The Gypsum Solution
Recently, we encountered a small amount of asbestos tiles during a basement remodeling project. Normally this would require a costly remediation, but we are now using a gypsum/cement based prodct that actually encapsulates the asbestos tiles. Once the tiles are encapsulated, it is completely safe to lay new tile, wood or carpet on top of the existing tiles. The gypsum also levels the old cement slab. While this underlayment product has been widely used in commercial properties, it has recently become more popular in residential renovations. While safe and effective, gypsum should still be applied by a professional – particularly when dealing with any form of asbestos.
Cement underlayments, especially ones with gypsum, must be kept fairly dry and are best suited for above grade applications. When installed below grade, a well-controlled environment that is cooled in the summer and heated in the winter is recommended. Even if the floor gets wet, for example from minor flooding, it can be dried using conventional floor drying. After the product has been dried it will be ready to accept any new flooring.
Asbestos is most commonly found in 9”x9” floor tiles in homes constructed as recently as the 1980’s. Some of these floor tiles can be 70% asbestos filler. Before the product is applied you need to ensure there are no loose tiles and the area has been properly prepared using damp mops to pick up any loose dirt. You never want to handle removing loose tiles on your own. Make sure to contact your local DEP office for a list of qualified contractors to remove the loose material in a safe way. Also never sand, grind, or use glue tiles to hold them down. This can be more dangerous. Once your basement is properly prepped, gypsum can be applied and your basement remodel can begin.