Most mid-to-high-rise projects that utilize our Infinity Structural System have a flat roof. A flat roof may be constructed of either an Epicore MSR concrete roof slab, an EPIC long-span roof deck (no concrete), or standard bar joists with B-deck. Lower-rise projects with a pitched roof generally use wood roof trusses since they are so much more economical than metal roof trusses. If the code does not allow wood roof trusses for your particular project’s classification, metal roof trusses may be required.