US Patent 10982441 Multiple layer substrate for roofing materials

Disclosed is a multiple layer substrate that can be used with a top asphalt applicator that eliminates the need for a bottom asphalt applicator and fines applied to the bottom asphalt layer. A low porosity or impermeable bottom layer prevents the flow of asphalt applied to the porous top layers of the substrate from penetrating the bottom surface. This eliminates the need for fines to prevent sticking of shingles in a shingle stack. In addition, substrate layers that combine fiberglass and polyester fibers in various configurations provide a substrate that can be used in typical shingle manufacturing and manufacturing of waterproofing products that is impact resistant.