Building roofing structure

Claim 1

A BUILDING STRUCTURE INCLUDING TWO SPACED GENERALLY PARALLEL ROOF SUPPORTS LYING GENERALLY IN THE SAME HORIZONTAL PLANE, A SELF-SUPPORTING GENERALLY HORIZONTAL ROOF SPANNING THE SPACE BETWEEN SAID SUPPORTS AND HAVING EDGE PORTIONS RESPECTIVELY OVERLYING AND SUPPORTED ONLY BY SAID ROOF SUPPORTS, SAID ROOF COMPRISING AN ASSEMBLY OF A MULTIPLICITY OF PREFORMED SHEET METAL SECTIONS BOTH LENGTHWISE AND WIDTHWISE OF THE ROOF, SAID SECTIONS BEING OF GENERALLY RECTANGULAR SHAPE IN OUTLINE AND EACH INCLUDING A TROUGH EXTENDING THERETHROUGH FROM ONE EDGE TO THE OPPOSITE EDGE, THE OTHER EDGE PORTIONS OF EACH SHEET SECTION BEING OFFSET UPWARDLY AND EXTENDING RESPECTIVELY LATERALLY OF THE TROUGH AND GENERALLY IN A PLANE PARALLEL TO THE BOTTOM OF THE TROUGH, THE SHEET SECTIONS OF THE ROOF BEING ARRANGED WITH THE EDGES ABUTTING AND WITH THE TROUGHS ALL EXTENDING IN A DIRECTION SPANNING THE ROOF SUPPORTS, A CONTINUOUS SOLDER JOINT JOINING ALL ADJACENT EDGES OF THE SHEET SECTIONS TO PROVIDE A WATERTIGHT ROOF, THE END PORTIONS OF THE ROOF CONTAINING SAID EDGES BETWEEN WHICH EXTEND THE TROUGHS CONSTITUTING THE EDGE PORTIONS OF THE ROOF OVERLYING AND SUPPORTED BY SAID SPACED ROOF SUPPORTS, A PLURALITY OF SPACED UPRIGHT BARS CARRIED BY BOTH OF SAID ROOF SUPPORTS, THE UPPER PORTION OF EACH BAR BEING SECURED TO THE OVERLYING EDGE PORTION OF THE ROOF SUPPORTED BY SAID SUPPORT, SAID BARS SUPPORTING SAID EDGE PORTIONS OF THE ROOF SPACED FROM THE SUPPORTS TO ALLOW FREE EXPANSION AND CONTRACTION OF THE ROOF IN ALL DIRECTIONS, SAID ROOF BEING SO FORMED AND ATTACHED TO SAID SUPPORTS AS TO HAVE A SLIGHT ARCH BETWEEN SAID SUPPORTS, WHEREBY A UNITARY WATER-TIGHT ROOF IS PROVIDED HAVING AN UNDULATING SURFACE WITH A LARGE INERTIA AND A MEAN THICKNESS EQUAL TO THE DEPTH OF THE TROUGHS PROVIDED IN THE SHEET SECTIONS.