Roof deck construction

A flat horizontally disposed roof deck comprising:

• spaced horizontally disposed purlins;
• a corrugated sheet of high tensile strength steel having a symmetrical rib pattern providing an equal distribution of steel above and below a neutral axis lying in a horizontally disposed plane passing through the center of the sheet, said corrugated sheet being supported from below by said spaced purlins;
• a sheet of smooth, incombustible, water-resistant, fiberglass reinforced, mineral board above said corrugated shet;
• a sheet of insulation material between said sheet of mineral board and said corrugated sheet of high tensile strength steel, said sheet of insulation material having grooves formed therein such that spaced troughs between the upper surface of the corrugated sheet and the lower surface of the sheet of insulation material are in fluid communication with each other;
• a vent means communicating with at least one of said troughts to maintain air pressure in said troughs substantially equal to ambient air pressure;
• threaded mechanical fasteners extending through the sheet of mineral board and through the sheet of corrugated steel, said fasteners being arranged to mechanically restrain ridges on the upper portion of the corrugated sheet above the horizontally disposed neutral axis in a fixed relationship relative to the sheet of mineral board to prevent horizontal movement of the ridges which would tend to flatten the corrugated sheet when a downwardly directed load is applied to the sheet of mineral board, said threaded mechanical fasteners being spaced along the length of the ridges to prevent buckling of upper portions of the ridges;
• and a waterproof covering bond to said sheet of mineral board.

A flat horizontally disposed roof deck comprising:

• spaced horizontally disposed purlins;
• a corrugated sheet of high tensile strength steel having upper and lower ribs arranged to form a symmetrical rib pattern providing an equal distribution of steel above and below a neutral axis lying in a horizontally disposed plane passing through the center of the sheet, said corrugated sheet being supported from below by said spaced purlins;
• means securing said lower ribs below the neutral axis to said purlins to form a span between the purlins;
• a sheet of smooth, incombustible, water-resistant, fiber-glass reinforced, mineral board above said corrugated sheet;
• a plurality of layers of felt adhered to the surface of the mineral board and bonded together by adhesive material;
• ventilator means extending above the layers of felt and communicating with passages between said sheet of mineral board and said corrugated sheet, said ventilator means being adapted to control temperature and pressure of air in the passages;
• and threaded mechanical fasteners extending through the sheet of mineral board and through the sheet of corrugated steel, said fasteners being arranged and spaced over the surface of the sheet of mineral board intermediate to edges of the mineral board to mechanically restrain each ridge on the upper portion of the corrugated sheet above the horizontally disposed neutral axis in a fixed relationship relative to the sheet of mineral board to prevent independent horizontal and vertical movement of each ridge which would tend to flatten or distort the corrugated sheet when a downwardly directed load is applied to the sheet of mineral board, said threaded mechanical fasteners being spaced along the length of the ridges to prevent buckling of upper portions of the ridges, said threaded mechanical fasteners being positioned such that the resistance to uniform and concentrated load deflection of the composite span is greater than the sum of the resistance to deflection of separate similar spans of the corrugated sheet alone and of the mineral board along which are not mechanically joined intermediate opposite ends of the respective spans.

A method of increasing the resistance to horizontal and vertical planar deflection of a modular structural composite roof deck comprising the steps of;

• positioning a sheet of corrugated material having a symmetrical rib pattern above and below a neutral axis across horizontally disposed purlins to form a horizontal span of corrugated material such that opposite ends of the span are supported by the purlins;
• securing lower portions of downwardly extending ribs on the horizontal corrugated sheet to the purlins;
• positioning a flat horizontally disposed sheet of high density material above the horizontally disposed sheet of corrugated material;
• and securing mechanical fasteners through the flat sheet and through upwardly extending ribs on the corrugated sheet oriented in a pattern to form a first truss comprising a horizontal section of said flat sheet spanning space between ribs in said corrugated sheet between adjacent mechanical fasteners and downwardly extending connector portions of said corrugated sheet between said ribs in a generally vertical plane extending transversely of the ribs in the corrugated sheet, and a second triangular shaped truss in the horizontal plane of the sheet, said second truss comprising a triangular segment of said flat sheet restrained by adjacent mechanical fasteners to ribs of a corrugated sheet in the span between purlins, said first and second trusses being intermediate opposite ends of the span and extending longitudinally and transversely of the span to prevent lateral and vertical distortion of the corrugated sheet as a results of force applied in the plane of the flat sheet.

A modular structural composite roof deck functioning as a structural diaphragm to provide rigidity to a building:

• spaced purlins;
• symmetrically corrugated sheet material supported from below and spanning the distance between said purlins;
• first fastener means securing downwardly extending ribs on the sheet of corrugated material to said purlins to form a horizontal span, said span having ends secured to said first fastener means to said purlins;
• a flat rigid sheet;
• and second fastener means mechanically joining the flat rigid sheet to upper ribs on the corrugated sheet between opposite ends of said span, said second fastener means oriented in a pattern at horizontally spaced locations transversely of the span and spaced locations longitudinally of the span to form a series of essentially triangular shaped trusses in the horizontal and vertical planes throughout and across the span between the purlins to stabilize and prevent lateral and vertical deformation of the individual ribs of the corrugated sheet to increase the resistance to horizontal and vertical planar deflection of the roof deck.