| abstract |
A cementitious board (100) and a method for manufacturing the cementitious board (100) has a facing layer (105) having an areal weight of about 300 grams/M2, and an air permeability rating of no greater than about 300 CFM/ft2 (FG 436-910 test method). The facing layer (105) reduces the penetration of a slurry (28) of cementitious material during the manufacture of the board (100), and passes water vapor from the slurry (28) while the slurry (28) cures. Binders, coatings or saturants (107) decrease pore size, increase or decrease the contact angle of liquids, promote adhesion to cementitious cores (101), promote adhesion to the facing layer (105) and promote adhesion or affinity to adhesive compositions used to join cementitious boards to exterior insulation systems and exterior finishing systems (EIS and EIFS). |