A skylight includes a frame curb assembly which is integrally molded to provide an upright external wall portion and a depending interior wall portion, the latter extending within the associated building structure and having a mounting flange which is adapted for fastening the entire assembly to the building structure from the inside of the building. The upright external wall has an integrally formed flashing flange extending outwardly to rest on an outside surface (roof) of the building. A bulbous bead is provided at the outermost extremity of each side of the flange to impart rigidity along each side. The bead is terminated in the vicinity of each corner of the flange to provide a fluid run-off.
