Patent ID: 7849649

Claim:
A non-combustible shear wall system for construction comprising: metal screw fasteners with winged drillers wherein the winged drillers are located above the point and below the first thread of the screw and protrude laterally from a shaft of the screw; light gauge cold rolled metal frame; a vertical shear diaphragm fastened by the fasteners to the light gauge cold rolled metal frame, the vertical shear diaphragm comprising a reinforced, lightweight, dimensionally stable cementitious panel and the frame comprising metal studs; the panel having a density of 65 to 90 pounds per cubic foot and capable of resisting shear loads when fastened to framing and comprising a continuous phase resulting from the curing of an aqueous mixture comprising, on a dry basis, 49 to 68 weight % of a blend of reactive powders, 23 to 35 weight % uniformly distributed lightweight filler, and 5 to 20 weight % alkali-resistant glass fibers, and optional superplasticizer; the continuous phase being uniformly reinforced with glass fibers and uniformly containing the lightweight filler particles, the lightweight filler particles comprising ceramic microspheres and optionally, at least one member selected from the group consisting of glass microspheres, fly ash cenospheres and perlite, the lightweight filler particles having a particle specific gravity of from 0.02 to 1.00 and an average particle size of about 10 to 500 microns (micrometers), wherein the reactive powders comprise, on a dry basis, 45 to 75 wt % calcium sulfate alpha hemihydrates, 20 to 40 wt % Portland cement, 0.2 to 3.5 wt % lime and 5 to 25 wt % of an active pozzolan comprising silica fume, wherein the panels are ⅜-¾ inch (9-19 mm) thick, and the system having the ⅜-¾ inch (9-19 mm) thick panels fastened to laterally braced said light gauge cold rolled metal frame when tested according to ASTM E-72-05, effective 2005, has a nominal wall shear capacity of 400 to 1200 pounds per linear foot, wherein the panels fastened to said light gauge cold rolled metal frame when tested according to ASTM D-1761-88, effective 1988 (reapproved 2000), has a dry lateral screw resistance of 350 to 550 pounds, wherein the shear wall system further comprises a layer of Type X fire rated gypsum wallboard attached to a side of the metal framing opposed to said shear diaphragm panel to form a second diaphragm, and wherein Type X fire rated gypsum wallboard are only on the one side of the frame opposed to the shear diaphragm, wherein the shear wall system fastened to the metal frame meets the performance of the 2 hour fire resistance test rating under ASTM E-119, effective 2003.