As a commercial roofer, you may be wondering about the potential for asbestos contamination in your projects.

This blog will take you through what you need to know about asbestos over-cladding and how to protect yourself and your workers. We’ll also provide some tips for safely removing any potential asbestos contamination.

Keep reading to learn more!

What Is Asbestos Over-cladding and Why Is It Used on Commercial Roofs?

Asbestos is a naturally occurring substance made up of a set of fibrous silicate minerals that have been used in roofing for decades because of their fire resistance and ability to tolerate intense heat and cold.

Asbestos over-cladding is a solution that is used to cover an existing roof that is in bad shape and cannot be repaired or replaced without a significant financial investment. Over-cladding is installing a new membrane over the top of an existing roof and fastening it to the current roof’s edges with metal straps or clips.

PVC, rubber, or TPO are commonly used for the over-cladding membrane.

In some circumstances, it could be a rubberised asphalt substance that looks like slate or asphalt. Over-cladding membranes are light and flexible, and they may be put over existing roofs in less than a day with no disturbance to the building’s operations.

Over-cladding membranes are typically not marketed asbestos-containing, but in older over-cladding products, the roofing materials may consist of a felt composite containing asbestos. These materials are no longer manufactured today, but some can still be found in older buildings.

When an entire roof is replaced, care is taken to remove all existing roofing products and dispose of them properly. Unfortunately, this is not the case with over-cladding. The old roofing materials are almost always left in place and recycled or salvaged for other uses in the construction process.

When the over-cladding membrane is installed over old felt roofing materials, the composite of the fibres in the over-cladding membrane creates new asbestos materials that can be released into the air when the old felt roofing materials break down over time due to weathering and age, and this can happen over relatively short periods of time.

How Can You Tell If Your Roof Contains Asbestos Over-cladding?

Inferior properties have led to asbestos being removed from countless products due to its health hazards. The mineral was frequently used in construction projects until its health consequences were realised.

The effects of asbestos on humans can be severe and deadly. When inhaled, asbestos is harmful to humans and associated with many fatal diseases, including lung cancer and mesothelioma. As a result, it’s no longer used in product construction or production. Buildings must be asbestos-tested before being refurbished or demolished.

Fortunately, there are simple methods that can be used to see if a roof contains asbestos over-cladding.

  • Start by inspecting the roof from top to bottom. Look for signs of damage and wear, such as chunks of the old roofing materials breaking up and ending up on the ground below the roof.
  • Next, check the insulation below the roof for any signs of damage, like crumbling and dropping fibres or crumbling insulation board.
  • Finally, check all flashings for signs of damage; examine metal fastenings throughout the building for any signs of corrosion, and look for signs of crumbling and peeling where they attach to the building.

Some signs of asbestos over-cladding may also be visible from inside the building.

For example, if a roof is being replaced as part of a renovation project, the renovation crew will have to remove and dispose of the old roofing materials. Any old roofing materials that can’t be recycled or salvaged should be removed carefully from the property and then disposed of at a waste facility that handles asbestos waste.

What Are the Risks Associated With Asbestos Over-cladding?

The risks vary depending on the amount and type of asbestos over-cladding present and if a person comes into contact with it.

After inhaling asbestos fibres from the material, the effects of asbestos over-cladding are gradual and can take years to manifest. People who work on buildings with over-cladding are more likely to acquire health problems.

Here is a list of potential risks:

  • Respiratory problems
  • Damage to lung tissue
  • Cancer Mesothelioma is a rare form of cancer that affects the lining of organs in the body, such as the lungs and abdomen.
  • Asbestosis is a condition where scar tissue builds up in the lungs due to inhaling asbestos fibres.
  • Idiopathic pulmonary fibrosis is a debilitating disorder in which the lungs become stiff and scarred, preventing them from functioning normally. This disease is fatal in 25% of all cases within three years of diagnosis.
  • Asbestos removal is a dangerous job that poses a substantial risk of exposure to airborne fibres.

These are just a few of the dangers of removing and disposing of asbestos over-cladding.

If you carry out this work, you must follow the regulations to ensure that the asbestos over-cladding is removed safely from your worksite. There’s no risk to others who may come into contact with the asbestos fibres released during the work. Other risks include disposing of the asbestos material in double-layered sheeting. Asbestos-containing materials must be disposed of in a two-layered sheet before they are removed from buildings to comply with regulations and ensure they do not present a health or environmental danger when they are removed from buildings.

How Do You Remove or Replace Asbestos Over-cladding?

Diagnosing the integrity of a roof’s substrate is the initial step for any person installing a new roof. The roof should be examined for damage (including leaks and cracks).

However, some older roofing systems include asbestos products. The safest way to ensure no asbestos contamination is to scrape the roofing substrate and replace it with new roofing materials. You can remove or replace over-cladding yourself, but safety precautions must be taken. Precautions must be taken to make the over-cladding safe to dispose of and ensure no asbestos contamination in the over-cladding or in the roof substrate that the over-cladding was covering up.

A specialist roofing company will have the equipment to safely remove all the over-cladding from your roof and replace it with a new roof. Removing and disposing of over-cladding can be dangerous and should only be done by trained professionals.

What Should You Do If You Suspect That Your Roof Contains Asbestos Over-cladding?

In finding asbestos cladding on your roof, it is crucial to begin immediately planning for its removal and replacement to prevent further exposure to hazardous fibres.

You may be able to resort to a variety of roof covering options that don’t contain asbestos, such as metal or concrete tiles or slates. If your contractor is convinced that your roof does contain asbestos cladding, the contractor should advise you on repair or replacement and disposal options.

Aware that risks occur during asbestos removal or abatement work, OSHA requires contractors to be licensed and certified to perform such projects.

Hazardous asbestos abatement or removal is not something amateurs can attempt; certified professionals should only do it. Contractors are specially trained to safely remove and dispose of asbestos material and follow strict regulations to keep workers safe.


Suppose you are a business owner with asbestos over a cladded roof. In that case, it is crucial to understand the risks associated with this material and take steps to remove or replace it as soon as possible.

Contact us today for more information about our asbestos removal services. We can help you determine if your roof contains asbestos over-cladding, and if so, we will work with you to develop a plan of action that keeps your employees and customers safe.