Patent ID: 8347575

Claim:
An acoustical flooring underlayment for placement between a subfloor and a finished floor, comprising: a mat constructed as a single piece having an upper surface, an opposite lower surface and including a plurality of self-supporting corrugations creating a plurality of depressions in said upper surface, said mat further including thickened nodes at points of said corrugations; and a layer of settable foam applied to said upper surface, and constructed and arranged to generally fill said depressions for creating a generally planar top surface configured for accommodating the finished floor such that tops of said nodes project above said top surface; wherein said mat forms a plurality of triangular trusses in vertical cross-section, and said lower surface includes a plurality of lower contact points located at the lower edges of the corrugations for contacting a substrate, said lower contact points being separated by voids defined by the corrugations to reduce the contact area between said mat and the subfloor, thereby disrupting acoustical continuity between the subfloor and the finished floor.