How to Identify Asbestos in Floor Tiles

The Minnesota Department of Health lists more than 3,000 different building materials that have been shown to contain asbestos. Before the hazards of asbestos were identified, asbestos fibres were often added to materials like floor tiles as a filler.

Though only laboratory testing can absolutely confirm the presence of asbestos, floor tiles which contain asbestos share certain characteristics. Special precautions should be taken when removing asbestos from your home.

Take a closer look at any tiles that are black, dark brown, dark grey or grey brown. Both asphalt and vinyl tiles in these colours may have asbestos fibres mixed in. Asphalt tiles will have the highest concentration of asbestos. Because asphalt was the main ingredient in these tiles, they were only manufactured in dark colours.

Determine the age of the flooring. Asbestos was a very popular ingredient in floor tiles between 1920 and about 1960. Daniel Rosato, in his book, "Asbestos: Its Industrial Uses," reports that by 1940, as much as 5 per cent of all floor tiling contained asbestos, increasing to 12 per cent by 1946 due to wartime shortages of other materials. Asbestos was also used in manufacturing older vinyl flooring. This flooring usually came in nine-inch square tiles and is thicker than modern vinyl flooring.

According to professional building inspector Daniel Friedman, older asphalt floor tiles and older vinyl tiles, as well as some older 12-inch vinyl tiles and sheet linoleum, likely contain asbestos. The mastic used to adhere these older tiles also may contain asbestos. If your house was built between 1920 and 1960 and the flooring is original, it likely contains some asbestos.

Send a sample of any suspect tiles to a testing laboratory. An accredited laboratory will confirm the presence of asbestos in your sample. Check with the lab to find out its requirements, but usually the lab will want three separate samples that measure at least ¾ inches square. Cut the sample out of the tile with a utility knife. Wear a mask as you do so and seal the samples in a resealable plastic bag. Cover the area from which you removed the sample with a piece of duct tape.