Abstract: An integrated roof system for buildings of the type wherein the roof structure is supported on spaced apart rafters, the system comprising a series of V-trusses extending between the rafters at spaced apart intervals, the V-trusses comprising independent load supporting units which are self-bracing and do not require interconnecting bracing members. The V-trusses are formed from half-truss sections having top and bottom chords interconnected by webbing, the half-truss sections being diagonally disposed with respect to each other with their bottom chords juxtaposed and their top chords interconnected by tie members. The system includes seat members at the ends of the top chords by means of which the V-trusses are secured to the rafters, and a roof structure adapted to be secured to the top chords of the V-trusses.