an edge beam construction including two vertical perforated rolled shapes with webs inverted toward the center of the beam , and a bottom track having a flange disposed in a vertical position against bottom lips of the vertical rolled shapes . the three basic components of the edge beam are positioned so as to provide access for press joining tools . a building module manufacturing method utilizes the light gauge steel rolled shapes that permit industrialized , automated manufacture of floor , roof and wall panels for modular housing and commercial structures with integrated mechanical and electrical systems and rigid framing for road transport without trailers . the module manufacturing method includes a novel method of constructing and positioning a gable .