A panel for a shaftwall system includes a panel body with a core and at least one outer facing layer and an opposite backing surface. A score line is formed in the facing layer, defining two folded panel portions. The panel is folded along the score line to form a folded edge, and the folded panel portions are arranged so that the backing surfaces of the panel portions contact each other. A companion shaftwall building structure system is provided, including a plurality of the panels defining an enclosure, each panel being a ½-inch thick wallboard panel having a “V”-shaped score line defining a pair of panel portions, the score line forms a tapered edge of the folded panel. A plurality of brackets is provided, each bracket defining a panel track dimensioned for slidingly accommodating the folded panel and retaining the panel in place without the use of fasteners.
