| 摘要 |
<p>Units are used in as a staggered series up the roof, with edge profiling to interlock with other tiles, can be walked on without involving roof hooks and ladders. The component (1) is made of transparent or translucent plastics, in the area between its edge profilings (4, 5) it is in the shape of a staircase tread (8), bounded by side pieces (9, 10). The plastics may be reinforced with fibreglass. The step may comprise deformed sections protruding to front and rear of the facing surface, combining to form a tread surface.</p> |
