SHINGLES
A roofing shingle (10) is conveniently formed from a square sheet metal blank. One corner of the blank is provided with a pair of open ended, back to back U-shaped slots (38) transverse to a diagonal passing through that corner. The two sides intersected by the slots are downwardly turned to form a small margin (12M, 14M), and the other two sides are upwardly turned to form a margin (16M, 18M) of similar width to the downwardly turned sides. The corner is also downwardly folded above the slots to form a margin of similar width to the other margins, and below the slots it is folded so as to be generally parallel to the central area of the shingle. A shingle support preferably of foamed sheet polystyrene is disposed on the under surface of the shingle. The shingles are layed course by course on a pitched roof in a diamond configuration, a shingle of an upper course engaging the respective downturned edges of two adjacent shingles of a lower course in the U shaped slots to lock the lower corner of the upper shingle mechanically in position. Nails or screws may be used to secure portions of the upper shingle remote from the mechanically locked corner. A downwardly turned side of the upper shingle and an upwardly turned side of a lower shingle will form a seal to resist the penetration of driven rain and capillary action. The shingled roof has an appearance of thickness, while heat transference between shingles is generally reduced in comparison to flat shingles.