| 摘要 |
<p>Roofing purlins which can be connected end to end across beams (2) are essentially made up of two semi-purlins (3,4) attached together on top of one another or side by side by nails, glue screws etc. The ends of each semi-purlin have identical chamfers (5,6) one of which is inverted with respect to the other. The chamfers at the ends of each semi-purlin may also be parallel and are pref. provided with fasteners to secure the purlins together.</p> |
