Patent ID: 7300515
Filing Date: 2007-11-27
Classification: B28B,B32B,C04B,D03D,D10B,E04C,Y10S,Y10T

Abstract:
1. A method of making a cementitious board useful in building construction, comprising: (a) layering an aqueous slurry between two layers of facing material, the slurry comprising, cementitious material and water, the facing material of at least one of the two layers comprising, an inner layer reinforced by reinforcing fibers, and a porous facing layer having a slurry facing side and an exterior side; (b) penetrating the slurry through both the inner layer and the reinforcing fibers, and contacting the slurry facing side of the porous facing layer with the slurry; (c) repelling said slurry by a hydrophobic material over at least the exterior side of the porous facing layer to resist slurry contamination of the exterior side, and to repel rain or water; (d) evaporating water from the slurry through pores of the porous facing layer, the pores being permeable to water vapor; and (e) solidifying the slurry to form a solidified cementitious material layer between the two layers of facing material.