Asbestos Cement Boarding

Written by Tom Yates . Edited

Fact Checked by William Wright, NEBOSH

Asbestos cement board was one of the more common construction products used before the 1990 asbestos ban and if you have an older property, it’s important to understand what it looks like, where it was used, and the dangers it poses and this is what we discuss below. 

Understanding Asbestos Cement Board

Asbestos was commonly mixed with other materials because of its enhancing properties and one of the most popular combinations was asbestos and cement. The cement was usually made with chrysotile asbestos and standard cement and then moulded into products like asbestos cement boards. Typical uses for these boards included:

• Wall cladding/sidings.
• Flooring materials.
• Fireproofing around boilers and heating systems.
• Building soffits.
• Garage walls & ceilings.

Asbestos sheets/boards are often used interchangeably but sheets were more commonly corrugated whereas boards were often flat. 

Why Was Asbestos Used in Cement Board?

Asbestos was added to cement because it improved its durability and strength but also added much needed flame resistance. Transite, which was one of the most popular asbestos cement[1] products was also known to be easy to work with and handle and was resistant to corrosion. 

What Does Asbestos Cement Board Look Like?

Asbestos cement boards are usually flat (corrugated sheets are considered a different product type and information can be found here about asbestos cement roofing sheets) and today more commonly found on roofs and walls of old outbuildings such as garages and outhouses.

The boards have a white/greyish colouration and are course to the touch. Due to the age, external asbestos cement boards will usually have natural growths such as lichen and moss. The white colouration can be more pronounced depending on the concentration of asbestos in the cement mixture and it was common for these boards to contain up to 30% asbestos.

 Asbestos cement board can look like regular cement too so the only sure-fire way to determine the contents is to used an asbestos sampling kit.

Is Asbestos Cement Board Still Common in the UK?

Many outbuildings and garages built in the UK used asbestos cement board (they where usually used for the ceilings and walls) but it is not common today due to the ban on asbestos that came into force in 1990. The general rule of thumb is that if your property was built before 1990, there is a chance it could contain asbestos cement board.

Also consider the date of your outbuildings though. For example, perhaps you did have an old garage, but it has been demolished and re-built in recent years. In instances like this, any potential asbestos has probably already been removed.

How Dangerous is Asbestos Cement Board?

Asbestos cement is considered non-friable so does not easily crumble into powder from hand pressure. However, it can still be especially dangerous depending on the condition. Condition is key. If the asbestos cement boards are intact and undamaged, the health risk is low.

However, if the boards are showing signs of wear and tear including cracks and chunks breaking off, there is a health risk as the fibres inside could become airborne. As per the HSE guidelines, most work with asbestos cement board including maintenance and removal (providing the boards are in a good condition) is classed as non-licensed work and therefore doesn’t need a licensed contractor. However if it’s a large scale removal project it could become licensable.

References

[1] – HSE – Asbestos Cement

[2] – HSE – Non-Licensed Work With Asbestos