Patent ID: 7243464

Claim:
A modular building system for constructing a substantially plastic building, comprising plastic walls erected in substantially parallel planes, a roof system spanning the walls, the roof system including a ridge beam structure, plural extruded plastic rafters, each rafter being connected to the ridge beam and extending normal to the ridge beam in a sloping orientation toward one of the walls, each rafter having opposing lateral sides, and a top side facing the outside of the building, a first rafter of the plural extruded plastic rafters having two external corner portions, each external corner portion having a hook-shaped projection, first and second extruded polymeric roof panels configured for connection to the opposing lateral sides of the first rafter to form an inclined roof structure, each roof panel having a hook-shaped projection on an edge adjacent the first rafter, a cap member configured for mounting over the top side of the first rafter, the cap member having cap channels for mating each of the hook-shaped projections on the first and second roof panels to corresponding hook-shaped projections on the external corner portions of the first rafter, the roof panels being securely held in place relative to the first rafter when the cap member is securely engaged over the top side of the first rafter.