Patent Publication Number: US-6990779-B2

Title: Roofing system and roofing shingles

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Patent application Ser. No. 09/663,255, filed on Sep. 15, 2000 now U.S. Pat. No. 6,586,353, which claims priority under 35 U.S.C. §119(e) to Provisional Patent Application No. 60/168,057, filed on Nov. 30, 1999; a continuation-in-part of U.S. patent application Ser. No. 09/897,308, filed on Jul. 2, 2001 now U.S. Pat. No. 6,673,432; and a continuation-in-part of U.S. patent application Ser. No. 10,211,663, filed Aug. 2, 2002 now U.S. Pat. No. 6,708,456, which claims priority under 35 U.S.C. §119(e) to Provisional Patent Application No. 60/331,808, filed on Nov. 20, 2001. This application also claims priority under 35 U.S.C. §119(e) to Provisional Patent Application No. 60/310,031, filed on Aug. 3, 2001. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates generally to a roofing system and to roofing shingles that may be utilized in the roofing system. In particular, the invention relates to the construction of roofing shingles featuring unique combinations of dimensions and a roofing system that utilizes the shingles. 
     BACKGROUND 
     Roofing products are often divided into three broad groups: shingles, roll roofing and underlayment. Shingles and roll roofing typically function as outer roof coverings designed to withstand exposure to weather and the elements. Asphalt shingles and roll roofing generally contain the same basic components which provide protection and long term wear associated with asphalt roofing products. Typically, the underlayment is first laid on top of the roof, and then the outer roofing covering (e.g., shingles or roll roofing) is installed on top of the underlayment. 
     Asphalt shingles (sometimes also referred to as composite shingles) are one of the most commonly used roofing materials. Asphalt shingles may include an organic felt or fiberglass mat base on which an asphalt coating is applied. The organic felt or fiberglass mat base gives the asphalt shingle the strength to withstand manufacturing, handling, installation and servicing activities, and the asphalt coating provides resistance to weathering and stability under temperature extremes. An outer layer of mineral granules is also commonly applied to the asphalt coating to form a weather surface which shields the asphalt coating from the sun&#39;s rays, adds color to the final product, and provides additional fire resistance. 
     Asphalt shingles are typically manufactured as strip or three tab shingles, laminated shingles, interlocking shingles, and large individual shingles in a variety of weights and colors. Even though asphalt shingles offer significant cost, service life, and fire resistance advantages over wood shingles, wood shingles are sometimes preferred due to their pleasing aesthetic features, such as their greater thickness as compared to asphalt shingles, which may result in a more pleasing, layered look for a roof. 
     Various asphalt shingles have been developed to provide an appearance of thickness comparable to wood shingles. Examples of such asphalt shingles are shown in U.S. Pat. No. 5,232,530 entitled “Method of Making a Thick Shingle”; U.S. Pat. No. 3,921,358 entitled “Composite Shingle”; U.S. Pat. No. 4,717,614 entitled “Asphalt Shingle”; and U.S. Pat. Des. No. D309,027 entitled “Tab Portion of a Shingle.” Some laminated asphalt shingles simulate the appearance of slate roofing shingles. See U.S. Pat. No. Des. 369,421. Each of the patents mentioned in this paragraph is incorporated by reference herein in its entirety. 
     In addition to these patents, significant improvements in the art of roofing shingles have been disclosed and patented in U.S. Pat. Nos. 5,369,929; 5,611,186; and 5,666,776; each entitled “Laminated Roofing Shingle”, issued to Weaver et al. and assigned to the Elk Corporation of Dallas. These patents disclose laminated roofing shingles developed to create the illusion of thickness or depth on a relatively flat surface by including a backer strip having striations of color beneath and between tabs wherein the color is uniform within the tab. Each of these three patents is also incorporated by reference herein in its entirety. 
     Additional improvements include the use of larger shingles having a buttlap section of greater than about 7 inches to provide a more pleasing appearance and a greater visual impact by providing enhanced dimensionality, as disclosed in pending U.S. patent application Ser. No. 09/401,392 entitled “Laminated Roofing Shingle” and filed on Sep. 22, 1999, which is incorporated herein by reference in its entirety. Shingles typically have a buttlap section, a part of which is exposed to the environment, and a headlap section, which is covered by the buttlap section of the shingle in the next row above. The headlap section is typically wide in order to (i) improve weatherproofing, (ii) insure that a majority of the roof is covered by at least one layer of buttlap section and at least one layer of headlap section, and (iii) aid in the production and handling of the shingle. Accordingly, heretofore the production of shingles having a greater exposure area (e.g., having a buttlap section of greater than 7 inches) has required retooling of existing machinery because standard equipment typically produces a shingle having a width of about 13.25 inches. The present invention enables the production on existing equipment lines of a variety of roofing shingles providing for enhanced exposure while still ensuring Class A fire resistance ratings. 
     SUMMARY OF THE INVENTION 
     The present invention is a roofing system having a multiplicity of courses of roofing shingles and interply material comprising at least one course of interply material overlapping at least about 10% of a first course of shingles. A second course of shingles overlaps at least a portion of the interply material and the first course of shingles such that more than about 40% of the first course of shingles is exposed after installation. The roofing system has a class A fire resistance rating. The present invention also includes the roofing shingles that may be utilized in the inventive roofing system. Such shingles may be asphalt roofing shingles. For any of the shingles, the width of the shingle is at least about 20% of the shingle&#39;s length. The asphalt shingles may be three tab shingles or laminated shingles. 
     In roofing systems of the present invention featuring laminated shingles, the shingles comprise first and second shingle sheets. The first shingle sheet has a headlap section and a buttlap section including a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. The width of the buttlap section is at least about 40% of the width of the shingle. The second shingle sheet is attached to the underside of the first shingle sheet and has portions exposed through the openings between the tabs. The second shingle sheet has at least first, second, and third horizontal striations thereon across at least partial portions of the second sheet which are exposed through the openings between the tabs. The striations comprise elongated quadrilateral areas. The striations provide a color gradation on at least partial portions of the second sheet which are exposed through the openings between the tabs. In another embodiment, a fourth horizontal striation is across at least partial portions of the second sheet which are exposed through the openings between the tabs. Again, the striations provide a color gradation on at least the partial portions of the second sheet which are exposed through the openings between the tabs. 
     The width of each of the striations on the second shingle sheet of each shingle may be approximately equal. In embodiments having three striations on the second sheet, the widths of the first and third striations may be approximately equal and approximately one-half the width of the second striation. Alternatively, the widths of the first and third striations may be approximately equal and substantially wider than the width of the second striation. Further, the third striation may be substantially wider than the second striation and the first striation may be approximately twice the width of the third striation. 
     In the roofing system of the present invention, shingles in each course bearing three striations of approximately equal width may be placed adjacent to shingles wherein the widths of the first and third striations are approximately equal and are approximately one-half the width of the second striation. Alternatively, shingles in each course bearing three striations of approximately equal width may be placed adjacent to shingles wherein the widths of the first and third striations are approximately equal and are substantially wider than the width of the second striation. Additionally, shingles in each course bearing three striations of approximately equal width may be placed adjacent to shingles wherein the third striation is substantially wider than the second striation and the first striation is approximately twice the width of the third striation. 
     Further, shingles in each course bearing four striations of approximately equal width may be placed adjacent to shingles bearing three striations wherein the widths of the first and third striations are approximately equal and are approximately one-half the width of the second striation. Moreover, shingles in each course bearing four striations of approximately equal width may be placed adjacent to shingles bearing three striations wherein the widths of the first and third striations are approximately equal and are wider than the width of the second striation. Also, shingles in each course bearing four striations of approximately equal width may be placed adjacent to shingles bearing three striations wherein the third striation is substantially wider than the second striation and the first striation is approximately twice the width of the third striation. 
     In all of the aforementioned laminated shingle embodiments, each of the tabs on the first shingle sheet of each shingle may have a different color contrast from one another. Additionally, the dimensions of one of the tabs on the first shingle sheet of each shingle may differ from the dimensions of others of the tabs. Each shingle may further comprise an interply alignment line positioned horizontally across the headlap section of the shingle. The interply alignment line may be positioned horizontally across a common bonding region of the shingle. 
     Each laminated shingle as described above may further comprise a transition stripe disposed between a pair of horizontal striations having a color value comprising a mixture of the colors associated with the pair of horizontal striations. The mixture of the colors may include from about 25% to 75% of the color value of each of the pair of horizontal striations. 
     The width of the buttlap section of each shingle in the roofing system described above may be at least about 70% of the width of the shingle while the interply material may have a width of at least about 100% of the width of the roofing shingle. Alternatively, the width of the buttlap section of each such shingle may be at least about 80% of width of the roofing shingle while the interply material may have a width of from about 105% to about 130% of the width of the roofing shingle. 
     Each shingle of the roofing system described above may have an exposure width of at least about 60% of the width of the shingle while the interply material has a width of at least about 100% of the width of the shingle. Alternatively, each such shingle may have an exposure width of at least about 64% of the width of the shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. 
     The roofing system of the present invention may alternatively include laminated shingles comprising a first shingle sheet having a headlap section and a buttlap section including a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. The width of the buttlap section may be at least about 40% of the width of the shingle. The shingle also includes a second shingle sheet attached to the underside of the first shingle sheet and having varying portions exposed through the openings between the tabs and below at least one of the tabs of the first shingle sheet. 
     In one embodiment, the width of the buttlap section of each shingle may be at least about 70% of the width of the shingle while the interply material has a width of at least about 100% of the width of the roofing shingle. Alternatively, the width of the buttlap section of each shingle may be at least about 80% of width of the roofing shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. Each shingle may have an exposure width of at least about 60% of the width of the shingle while the interply material has a width at least about 100% of the width of the shingle. Alternatively, each shingle may have an exposure width of at least about 64% of the width of the shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. 
     The roofing system of the present invention may alternatively include three tab asphalt shingles. In such systems, each shingle may have an exposure width of at least about 60% of the width of the shingle while the interply material has a width at least about 100% of the width of the shingle. Alternatively, each shingle may have an exposure width of at least about 64% of the width of the shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. 
     In the embodiments of the roofing system summarized above, the interply material is comprised of a water and fire retardant material. The interply material may be comprised of a substrate having an ionic charge coated with a coating having essentially the same ionic charge. The coating consists essentially of a filler material and a binder material. The binder material bonds the filler material together and to the substrate. The coating does not bleed through the substrate. The interply material may be from 10% to 25% by weight glass fibers and the coating may be from 84% to 96% filler selected from the group consisting of fly ash, charged calcium carbonate, ceramic microspheres and mixtures thereof, and from 16% to 4% acrylic latex binder material. 
     Alternatively, the interply material may be comprised of a substrate having an ionic charge coated on one side with a coating having essentially the same ionic charge. Again, the coating consists essentially of a filler material and a binder material and the binder material bonds the filler material together and to the substrate. The coating does not bleed through the substrate. The substrate is covered on the other side with a water vapor impermeable material selected from the group consisting essentially of metal foils and preformed plastic films. The water vapor impermeable material is attached to the coated substrate with an adhesive. Such materials are described in pending U.S. application Ser. No. 09/897,308 filed on Jul. 2, 2001 which is incorporated by reference herein in its entirety. 
     Additionally, the interply material may be comprised of a substrate having an ionic charge coated on both sides with a coating having essentially the same ionic charge. The coating again consists essentially of a filler material and a binder material and the binder material bonds the filler material together and to the substrate. The coating does not bleed through the substrate. One side of the coated substrate is covered with a water vapor impermeable material selected from the group consisting essentially of metal foils and preformed plastic films. The water vapor impermeable material is attached to the coated substrate with an adhesive. Alternatively, one side of the coated substrate may be covered with a metal foil water vapor barrier material and the other side of the coated substrate may be covered with a preformed plastic film water vapor impermeable material. Both water vapor impermeable materials may be attached to the coated substrate with an adhesive. Further, both sides of the coated substrate may be coated with the same water vapor impermeable material, either a metal foil or a preformed plastic film, which may be attached to the coated substrate with an adhesive. In such embodiments, the coating may be from 84% to 96% filler selected from the group consisting of fly ash, charged calcium carbonate, ceramic microspheres and mixtures thereof and from 16% to 4% acrylic latex binder material. Alternatively, a water proof coating may be used instead of the impermeable films listed above. 
     The adhesive for the embodiments described above is selected from the group consisting essentially of low density polyethylene, high density polyethylene, polyethylene-vinyl acetate, polypropylene, polyvinylidene chloride, nylon, polyester and mixtures thereof. Alternatively, an asphaltic adhesive, such as an asphaltic adhesive similar to standard laminating adhesives, may be used. 
     In the roofing system of the present invention, alternative interply materials may also be employed. One such material is comprised of a roll roofing product including a fiberglass substrate coated with asphaltic material and mineral granules. Another such interply material is comprised of asphalt impregnated felt underlayment material. 
     In a further embodiment of the present invention, the roofing system comprises a roof deck of a building, a first layer of underlayment material attached to the roof deck, a second layer of the underlayment material attached to the first layer, and a multiplicity of courses of roofing shingles attached to the second layer of underlayment material. The underlayment material may be any of the interply materials described above with the exception of the roll roofing and felt underlayment type products. 
     The present invention also relates to a laminated roofing shingle comprising a first shingle sheet and a second shingle sheet. The first shingle sheet has a headlap section and a buttlap section. The buttlap section may be at least about 60% of the width of the shingle. The first shingle sheet includes a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. 
     The second shingle sheet is attached to the underside of the first shingle sheet and has portions exposed through the openings between the tabs. The second shingle sheet has at least first, second, and third horizontal striations thereon across at least partial portions of the second sheet which are exposed through the openings between the tabs. 
     The striations comprise elongated quadrilateral areas and provide a color gradation on at least partial portions of the second sheet which are exposed through the openings between the tabs. Alternatively, the second shingle sheet may further comprise at least a fourth horizontal striation thereon across at least partial portions of the second sheet which are exposed through the openings between the tabs. 
     In the aforementioned laminated roofing shingle of the present invention, the width of each of the striations may be approximately equal. In embodiments having three striations on the second sheet, the widths of the first and third striations may be approximately equal and be approximately one-half the width of the second striation. Alternatively, the widths of the first and third striations may be approximately equal and substantially wider than the width of the second striation. Further, the third striation may be substantially wider than the second striation and the first striation may be approximately twice the width of the third striation. 
     Each of the tabs of the laminated shingles described above may have different color contrasts from one another. Additionally, the dimensions of one of the tabs of the laminated shingles described above may differ from the dimensions of others of the tabs. 
     An alternative laminated roofing shingle of the present invention also comprises first and second shingle sheets. The first shingle sheet has a headlap section and a buttlap section including a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. The width of the buttlap section may be at least about 60% of the width of the shingle. The second shingle sheet is attached to the underside of the first shingle sheet and has varying portions exposed through the openings between the tabs and below at least one of the tabs of the first shingle sheet. 
     In one embodiment of each of the laminated shingles described above, the width of the buttlap section of the shingle may be at least 70% of the width of the shingle. In another embodiment, the width of the buttlap section of the shingle may be at least about 80% of width of the roofing shingle. The laminated roofing shingles of the present invention may have an exposure width of at least about 60% of the width of the shingle, preferably an exposure width of at least about 64% of the width of the shingle. 
     The present invention also includes three tab roofing shingles having an exposure width of at least about 60% of the width of the shingle, preferably an exposure width of at least 64% of the width of the shingle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which: 
         FIGS. 1 and 1A  are perspective views of partial roofing sections covered with embodiments of the roofing system of the present invention; 
         FIGS. 2 and 2A  are perspective views of laminated shingles incorporating embodiments of the present invention; 
         FIG. 3  is a top plan view of the shingle of  FIG. 2 ; 
         FIG. 4  is a lower edge view of the shingle of  FIG. 2 ; 
         FIGS. 5 and 5A  are left side views of the shingles of  FIGS. 2 and 2A ; 
         FIG. 6  is an isometric, schematic drawing of a sheet of roofing material incorporating one embodiment of the present invention from which components for the shingle of  FIG. 2  may be obtained; 
         FIG. 7  is an exploded isometric view showing shingle components taken from the sheet of roofing material in  FIG. 6 , which may be used to form the shingle of  FIG. 2 ; 
         FIG. 8A  is an exploded isometric view showing shingle components taken from a sheet of roofing material according to another embodiment of the present invention; 
         FIG. 8B  is an enlarged drawing of a portion of a backer strip of  FIG. 8A  with transition stripes disposed between adjacent horizontal striations; 
         FIG. 9  is a perspective view of a partial roofing section covered with another embodiment of the roofing system of the present invention; 
         FIG. 10  is a top plan view of the shingle shown in  FIG. 9 ; 
         FIG. 11  is a left side view of the shingle shown in  FIG. 9 ; 
         FIG. 12  is a perspective view of a partial roofing section covered with an alternative embodiment of the roofing system of the present invention; 
         FIG. 13  is a top plan view of the shingle featured in the roofing system of  FIG. 12 ; 
         FIG. 14  is a front view of a laminated shingle of the present invention; 
         FIG. 15  is a back view of the shingle of  FIG. 14 ; and 
         FIG. 16  is a layout view of an embodiment of the roofing system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The roofing system and roofing shingles of the present invention provide the aesthetic benefits of large shingles without requiring the retooling of existing machinery. Accordingly, these shingles can be produced by adjusting existing production processes with little or no capital expenditures. The roofing composite material of the present invention also weighs less than a conventional shingle of equivalent exposure size, thus reducing freight costs and roof loads. 
     The roofing system, examples of which are illustrated in  FIGS. 1 ,  9 ,  12  and  16 , has a multiplicity of courses of roofing shingles and interply material comprising at least one course of interply material overlapping at least about 10% of a first course of shingles, and a second course of shingles overlapping at least a portion of the interply material and the first course of shingles. More than about 40% of the first course of shingles is exposed after installation. The roofing system has a Class A fire resistance rating. 
     Shingles employed in the roofing system of the present invention may be asphalt or composite shingles. The width of the shingles may be at least about 20% of the length of the shingles. 
     The asphalt shingles may be laminated shingles. In one embodiment, as illustrated in  FIGS. 1–8 , each laminated shingle comprises a first shingle sheet having a headlap section and a buttlap section including a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. The width of the buttlap section is at least about 40% of the width of the shingle. A second shingle sheet is attached to the underside of the first shingle sheet and has portions exposed through the openings between the tabs. The second shingle sheet has at least first, second, and third horizontal striations thereon across at least partial portions of the second sheet which are exposed through said openings between the tabs. 
     The first striation comprises a first elongated quadrilateral area. The first striation has a substantially uniform dark color throughout the first quadrilateral area. The second striation comprises a second elongated quadrilateral area below the first striation. The second striation has a substantially uniform color throughout the second quadrilateral area, the color of the second striation being lighter than the color of the first striation. The third striation comprises a third elongated quadrilateral area below the second striation. The third striation has a substantially uniform color throughout the third quadrilateral area. The color of the third striation is lighter than the color of the second striation. At least the second and third striations provide a color gradation on at least partial portions of the second sheet which are exposed through the openings between the tabs. 
     The roofing system of the present invention, illustrated in  FIGS. 1–8 , may further comprise on the second shingle sheet of each laminated roofing shingle at least a fourth horizontal striation thereon across at least partial portions of the second sheet which are exposed through the openings between the tabs. The fourth striation comprises a fourth elongated quadrilateral area below the third striation. The fourth striation has a substantially uniform color throughout the fourth quadrilateral area. The color of the fourth striation is lighter than the color of the third striation. At least the second, third, and fourth striations provide a color gradation on at least partial portions of the second sheet which are exposed through the openings between the tabs. 
     The width of each of the striations on the second shingle sheet of each shingle may be approximately equal, whether there are three, four or more striations on the second shingle sheet. In embodiments where three striations are employed, the widths of the first and third striations may be approximately equal and approximately one-half the width of the second striation. Alternatively, the widths of the first and third striations may be approximately equal and substantially wider than the width of the second striation. In another embodiment, the third striation may be substantially wider than the second striation and the first striation may be approximately twice the width of the third striation. 
     In the roofing system of the present invention, the shingles in each course bearing striations of approximately equal width may be placed adjacent to shingles wherein the widths of the first and third striations are approximately equal and are approximately one-half the width of the second striation. Alternatively, the shingles in each course bearing striations of approximately equal width may be placed adjacent to shingles wherein the widths of the first and third striations are approximately equal and are substantially wider than the width of the second striation. In another embodiment, the shingles in each course bearing striations of approximately equal width may be placed adjacent to shingles wherein the third striation is substantially wider than the second striation and the first striation is approximately twice the width of the third striation. 
     Further, shingles in each course bearing four striations of approximately equal width may be positioned adjacent to shingles bearing three striations wherein the widths of the first and third striations are approximately equal and are approximately one-half the width of the second striation. Moreover, shingles in each course bearing four striations of approximately equal width may be placed adjacent to shingles bearing three striations wherein the widths of the first and third striations are approximately equal and are substantially wider than the width of the second striation. In an additional embodiment, shingles in each course bearing striations of approximately equal width may be placed adjacent to shingles bearing three striations wherein the third striation is substantially wider than the second striation and the first striation is approximately twice the width of the third striation. 
     In all of the aforementioned laminated shingle embodiments, each of the tabs on the first shingle sheet of each shingle may have a different color contrast from one another. Additionally, the dimensions of one of the tabs on the first shingle sheet of each shingle may differ from the dimensions of others of the tabs. Each shingle may further comprise an interply alignment line positioned horizontally across the headlap section of the shingle. The interply alignment line may be positioned horizontally across a common bonding region of the shingle. 
     Each laminated shingle as described above may further comprise a transition stripe disposed between a pair of horizontal striations having a color value comprising a mixture of the colors associated with the pair of horizontal striations. The mixture of the colors may include from about 25% to 75% of the color value of each of the pairs of horizontal striations. 
     The width of the buttlap section of each shingle in the roofing system described above may be at least about 70% of the width of the shingle while the interply material may have a width of at least about 100% of the width of the roofing shingle. Alternatively, the width of the buttlap section of each such shingle may be at least about 80% of width of the roofing shingle while the interply material may have a width of from about 105% to about 130% of the width of the roofing shingle. Each shingle of the roofing system described above may have an exposure width of at least about 60% of the width of the shingle while the interply material has a width of at least about 100% of the width of the shingle. Alternatively, each such shingle may have an exposure width of at least about 64% of the width of the shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. 
     The roofing system of the present invention may alternatively include laminated shingles illustrated in  FIGS. 9–11  comprising first and second shingle sheets. The first shingle sheet has a headlap section and a buttlap section including a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. The width of the buttlap section is at least about 40% of the width of the shingle. The second shingle sheet is attached to the underside of the first shingle sheet and has varying portions exposed through the openings between the tabs and below at least one of the tabs of the first shingle sheet. The width of the buttlap section of each shingle may be at least about 70% of the width of the shingle while the interply material has a width of at least about 100% of the width of the roofing shingle. Alternatively, the width of the buttlap section of each shingle may be at least about 80% of width of the roofing shingle while the interply material has a width of from about 105% to about 130% of the width of the roofing shingle. Each shingle may have an exposure width of at least about 60% of the width of the shingle while the interply material has a width at least about 100% of the width of the shingle. Alternatively, each shingle may have an exposure width of at least about 64% of the width of the shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. 
     The roofing system of the present invention may alternatively include three tab asphalt shingles. In such a system, each shingle may have an exposure width of at least about 60% of the width of the shingle while the interply material has a width at least about 100% of the width of the shingle. Alternatively, each shingle may have an exposure width of at least about 64% of the width of the shingle while the interply material has a width of from about 105% to about 130% of the width of the shingle. 
     In the embodiments of the roofing system summarized above, the interply material is comprised of a water and fire retardant material. The interply material may be comprised of a substrate having an ionic charge coated with a coating having essentially the same ionic charge. The coating consists essentially of a filler material and a binder material. The binder material bonds the filler material together and to the substrate. The coating does not bleed through the substrate. Such an interply material is described in U.S. Pat. No. 5,965,257, the entirety of which is incorporated herein by reference, and is sold by Elk Corporation of Dallas, Tex. as VersaShield®. The interply material may be from 10% to 25% by weight glass fibers and the coating may be from 84% to 96% filler selected from the group consisting of fly ash, charged calcium carbonate, ceramic microspheres and mixtures thereof, and from 16% to 4% acrylic latex binder material. 
     Alternatively, the interply material may be comprised of a substrate having an ionic charge coated on one side with a coating having essentially the same ionic charge. The coating again consists essentially of a filler material and a binder material and the binder material bonds the filler material together and to the substrate. The coating does not bleed through the substrate. The substrate is covered on the other side with a water vapor impermeable material selected from the group consisting essentially of metal foils and preformed plastic films. The water vapor impermeable material is attached to the coated substrate with an adhesive. Elk Corporation markets materials including the preformed plastic film as VersaShield® Vapor Seal-II™ and Elk markets materials including the metal foils as VersaShield® ThermoClad-II™. 
     Additionally, the interply material may be comprised of a substrate having an ionic charge coated on both sides with a coating having essentially the same ionic charge. The coating again consists essentially of a filler material and a binder material and the binder material bonds the filler material together and to the substrate. The coating does not bleed through the substrate. One side of the coated substrate is covered with a water vapor impermeable material selected from the group consisting essentially of metal foils and preformed plastic films. The water vapor impermeable material is attached to the coated substrate with an adhesive. Alternatively, one side of the coated substrate may be covered with a metal foil water vapor barrier material and the other side of the coated substrate may be covered with a preformed plastic film water vapor impermeable material. Both water vapor impermeable materials may be attached to the coated substrate with an adhesive. Further, both sides of the coated substrate may be coated with either a metal foil water vapor impermeable material or a preformed plastic film water vapor impermeable material which may be attached to the coated substrate with an adhesive. The adhesive for the embodiments described above is selected from the group consisting essentially of low density polyethylene, high density polyethylene, polyethylene-vinyl acetate, polypropylene, polyvinylidene chloride, nylon, polyester and mixtures thereof. In such embodiments, the coating may be from 84% to 96% filler selected from the group consisting of fly ash, charged calcium carbonate, ceramic microspheres and mixtures thereof and from 16% to 4% acrylic latex binder material. 
     In the roofing system of the present invention, alternative interply materials may also be employed. One such material is comprised of a roll roofing product including a fiberglass substrate coated with asphaltic material and mineral granules. Such interply materials include Ridglass TG-2 sold by Ridglass Shingle Manufacturing Co. of Fresno, Calif.; OCF Roll Roofing sold by Owens Corning of Toledo, Ohio and Black Warrior sold by Black Warrior Roofing, Inc. of Tuscaloosa, Ala. Another such interply material is comprised of asphalt impregnated felt underlayment material. That type of interply material is sold as Fontana Vulca-Seal 40 by Fontana Paper of Fontana, Calif. and a monoasphaltic barrier product available from Vliepa of Bracht, Germany. Suitable interply materials include JM Sure Grip and JM Nord Shield, available from Johns Manville, and GAF Weatherwatch, available from GAF. 
     In a further embodiment of the present invention, the roofing system comprises a roof deck of a building, a first layer of underlayment material attached to the roof deck, a second layer of the underlayment material attached to the first layer, and a multiplicity of courses of roofing shingles attached to the second layer of underlayment material. The underlayment material may be any of the interply materials described above with the exception of the roll roofing and felt underlayment type products. 
     The present invention also relates to a laminated roofing shingle comprising a first shingle sheet and a second shingle sheet. The first shingle sheet has a headlap section and a buttlap section. The buttlap section is at least about 60% of the width of the shingle. The first shingle sheet includes a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. 
     The second shingle sheet is attached to the underside of the first shingle sheet and has portions exposed through the openings between the tabs. The second shingle sheet has at least first, second, and third horizontal striations thereon across at least partial portions of the second sheet which are exposed through the openings between the tabs. The first striation comprises a first elongated quadrilateral area. The first striation has a substantially uniform dark color throughout the first quadrilateral area. The second striation comprises a second elongated quadrilateral area below the first striation. The second striation has a substantially uniform color throughout the second quadrilateral area. The color of the second striation is lighter than the color of the first striation. The third striation comprises a third elongated quadrilateral area below the second striation. The third striation has a substantially uniform color throughout the third quadrilateral area. The color of the third striation is lighter than the color of the second striation. At least the second and third striations provide a color gradation on at least partial portions of the second sheet which are exposed through the openings between the tabs. 
     The laminated roofing shingle of the invention may further comprise on the second shingle sheet at least a fourth horizontal striation thereon across at least partial portions of the second sheet which are exposed through the openings between the tabs. The fourth striation comprises a fourth elongated quadrilateral area below the third striation. The fourth striation has a substantially uniform color throughout the fourth quadrilateral area. The color of the fourth striation is lighter than the color of the third striation. At least the second, third, and fourth striations provide a color gradation on at least partial portions of the second sheet which are exposed through the openings between the tabs. 
     In the aforementioned laminated roofing shingles of the present invention the width of each of the striations may be approximately equal. In embodiments having three striations on the second sheet, the widths of the first and third striations may be approximately equal and approximately one-half the width of the second striation. Alternatively, the widths of the first and third striations may be approximately equal and substantially wider than the width of the second striation. Further, the third striation may be substantially wider than the second striation and the first striation may be approximately twice the width of the third striation. 
     Each of the tabs of the laminated shingles described above may have different color contrasts from one another. Additionally, the dimensions of one of the tabs may differ from the dimensions of others of the tabs. 
     An alternative laminated roofing shingle of the present invention also comprises also first and second shingle sheets. The first shingle sheet has a headlap section and a buttlap section including a plurality of tabs which are spaced apart to define one or more openings between the tabs. Each of the tabs has a relatively uniform color throughout the tab. The width of the buttlap section is at least about 60% of the width of the shingle. The second shingle sheet is attached to the underside of the first shingle sheet and has varying portions exposed through the openings between the tabs and below at least one of the tabs of the first shingle sheet. 
     In one embodiment of each of the laminated shingles described above, the width of the buttlap section of the shingle is at least 70% of the width of the shingle. In another embodiment, the width of the buttlap section of the shingle is at least about 80% of width of the roofing shingle. The laminated roofing shingles of the present invention may have an exposure width of at least about 60% of the width of the shingle. Alternatively, the laminated shingles may have an exposure width of at least about 64% of the width of the shingle. 
     The present invention also includes three tab roofing shingles having an exposure width of at least about 60% of the width of the shingle, preferably an exposure width of at least about 64% of the width of the shingle. 
     According to one exemplary embodiment of the present invention, a laminated shingle  20  is illustrated in  FIGS. 2 to 5 . The laminated shingle  20  preferably comprises a first shingle sheet  30  attached to a second shingle sheet  50 . First shingle sheet  30  has a generally rectangular configuration defining a headlap section  32  of the laminated shingle  20 , with a plurality of tabs  36  extending therefrom to define a buttlap section  34  of the laminated shingle  20 . Tabs  36  may also be referred to as “dragon teeth.” A plurality of openings  38  are formed between adjacent tabs  36 . The second shingle sheet  50  also has a generally rectangular configuration and is disposed beneath tabs  36  with portions of the second shingle sheet  50  exposed through the plurality of openings  38 . 
     Various techniques such as gluing may be used to attach the second shingle sheet  50  to the underside of the first shingle sheet  30 . The resulting laminated shingle  20  has a generally rectangular configuration defined in part by longitudinal edges  22  and  24  with lateral edges  26  and  28  disposed there between. Longitudinal edge  22  is defined by an end of headlap section  32  and constitutes the upper edge of the laminated shingle  20 . Longitudinal edge  24  is defined by an end of buttlap section  34  and constitutes the lower (or leading) edge of laminated shingle  20 . A plurality of release tape strips  40  or a continuous line of release tape may be disposed on the exterior of first shingle sheet  30  on the headlap section  32  of the shingle. Preferably, the release tape is placed on the back of headlap section  32 . Self sealing adhesive strips or a continuous line of sealant material (not shown) can also preferably be disposed on the interior or unexposed side of second shingle sheet  50  near longitudinal edge  24 . 
     The resulting laminated shingle  20  also preferably has an interply alignment line  41 , which will be discussed in greater detail below. Although the interply alignment line  41  can be positioned anywhere in the headlap section  32 , it is preferably positioned in common bonding region  33  of laminated shingle  20 . The common bonding region  33  is the only region of the laminated shingle where there are two layers of material throughout the length of the laminated shingle. 
     First shingle sheet  30  may sometimes be referred to as a “tab sheet” or a “dragon tooth sheet,” and second shingle sheet  50  may sometimes be referred to as a “backer strip” or “shim.” In addition, openings  38  formed between adjacent tabs  36  with portions of backer strip  50  disposed thereunder may sometimes be referred to as “valleys.” Depending upon the desired application and appearance of each laminated shingle  20 , tabs  36  may have equal or different widths and may have a square, rectangular, trapezoidal, or any other desired geometric configuration. In the same respect, openings  38  may have equal or different widths and may have a square, rectangular, trapezoidal or any other desired geometric configuration. As will be explained later in more detail, laminated shingles  20  may be formed from a sheet  80  of roofing material shown in  FIG. 6  with tabs  36  and openings  38  formed as a “reverse image” of each other. 
     For the preferred embodiment of the present invention, laminated shingle  20  may be formed from an asphalt coated fiberglass mat. If desired, the present invention may also be used with shingles formed from organic felt or other types of base material. Accordingly, the present invention is not limited to use with shingles including a fiberglass mat. 
     The exposed outer surface or weather surface  42  for shingle  20  is defined in part by tabs  36  and the portions of backer strip  50  which are exposed through openings  38  between adjacent tabs  36 . Weather surface  42  of laminated shingle  20  may be coated with various types of mineral granules to protect the asphalt coating, to add color to laminated shingle  20  and to provide fire resistance. For some applications, ceramic coated mineral granules may be used to form the outer layer comprising weather surface  42 . Also, a wide range of mineral colors from white and black to various shades of red, green, brown and any combination thereof may be used to provide the desired color for shingle  20 . The underside of shingle  20  may be coated with various inert minerals with sufficient consistency to seal the asphalt coating. 
     According to the present invention, three or more horizontal striations are provided on the surface of backer strip  50  which is exposed through openings  38 . The horizontal striation nearest the headlap section of the shingle is made a uniformly dark color. Other horizontal striations are each made of a uniform color which together provide a color gradient or gradation according to the teachings of U.S. Pat. Nos. 5,369,929; 5,611,186; and 5,666,776, which are incorporated herein by reference in their entireties. The color of the striation nearest the headlap section may be black or may be selected to be consistent with (i.e., to continue) the color gradation of the other horizontal striations. 
     The laminated shingles of the present invention have a buttlap section  34 , which is at least about 60%, preferably at least about 70%, and more preferably at least about 80% of the width of the laminated shingle, i.e., the combined width of the buttlap section  34  and the headlap section  32 . The term “about,” as used herein, means ±10% of the stated value. For example, an exemplary shingle having the dimensions of 13.25 inches in width and 36 inches in length would have a buttlap section of at least about 8 inches in width (preferably at least about 9.3 inches and more preferably at least about 10.6 inches). Accordingly, the laminated shingles of the present invention have an exposure width of at least about 60%, preferably at least about 64% of the width of the laminated shingle, i.e., the combined width of the buttlap section  34  and the headlap section  32 . The exposure width is the portion of the buttlap section  34  that is exposed to the environment when the shingle is laid up on a roof. For example, an exemplary shingle having the dimensions of 13.25 inches in width and 36 inches in length would have an exposure width of at least about 8 inches, preferably at least about 8.5 inches. 
     Using the foregoing unique combination of buttlap section (exposure) dimension and arrangement of color striations, the laminated shingle according to the present invention provides a significantly greater visual appearance than existing laminated shingles. While the improvement in visual appearance is applicable to all types of roofs, it is especially significant on low-sloped roofs (i.e., those roofs having less than six feet of rise for every twelve feet of run). 
     In preferred embodiments, the laminated shingle illustrated in  FIGS. 1 through 4  has a width of 12 inches and a length of 35.5 inches. The exposure is 8.5 inches. The backer strip is 9.75 inches wide. The interply alignment line is located 10.5 inches from the bottom of the shingle and the nail zone is 8.75 inches to 9.25 inches from the bottom of the shingle. Both the release tape and the self seal sealant are on the back of the shingle. The interply material is 18 inches wide. In the roofing system, the interply is at least double ply with one inch of triple ply overlap. 
     Another exemplary embodiment of the present invention is shown in  FIGS. 9 ,  10  and  11  which illustrate the inventive roofing system and laminated shingle  120 .  FIG. 9  illustrates courses of shingles  120  and interply material  260 . The laminated shingle  120  preferably comprises a first shingle sheet  130  attached to a second shingle sheet  150 . First shingle sheet  130  has a generally rectangular configuration defining a headlap section  132  with a plurality of tabs  136  extending therefrom to define a buttlap section  134  of the laminated shingle  120 . A plurality of openings  138  are formed between adjacent tabs  136 . The second shingle sheet  150  also has a generally rectangular configuration and is disposed beneath tabs  136  with portions of the second shingle sheet  150  exposed through the plurality of openings  138  and below at least one of the tabs  136 . 
     As in the aforementioned laminated shingle embodiment, various techniques such as gluing may be used to attach the second shingle sheet  150  to the underside of the first shingle sheet  130 . The resulting laminated shingle  120  has a generally rectangular configuration defined by longitudinal and lateral edges as noted above with respect to the other embodiment of a laminated shingle. A plurality of release tape strips  140  or a continuous line of release tape may be disposed on the back of the second shingle sheet  150 . Self sealing adhesive strips  142  or a continuous line of sealant material may be disposed as illustrated. 
     The resulting laminated shingle  120  also preferably has an interply alignment line  141  which will be discussed in greater detail below. Although the interply alignment line  141  can be positioned anywhere in the headlap section  132 , it is preferably positioned in the common bond region  133  of the laminated shingle  120 . 
     The phraseology noted above regarding “tab sheet”, “backer strip”, etc. is also applicable to the laminated shingle embodiment in  FIGS. 9–11 . Also, the exposed outer surface or weather surface  142  for shingle  120  is defined in part by tabs  136  and the portions of backer strip  150  which are exposed through openings  138  and below tabs  136 . The weather surface  142  of laminated shingle  120  may be coated with various types of mineral granules as noted above. 
       FIGS. 12 and 13  illustrate the roofing system of the present invention employing three tab shingles. In  FIG. 12 , a multiplicity of courses of roofing shingle  220  and interply material  360  are shown on a portion of a roof. An interply alignment line  241  and self-sealing adhesive strips  242  are also illustrated. Three tab shingles are single ply roofing materials usually comprising a strip of asphalt roofing material which has been cut to show three separate tabs  236 . 
     For the laminated shingle depicted in  FIGS. 9–11 , the preferred dimensions of the shingle are 12–5.8 inches width by 38 inches length. The exposure is 7 inches and the backer strip is 8 inches wide. The interply alignment line is 9 inches from the bottom of the shingle and the nail zone is 7.25 inches to 7.75 inches from the bottom of the shingle. The interply is 16 inches wide. The tab lengths are 5¾ inches to 7 inches long. There are 54 shingles per square and 18 shingles per bundle. 
     For the shingles depicted in  FIGS. 12 and 13 , the preferred dimensions are 9 inch width by 36 inch length. The exposure is 5 inches. The interply alignment line is located 7 inches from the bottom of the shingle. Release tape is on the back of the shingle and the self-seal sealant is on the front. The interply material is 10.5 inches wide. 
     Table I below provides a shingle product comparison between typical prior art shingle dimensions and the roofing shingles and roofing system of the present invention: 
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE I 
               
               
                   
               
               
                   
                   
                   
                   
                   
                 Reduced 
                 Reduced 
                 Wt./material 
               
               
                 Shingle Type 
                 Exposure 
                 Length 
                 Width 
                 Sq. wt. 
                 Width 
                 Sq. wt. 
                 savings 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 3 Tab asphalt 
                 5 
                 36 
                 12 
                 210 
                 9 
                 160 
                 24% 
               
               
                 Large asphalt 
                 8.25 
                 36 
                 19 
                 350 
                 12 
                 250 
                 29% 
               
               
                 State 
                 6 
                 12 
                 14 
                 1200 
                 10 
                 850 
                 29% 
               
               
                 Wood 
                 10 
                 Varies 
                 24 
                 200 
                 16 
                 150 
                 25% 
               
               
                   
               
            
           
         
       
     
     While many different shingle dimensions may be utilized with the present invention, exemplary dimensions are provided in  FIG. 14 . In that embodiment, the laminated shingles are not less than 100 lb./100 ft. 2  As illustrated in  FIGS. 14 and 15 , the area of each shingle is 3.52 ft. 2  and 48 shingles cover 100 sq. ft. of deck surface. Other characteristics of the roofing system illustrated in those figures are as follows: 
     Dimensions and Tolerances:
         Length—not exceeding +/−½″   Width—not exceeding +/−¼″       

     Interply Requirements:
         Materials:
           VersaShield Underlayment available from Elk Corporation of Dallas.   D4601 Type I Base Sheet, an asphalt coated glass fiber based sheet used in roofing. For the present invention Type I materials are preferred over the heavier, more expensive Type II materials. Acceptable materials are available as ZBASE from Black Warrier Roofing, Inc. of Tuscaloosa, Ala.   D2626 Base Sheet, an asphalt saturated and coated organic felt based sheet used in roofing and available as Vulca-Seal from Fontana Paper of Fontana, Calif.   ICBO AC-165 Underlayment, an asphalt coated glass fiber mat roof underlayment available as TG-2 SBS all purpose underlayment/base sheet from Ridglass Shingle Manufacturing Co. of Fresno, Calif.   D1970 Fully Adhered membrane, an ice and water self adhering polymer modified bituminous sheet material used as steep roofing underlayment for ice dam protection available from CertainTeed, GAF, W. R. Grace, Carlisle, Tamko and others.   Vliepatex Coating B Interply Material available from Vliepa of Bracht, Germany.   
           Dimensions:
           Minimum 15″ wide   
               

     Application:
             To be placed 2″ above the shingle exposure horizontally across the roof.   End laps a minimum of 6″.           

     Returning to  FIGS. 1 through 4 , the exemplary embodiment shown includes a backer strip  50  with four horizontal striations  52 ,  54 ,  56 , and  58 . Striation  58 , the striation adjacent the headlap section of the shingle, is a uniformly dark-colored striation. The horizontal striations  52 ,  54 , and  56  are colored striations that provide a color gradient or gradation from a light color near the leading edge  24  to a dark color near the upper portion of each opening  38 . The color of the horizontal striation  58  may be selected to be consistent with (i.e., to continue) the color gradient or gradation of the other striations (so that striations  52  through  58  altogether provide a color gradient or gradation). Preferably, the width of each striation is approximately equal. In addition, for aesthetic reasons, it is preferred that the width of each striation be in the range of about one to about two inches. 
     The number of horizontal striations and the width of each striation on backer strip  50  may be varied depending upon the desired aesthetic appearance of the resulting laminated shingle  20 . It is preferred, however, for a shingle to have an exposure width of 7 to 9 inches and from three to six horizontal striations thereon. 
     Each striation may have a different color to establish the desired amount of contrast. For the purposes of this patent application, a different color may include a different tone. In addition, contrast for purposes of this patent application is defined as the degree of difference in the tone or shading between areas of lightest and darkest color. For some applications, a gradual change in contrast associated with a large number of striations may provide the appearance of depth or thickness associated with wood or other natural products. Also, the amount or degree of contrast in the color gradient exposed in each opening  38  may be varied depending upon the desired aesthetic appearance. An important feature of the present invention is the ability to vary the color gradient and the amount of contrast to provide the desired illusion or appearance of thickness on the finished roof. 
       FIGS. 6–8A  show one procedure for fabricating a laminated shingle  20  from a sheet  80  of roofing material. Various procedures and methods may be used to manufacture sheet  80  from which shingles incorporating the present invention may be fabricated. Examples of such procedures are contained in U.S. Pat. No. 1,722,702 entitled “Roofing Shingle”; U.S. Pat. No. 3,624,975 entitled “Strip Shingle of Improved Aesthetic Character”; U.S. Pat. No. 4,399,186 entitled “Foam Asphalt Weathering Sheet for Rural Roofing Siding or Shingles”; and U.S. Pat. No. 4,405,680 entitled “Roofing Shingle.” Each of these patents is incorporated by reference herein in its entirety. 
     Sheet  80  is preferably formed from a fiberglass mat placed on a jumbo roll (not shown) having a width corresponding to the desired sheet  80 . Laminated shingles  20  are typically fabricated in a continuous process starting with the jumbo roll of fiberglass mat. As previously noted, laminated shingle  20  may also be fabricated using organic felt or other types of base material. 
     Sheet  80  shown in  FIG. 6  preferably comprises a fiberglass mat with an asphalt coating which both coats the fibers and fills the void spaces between the fibers. A powdered mineral stabilizer (not shown) may be included as part of the asphalt coating process. A smooth surface of various inert minerals of sufficient consistency may be placed on the bottom surface of sheet  80  to seal the asphalt coating. 
     Top surface  82  is preferably coated with a layer of mineral granules such as ceramic coated stone granules to provide the desired uniform color portions and the color gradient portions associated with weather surface  42  of shingle  20 . Typically, the mineral granules are applied to the sheet  80  while the asphalt coating is still hot and forms a tacky adhesive. 
       FIG. 6  shows a schematic representation of a roller  86  and mineral granule hopper  90  which may be used to provide the desired granular surface coating to sheet  80 . The hopper  80 , which may be any hopper which is well known in the art, includes a plurality of partitions  91  which divide the hopper  90  into three sets of compartments: a set of compartments  92 ,  94 ,  96  and  98  at each end of the hopper and a central compartment  99  between the ends. The central compartment  99  of hopper  90  contains a uniform mixture of the mineral granules which will produce the desired color on dragon teeth or tabs  36  and the other portions of first shingle sheet  30 , which will be exposed to the environment. This transfer of mineral granules is sometimes referred to as a “color drop.” The rotation of roller  86  and the movement of sheet  80  are coordinated to place the desired color drop on each shingle  20 . 
     For the embodiment of the present invention shown in  FIGS. 6–8A , each first shingle sheet  30  will have the same uniform mixture of mineral granules on both the headlap section and the buttlap section. For the embodiment shown in  FIGS. 1 to 4 , headlap section  32  may have the same layer of mineral granules as buttlap section  34  or headlap section  32  may have a neutral or non-colored layer of mineral granules. The surface layer on headlap section  32  may be varied as desired for each application. 
     Different colored mineral granules corresponding to the desired color of horizontal striations  52 ,  54 ,  56 , and  58  are preferably placed in the appropriate compartments  92 ,  94 ,  96 , and  98 , respectively. As sheet  80  passes under roller  86 , mineral granules from the appropriate compartment in hopper  90  will fall onto roller  86  and will be transferred from roller  86  to top surface  82  of sheet  80 . The volume or pounds per square foot of mineral granules placed on surface  82  is preferably the same throughout the full width of sheet  80 . However, by dividing the hopper  90  into compartments, the color of various portions of sheet  80  may be varied including providing horizontal striations  52 ,  54 ,  56 , and  58  for backer strip  50 . 
     It is important to note that conventional procedures for fabricating shingles having an exterior surface formed by mineral granules include the use of granule blenders and color mixers, along with other sophisticated equipment to ensure a constant uniform color at each location on the exposed portions of the shingles. Extensive procedures are used to ensure that each color drop on a sheet of roofing material is uniform. The color drop between shingles may be varied to provide different shades or tones in color. However, within each color drop, concerted efforts have traditionally been made to insure uniformity of the color on the resulting shingle associated with each color drop. 
     Once the color drop process is complete, the sheet  80  is allowed to cool. After the sheet  80  is cooled, it is then cut. As shown by dotted lines  84 ,  86 , and  88  in  FIG. 6 , sheet  80  may be cut into four horizontal lengths or lanes  60 ,  62 ,  64 , and  66 . The width of lanes  62  and  64  corresponds with the desired width for first shingle sheet  30 . The width of lanes  60  and  66  corresponds with the desired width for second shingle sheet  50 . 
     The cut along dotted line  86  corresponds with the desired pattern for dragon teeth  36  and associated openings  38 . For some applications, more than four lanes may be cut from a sheet of roofing material similar to sheet  80 . The number of lanes is dependent upon the width of the respective sheet of roofing material and the desired width of the resulting shingles. 
     Sheet  80  may also be cut laterally to correspond with the desired length for the resulting first shingle sheet  30  and second shingle sheet  50 . As shown in  FIGS. 5 ,  7 , and  8 A, each lateral cut of sheet  80  results in two backer strips  50  and two first shingle sheets  30  which may be assembled with each other to form two laminated shingles  20 . The resulting laminated shingles  20  may be packaged in a square for future installation on a roof as is well known in the art. 
     The cutting of sheet  80  and the assembly of laminated shingles  20  may be performed in a number of ways. For example, the laminated shingles  20  may be produced through an off-line lamination process in which the sheet  80  is cut both longitudinally and laterally and then the tab sheets and backer sheets, which are produced, are matched and attached together. Alternatively, and more preferably, the laminated shingles  20  may be produced in a continuous in-line lamination process in which the sheet  80  is cut longitudinally by a rotary die cutter, producing horizontal lengths (such as lanes  60 ,  62 ,  64 , and  66 ), which consist of continuous tab sheet strips and backer sheet strips. The tab sheet strips and backer sheet strips are joined and adhered together to produce laminated shingle strips through means well known in the art. The laminated shingle strips may then be passed through a cutting cylinder, which cuts the strips into individual shingles. After discrete shingles are formed, they can be processed with commonly used apparatus for handling shingles, such as a shingle stacker to form stacks of shingles and a bundle packer to form shingle bundles. 
     It is important to note that a color gradient of the present invention may be placed on shingles using various procedures and various types of materials. The present invention is not limited to shingles formed by the process shown in  FIGS. 6–8A . 
       FIG. 8A  is an exploded isometric view showing shingle components taken from a sheet of roofing material according to another embodiment of the present invention. In the embodiment of  FIG. 8A , as better shown in  FIG. 8B , which is an enlarged drawing of a portion of a backer strip of  FIG. 8A , transition stripes  152  and  154  are disposed between adjacent pairs  52 / 54  and  54 / 56  of the horizontal striations  52 ,  54  and  56 . Each transition stripe has a color value that is a mixture of the colors associated with the two horizontal striations adjacent to the transition stripe. The transition stripes may be used when the difference in contrast between adjacent horizontal striations is sufficiently great that a shingle would present a confused or disjointed appearance without the transition stripes. The transition stripes may be applied as described in U.S. Pat. No. 5,611,186, which is incorporated by reference herein in its entirety. 
     The present invention also provides a roofing system including (i) a first laminated shingle, as described above, which is located in a first row of shingles, (ii) an interply layer disposed on top of the headlap portion of the first laminated shingle, and (ii) a second laminated shingle, as described above, disposed on top of the interply layer, wherein the second laminated shingle is located in a second row of shingles horizontally adjacent, i.e., above, to the first row of shingles. Accordingly, an interply layer is placed in between each pair of shingles located in horizontally adjacent rows. A limited lateral offset can preferably be provided between horizontally adjacent rows such that any given pair of shingles located in horizontally adjacent rows is positioned to provide a limited lateral offset to each other. The interply layer is preferably placed on top of the first laminated shingle so that the bottom edge of the interply layer is lined up with the interply alignment line of the first laminated shingle, as described above. This roofing system can be repeated to cover the entire roof, e.g., a second interply layer is placed on top of the second laminated shingle, which is located in the second row of shingles, and a third laminated shingle is placed on top of the second interply layer, wherein the third laminated shingle is located in a third row of shingles located horizontally adjacent to the second row of shingles and so on up toward the peak of the roof. 
     The interply layer can be of any width and length suitable to the application. Preferably, the width of the interply layer is at least about 100%, more preferably from about 105% to about 130%, most preferably from about 105% to about 121% of the width of the laminated shingle. For example, when an exemplary laminated shingle having a width of 13.25 inches is utilized in the roofing system, the interply layer can have a width preferably of about 13.25 inches, more preferably from about 14 inches to about 17.2 inches, and most preferably from about 14 inches to about 16 inches. A plurality of self sealing adhesive strips or a continuous line of self sealing adhesive can preferably be disposed on one or more sides and near one or more edges of the interply layer to secure the interply layer between shingles in horizontally adjacent rows and the roof. 
     Without wanting to be limited by any one theory, it is believed that the interply layer can effectively replace a large headlap section of a shingle, which was typically believed to be needed for effective protection from the elements. Accordingly, the interply layer can be made of any weather proofing material known in the art. Preferably, the interply layer is made of material that is both fire and water resistant. 
     An exemplary roofing system according to the present invention is illustrated in  FIG. 1 . As shown in  FIG. 1 , a plurality of laminated shingles  20  may be installed on a roof or other structure (not shown) to provide protection from the environment and to provide an aesthetically pleasing appearance. The normal installation procedure for laminated shingles  20  includes placing each shingle  20  on a roof in an overlapping configuration with an interply layer  160  disposed in between horizontally adjacent rows of shingles. Typically, an interply layer  160  is disposed on the headlap section  32  of one shingle  20 , and preferably the interply layer  160  will be disposed such that the bottom edge  162  of the interply layer is aligned with an interply alignment line  41 . The top edge  166  of the interply layer is preferably disposed on the surface of the roof, e.g. by nailing. A plurality of self sealing adhesive strips or a continuous line of self sealing adhesive can preferably be disposed on the bottom of interply layer  160  near edge  162  of the interply layer to secure the interply layer between shingles in horizontally adjacent rows and on to the roof. Next the buttlap section  34  of one shingle  20  is disposed on top of the interply layer so that the buttlap section is also disposed on top of the headlap section of another shingle  20  in the horizontally adjacent row below. Self-sealing adhesive (not shown) can be used to secure the overlapping shingles  20  on to the interply layer  60 . Also, a limited lateral offset is preferably provided between horizontally adjacent rows of shingles  20  to provide an overall aesthetically pleasing appearance for the resulting roof. 
     Although the present invention has been described with reference to certain preferred embodiments, various modifications, alterations, and substitutions will be apparent to those skilled in the art without departing from the spirit and scope of the invention, as defined by the appended claims.