US Patent 10301828 Underlayment material

An underlayment material made of a laminate of a nonwoven thermoplastic fabric having a dimensional stability of less than 1% when exposed to a temperature of 82° C. when tested in accordance with ASTM D 1204 in both machine- and cross-directions and a thermoplastic barrier layer provides a combination of an improved dimensional stability, resistance to sliding along a roof deck and protection as a moisture barrier when used in roofing and flashing structures.