| abstract |
A method of making a cementitious board (100) useful in building construction is disclosed. A cementitious board is made by: (a) Layering an aqueous slurry (28) between two layers of facing material (23, 32) where the slurry comprises a cementitious material and water. The facing material of at least one of the two layers comprises an inner layer reinforced by reinforcing fibres, 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 fibres, and contacting the slurry facing side of the porous facing layer with the slurry; (c) Repelling the 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 (42) through pores of the porous facing layer, the pores being permeable to water vapour; and (e) Solidifying the slurry (48) to form a solidified cementitious material layer between the two layers of facing material. |