Patent ID: 8597753

Claim:
A self-adhesive heating underlayment system comprising: a flexible electrical heating element including substantially planar body having top and bottom surfaces; a lower waterproof membrane having a top surface attached across at least a portion of said bottom surface of said flexible heating element wherein at least a first lateral edge of said lower waterproof membrane extends beyond a corresponding lateral edge of the flexible heating element defining a lower sealing flap; a first release sheet releaseably attached to a top surface of the lower sealing flap, wherein said first release sheet covers an adhesive surface of said lower sealing flap; an upper waterproof membrane having bottom surface attached across at least a portion of a top surface of the flexible heating element wherein at least a first lateral edge of said upper waterproof membrane extends beyond the corresponding lateral edge of the flexible heating element defining a upper sealing flap; a second release sheet releaseably attached to a bottom surface of the upper sealing flap, wherein said second release sheet covers an adhesive surface of said upper sealing flap; and a bottom release sheet releaseably attached to a bottom surface of the lower waterproof membrane, wherein the bottom release sheet covers an adhesive surface of the lower waterproof membrane that is adapted for adhesive attachment to a surface.