FLY ASH-FREE COATING FORMULATION FOR FIBROUS MAT TILE BACKERBOARD

摘要

Mat-faced cementitious board including: (a) a cementitious core; (b) a fibrous mat having an inner first surface facing at least one face of the cementitious core, and an outer second surface, wherein the inner first surface and the outer second surface are opposed; (c) a hydrophobic, non-setting coating resulting from applying to the outer second surface of the fibrous mat a layer of hydrophobic finish composition including: (i) about 50 to about 80 weight % non-setting, inorganic filler having a mean particle diameter of about 12 microns to about 35 microns, (ii) about 20% to about 50 weight % an aqueous dispersion of a film-forming polymer, (iii) 0% to about 30 weight % additional water; (iv) an absence of fly ash, (v) an absence of pozzolanic material, (vi) an absence of hydraulic cement, (vii) an absence of calcium sulfate hemihydrate, and (viii) an absence of calcium sulfate anhydrite.