The Hidden Dangers of an Asbestos Roof

The Hidden Dangers of an Asbestos Roof

Have you ever wondered whether that old cement roof on your home is safe? If your house (or any structure) was built before the 1990s, there’s a chance it contains asbestos roofing. That doesn’t always mean immediate danger, but it’s something you should understand clearly, especially as those sheets age, crack, or when renovations are underway.

Let’s walk through what asbestos is, why it was used, how to tell if there is asbestos on the roof, and what to do if you suspect it’s there.

What Is Asbestos and Why Was It Used in Roofing?

Asbestos is a naturally occurring mineral that forms in long, thin fibres. These Asbestos fibres are fire-resistant, heat‑resistant, durable, and difficult to break down. This is why they were used so heavily in construction for decades.

From the 1940s through to around the 1980s, asbestos was added to many building products. From roofs, walls, pipes, to insulation,  it was everywhere.  In roofing, asbestos was usually mixed with cement to make asbestos sheets and shingles that could withstand heat, fire, and weather damage. 

Asbestos provided thermal insulation, which helped to moderate temperatures in homes, especially in hot or cold climates. And it was cost-effective as well. Because of all these benefits, asbestos was seen as a “miracle” add-on until the health implications became better understood.

Common Types of Asbestos Roofing Materials

When people talk about asbestos roofing, they refer to several forms:

Corrugated Cement Sheets (e.g. “Super Six”)

One of the most well-known asbestos roofing products in Australia was Super Six (also sometimes called “Super 6”). These are corrugated cement sheets reinforced with asbestos fibres. They were used for roofs, sheds, garages, and more.

Other Bonded Asbestos Roofing Products

  • Flat fibre cement sheets/slates
  • Asbestos cement tiles
  • Asbestos shingles (though less common in roofing, more in walls or smaller structures)
  • Asbestos roofing flashings, guttering, and ridge caps — parts of the roofing system that may also include asbestos content

Asbestos-containing roofing elements were common for a long time. From the 1940s right through the late 1980s, and in some areas even into the early 1990s, it was one of the go-to construction materials. In Australia, it wasn’t until December 2003 that asbestos was completely banned from being made, imported, or used.

What that means today is simple: if your asbestos roof tiles or any part of your building was in place before the 1990s (and definitely before 2003), there’s a chance it could contain asbestos.

How to Identify Asbestos in the Roof

Knowing whether your roof has asbestos is tricky because you can’t rely on just looks or touch. But there are clues and a process to follow.

Signs Your Roof Might Contain Asbestos

  • The roof is old (pre‑1990s) and hasn’t been replaced. Note the roof’s age and installation era.  If a house dates from periods when asbestos was common, that raises suspicion.
  • The roofing material looks like cement sheeting (thick, heavy, grey). Also see whether other parts of the building (walls, eaves, gutters) use similar materials.
  • You see “Super Six” or other brand stamps on sheeting
  • The edge, ridges, or flashings look rough or fibrous
  • The material is brittle, flaking, chalky, or showing signs of wear

But visual inspection alone is not reliable. Many modern fibre cement products mimic the look of asbestos sheets. The only way to know for sure is to have a sample tested.

The Importance of Laboratory Testing

  • Use a NATA-accredited laboratory in Australia. In NSW, SafeWork NSW emphasizes that only laboratory analysis can confirm asbestos presence.
  • Never take a sample yourself unless trained and equipped. Disturbing the sample even a bit can release dangerous fibres.
  • A licensed asbestos assessor or removalist can do this safely. They’ll collect the sample, submit it, and interpret the results.

When testing, professionals consider age, material type, condition, and appearance to decide the risk.

How Dangerous Is Asbestos Roofing?

It’s all about how the asbestos is behaving. This depends on whether it’s bonded or friable, and whether it’s being disturbed. Know the difference between bonded vs friable asbestos:

  • Bonded (non‑friable) asbestos is asbestos mixed into a matrix (like cement).  The fibres are locked in. In this state, it’s more stable and less likely to release fibres unless damaged.
  • Friable asbestos is the kind that can be crumbled by hand.  It’s loose and dangerous because fibres can easily become airborne.

Most roof asbestos was installed as bonded material. But this doesn’t mean it remains safe forever.

How Bonded Asbestos Becomes Friable Over Time

Age, weathering, hail, wind, debris, heavy corrosion, water damage. These all can degrade bonding and make asbestos sheets brittle. Asbestos fibres can escape into the air when they get loose or fractured. A roof that seemed fine decades ago won’t necessarily stay safe forever.

Health Hazards Associated with Asbestos Roofs

If you accidentally breathe in asbestos, it is very dangerous. It causes illnesses that are serious and often fatal. But they don’t show up right away. It can take decades before symptoms appear. The risk comes when asbestos is disturbed. The fibres are microscopic, but once they’re in the air and you breathe them in, they can get stuck deep in your lungs. Over time, that can lead to scarring, inflammation, and disease.

Common Health Risks from Asbestos Exposure

  • Asbestosis: Chronic lung scarring. Leads to breathing difficulties
  • Mesothelioma:  A  rare, aggressive cancer of the lung lining or abdomen, basically always caused by asbestos
  • Lung cancer:  Especially higher risk for smokers exposed to asbestos
  • Pleural plaques, pleural thickening, pleural effusions:  Changes in the lung lining

The World Health Organization (WHO) states there is no safe level of asbestos exposure. Even small amounts can be harmful over time.

Is It Necessary to Remove an Asbestos Roof?

You’ll often hear mixed advice about whether you must remove it. The short answer: not always, but removal has strong arguments in many cases. The following are the legal requirements in NSW:

  • If the asbestos is bonded and in good condition, it does not have to be removed under NSW law.
  • But once it becomes friable, or you plan work that may disturb it, removal by a licensed professional is required.
  • In NSW, if you intend to remove more than 10 m² of bonded (non-friable) asbestos or any amount of friable asbestos, you must notify SafeWork NSW at least 5 calendar days before starting. 

So, leaving it in place can be acceptable but only under certain conditions.

Why Many Homeowners Choose to Replace an Asbestos Roof Anyway

Even when removing the asbestos roof isn’t mandatory, many consider licensed asbestos removal as the safer, longer-term choice. 

  1. Aging Material Becomes Risky: Asbestos roofing doesn’t last forever. Over the years, it can wear down, crack, and eventually turn brittle, and that’s when it becomes dangerous.
  2. Difficulties Selling: Buyers get cautious about homes with asbestos roofs. It can make selling your home slower, or force you to drop the price.
  3. Insurance Issues: Some insurers won’t cover a property with asbestos. Others will, but they’ll charge you more for the risk.
  4. Peace of Mind: Once it’s gone, it’s gone. You don’t have to worry about it anymore, especially if you’re planning renovations or adding onto the house.
  5. Modern Alternatives: Modern roof materials, like steel, tile, and composite, are safer and tougher. They usually look better, too.

What to Do if You Have an Asbestos Roof

If Your Roof Is Intact and in Good Condition:

  • Don’t disturb the asbestos roof tiles to avoid releasing fibres.
  • Inspect the roof for damage from time to time.
  • Contact professionals for surface sealing or painting. This encapsulates asbestos fibres.
  • Avoid high-pressure cleaning, drilling, sanding, or walking on brittle sheets.

If Your Roof Shows Damage or Deterioration:

  • Contact a licensed asbestos professional for inspection.
  • Plan for safe removal and replacement.
  • Only a licensed asbestos professional, such as PureSafe, should remove asbestos safely. It ensures safety and legal compliance
  • Always mist down asbestos surfaces during removal. It minimizes fibre release.
  • Double-wrap and label asbestos waste. Only transport to an approved disposal facility.

Safety Precautions When Dealing with Asbestos Roofing

If there is asbestos in the roof or you suspect there is, you should know what to avoid and also what to do to keep everyone safe.

What to Avoid

  • Do not drill, cut, sand, or use high-pressure water/steam on asbestos roofing. These actions release fibres into the air.
  • Never walk on panels that look brittle or aged, as they may crack and release dust, or collapse.
  • Don’t attempt asbestos roof replacement or DIY removal of large areas. It is legally and practically dangerous.

What You Should Do

  • Hire a licensed asbestos removalist/assessor for testing, risk assessment, and removal
  • Wear proper PPE (respirator, coveralls, gloves) if you must be near the area
  • Follow SafeWork NSW and local council rules for asbestos roof replacement or removal, disposal, and notification
  • Contain the area. Seal it off, use drop sheets, and prevent dust migration
  • Get a clearance / third‑party certificate after removal, so the area is certified safe before reoccupation

SafeWork NSW also warns against using high‑pressure water or compressed air on asbestos roof tiles.  It can spread fibres everywhere and cause major contamination. 

Once the removal of asbestos in roof starts, the air has to be monitored. Fibre levels must stay below the set limit (e.g., 0.02 fibres/mL). If they rise above that, work must stop immediately and SafeWork must be notified.

And finally, disposal is not optional. Asbestos waste has to go to an approved facility that’s licensed to handle it. Dumping it illegally is a serious offence.

Conclusion

An asbestos roof might seem like just another old part of your home, but it’s a serious matter, especially as it ages or becomes disturbed. If you suspect asbestos in your roof, take it seriously. Don’t disturb the asbestos in roof. Get it professionally inspected. And if it’s confirmed, follow safe protocols or replace it altogether.

With the right care, you can eliminate the health risk and ensure your home and health remain protected.

FAQs

Asbestos in a roof refers to roofing materials such as cement sheeting or tiles that contain asbestos fibres. Asbestos roofs were commonly used in older buildings before asbestos bans.

If the asbestos roof is still solid and you don’t mess with it, the risk is pretty low. The trouble starts when it cracks, wears down, or you cut, drill, or pressure‑wash it. That’s when fibres can get into the air, and breathing them in is what causes health problems.

If the asbestos roofing is in bad shape, or you’re planning renovations or selling, removal is usually the safest move. If it’s still intact and hasn’t been touched, you might leave it for now.  Just keep an eye on it. Also, don’t disturb it.

You can’t reliably tell if there is asbestos in the roof by sight. A licensed assessor must take a sample and send it to a lab for analysis.

An asbestos sheet is basically a cement sheet with asbestos fibres mixed in. Builders used them everywhere, from roofs, walls, and cladding, because they were strong, weather‑resistant, and cheap.

The cost to remove an asbestos roof vary widely depending on size, access, location, and disposal costs. Cost depends on the situation. It can range from a few tens to hundreds of dollars per square metre. You can request a free quote with PureSafe.

Many asbestos roofing installations were expected to last 30 to 50 years or more. In reality, it depends on the climate, how well it’s been looked after, and how much damage it’s taken over time.