Black Mastic – The Spectre in Your Flooring


Did you know? Most homes from the 20th century used black mastic for gluing linoleum and ceramic tile. Now, we know, that was a long time ago. So, we can assume that the thought of renovating or retiling your home has occurred to you many times. Before you go ahead with your desires, we must mention that black mastic used to contain asbestos! 

Mastic referred to any form of flooring adhesive similar to glue. Modern mastics are water-based, and they don’t contain asbestos. So, if your home is new (after the 1990s), it likely does not contain black mastic. Many manufacturers, builders and home renovators added asbestos to the glue-like substance to make it durable and fire retardant. Since asbestos is a fibrous material that can withstand the tides of time, it is common to find asbestos in the insulation, and hot water pipes of homes built before the 1980s in Australia.  

Why is asbestos detection tough?

The tricky part of dealing with black mastic is that you will only be able to see it after you remove the flooring. It is black, but Advanced Deconstruction experts report seeing traces of other colours in the mastic. Some of the older adhesives used were also black, but they did not contain asbestos. Therefore, you cannot use the colour as an identifying trait. There is more to black mastic than the shade. You must check the material for its flatness. Black mastic usually lacks gaps, bumps and ridges. It lies entirely flat with a hint of swirls from the application. However, you will not be able to notice any asbestos fibres within the mastic. It is best not to scrape it or sand it due to the high risk of exposing oneself to asbestos fibres.

What are the chances of your home containing asbestos in the mastic?

Black mastic was popular in the first half of the 20th century. Any houses built between 1900 and 1960 is highly likely to have asbestos in its flooring. Only a handful of companies produced similar asbestos-based adhesives till the mid-1980s. Therefore, a few homes in suburban Brisbane have traces of asbestos in their mastic. Your home could be one of them if you built or remodelled your house around the mid-1980s. The only way to be sure about the presence of asbestos is by conducting thorough testing. There are plenty of DIY asbestos testing kits now available online, but it is smart not to disturb the black mastic unless you have proper training and adequate safety gear for the task.

When is black mastic safe?

You may have heard many homeowners state that black mastic is safe, while most abatement companies declare it unsafe. It can be confusing for any resident since these abatement companies make a living by detecting and removing asbestos from buildings. However, both arguments are valid. Black mastic is safe when you do not disturb the flooring. If you are planning to remodel your home and change the flooring tiles, you might come in contact with friable asbestos that is highly toxic. Scraping or sanding it manually can release the minuscule fibres into the air that can enter one’s respiratory tract and sow the seeds of chronic diseases.