How to Identify an Asbestos Roof in Perth

5 min read

If your Perth home was built before 1990, there’s a real chance your roof contains asbestos. Asbestos cement sheeting was one of the most commonly used roofing materials in Western Australia from the 1940s through to the mid-1980s, and some products remained available into the early 1990s.

Before you panic - asbestos roofing that’s in good condition and left undisturbed is generally considered low risk. But you need to know what you’re dealing with so you can manage it safely.

What Does Asbestos Roofing Look Like?

Asbestos cement roofing in Perth typically comes in two forms:

Corrugated sheets (Super Six) - These look like standard corrugated iron but are made from cement reinforced with asbestos fibres. They’re thicker and heavier than metal sheeting, and if you tap them they sound dull rather than metallic. The corrugation profile is typically wider than modern metal sheeting.

Flat sheets - Used on some flat or low-pitch roofs, eaves, and soffits. These are smooth, flat panels that look like compressed cement board.

Key identification features:

• Grey, weathered appearance (may be painted)
• Thicker and heavier than metal sheeting
• Dull sound when tapped (not metallic ring)
• May show surface weathering, moss, or lichen
• Wide corrugation profile on corrugated sheets
• Often has a slightly rough, fibrous texture on cut edges

How to Confirm It’s Asbestos

You cannot confirm asbestos content just by looking at it. The only way to know for certain is to have a sample tested by an accredited laboratory. In Perth, a licensed asbestos assessor can take a small sample safely and have it analysed.

Never try to take a sample yourself. Cutting, drilling, or breaking asbestos cement releases dangerous fibres into the air. Even scraping the surface can release fibres.

If you’re unsure about your roof material and your home was built before 1990, treat it as asbestos until proven otherwise.

Is an Asbestos Roof Dangerous?

Asbestos cement roofing is classified as bonded (non-friable) asbestos, meaning the asbestos fibres are locked within the cement matrix. When the material is in good condition, fibres are not released into the air and the risk is low.

The risk increases when the material is:

• Damaged - broken, cracked, or chipped sheets expose fibres
• Weathered - severe surface degradation can release fibres
• Disturbed - cutting, drilling, sanding, pressure washing, or breaking releases fibres
• Deteriorating - old asbestos cement becomes more friable over time

Important: You should never pressure wash an asbestos roof. High-pressure water blasts fibres into the air and contaminates the surrounding area.

Your Options for an Asbestos Roof

Option 1: Leave It in Place and Monitor

If your asbestos roof is in reasonable condition - no major cracks, not heavily weathered, not releasing fibres - you can leave it in place and monitor it annually. This is the most common approach and is acceptable under WA regulations.

You should avoid walking on it, pressure washing it, or doing any work that disturbs the surface.

Option 2: Encapsulation (Painting Over)

An asbestos roof in fair condition can be painted with a specialist encapsulating coating. This seals the surface, prevents fibre release, and extends the material’s life. The roof must be carefully cleaned using low-pressure methods (no pressure washing) before coating.

This work must be done by contractors licensed to handle asbestos. It’s significantly cheaper than removal and can extend the roof’s useful life by many years.

Option 3: Removal and Replacement

If the asbestos roof is badly deteriorated, damaged, or you simply want it gone, removal and replacement is the permanent solution.

In Western Australia, asbestos removal must be carried out by a licensed asbestos removalist. For roofs over 10 square metres, a Class A or Class B licence is required. The removed material must be disposed of at an approved facility.

Replacement is typically with Colorbond metal roofing, which is lighter, more durable, and won’t pose any future health concerns. Once the asbestos is gone, a roof replacement gives you a clean, modern roof with decades of life ahead of it.

WA Regulations You Need to Know

• Asbestos removal over 10m² requires a licensed removalist
• A removal plan must be submitted to WorkSafe WA before work begins
• The area must be cordoned off and appropriate signage displayed
• Removed material must be wrapped, labelled, and disposed of at a licensed facility
• Air monitoring may be required during removal
• You cannot put asbestos materials in regular skip bins or landfill

What About Asbestos in Other Parts of the Home?

While this article focuses on roofing, many Perth homes of the same era also contain asbestos in:

• Eave linings and soffits
• Internal wall and ceiling sheets (flat fibro)
• Bathroom and laundry wall linings
• Fencing
• Textured coatings (some older spray-on textures)

If you’re planning any renovations on a pre-1990 home, get an asbestos survey done first.

The Key Takeaway

An asbestos roof isn’t an emergency - but it does need to be managed responsibly. Know what you have, monitor its condition, and when the time comes for removal, use licensed professionals.

If you’re unsure about your roof material, the safest first step is to book a professional roof inspection. Knowing for certain what you’re dealing with puts you in control of the situation.