We are remodling out bathroom - house built 1960/61. We have removed our ceramic tile on the floor, but I am wondering what is under the tile and the likely hood it might contains asbestos? It is about 1.5" thick concrete/plaster like substance over a metal mesh. Not sure what is under the metal mesh. In some places it is badly crumbling,so I would also like to know how to patch or should we just remove and replace?