摘要 |
<p>The invention relates to a method in connection with a roof drainage apparatus and a roof drainage apparatus. The invention comprises a trough (2) recessed in a roof structure (1), an opening (3) arranged in the bottom of the trough, a water-outlet tube (4) joined to the opening and a means (5) for changing an open water flow into a closed flow when the water flow is increasing. For intensifying the drainage, an element (6) is positioned in the water-outlet tube (4) at a throat after the opening (3), by means of which element the cross-sectional area of the water-outlet tube (4) is regulated in such a manner that the shape of the cross-section of the water-outlet tube (4) remains substantially unchanged at the regulation.</p> |