Roof panels with stiffened endlaps

An improved four corner sealing assembly in which an upper pair of interlocking standing seam joint panels and a lower pair of interlocking standing seam joint panels meet in a lapped four corner juncture area, an upper end of the two lower panels being overlapped by a lower end of the two upper panels at the juncture area, one panel of each of the upper panel pair and the lower panel pair having an upstanding male side lap portion forming an upper male surface, the other panel of each of the upper panels and the lower panels having an upstanding female side lap portion overlapping the respective male side lap portions, each of the female side lap portions having a longitudinally disposed sealant cavity and a side lap sealant strip predeterminedly disposed in conjunction with the sealant cavity, the sealant strip veering near the juncture area, at least one of the male side lap portions notched at the juncture area to overlap the ends and so that the upper male surface of said male side lap portions are received within the female side lap portions, at least one of the female sidelap portions being notched to be aligningly interlapped and sealed with the other of the female side lap portions, an end lap sealant positioned between the overlapping lower ends of the upper panels and the upper ends of the lower panels, the end lap sealant disposed to extend upwardly between the upstanding leg portions of the notched male side lap portions and also between female upstanding leg portions so as to sealingly engage the side lap sealant strip in the female side lap portions.