Asbestos Mastic, Sealant, Beading, Filler & Putty – Everything You Need to Know

During the asbestos craze that spanned from the early 1900s to the 1990s, this fibrous mineral was combined with a dizzying array of construction products and widely used in both commercial and residential developments.

One area it was used was to create adhesive or sealing products like mastic, filler, putty, and beading. Below, I explore these products together with how and why they were used, if they are still common in the UK today, and their potential dangers.

Understanding Asbestos Mastic and Other Adhesive Products

Asbestos (mainly chrysotile or white asbestos) was added to adhesive and sealant products to give them additional benefits such as fire proofing and enhanced durability. Examples of these products included: 

  • Asbestos mastic.
  • Asbestos sealant.
  • Asbestos beading.
  • Asbestos window putty.

Mastic was the most common product but asbestos window putty was widely used too. The mineral was easy to work with and thus it was a cheap and popular additive and saw widespread use in the UK between the early 1920s and 1990s.

Why Was Asbestos Used to Create Mastic and Putties?

Construction adhesive and window putty typically had poor fireproofing and durability and this is why asbestos was added. Asbestos has excellent durability and strength, but also fire-resistant properties.

Therefore, when combined to make mastic, sealant, beading, and putty, the resulting product was infinitely superior. 

What Does Asbestos Mastic and Other Adhesives Look Like?

Asbestos products are notoriously difficult to identify and this is no different with asbestos mastic and other sealing products. Mastic is usually the easiest to identify as it was usually black and over time would develop white and grey spots.

The adhesives and sealant are usually thick compared to modern synthetic products but things like asbestos window putty and sealants are especially difficult to identify as they look like normal products. 

The only way to be sure is to have the material tested. One way is to use an asbestos home testing kit. These kits allow you to take samples safely to be sent off to a certified lab for analysis. You can get the results back quickly and get all the PPE required to work without the risk of contamination. 

Is Asbestos Mastic Still Common in the UK?

If your property or premises was built after 1999 there is virtually no chance it contains any asbestos mastic or other asbestos products. Asbestos was fully banned in the UK in 1999 but before this from the early 1920s it was extensively used.

The older your property is before 1999, the higher the chance that it could contain asbestos mastic or windows with asbestos putty. Aside from considering the age of your property, think about the individual items inside that could contain asbestos mastic or putty such as floor tiles, ceiling tiles, felt roofs, and windows.

If any of these items are original from the time the property was built, they could contain asbestos whereas if they have been replaced after 1999, the chance is slim to none. 

How Dangerous is Asbestos Mastic and Other Adhesives?

Asbestos mastics and putties are considered to be lower-risk items but that doesn’t mean that they don’t pose a potential health risk. When undisturbed and undamaged, asbestos mastic shouldn’t cause any issues. It’s only when the asbestos fibres escape into the air where they can be inhaled that the health risk occurs. 

Therefore, you have to assess the quality of the adhesive and the items it is fixed too. For example, if you have a felt roof that is damaged and coming lose where you can clearly see the adhesive, this could be an issue. 

It’s advised to not attempt to remove any product containing asbestos adhesive yourself either. Generally, removal of asbestos mastic is classed as non-licensable asbestos removal[1], but it’s a tough substance and usually requires professional tools and equipment to remove safely.


[1] – HSE – Non-Licensed Work with Asbestos

The content on this page/article was last updated on the 6th December 2023 by our team and was reviewed and fact checked by William Wright, DipNEBOSH on the 6th December 2023.

William is a qualified health & safety consultant who holds NEBOSH & IOSH certifications.