Abstract: A plurality of identical metal roof panels are secured to the roof purlins by spaced metal clips. Each roof panel, which may be installed without regard to end-to-end orientation in its own plane, includes deformable tabs extending outwardly of its side edges. Adjacent roof panels are interlocked with each other by interengagement of the tabs in response to positioning of the panels in place. The clips which secure the roof panels to the purlins are also provided with deformable tabs arranged to interengage with the tabs of the roof panels thereby to hold the roof panels in place even prior to bending of the tabs. The tabs are bent downwardly and a sealing strip is fitted over the bent tabs to weatherproof the seam. The roof is constructed using these panels by proceeding from one end of the building to the other in a single pass.