Patent ID: 9091084
Filing Date: 2015-07-28
Classification: E04D,E04F,F16B,Y10T

Abstract:
1. A method for fastening a corrugated flexible bitumen sheet on an underlying support structure as part of a roof construction or wall construction, wherein the method comprises: providing a screw with a head, a stem, and a threading as part of the stem; providing the threading with a rib having a pitch, a minor diameter between windings of the rib, and a major diameter around the rib, wherein the ratio between the pitch and the major diameter is between 0.31 and 0.39; wherein the threading has a pitch between 1.2 mm and 1.5 mm; providing the screw with a drill point at the tip of the screw and wherein a ratio between a length of the drill point relative to the diameter of the drill point is between 1.40 and 1.48; and driving the screw through the sheet and into the support structure without first forming a hole for the screw in the sheet.