Subfloor is material that goes under flooring materials, and subfloor can be made out of medium-density fiberboard, concrete board and cement board. Use a subfloor material that will resist moisture withhelp from a professional carpenter, woodworker and handyman in this free video on home improvement and subfloor work. Expert: Stephen G. Anthony Bio: Stephen G. Anthony is a professional carpenter, woodworker and handyman based in New York City and south Florida. Filmmaker: Paul Muller