Abstract: A roof panel that is lightweight and structurally strong, and that can be assembled with other panels to form large area surfaces, comprises a rectangular panel made with an extruded U-shaped channel frame member, that is mitered at the corners. The frame is enclosed by two sheet members that are attached by adhesive bond supplemented by screws or other type fasteners to the outer surface arms of the frame. The base portion of the U-shaped channel member has a flange extension on one side whereby the two edges of two adjacent panels can be bolted together. A resilient sealing gasket is placed between the two flange extensions, of the U member so that as the bolts tighten the two members together, the joint between is sealed by the gasket. After the two panels are joined in this manner, a specially shaped inverted U shaped ridge cover channel is placed over the sealed joint, and is latched into notches, which hold the cover in place.