Multi-layer roofing shingles and methods for installing them

Abstract

One aspect of the disclosure is roofing shingle including a first shingle layer having a top surface, a first side edge, and a second side edge positioned opposite the first side edge. The roofing shingle also includes a second shingle layer at least partially laminated to the top surface of the first shingle layer, where the second shingle layer includes a first side edge offset a sidelap distance from the first side edge of the first shingle layer such that a side portion of the top surface of the first shingle layer is exposed, and a second side edge extending beyond the second side edge of the first shingle layer so as to overlap the second side edge of the first shingle layer by the sidelap distance.

What is claimed is: 
     
         1 . A roofing shingle having a headlap zone disposed above an exposure zone, the roofing shingle comprising:
 a first shingle layer having a top surface, a top edge disposed in the headlap zone, a bottom edge disposed in the exposure zone, a first side edge, and a second side edge positioned opposite the first side edge;   a second shingle layer at least partially laminated to the top surface of the first shingle layer, wherein the second shingle layer comprises a top edge disposed in the headlap zone, a bottom edge disposed in the exposure zone, a first side edge offset a first sidelap distance from the first side edge of the first shingle layer such that a side portion of the top surface of the first shingle layer is exposed, and a second side edge extending beyond the second side edge of the first shingle layer so as to overlap the second side edge of the first shingle layer by a second sidelap distance.   
     
     
         2 . The roofing shingle of  claim 1 , wherein the bottom edge of the second shingle layers is offset from the bottom edge of the first shingle layer such that a bottom portion of the top surface of the first shingle layer is exposed. 
     
     
         3 . The roofing shingle of  claim 1 , wherein the top end of the second shingle layer extends beyond the top edge of the first shingle layer so as to overlap the top edge of the first shingle layer. 
     
     
         4 . The roofing shingle of  claim 1 , wherein the sidelap distance is at least 4 inches. 
     
     
         5 . The roofing shingle of  claim 1 , wherein a height of the headlap zone is no greater than 2 inches. 
     
     
         6 . The roofing shingle of  claim 18 , wherein a height of the exposure zone is at least 6 inches. 
     
     
         7 . The roofing shingle of  claim 1 , wherein the first sidelap distance is substantially equal to the second sidelap distance. 
     
     
         8 . The roofing shingle of  claim 1 , wherein the second shingle layer comprises a plurality of tabs formed in the exposure zone of the roofing shingle, the plurality of tabs separated by one or more gaps extending from the bottom edge of the second shingle layer to the headlap zone of the roofing shingle. 
     
     
         9 . The roofing shingle of  claim 8 , wherein the bottom edge of the first shingle layer comprises one or more notches, wherein each notch in the one or more notches is aligned with a respective gap in the second shingle layer. 
     
     
         10 . The roofing shingle of  claim 8 , wherein at least the first side edge of the second shingle layer is disposed completely within the headlap zone, e.g., wherein both the first side edge of the second shingle layer and the second side edge of the second shingle layer are disposed completely within the headlap zone. 
     
     
         11 . The roofing shingle of  claim 8 , wherein the second edge of the second shingle layer extends beyond the second edge of the first shingle layer such that one of the tabs in the plurality of tabs is positioned over the second edge of the first shingle layer. 
     
     
         12 . The roofing shingle of  claim 8 , wherein each gap in the one or more gaps comprises a width that is different from a width of at least one adjacent gap. 
     
     
         13 . The roofing shingle of  claim 8 , wherein each gap in the one or more gaps comprises a respective width of at least 0.5 inches. 
     
     
         14 . The roofing shingle of  claim 8 , wherein each tab in the plurality of abs comprises a width that is different from a width of at least one adjacent tab. 
     
     
         15 . The roofing shingle of  claim 8 , wherein each gap in the one or more gaps comprises a respective width that increases from the bottom edge of the first shingle layer toward the headlap zone of the roofing shingle, such that each tab comprises a respective width that decreases from the bottom edge of the second shingle layer toward the headlap zone of the roofing shingle. 
     
     
         16 . A roofing shingle system comprising:
 a first plurality of roofing shingles arranged laterally edge to edge to form a first course, the first plurality of shingles comprising:
 a first roofing shingle and a second roofing shingle, wherein the second side edge of the first shingle layer of the first roofing shingle and the first side edge of the first shingle layer of the second roofing shingle are abutted against each other to form a first butt joint, wherein the second side edge of the second shingle layer of the first roofing shingle and the first side edge of the second shingle layer of the second roofing shingle are abutted against each other to form a second butt joint; and 
   a second plurality of roofing shingles, arranged laterally edge to edge to form a second course, wherein the second course is positioned such that an exposure zone of each roofing shingle in the second plurality of roofing shingles overlaps the headlap zone of at least one of the roofing shingles in the first plurality of roofing shingles,   wherein each of the first roofing shingle and the second roofing shingle of the first plurality of shingles, and each roofing shingle in the second plurality of roofing shingles, is the roofing shingle of  claim 1 .   
     
     
         17 . The roofing shingle system of  claim 16 , wherein the first butt joint is positioned beneath the second shingle layer of the second roofing shingle such that the second shingle layer of the second roofing shingle substantially covers the first butt joint. 
     
     
         18 . The roofing shingle system of  claim 16 , wherein the second butt joint is positioned substantially within the headlap zone of the first and second roofing shingles, such that the second butt joint is covered by the second course of roofing shingles. 
     
     
         19 . A roof comprising a roof deck having an upper end and a lower end, and the roofing shingle system of  claim 16  fastened thereto, the headlap zones of the roofing shingles being disposed toward the upper end of the roof deck and the exposure zones of the roofing shingles being disposed toward the lower end of the roof deck. 
     
     
         20 . A method for installing a roof according to  claim 19 , the method comprising:
 positioning the first roofing shingle on the roof deck;   positioning the second roofing shingle on the roof deck such that the second side edge of the first shingle layer of the first roofing shingle and the first side edge of the first shingle layer of the second roofing shingle are abutted against each other to form a first butt joint, wherein the second side edge of the second shingle layer of the first roofing shingle and the first side edge of the second shingle layer of the second roofing shingle are abutted against each other to form a second butt joint;   fastening each roofing shingle in the first plurality of roofing shingles to the roof deck in a laterally edge-to-edge manner to form the first course; and   fastening each roofing shingle in the second plurality of roofing shingles to the roof deck in a laterally edge-to-edge manner to form the second course, wherein the exposure zone of each roofing shingle in the second plurality of roofing shingles overlaps the headlap zone of at least one roofing shingle of the first plurality of roofing shingles.