R-2 apartment building with separation of units by fire partition terminating at a fire-resistance rated roof/ceiling assembly, UL P533. Apartment building is 30 feet wide with 46 feet trusses creating an 8 feet porch (open) on each side of the building. The building interior is constructed to the assembly requirements with rc channel and rated dry wall. Should the porches have the same ceiling construction? Is the rated roof/ceiling assembly required to cover the entire bottom chord of the truss?