Patent ID: 8316621
Filing Date: 2012-11-27
Classification: E04C,E04D

Abstract:
1. A roof structure comprising: (a) a plurality of cold-formed columns, each column comprising a pair of vertical posts attached to each other in juxtaposition, each post of a substantially tapered I-beam cross section comprising an elongate vertical column web interconnecting a pair of column flanges wherein the outer vertical surfaces of the column flanges are horizontal, the cross-section of each column symmetrical about central horizontal and vertical axes; (b) a plurality of cold-formed girders supported by the plurality of columns, each girder of a substantially tapered I-beam cross section comprising an elongate girder web interconnecting a pair of upper and lower girder flanges wherein the top and bottom surfaces of the girder flanges are horizontal, the cross-section of each girder symmetrical about central horizontal and vertical axes; (c) a plurality of cold-formed beams supported by the plurality of girders, each beam comprising a tapered I-beam comprising an elongate beam web interconnecting a pair of upper and lower beam flanges wherein the top and bottom surfaces of the beam flanges are horizontal the cross-section of each beam symmetrical about central horizontal and vertical axes; (d) a plurality of open web joists supported by the plurality of beams, each joist comprising a cold-formed upper chord, a cold-formed lower chord, and a triangulated open web interconnecting the upper and lower chords wherein, the open web comprises a plurality of angled open web members, each open web member interconnecting the upper and lower chords by means of forging, the cross-section of each joist symmetrical about a central vertical axis; and (e) a plurality of roof boards supported by the plurality of joists.