Patent ID: 7635657

Claim:
A gypsum wallboard comprising: a gypsum core having a planar first major face and a planar second major face; a coated non-woven first glass fiber mat facing material suitable for level 4 finishing adhered on a non-coated side to and covering the planar first major face of the gypsum core, wherein the coated non-woven first glass fiber mat facing material comprises a majority of glass fibers of a nominal fiber diameter between about 8 and about 11 microns and a fiber length between about ¼ and about ¾ inch, the glass fibers of the coated non-woven first glass fiber mat facing material being bound together with an adhesive binder comprising an acrylic-type adhesive binder, wherein the coated non-woven first glass fiber mat facing material has a coating comprising a dried aqueous mixture comprising (i) a mineral pigment, (ii) a polymer adhesive binder and optionally (iii) an inorganic adhesive binder, and wherein said coated non-woven first glass fiber mat facing material has a basis weight of between about 1.7 and 2.0 pounds per 100 square feet before application of the coating; and an optionally coated non-woven second glass fiber mat facing material adhered on a non-coated side to and covering the planar second major face of the gypsum core, wherein the optionally coated non-woven second glass fiber mat facing material comprises a majority of glass fibers of a nominal fiber diameter of at least about 13 microns but not more than about 16 microns and a fiber length of at least about ¾ inch but not more than about 1 inch, the glass fibers of the coated non-woven second glass fiber mat facing material being bound together with an adhesive binder comprising an acrylic-type adhesive binder, and wherein said optionally coated non-woven second glass fiber mat facing material has a basis weight, before application of the optional coating, of between 1.8 and 2.2 pounds per 100 square feet.