I used a self-leveling concrete type mix... Level Quik ?(something like that) ... about $30 per bag but it worked well over a concrete sub floor for me. I was tiling over the top so it didn't need to be absolutely perfect since the thinset could take care of minor issues. I know it can be used over wood sub-floors but didn't read the prep part for that since it didn't apply. Dries quick enough to tile the next day also..... good luck
Pete


Reply With Quote