CPC B32B 27/12 (2013.01) [B32B 13/14 (2013.01); B32B 37/15 (2013.01); B32B 2307/7246 (2013.01)] | 19 Claims |
1. A reinforcing layer for a cementitious board comprising an alkali-resistant fabric, a non-porous membrane, and a first non-woven mat, wherein the alkali-resistant fabric comprises a glass fabric laid scrim, wherein the first non-woven mat is directly in contact with the non-porous membrane and the alkali-resistant fabric and wherein the non-porous membrane comprises a polymeric film having a filler content of less than 5 weight % based on the total weight of the polymeric film, the non-porous membrane having a thickness of less than 5 mils, wherein the non-porous membrane has a breaking strength of greater than 170 psi as measured by ASTM D751.
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