A roof panel juncture securely couples in a water sealed, abutting manner facing edges of adjacent, generally planar roof panels along the pitch of the roof. Each panel includes an upper sheet metal facing, a lower vinyl covered wood facing, and a core of rigid foam insulation sandwiched therebetween. The lateral edges of the panel's upper sheet metal facing are each provided with a 90.degree. upturned portion, the upper end portion of which is further bent downward at an acute angle toward the plane of the sheet metal facing to form a hook and drip-edge. The adjacent upturned facing edge portions of abutting panels are adapted to receive in sliding engagement along the lengths thereof a generally concave, elongated, linear roof batten which maintains adjacent roof panel edges in tight-fitting engagement so as to form a water-tight seal therebetween. The adjacent lateral edges of the lower facings of each of the roof panels are adapted to receive a ceiling batten therebetween along the length of the panels. The ceiling batten includes a lower slot along the length thereof which, in combination with a snap-in strip plate, forms an enclosed raceway for wire runs. A blocking spline is inserted in facing edges of adjacent panels and is maintained in position by the ceiling batten and provides a heat conduction break in the roof and reinforces the roof panel juncture.