| 摘要 |
<p>The corrugated panels, for use on roofs or walls, are made of asbestos cement or plastic. They are designed so as to prevent the formation of fissures on the apexes of the corrugations, normally caused along the ridge by excessive stressing, caused by screws, or by treading, in the cases of roofs. There is a variation in the height of one corrugation apex, or in the ehight or thickness of a number of these. The apexes may be shaped or reinforced only in the fixture areas. The height may be varied, by shaping, at periodic intervals.</p> |
