and other things from rubbing against the surface.
- Check that the gutters and downpipes work and are undamaged.
- Put what comes out of gutters and drains into heavy-duty plastic bags and take it to licensed disposal sites.
- Check that soakwells are in place to take the run-off from an asbestos cement roof’s downpipes.
How that bagged waste is wrapped, labelled and carried under WA’s regulations is set out in the guide to wrapping and carrying asbestos waste.
The eaves
Eaves lining sits on HealthyWA’s list of places outside a home where asbestos is found. After a fire, HealthyWA says damaged asbestos on a property will most often be asbestos cement sheeting, and it names fences, walls, roofs and eaves. Taking down a stretch of eaves can pass the 10 m² line for a homeowner faster than it looks: the guide to who may remove asbestos from a WA home works one through.
WA Health’s About asbestos page, last reviewed in April 2026, carries its guidance to councils on asbestos cement roofs.