Abstract:
The present invention relates generally to roofing systems. The present invention relates more particularly flashings for use in roofing systems in which structures such as photovoltaic modules are affixed to a roof on top of an underlying roof covering such as shingles, tiles, shakes or slates. For example, in one embodiment, the present invention provides a flashing element including a substantially flat plate having a top side and a bottom side disposed facing the roof deck, the plate having a hole formed therein, the plate having a recess formed in its bottom side surrounding the hole; and a spacer disposed in the recess between the roof deck and the bottom side of the plate, the spacer having a thickness at least about as great as the thickness of the recess, the spacer not substantially occluding the hole in the plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 61/582,507, filed Jan. 3, 2012, which is hereby incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to roofing systems. The present invention relates more particularly flashings for use in roofing systems in which structures such as photovoltaic modules are affixed to a roof on top of an underlying roof covering such as shingles, tiles, shakes or slates. 
         [0004]    2. Summary of the Related Art 
         [0005]    The search for alternative sources of energy has been motivated by at least two factors. First, fossil fuels have become increasingly expensive due to increasing scarcity and unrest in areas rich in petroleum deposits. Second, there exists overwhelming concern about the effects of the combustion of fossil fuels on the environment due to factors such as air pollution (from NO x , hydrocarbons and ozone) and global warming (from CO 2 ). In recent years, research and development attention has focused on harvesting energy from natural environmental sources such as wind, flowing water, and the sun. Of the three, the sun appears to be the most widely useful energy source across the continental United States; most locales get enough sunshine to make solar energy feasible. 
         [0006]    Accordingly, there are now available components that convert light energy into electrical energy. Such “photovoltaic cells” are often made from semiconductor-type materials such as doped silicon in either single crystalline, polycrystalline, or amorphous form. The use of photovoltaic cells on roofs is becoming increasingly common, especially as device performance has improved. They can be used to provide at least a significant fraction of the electrical energy needed for a building&#39;s overall function; or they can be used to power one or more particular devices, such as exterior lighting systems. 
         [0007]    Photovoltaic devices are often provided as separate modules to be attached to a roof. Such modules are often heavy, and therefore must be securely fastened to the roof deck or to some structural support element. To do so, the existing roof coverings (e.g., asphalt shingles) must be penetrated. For example, in some systems a rack attaches to a roof mount bracket that is bolted through the roof covering to the rafters supporting the roof deck. These penetrations can cause undesirable roof leaking Accordingly, a water-resistant flashing is needed to prevent water intrusion at the point(s) of penetration. 
       SUMMARY OF THE INVENTION 
       [0008]    One aspect of the present invention is a flashing element disposed on a roof, the flashing element including
       a substantially flat plate having a top side and a bottom side disposed facing the roof deck, a first end and a second end opposing the first end with a first dimension extending therebetween, the first end disposed toward the top of the roof; the second end disposed toward the bottom of the roof, and a third end and a fourth end opposing the third end with a second dimension extending therebetween, the plate having a hole formed therein, the plate having a recess formed in its bottom side surrounding the hole; and   a spacer disposed in the recess between the roof deck and the bottom side of the plate, the spacer having a thickness at least about as great as the thickness of the recess, the spacer not substantially occluding the hole in the plate       
 
         [0011]    Another aspect of the invention is a mounting system disposed on a roof, the roof including a roof deck and a roof covering disposed thereon, the mounting system a flashing element as described herein, the flashing element disposed with its hole disposed over the roof covering; a mounting element; and a fastener affixing the mounting element to the roof, the fastener being disposed through the hole and penetrating the roof covering. 
         [0012]    Another aspect of the invention is a method for installing a mounting system as described herein on a roof, the method including disposing the flashing element on the roof; then disposing the fastener through the hole in the plate; and disposing the sealant in the recess between the spacer, the plate, and the roof covering. 
         [0013]    Another aspect of the invention is a kit for installing a flashing element or a mounting system as described herein, the kit including
       a substantially flat plate having a top side and a bottom side disposed facing the roof deck, a first end and a second end opposing the first end with a first dimension extending therebetween; and a third end and a fourth end opposing the third end with a second dimension extending therebetween, the plate having a hole formed therein, the plate having a recess formed in its bottom side surrounding the hole; and   a spacer sized to be disposed in the recess between the roof deck and the bottom side of the plate, the spacer having a thickness at least about as great as the thickness of the recess, the spacer being configured to not substantially occlude the hole in the plate when disposed in the recess.       
 
         [0016]    In certain aspects, the flashing elements, mounting systems, methods and kits of the present invention can result in a number of advantages over the prior art. For example, in certain embodiments, the present invention can provide secure attachment of a bulky structure such as a photovoltaic module to a roof without causing a leak point on the roof. Other advantages will become apparent to the person of skill in the art in view of the present disclosure. 
         [0017]    The accompanying drawings are not necessarily to scale, and sizes of various elements can be distorted for clarity. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is schematic top view and a schematic cross-sectional view of a plate for use in one embodiment of the invention; 
           [0019]      FIG. 2  is a schematic perspective view and a schematic top view of a spacer for use in one embodiment of the invention; 
           [0020]      FIG. 3  is a schematic cross-sectional view of a flashing element disposed on a roof according to one embodiment of the invention; 
           [0021]      FIG. 4  is a partial schematic cross-sectional view of a flashing element according to another embodiment of the invention; 
           [0022]      FIG. 5  is a schematic cross-sectional view of a plate for use in one embodiment of the invention; and 
           [0023]      FIG. 6  is a partial schematic cross-sectional view of a flashing element disposed on a roof according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    One embodiment of a flashing element according to one aspect of the invention includes a plate and a spacer. An example of a plate  110  according to one embodiment of the invention is shown in top schematic view in  FIG. 1 , and in cross-sectional schematic view in  FIG. 2 . The plate  110  is substantially flat (i.e., but for the raised portion, described in more detail below), and has a top side  112  and a bottom side  113 . The plate also has (e.g., in the plane of the plate) a first end  114  and a second end  115  opposing the first end, with a first dimension  116  extending between them; and a third end  117  and a fourth end  118  opposing the third end, with a second dimension  119  (e.g., perpendicular to the first dimension) extending between them. The plate also has a hole  120  formed therein; and a recess  125  formed in its bottom side  113  surrounding the hole. 
         [0025]    The flashing element also includes a spacer. An example of a spacer  130  according to one embodiment of the invention is shown in perspective view and in top view in  FIG. 2 . The spacer is sized to fit within the recess on the bottom side of the plate. The spacer shown in  FIG. 2  has an opening  135  (here, a hole) formed therein, such that when the spacer is disposed in the recess, its opening can be aligned with the hole in the plate. The spacer has a thickness at least about as great as the thickness of the recess. For example, in certain embodiments, the thickness of the spacer is in the range of about 1 mm to about 10 mm in thickness. In certain embodiments, the thickness of the spacer is within about 40 mils, within about 20 mils, or even within about 15 mils of the thickness of the recess. Accordingly, when the plate and the spacer are affixed to the roof with a fastener penetrating through the opening, the spacer can close the opening so as to protect the penetration point and the surrounding area from moisture intrusion. 
         [0026]      FIG. 3  is a cross-sectional view of the flashing element (along the first dimension) as installed on a roof deck. The plate  110  is disposed on roof deck  150 , directly upon an existing roof covering  155 . The bottom side of the plate  110  faces the roof deck  150 . The first end  114  is disposed toward top of the roof and the second end  115  is disposed toward the bottom of the roof. The third and fourth ends, not shown in this view can, for example, face opposed lateral edges of the roof. The spacer  130  is disposed in the recess between the roof deck and the bottom side of the plate. The spacer does not substantially occlude the hole in the plate. For example, in the embodiment of  FIG. 3 , the opening of the spacer is aligned with the hole of the plate. 
         [0027]    In certain embodiments, there is a gap between one or more of the outside edges of the spacer and the inside edge of the recess. For example, in the embodiment of  FIG. 3 , there is a gap  137  between the outside edges of the spacer and the inside edges of the recess. The gap can be, for example, in the range of about 0.5 mm to about 10 mm, or about 1 mm to about 5 mm in thickness. In certain embodiments, the gap completely surrounds the spacer, such that substantially no edges of the spacer are in contact with the inside edge of the recess of the plate. 
         [0028]    In the embodiment of  FIG. 3 , the spacer and the plate are provided as separate pieces. In other embodiments, however, the spacer can be provided as attached directly to the plate. For example, the spacer can be glued or otherwise affixed to the plate. In other embodiments, the spacer is integrally formed with the plate. For example,  FIG. 4  is a cross-sectional view of a flashing element in which the spacer  430  is integrally formed with the plate  410 . In certain embodiments, and as shown in  FIG. 4 , the spacer has an opening formed therein, and the flashing element includes one or more channels  438  that allow fluid communication between the opening of the spacer and the outside surface of the spacer. In such embodiments, if a liquid sealant is disposed into the opening, it can flow through the one or more channels to the outside surface of the spacer. 
         [0029]    A variety of materials can be used in the construction of the spacer. In certain embodiments, the spacer is made from a polymeric material. For example, the spacer can be formed from neoprene, rubber, nylon, polyolefin such as polyethylene (e.g., UHMW PE) or silicone. In other embodiments, the spacer is made from metal or a composite material. For example, in one embodiment, the spacer is formed from a metal coated with a rubberized or elastomeric material. In certain embodiments, the spacer has a Shore A hardness in the range of 30-70, and sufficient to remain in place and substantially avoid flow under compression.. 
         [0030]    Similarly, a variety of materials can be used in the construction of the plate. In certain embodiments, the plate is substantially rigid, for example, as rigid as 10 mil thick aluminum. In one embodiment, the plate is made from a metallic material, such as aluminum. The metallic material can in some embodiments be painted or surface treated, as is conventional for roof flashings. In other embodiments, the plate is formed from polymer or a composite material. 
         [0031]    The plate can be formed in a variety of shapes. For example, in certain embodiments, the plate is substantially rectangular, for example, as shown in  FIG. 1 . However, other shapes can also be used, for example, other quadrilateral shapes such as trapezoidal or parallelogram; triangular. In certain embodiments, the first dimension is in the range of about 4 inches to about 24 inches. For example, in one embodiment, the first dimension is in the range of about 6 inches to about 18 inches. In certain embodiments, the second dimension is in the range of about four inches to about 20 inches. For example, in one embodiment, the second dimension is in the range of about 6 inches to about 14 inches. In certain embodiments, the first dimension is longer than the second dimension. 
         [0032]    As noted above, the plate has a recess formed in its bottom side. In certain embobdiments, as shown in  FIG. 1 , the recess is formed by a raised portion of the plate. In other embodiments, for example as shown in the cross-sectional schematic view of  FIG. 5 , the recess  525  is formed by a thinned portion of the plate. In certain embodiments, the recess is in the range of about 1 cm to about 6 cm in width. In certain embodiments, the recess is in the range of about 1 mm to about 15 mm in thickness. 
         [0033]    Another aspect of the invention is a mounting system disposed on a roof. An example of a mounting system according to this embodiment is shown in  FIG. 6 . The roof includes a roof deck  650 , which has a roof covering  655  disposed thereon. The mounting system includes a flashing element  600  as described above disposed on the roof, with its hole disposed over the roof covering. The mounting system also includes a mounting element  660 , and a fastener  665  affixing the mounting element to the roof. The fastener  665  is disposed through the hole, and penetrates the roof covering. In this embodiment, the fastener affixes the mounting bracket to a roof structural element, here, a rafter  657  supporting the roof deck  650 . In certain embodiments, the fastener can be affixed to as to apply pressure on the spacer, so that it can act as a gasket to seal the penetration through the roof covering from moisture. 
         [0034]    In certain embodiments, and as shown in  FIG. 6 , the mounting system also includes a sealant disposed in the recess. In  FIG. 6 , sealant  680  is seals the spacer to the plate, providing further moisture resistance to the system. In certain embodiments, the sealant can also be provided in the area in the recess around the fastener (e.g., in a hole in the spacer). The sealant can be, for example, a waterproof adhesive or a caulking material. The sealant can be applied in a liquid or semisolid form, such that it covers the surface and helps to seal the penetration in the roof covering from moisture. The sealant can in some embodiments also protrude through the hole in the flashing and up along the fastener on the mounting element. The sealant can also flow underneath and/or on top of the spacer to provide additional sealing. 
         [0035]    The mounting systems of the present invention can be used in conjunction with a variety of roof coverings. For example, in certain embodiments, the roof covering is a set of overlapping roofing elements, such as shingles, shakes or tiles. In certain embodiments, the roof covering has an rms roughness of at least 100 μm, at least 250 μm, or even at least at least 500 μm. For example, in certain embodiments, the roof covering is a set of overlapping granule-coated asphalt shingles. In other embodiments, the roof covering is textured (e.g., formed from a natural textured material such as wood; or formed to look like a natural material). When a sealant is used in conjunction with rough roof coverings, the sealant can flow between the spacer and the roof covering, filling voids and providing additional sealing. 
         [0036]    In certain embodiments, the first end of the plate is disposed underneath an overlying roofing element of the roof covering. For example, when the roof covering is a set of overlapping roofing elements, the flashing element can be with its hole disposed over a first roofing element; and the first end of the flashing element can be disposed underneath an overlapping second roofing element. For example, as shown in  FIG. 3 , the hole  120  of the plate is disposed over the first roofing element  155 , and the first end  114  of the plate is disposed under an overlying second roofing element  157 . 
         [0037]    The mounting systems of the present invention can be used in conjunction with a variety of roof-mounted systems. For example, in certain embodiments, the mounting element is a mounting bracket. The mounting bracket can, for example, mount a photovoltaic module to the roof. In other embodiments, the mounting bracket mounts a heating or cooling system element; a decorative element; or an electrical power component to the roof. 
         [0038]    Another aspect of the invention is a method for installing a mounting system as described herein to a roof. The method includes disposing the flashing element on the roof; then disposing the fastener through the hole in the plate; then disposing the sealant through the hole in the plate; and disposing the sealant in the recess between the spacer, the plate, and the roof covering. In certain embodiments, the sealant is disposed in the recess before the fastener is disposed through the hole in the plate. In other embodiments, the sealant is dispersed in the recess after the fastener is disposed through the hole in the plate. In certain embodiments, the method further includes, for example while disposing the flashing element on the roof or at a time thereafter, disposing an overlying roofing element on the first end of the plate. 
         [0039]    Another aspect of the invention is a kit for installing a flashing element or a mounting system as described herein. The kit includes a plate as described herein, together with a spacer as described herein. For example, in one embodiment, the kit includes a substantially flat plate having a top side and a bottom side disposed facing the roof deck, a first end and a second end opposing the first end with a first dimension extending therebetween; and a third end and a fourth end opposing the third end with a second dimension extending therebetween, the plate having a hole formed therein, the plate having a recess formed in its bottom side surrounding the hole; and a spacer sized to be disposed in the recess between the roof deck and the bottom side of the plate, the spacer having a thickness at least about as great as the thickness of the recess, the spacer being configured to not substantially occlude the hole in the plate when disposed in the recess. In certain embodiments, the kit can further include a fastener sized to fit through the hole in the plate. In certain embodiments, the kit can further include a mounting element such as a mounting bracket, configured to be affixed to a roof by the fastener. 
         [0040]    It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.