Patent ID: 8034416

Claim:
A method for making a mold-and moisture-resistant gypsum board, said method comprising: (a) applying a plaster slurry that forms a gypsum core to an upper and a lower facing sheet to form a structure in which the plaster slurry is sandwiched between the upper and lower facing sheets, at least one of the upper or the lower facing sheet having previously been treated with a heat reactive resin so that the heat reactive resin is impregnated into at least one of the upper or the lower facing sheets; and (b) heating the structure sufficiently to cure said heat reactive resin and dry said gypsum core, thereby yielding said gypsum board, wherein the at least one of the upper or the lower facing sheet impregnated with the heat reactive resin has a total thickness (t), and wherein the heat reactive resin is impregnated into the at least one of the upper or the lower facing sheet a depth ranging from about t-50 μm to about t-10 μm to provide a thickness of about 10 μm to about 50 μm between the heat reactive resin and a surface of the at least one of the upper or the lower facing sheet that is contiguous with the gypsum core that is substantially free of the heat reactive resin.