Ceramic Tile Over Black Mastic

Common in homes built in the 20th century black mastic was used as an adhesive for ceramic tile linoleum and other flooring materials.

Ceramic tile over black mastic.

But after the tiles came up we discovered that they had been secured with black mastic. Tiling over black cutback i tore up old 9x9 tiles and disposed of them properly and now i m shopping for tile to replace it. I ve read i can just put a modified thinset that will adhere to the cutback. If the adhesive is softened by water then it should be removed by shot blasting.

There are also black colored latex based vinyl adhesives that will not hold up under ceramic tile if they get wet. Generally chemical removal is not a good idea because the solvents used to remove the adhesive can drive bond breakers deeper into the concrete. So now we need to figure out the safest way to proceed with getting new tiles in in light of that potentially dangerous material. The tiles were not asbestos we had them tested.

When the building was converted to residential the developer removed the. Under the old tiles is pretty smooth black mastic. I want to tile a concrete floor removed the 9 tiles covering it with an air chisel and 2 days work to find black cutback mastic still somewhat sticky after 50 years. The adhesive did test positive for asbestos 4 5.

Possibly renting a floor grinder with a carbide tip but haven t tried it yet. Can t possibly remove it by scraping and sanding or grinding will only gum up the apparatus.