Patent ID: 7786028

Claim:
A prefabricated building construction underlayment roll good, comprising: a flexible nonwoven mat of polymeric fibers; the nonwoven mat having a length, a width, and a thickness, the nonwoven mat having a top major surface and a bottom major surface that are each defined by the length and the width of the nonwoven mat; the polymeric fibers being substantially uniformly dispersed throughout the nonwoven mat; the polymeric fibers being generally continuous spunbond polyester fibers that have inner fiber cores and outer fiber sheaths; the fiber cores being of a first polyester material and the fiber sheaths being of a second polyester material; the second polyester material of the fiber sheaths having a lower temperature softening point than a softening point temperature of the first polyester material of the fiber cores; the polymeric fibers being bonded together at their points of intersection by the second polyester material of the fiber sheaths; and interstices of the nonwoven mat being at least partially filled by a portion of the second polyester material of the fiber sheaths that has been dispersed into the interstices to reduce the porosity of the nonwoven mat; wherein the polymeric fibers of the nonwoven mat are further entangled after the nonwoven mat has been initially formed to provide the nonwoven mat with a greater resistance to delamination; a reinforcement contained in the nonwoven mat; a hydrophobic binder coating layer overlying the polymeric fibers of the nonwoven mat on the top major surface of the nonwoven mat and being substantially coextensive with the top major surface of the nonwoven mat; the hydrophobic binder coating layer further closing interstices of the nonwoven mat to form a flexible liquid water transmission resistant nonwoven mat composite that is more water transmission resistant than the flexible nonwoven mat; and a filled asphalt, modified bitumen, or non-asphaltic polymeric film overlying and substantially coextensive with the hydrophobic binder coating layer to form a flexible waterproof nonwoven mat composite.