DEAR AUDREY: The plumber has no way of knowing whether the floor tiles contain asbestos unless he had a sample of the material tested by a laboratory. If the tiles measure 9 inches square, they most likely do contain asbestos, but that type of asbestos is not regarded as a significant health hazard because it is non-friable material. Friable asbestos is material that is easily crumbled and can readily release fibers into the air. Besides this, the floor tiles are entirely encapsulated by the top layer of flooring and are not in contact with the air in your home.
In all likelihood, the previous owners were unaware of tiles under the flooring or that the tiles might contain asbestos, which would account for their lack of disclosure.
If you do any remodeling that involves removal of old flooring, you should send a sample of the tiles to an asbestos lab. If the material is determined to contain asbestos fibers, you can hire an asbestos contractor to have it removed. Otherwise, you can leave the tiles where they are without worry.
To write to Barry Stone, visit him on the web at www.housedetective.com.
ACTION COAST PUBLISHING