A floor assembly includes a plurality of transverse stringers spaced from one another in the longitudinal direction of the floor assembly. The assembly also includes a plurality of transverse bottom flanges, each transverse bottom flange being coupled to a lower portion of a respective transverse stringer and to a neighboring transverse bottom flange along respective transversely extending side edges thereof. A top flange comprising a supporting sheet is coupled to an upper portion of each transverse stringer. A plurality of longitudinal panels are supported by the supporting sheet and coupled to one another along respective longitudinally extending edges thereof to form a floor surface, each longitudinal panel in the plurality of longitudinal panels having at least one longitudinally extending rib depending substantially perpendicularly from a bottom surface thereof. The at least one rib is coupled to a top surface of the supporting sheet.