| 摘要 |
Two diametrically opposite corners of roofing tiles are cut off to provide cut-outs which are stepped in several steps so as to have at least two edge portions parallel to the side edges of the tile, said edge portions lying closely adjacent matching edge portions of diagonally adjacent tiles of the roofing with a small clearance, whereby the passage or joint formed by the opposed matching edge portions will comprise two parallel non-aligned stretches with a connecting transverse, preferably wider stretch serving as an expansion chamber. |
