I started to demo my bathroom and it is a house from 1950. There is metal lathe, some sort of board and a really hard material - almost concrete like - it is so hard I have to beak it with a hammer drill or sledge hammer - unreal. On top of the hard material there is tile. Do I have any reason to believe that there may be asbestos in this hard material? I know I am not showing any pictures but just looking for some insight in general. Thanks!