Asbestos Roofing Sheets

If you have a home in the USA that was built before 1990 then there is a chance that it could contain asbestos. Asbestos was used heavily in the USA from the late 1800s through to the 1980s and it is not completely banned today unlike most other countries.

While asbestos has many effective properties like its heat resistance, it can also cause serious health problems including mesothelioma and asbestosis. When the fibres of the asbestos minerals are disturbed, you can breathe them in which can cause slow but permanent lung damage.

One of the main ways in which asbestos was used was in roofing sheets. These were widely available and were used for housing and garage roofs from the 1940s onwards. If you have checked your roofing and feel that it looks a little suspect, we have provided useful information about asbestos roofing sheets and how to test for them below.

What are Asbestos Roofing Sheets?

Asbestos roofing sheets are made from asbestos cement. You can find more information about asbestos cement in this guide as it was also used in other products. The sheets were either flat but more commonly corrugated with peaks and troughs as this helped with rainwater dispersal and gave them better weather resistance.

CACS as they are known (Corrugated Asbestos Cement Sheets) are among the most common types of asbestos products and they were widely used for building roofs but also for garages. The sheets would be typically laid together and overlapped on slanted roofs.

The asbestos cement used to create these roofing sheets was a mixture of traditional cement and asbestos, but the exact percentage of asbestos would vary depending on the manufacturer. It was widely used because it was more durable than other products like drywall, but also easier to use than 100% concrete solutions.

In terms of overall production and usage, it is estimated that asbestos roofing sheets account for approximately 90% of the world’s asbestos products.

How to Identify Asbestos Roofing Sheets?

A common theme with asbestos products is that they can be incredibly difficult to identify. This is because asbestos was just a component of the product and therefore it was often indistinguishable from non-asbestos products.

Also, for most products there wasn’t a universal design or even the same percentage of asbestos used to this created a heap of manufacturing variations.

However, asbestos roofing sheets are a little easier to identify. They are most commonly corrugated sheets although they can be flat sheets too. The corrugated sheets will look weathered and have white mottling on them which is the asbestos content.

This mottling depends on the percentage of asbestos used in the cement. You will most commonly find asbestos roofing sheets on garage or outhouse roofs but they were also used on properties and smaller structures.

When did They Stop Using Asbestos in Roofing Sheets?

Asbestos sheet production stopped in the USA in the 1980s. Furthermore, there are no active asbestos mines in the country, but the product is still imported, and it is not fully banned. American companies that were known to produce asbestos roofing sheets included Celotex, GAF Corporation, National Gypsum Company, and Johns Manville.

Although production of asbestos roofing sheets ceased in the 1980s, there was an overlapping period where manufacturers sold their excess stocks. This means that we have a clear cut off point of 1990 for safety precautions.

If your property was built before 1990 then there is no guarantee that it doesn’t contain some trace of asbestos. Furthermore, the older your property is before this cut off year then the higher the chance that it contains asbestos roofing sheets or other asbestos cement products.

How to Deal With Asbestos Roofing Sheets?

CACS are actually considered to be some of the least dangerous asbestos products, and they are generally classified as low risk. However, that doesn’t mean you shouldn’t take precautions or ignore the product if it is present on your property.

Testing for Asbestos Roofing Sheets

As mentioned above, asbestos roofing sheets are easier to identify but it can be difficult to be 100% certain as they can look like regular cement sheets. The fastest and safest way to be sure is to use an asbestos testing kit.

We sell these sampling kits, and they are readily available for US customers. In the kit you get complete instructions, PPE for your own safety, sample bags, and a prepaid envelope to send off your samples to our labs.

On receipt of the samples, our lab will typically get the results back to you within 72 hours via email. This includes a certificate showing the results and the asbestos content (if any) of the sample. The kits are easy to use, and they are much more convenient than paying for a testing service from a specialist asbestos company.

Removing Asbestos Roofing Sheets

Due to the low-risk nature of asbestos roofing sheets it’s not actually imperative that you have them removed. If they are fixed to your property securely and there is no external damage, there is a minimum health risk.The problem arises if chunks are broken, or the sheets are damaged. If there is any damage, the asbestos fibres could be released into the air and inhaled. If you notice damage, don’t try and remove the sheets yourself – it is much safer to seek professional assistance and get them replaced by a qualified asbestos removal company.

Cleaning and Maintenance of Asbestos Roofing Sheets

In some countries like Australia, it is actually illegal to clean asbestos roofing sheets with power sprays but in the USA there is no such restriction. If you do want to clean your roofing, then you must be incredibly careful not to damage the sheets.

Using a power wash could dislodge particles and release asbestos in the air. If you do clean it, wear full PPE at all times including gloves and a breathing mask and make sure that the area is properly cordoned off so your family can’t come into contact with the asbestos.

Similarly, you could potentially paint the asbestos roofing sheets but this isn’t common and they are typically left untreated.