Patent ID: 8516762

Claim:
An apparatus for supporting a concrete floor comprising: at least two joist assemblies, each joist assembly includes a male frame member and a female frame member, said male frame member includes a male bottom support member and a top support member, a plurality of male guide openings are formed through said male frame member, at least one guide projection extends from a perimeter of each one of said plurality of male guide openings, said female frame member includes a female bottom support member and a top flange, a plurality of female guide openings are formed through said female frame member, each one of said plurality of female guide openings are sized to receive said at least one guide projection; means for securing a top of said male frame member to a top of said female frame member, said means for securing capturing said top support member and said female frame member; means for securing a bottom of said male frame member to a bottom of said female frame member; and means for retaining a distance between two adjacent joist assemblies of said plurality of joist assemblies, where an accessible opening remains at a location of the plurality of male guide openings and the plurality of female guide openings after the male frame member and the female frame member have been secured to one another wherein the accessible opening is configured such that at least ductwork can fit therethrough.