US Patent 7204063 Roofing shingle with headlap seal and improved coverage

A roofing shingle for enhanced wind/rain durability embodies two transverse lines of adhesion. A first discontinuous line of adhesive joins the butt edge of an overlying shingle to the underlying shingle. Secondly, a band of sealant adjacent the top edge of an underlying shingle seals against an overlying shingle to prevent penetration by wind driven rain to the roof deck. A reduced headlap is thereby permitted, thereby either reducing shingle size or extending shingle coverage. Exposed portions of the sealant band improve the erosion resistance of underlying shingles.