| 摘要 |
<p>This under-roofing material for roofs to be covered with tiles, slates and the like consists of a sheet of agglomerated fibres coated on one face with a layer of bitumen just sufficient for constituting when cooled a micro-perforated structure preventing the passage of liquid by capillarity while permitting the passage or air or vapor, this material having a strength sufficient to withstand the fall of objects or personnel during its use, and being essentially liquid-tight and pervious to air and vapors.</p> |
