| abstract |
Cement board for building construction, comprising: a layer / core (101) of cementitious material located between a first coating layer (22, 105) and a second coating layer (32, 106); having at least one of said layers (22,32,105,106) of coating glass fibers bonded together with a resinous binder composition; the resin binder composition having a hydrophilic affinity, or adhesive affinity, or a combination thereof, for said cementitious material when wet; said at least one coating layer being impervious to the penetration of a precursor slurry of said cementitious material and being permeable to air and water vapor for the passage of water vapor from said slurry, wherein said at least one layer of The lining has a denser, thermoplastic and / or light weight fiberglass layer (111) denser, bonded to a stronger and more porous coating layer (104), and the more porous coating layer (104) is included in the layer / core (101), characterized in that a resinous coating (107), which is adherent to gypsum and differs from said resinous binder, has been applied only to the lining side of the core of the light weight layer (111) plus Dense and totally around the layer (104) of more porous coating to promote adhesion to the cement layer / core (101). |