Abstract: A method of producing a cambered composite joist and concrete panel assembly, and the assembly so produced, comprising the steps of providing a negatively cambered casting mold, positioning at least one negatively cambered composite joist with a bottom chord joined to a web member having non-attached top apices into the mold such that the top apices rest within the mold, pouring concrete into the mold and allowing it to harden to form a cambered concrete panel with the joists extending from the panel, removing the assembly from the mold and inverting it such that the precast camber in the panel flattens out from the effects of the weight of the panel and creep during final curing.

Abstract: A steel joist is disclosed consisting of a web, a bottom chord and a double top chord construction consisting of two elongated substantially identical portions each being of S cross-section and being connected to or integral with the web.

Abstract: A flange hanger adapted for use in conjunction with a steel frame building for connecting spanner bars used in the "HAMBRO" floor system is formed with an elongated shape having a first flange for welding to a steel frame member of the building and a second flange adapted to depend vertically from the welded flange. The second flange is provided with a plurality of horizontally elongated slots to receive the ends of spanner bars and provide horizontal and vertical support therefor.

Abstract: A steel joist having an upper chord, a web, and a lower chord; the upper chord consisting of an S shaped cross section elongated member having in one form a lower reverse flange at the base of the S, the flange being connected to the web so that the center of gravity of the joist is in the region of its central axis, the region between the base of the S and the reverse flange including an inclined step.

Abstract: A steel joist formwork and a composite steel and concrete floor structure provided with a top chord, a bottom chord and a web joining the top and bottom chords with the top chord being serpentine shaped like and S or Z and including top and bottom, generally horizontal portions and an intermediate portion integrally connecting opposite edges of the top and bottom portions with the top and intermediate portions substantially being adapted to be embedded in the concrete floor to cause the floor and steel joists to act structurally as a composite beam. Either the web or a leg depends vertically from the free end of the bottom portion of the top chord, and the web joining the top and bottom chords is substantially slid or is, an open web formed of a zig-zag bar member. There is also disclosed a building system and erecting method utilizing steel joists spaced apart by spanner bars which also support rigid panels which act as formwork for the pouring of concrete.