Patent Publication Number: US-10323417-B2

Title: Methods, systems and apparatus for roof de-icing

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit or priority under 35 C.F.R. § 119(e) to U.S. Patent Application No. 62/043,282, filed on Aug. 28, 2014, the contents of which are incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Typically, in the construction of homes it is important to protect roofs from leaks due to ice and rain. Traditionally, felt paper was secured to wooden roofs underneath shingles. The felt paper would absorb ice or water that penetrated the shingles, preventing it from reaching the underlying wood. Nailing the felt paper to the roof, however, caused spaces around the nail through which water could seep. The water could follow the nail into the wood, causing leaks in the home. To solve this problem, water shields began to include an adhesive backing to fasten the shield to the wood, instead of using nails. The adhesive backing includes a peel-able strip which, when removed, exposes the adhesive layer for affixing the water shield to the unprotected wooden roof. The top of these water shields were made of a rubberized asphalt material, which created a gasket effect on the shaft of the nail driven through it. These water shields were successful in preventing many types of leaks. 
     In colder climates, however, ice dams can form and allow water to penetrate or flow under the water shield. For example, an ice dam can prevent melt-water from flowing downward off the roof, which can result in the water seeping into the house above the ice and water shield coverage area. Ice dams occur when snow accumulates on the roof of a house with inadequate insulation. Heat conducted through the insufficiently insulated roof, and warm air from the space below, warms the roof and melts the snow on areas of the roof that are above living spaces. It does not, however, melt the snow over cold areas, such as roof overhangs. In these situations, melt-water from the heated areas of the roof flows down the roof, under the blanket of snow, onto the overhang and into the gutter, where colder conditions permit it to freeze. Eventually, ice accumulates along the overhang and in the gutter. Snow that melts later cannot drain properly, backs up on the roof and can result in damaged ceilings, walls, roof structure, and insulation. To avoid this many building codes require a water shield covering the roof two feet into the living space. 
     Additionally, in the past, heating wires and cable-based deicing systems have been disposed on top of the shingles on roofs. These remedial routes provide heat to melt channels in the deposited ice to restore drainage of water through accumulated ice and snow thereby preventing the problems resulting from ice dams. However, since the solution is topical and restricted to the formation of channels at selective areas under severe weather conditions, the efficacy of these solutions is not adequate to prevent leaks from ice dam formation. Furthermore, heating wires and cable-based deicing systems are visible and aesthetically unsightly, easily damaged, and needed to be replaced frequently. 
     A need for a robust solution that address the ice dam problem persists. 
     SUMMARY 
     In an aspect a heating system includes a grounded shield layer made of a continuous piece of metal; a heating element; and a rear adhesive layer comprising of a flame retardant material. The heating element is disposed between the grounded shield layer and the rear adhesive layer; and the rear adhesive layer has a bottom surface that is configured to adhere to at least one of a shingle or an area of a roofing deck. Additionally, a controller is included and is configured to control the flow of electricity to the heating element as a function of a temperature and at least one of a moisture level and a precipitation level. 
     In some embodiments, the grounded shield layer has a transverse dimension forming two transverse edges which is shorter than the width of the rear adhesive layer; and the rear adhesive layer is configured to fold over at least one of the transverse edges of the grounded shield layer to form a region of folded-over rear adhesive strip. In some other embodiments, the region of the folded rear adhesive strip is adhered to a shingle disposed on top of the heating system. 
     In some embodiments, the grounded shield layer is flexible. 
     In some embodiments, the grounded shield layer is made of a metal-containing electrically conducting foil. In some other embodiments, the metal-containing electrically conducting foil is painted over with a weather resistant and UV resistant paint. 
     In some embodiments, the controller is configured to control the flow of electricity continuously, at specific intervals and/or with manual regulation of an operator. 
     In some embodiments—the controller is configured to flow electricity when the ambient temperature is below a predetermined threshold. 
     In some embodiments, the rear adhesive layer is covered by a release liner that is configured to be removed before installation. 
     In some embodiments, the flame retardant material comprising the rear adhesive layer is selected from a group consisting of flame retardant acrylic adhesives, flame retardant epoxy adhesives, flame retardant silicone adhesives, flame retardant polyether adhesives, flame retardant foams, flame retardant rubber compounds, flame retardant polyurethane, flame retardant non-woven fabric and combinations thereof. 
     In some embodiments, the heating element includes a pair of longitudinal stripes spaced apart from each other; and a plurality of transverse bars configured to be spaced apart from each other to cause substantially uniform heating and extending between the longitudinal stripes. In some other embodiments, the pair of longitudinal stripes are made of a material comprising copper. 
     In some embodiments, the heating system further includes an additional adhesive layer including of a flame retardant material; wherein, the additional adhesive layer is disposed on top of the grounded shield layer and configured to adhere to the shingle disposed on top of the heating system. In some other embodiments, the flame retardant material comprising the additional adhesive layer is selected from a group consisting of flame retardant acrylic adhesives, flame retardant epoxy adhesives, flame retardant silicone adhesives, flame retardant polyether adhesives, flame retardant foams, flame retardant rubber compounds, flame retardant polyurethane, flame retardant non-woven fabric and combinations thereof. 
     In an aspect a heated roof system includes a first course of shingles or an area of a roofing deck; a second course of shingles wherein, the second course of shingles is disposed over at least one of a part of the first course of shingles and a part of the area of the roofing deck to create an area of overlap. The heated roof system further includes a heating system disposed in the area of overlap, wherein, the heating system includes a grounded shield layer made of a continuous piece of metal; a heating element; and a rear adhesive layer including a flame retardant material. The heating element is disposed between the grounded shield layer and the rear adhesive layer; wherein the rear adhesive layer has a bottom surface that is configured to adhere to at least one of a shingle or an area of a roofing deck. Additionally, a controller is included that is configured to control the flow of electricity to the heating element as a function of a temperature and at least one of a moisture level and a precipitation level. 
     In some embodiments, the first course of shingles is installed over an overhang of a roof. 
     In some embodiments, the grounded shield layer has a transverse dimension forming two transverse edges which is shorter than the width of the rear adhesive layer; and wherein, the rear adhesive layer is configured to fold over at least one of the transverse edges of the grounded shield layer to form a region of folded-over rear adhesive strip. In some other embodiments, the region of folded rear adhesive strip is adhered to the second course of shingles disposed on top of the heating system. In some other embodiments, the second course of shingles disposed on top of the heating system remain adhered to the region of folded-over adhesive strip upon exposure to a high speed wind. In some other embodiments, the high speed wind is a hurricane force wind of speeds greater than 130 mph. 
     In some embodiments, the grounded shield layer is flexible. 
     In some embodiments, the grounded shield layer is made of a metal-containing electrically conducting foil. In some other embodiments, the metal-containing electrically conducting foil is painted over with a weather resistant and UV resistant paint. 
     In some embodiments, the controller is configured to control the flow of electricity continuously, at specific intervals and/or with manual regulation of an operator. 
     In some other embodiments, the controller is configured to flow electricity when the ambient temperature is below a predetermined threshold. 
     In some other embodiments, the rear adhesive layer is covered by a release liner that is configured to be removed before installation. 
     In some other embodiments, the flame retardant material comprising the rear adhesive layer is selected from a group consisting of flame retardant acrylic adhesives, flame retardant epoxy adhesives, flame retardant silicone adhesives, flame retardant polyether adhesives, flame retardant foams, flame retardant rubber compounds, flame retardant polyurethane, flame retardant non-woven fabric and combinations thereof. 
     In some other embodiments, the heating element includes a pair of longitudinal stripes spaced apart from each other; and a plurality of transverse bars configured to be spaced apart from each other to cause substantially uniform heating and extending between the longitudinal stripes. In some other embodiments, the pair of longitudinal stripes of the heating element are made of a material comprising copper. 
     In some embodiments, the heated roof system further includes an additional adhesive layer including of a flame retardant material; wherein, the additional adhesive layer is disposed on top of the grounded shield layer and configured to adhere to the shingle disposed on top of the heating system. In some other embodiments, the flame retardant material comprising the additional adhesive layer is selected from a group consisting of flame retardant acrylic adhesives, flame retardant epoxy adhesives, flame retardant silicone adhesives, flame retardant polyether adhesives, flame retardant foams, flame retardant rubber compounds, flame retardant polyurethane, flame retardant non-woven fabric and combinations thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The above and other objects and advantages of the present disclosure will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout. 
         FIG. 1  shows a house with an unprotected wooden roof that includes an overhang which extends beyond a heated living area of the house; 
         FIG. 2  shows a standard 3-tab shingle; 
         FIG. 3  shows a typical installation include a couple of courses of shingles installed on a roof; 
         FIG. 4A  shows an exploded view of an exemplary heating system  400 , in accordance with an embodiment of the invention; 
         FIG. 4B  shows in more detail the electrical connections between heating system disposed adjacent to each other, in accordance with an embodiment of the invention; 
         FIG. 4C  shows an image of an embodiment of the heating system in accordance with this disclosure; 
         FIG. 4D  shows the heating element with an exemplary buss bar pattern  411  that can be printed on the polyester film; 
         FIG. 4E  shows a photograph of one embodiment of the heating element; 
         FIG. 4F  shows an embodiment of a heating system with the grounded shielded layer peeled off to reveal the electrical connections s to the heating element and the ground wire; 
         FIG. 4G  shows the placement of the ground wire under the grounded shield layer; 
         FIG. 5  shows an exemplary cut-away view of three courses of heating systems installed under roofing shingles; 
         FIG. 6  shows a side view of 3 courses of heating systems under roofing shingles; 
         FIG. 7  shows an exemplary installation of heating systems on a roof; 
         FIG. 8A  shows an exemplary installation of heating systems on a “hip” portion of a roof; 
         FIG. 8B  shows an alternate connecting arrangement for the three groups of heating systems using a 3-way jumper; 
         FIG. 9  shows an embodiment of power cords used in the connection of the heating system; 
         FIG. 10A-10F  are a series of figures illustrating an exemplary installation process of a heating system; 
         FIGS. 11A and 11B  show the set-up for the Fan-Induced Method used for evaluation of the resistance of shingles to high speed winds; 
         FIG. 12  is an exemplary system with a control unit; and 
         FIG. 13  is an exemplary process of controlling a heating system. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments, of the invention can provide techniques for preventing and eliminating ice dams and snow buildup of the roofs. In an aspect, a heating system includes a grounded shield layer made of a continuous piece of metal, a heating element; and a rear adhesive layer. The heating element is disposed between the grounded shield and the rear adhesive layer and the rear adhesive layer is made of a flame retardant material. The rear adhesive layer also has a bottom surface that is configured to adhere to at least one of a shingle or an area of a roofing deck. Additionally, a controller is included and is configured to control the flow of electricity to the flexible heater as a function of a temperature and at least one of a moisture level and a precipitation level. 
     Referring to  FIG. 1 , a house  100  is shown with an unprotected wooden roof  110 . The wooden roof  110  includes an overhang  120  that extends beyond a heated living area of the house  100 . Overhang  120  is typically an area where ice dams can form. Typically, the roof  110  is covered with shingles, such as standard asphalt shingles, although other types of shingles can be used, such as, wood, clay, metal, etc. 
     Referring to  FIGS. 2-3 , a standard 3-tab shingle  200  is shown. The shingle  200  includes a nailing portion  205 , and three tabs  210 . In a typical installation, shingles  200  are applied to the roof  110  in a series of rows called courses (e.g.,  305  in  FIG. 3 ). Typically, a starter course of shingles is nailed to the roof  110  in such a manner that a top  215  of the shingle is even with the bottom of the roof  110  (e.g., the first starter course of shingles is installed upside down). In some embodiments, the tabs  210  may be cut off the starter course. A first course is then applied on top of the starter course such that a bottom  220  of the shingle is even with the bottom of the roof  110  (e.g., the first course can be applied directly on top of the starter course). In order to cover the rest of the roof  110 , subsequent courses of the singles  200  are applied in a partially-overlapping manner such that the tabs  210  of one course of shingles are placed over the nailing portion  205  of the course below it. 
     There are several possibilities for where to install the heating system on a roof structure: under the shingle, on the roof deck, or under the roof deck. In some embodiments, the location between the shingles and the underlying roof structure where there are no nails can be a preferred location for installing the presently disclosed heating system. The presently disclosed heating system can be affixed both to the underlying roof structure and to the shingles disposed on top of the heating system by using, for example, an adhesive. This is an advantage over prior known deicing systems since this heating system does not require nails for installation and may be attached to the shingles with only adhesives. 
       FIGS. 4A and 4B  shows an exploded view of an exemplary heating system  400 , in accordance with an embodiment of the invention.  FIG. 4A  shows that the heating system  400  includes a rear adhesive layer  401 , a heating element  402 , a grounded shield layer  403 , and folded-over rear adhesive strips  404 . Optionally, the heating system may also include a release liner  105  that needs to be removed prior to installation. 
     In some embodiments, the rear adhesive layer  401  can have flame retardant properties. In certain embodiments, the flame retardant material used for making the rear adhesive layer is selected from a group consisting of flame retardant acrylic adhesives, flame retardant epoxy adhesives, flame retardant silicone adhesives, flame retardant polyether adhesives, flame retardant foams, flame retardant rubber compounds, flame retardant polyurethane, flame retardant non-woven fabric and combinations thereof. In certain other embodiments, the rear adhesive layer  401  can include a Nitto 2125FR flame retardant butyl compound. 
     In certain embodiments, the rear adhesive layer  401  can be 1.25 mm thick and 7-9″ wide. This rear adhesive layer  401  can be dimensioned larger than the heating element  402  and the grounded shield layer  403  such that its edges can fold over the edges of both heating element  402  and grounded shield layer  403  to form folded-over adhesive strips  404 . In this way, the rear adhesive layer  401  can serve to bond the heating system to both the underlying roof structure, such as the underlying shingles, metal leaves or roof deck, as well as to roofing shingles or metal leaves disposed on top of the heating system. This methodology and fold-over structure provides for securing the layers of the heating system to the roof and renders the deicing system wind resistant, such that wind gusts would not impact the structural integrity of the deicing system (e.g., such that wind gusts would not be able to dislodge the heating system from the roof, or dislodge roofing shingles bonded to the heating system). In some embodiments the heating system can endure high hurricane force high speed winds with speeds greater than 130 mph. 
     In some embodiments, heating element  402  can be a heating element produced by Calorique (e.g., model no. IND4-10W120V), and can be a 4-7 inch wide 40 to 120 watts per square foot heating element. Conductive carbon compounds can be rotary screen printed on 0.004 inch (4 mil) polyester film using flat bed or rotary screen or gravure printing process with conductive silver polymer printed buss bars which is laminated with a 0.005 inch (5 mil) dry film polyester film with silver adhesive. 
       FIG. 4B  shows in more detail the electrical connections between heating systems disposed adjacent to each other, in accordance with an embodiment of the invention. Each heating element  402  can include power cords having a female end  405  or a male end  406 , which mate as shown in  FIG. 4B . The power cords include a ground wire  408  to ensure a common electrical ground among multiple heating systems connected to each other. These power cords, including the continuous ground wire  408 , can be disposed above the grounded shield layer  403 , alongside grounded shield layer  403 , or between grounded shield layer  403  and heating element  402 . In some embodiments, the ground wire  408  is 18 American Wire Gauge (AWG). In some embodiments, the ground wire  408  is rated to be used at 600V. In some embodiments, the ground wire  408  is sheathed inside a flame retardant and suitable for use at 90° C. (194° F.) and lower temperatures in dry locations, and at 60° C. (140° F.) and lower temperatures when exposed to moisture. 
     The connection system disclosed in  FIG. 4B  can be waterproof (IP68) and polarized. The connection system can also include a termination plug  407  which safely caps the end of a connection if it is not in use. This connection system allows the heating systems to be installed in roof valleys, on roof hips, and around corners. The connection system also allows multiple courses of heating systems to be powered using the same circuit and the same controller. 
       FIG. 4C  shows an image of an embodiment of the heating system in accordance with this disclosure. Shown in the image are the grounded shield layer  403 , folded-over rear adhesive strip  404 , and the male and female connectors  405  and  406 , respectively. 
       FIG. 4D  shows the heating element  402  with an exemplary buss bar pattern  411  that can be printed on the polyester film, although other types of buss bar patterns are also possible. During the lamination process, two tin plated  411  copper buss bars can be inserted. A 24 to 240 Volt voltage can be applied to the heating elements for generation of heat. 
     The heating element  402  can be a plastic substrate on which is printed heating element  430 , although other substrates are possible (e.g., rubber, metal). For example, the heating element  402  can be a pattern of conductive resistive ink that generates heat as electricity passes through it (e.g., via Joule heating). The heating element  402  can include i) a pair of longitudinal stripes  411  extending parallel to and spaced apart from each other and ii) a plurality of bars  412  spaced apart from each other and extending between and electrically connected to the stripes  411 . In this configuration, one of the longitudinal stripes  411  can act as a positive bus, and the other longitudinal stripe  411  can act as an negative bus, thus causing a flow of electricity through the bars  412 . An embodiment of the heater  402  is described more fully in each of the following U.S. Pat. Nos. 4,485,297, and 4,733,059 each of which are incorporated by reference herein. Other configurations of the heater  425  are possible. A photograph of one embodiment of the heating element is  402  is shown in  FIG. 4E . 
       FIG. 4F  shows an embodiment of a heating system with the grounded shielded layer  403  peeled off to reveal the electrical connections s to the heating element  402  and the ground wire  408 . The connector  413  is attached the bus  411 . In some embodiments, the connector may be used as neutral as well. In some embodiments, the connector  413  is crimp styled. In some embodiments, the connector  413  is 0.76 mm thick, barrel range 1.25-2.0 mm and insulated. In some embodiments, the insulation may be a 3M Flame Barrier series insulation tape, such as, FRB NC-127. A blind rivet spacer  414  is provided to connect the ground wire  408  with the top grounded shield layer  403 . A high temperature ring connector  415  may be connected to the ground wire  408 . The ground wire  408  and connector  413  may be connected to the male or female connectors  405  or  406 , as shown in the image. 
     The spacing of the bars  412  can be configured to cause substantially uniform heating. For example, the width of each bar  412  can be greater than the space between adjacent bars, and the space between bars  412  can be less than an inch, preferably in the range of about ⅛″ to 1″. The widths of the heating bars is typically in the range of about ⅛″ to about 2″, preferably about ¼″ to ½″, although other widths are possible. Other pattern designs for the arrangement of the heater  425  are possible, such as those disclosed in U.S. Pat. No. 4,485,297, which is incorporated by reference herein in its entirety. 
     The heater  402  can also contains electrodes connected to copper strips extending from an end of the longitudinal stripes  411 . Generally, as described in U.S. Pat. No. 4,485,297, the electrodes can provide an electrical connection between the heater  425  and a control unit, which can be, in turn, connected to a power source. 
     In some embodiments, a ground wire  408  may be placed under the grounded shield layer.  FIG. 4G  shows the placement of the ground wire  408  under the grounded shield layer  403 . 
     In some embodiments, grounded shield layer  403  provides electrical safety. Grounded shield layer  403  can comprise an 0.002 inch to 0.005 inch (2 to 5 mils) thick metal-containing electrically conducting. In some embodiments, the grounded shield layer is flexible. In some embodiments, the metal-containing electrically conducting is made of aluminum, nickel, brass, carbon steel, stainless steel, or a copper-containing alloy that acts as a grounded shield. 
     In certain other embodiments the grounded shield layer  403  is bonded to a second adhesive layer  409 , which is optional, and made of a flame retardant material. In some embodiments the thickness of the second adhesive layer  409  is 1.25 mm. In certain embodiments, the flame retardant material used for making the optional second adhesive layer  409  is selected from a group consisting of flame retardant acrylic adhesives, flame retardant epoxy adhesives, flame retardant silicone adhesives, flame retardant polyether adhesives, flame retardant foams, flame retardant rubber compounds, flame retardant polyurethane, flame retardant non-woven fabric and combinations thereof. In certain other embodiments, the rear adhesive layer  401  can include a Nitto 2125FR flame retardant butyl compound. 
     In some embodiments, the folded-over rear adhesive strips  404  can be used to adhere the heating system to the shingles above, but in other embodiments, the second layer of adhesive  409  (separate and apart from the rear adhesive layer  401 ) can be used to bond the heating system to the shingles above more securely. 
     In an aspect, a heated roof system includes a first course of shingles or an area of the roofing deck; a second course of shingles wherein, the second course of shingles is disposed over at least some part of the first course of shingles or the area of the roofing deck to create an area of overlap; and a heating system disposed in the area of overlap. The heating system includes a grounded shield layer made of a continuous piece of metal; a heating element; and a rear adhesive layer including flame retardant materials; wherein, the heating element is disposed between the grounded shield and the rear adhesive strip; wherein the rear adhesive layer has a bottom surface that is configured to adhere to at least one of a shingle or an area of a roofing deck. The heated roof system also includes a controller configured to control the flow of electricity to the flexible heater as a function of a temperature and at least one of a moisture level and a precipitation level. 
       FIG. 5  shows an exemplary cut-away view of three courses of the heating system installed under roofing shingles  502 , in accordance with an embodiment of the invention. As can be seen, the heating systems  400  are installed beneath shingles  502  so as to be out of view and protected from damage by the elements.  FIG. 5  also shows the folded-over rear adhesive strip  404  underneath the cut-away of the shingles  502  and how the female and male connectors  405  and  406 , respectively, connect the adjacent heating systems. 
       FIG. 6  shows a side view of 3 courses of heating systems under roofing shingles, in accordance with an embodiment of the invention. As can be seen, folded-over rear adhesive strips  404  can serve to bond the heating system to the roofing shingle above the heating system  400 . 
       FIG. 7  shows an exemplary installation of heating systems  400  on a roof  700 , in accordance with an embodiment of the invention. The heating systems  400  are shown installed along a “valley”  702  and lower edges  708 . Three groups of heating systems have been shown connected using a three-way jumper  404  positioned at the bottom of valley  702 . The three-way jumper  704  can be useful for connecting multiple groups of heating systems together into one interconnected system. In other embodiments (not shown), four-way, five-way jumpers can also be used. Jumpers that can connect even larger number of heating systems are also possible. A 3-foot power cord  706  provides power to the heating systems installed along both valley  702  and lower edges  708 . 
       FIG. 8A  shows an exemplary installation of the heating systems  400  on a “hip” portion  802  of a roof. As shown, three groups of the heating systems can also be installed, one along the “hip”  502 , one along a right edge  804 , and one along a left edge  806 .  FIG. 8B  shows an alternate connecting arrangement for the three groups of heating systems using a 3-way jumper  704 , as disclosed in  FIG. 7 . 
       FIG. 9  shows an embodiment of power cords  902  and  906  used in the connection of the heating system  400 . Power cords  902  and  906  are similar to each other except that they are of different lengths and power single, double or triple courses, as illustrated.  FIG. 6  also includes single jumpers,  607  (6″ jumper), and  608  (12″), a three-way jumper  910 , and a termination plug  911 . 
       FIG. 10A-10F  are a series of figures illustrating an exemplary installation process of a heating system  400 . As a first step, as shown in  FIG. 10A , a technician can break a shingle seal and lift the shingle flap. As a second step, as shown in  FIG. 10B , the technician can peel off/remove a small corner of a protective layer  425  from the adhesive layer  401 . Then, the technician can position the heating system under the shingle, remove the rest of the protective layer (rear release liner  425 ), and press the heating system to the roof underneath to secure the adhesive bond. As a third step, as shown in  FIG. 10C , the technician can install adjacent heating system and make the electrical connections by mating the male and female plugs. As part of this step, as shown in  FIG. 10D , the technician can add a termination plug to the ends of any power cords not connected to another heating system. As shown in  FIG. 10E , the technician can also connect two courses of heating systems using a COR9 power cord. As a fourth step, as shown in  FIG. 10F , the technician can peel off a protective layer from the top part of the heating system (either attached to the fold-over rear adhesive strips  404 , and/or the optional second layer of adhesive  409  attached to the grounded shield layer  403 ), then press down the shingle flap to secure the adhesive bond. 
     The heating system in accordance with this disclosure has several advantages. Some of these are discussed below in the examples that follow. 
     Resistance to High Force Winds: 
     The current systems available in the industry use nails to hold the shingles  502  in place. As shown in  FIG. 6  the course of shingle that runs on the top overlays the shingles in the course below and the shingles in the top course can be easily lifted up. In fact, as described below in this disclosure, this feature is utilized for easy installation of the heating system using the heating system in accordance with this disclosure. 
     Additionally, inserting a heating system between the area of overlay between the two courses of shingles further increase the ease with which the shingle of the top course may be lifted up. Thus, high speed wind can lift up the shingles on the top course making the roof prone to leakage in rain. This in certain instances can also void the warranty offered by the shingle manufacturer. 
     However, in accordance with this disclosure, the bonding of the top shingle to the folded-over rear adhesive strip  404  or the optional adhesive layer  409  improves the integrity of the installed structure. In one embodiment, the heating system used for deicing can be installed without the use of any nails, which is an advantage over prior known deicing systems. In another embodiment, the heating system used for deicing can be installed with nails for added security and structural integrity. The adhesive layers bonding the heating system to the roof or shingle underneath and to the shingles above have been tested for wind uplift by Architectural Testing, a division of Intertek, in accordance with ASTM D3161-09 Standard Test Method for Wind Resistance of Asphalt Shingle (Fan-Induced Method) and met the standard up to 130 MPH with no damage to the roof, even though no nails were used during installation.  FIGS. 11A and 11B  show the set-up for the Fan-Induced Method used for evaluation of the resistance of shingles to high speed winds. 
     In some embodiments, the heating system  400  used for deicing can be installed without the use of any nails, which is an advantage over prior known deicing systems. In some other embodiments, the heating system  400  used for deicing can be installed with nails for added security and structural integrity. 
     Prevention of Corrosion of Electrical Components 
     As the heating element  402  is shielded and protected by the grounded shield layer  403  and the rear adhesive layer  401 , exposure to moisture and precipitation is mitigated and prevented. This is protection is critical. As described above, the bus bar of the heating element  402  is made of copper in many embodiment. Exposure of the metal, such as copper, in the bus bar to water and moisture can result in the onset of corrosion causing the formation of metal oxide, such as, copper oxide. Formation of oxides in heating elements can significantly raises the potential of arcing which poses the hazard of electrical fires. 
     Further, in some embodiments, the grounded shield layer  403 , is also painted with a weather and UV resistant paint to prevent the metallic material used for the grounded shield layer  403  from corrosion. In some embodiments, where aluminum foil is used for the grounded shield layer  403 , this becomes important. Aluminum and its alloys are inherently prone to pitting corrosion. Pits formed in the grounded shield layer  403  from elongated exposure to precipitation and moisture can result in ingress points in the grounded shield layer  403  from where water may seep into the cavity where the heating element  402  is located. This can result in electrical faults, short circuiting and even result in a fire hazard. 
     As another method of improving the reliability and safety in operation of the heating device, in some embodiments, a ground fault circuit interrupter (GFCI) is included in the circuit when power connections are made to the heating system  400 . The GFCI measures variations in the current flow. In some embodiments, upon detection of a current fluctuation that is greater than 5 mA, the GFCI trips the circuit and causes the electric power to be shut off and thereby causing the current flow to stop. This prevents potential serious damage, such as, electrical fire from short circuits, arcing, etc. 
     Flame Retardant Properties 
     In addition to the provision for a GFCI, as discussed above, the rear adhesive layer  401 , the folded-over rear adhesive strip  404  and the optional second adhesive layer  409  are made from materials that are flame retardant. This conscious selection of material further enhances the ability of the heating system  400  to mitigate fire hazard while performing exposed to the weather and elements of nature in close contact and/or close proximity with flammable materials, such as, asphalt shingles and ply board roof decks. Since the design of the heating system  400  ensures that the heating element does not come in direct contact with the shingle or the roof deck, the risk of fire is significantly reduced. 
     In some embodiments of the heating system  400  in accordance with this disclosure also conform to the UL 499 Electric Heating Appliance standard. 
     Referring to  FIG. 12 , the heating system  400  can be controlled by control unit  1205 . The control unit  1205  is preferably installed in an area of house  100  not exposed to the elements, and is electrically connected to the heating system  400 . The control unit  1205  can be connected to the heating system  400 , a thermostat/sensor  1210 , a moisture/precipitation sensor  1215 , and a power source  1220 . The thermostat/sensor  1210  can be part of the control unit  1205 , or can be a separate unit that connects to the control unit  1205 . In addition, while shown separately, the thermostat/sensor  1210  and moisture/precipitation sensor  1215  can be combined in a single sensor unit. Preferably, the thermostat/sensor  1210  and moisture/precipitation sensor  1215  are installed at the coldest area around the gutter of the house, in a place that is not subject to direct sunlight to ensure that when the moisture/precipitation sensor  1215  is dry, the entire gutter area is dry. In this position, thermostat/sensor  1210  can also determine the ambient air temperature. Control unit  1205  can use information from thermostat/sensor  1210  and moisture/precipitation sensor  1215  to make a determination as to whether power should be supplied to the heating system  400 . While the moisture/precipitation sensor  1215  is described as being a combined sensor, another configuration is a sensor that only detects moisture or only detects precipitation. 
     In operation, referring to  FIG. 13 , with further reference to  FIGS. 1-12 , a process  1300  for controlling the heating system  400  using the control unit  1205  includes the stages shown. The process  1300 , however, is exemplary only and not limiting. The process  1300  may be altered, e.g., by having stages added, changed, removed, or rearranged. The process  1300  can be i) continuously run so that the heating system  400  is always ready, ii) run at specified intervals (e.g., every 20 minutes), and iii) at the direction of an operator. 
     At stage  1305 , the control unit  1205  measures outside air temperature. This can be done by measuring the ambient temperature with thermostat/sensor  1210 . 
     At stage  1310 , the control unit  1205  then determines whether the ambient temperature is at or below a predetermined threshold. For example, the control unit can determine if the temperature is at or below 32 degrees Fahrenheit. In other embodiments, the temperature can be set a few degrees higher than freezing, such as 35 degrees Fahrenheit. If the temperature is at or below the predetermined threshold, the process  1300  continues to stage  1315 , otherwise the process  1300  continues to stage  1305 . 
     At stage  1315 / 1320 , the control unit  1205  uses moisture/precipitation sensor  1215  to determine if the sensed moisture and/or precipitation level is at or above a predetermined threshold. If the moisture and/or precipitation level is above the threshold, the process  1300  continues to stage  1325 , otherwise the process continues to stage  1305   
     At stage  1325 , the control unit  1205  activates the heating system  400  by supplying power from power source  1220 . The control unit  1205  preferably keeps the heating system  400  activated until the precipitation and/or moisture level falls below the predetermined threshold, and/or the temperature exceeds the predetermined threshold. The control unit  1205  can also be configured to activate the heating system  400  for a predetermined time period (e.g., 2 hours) after the temperature and moisture/precipitation thresholds are triggered. 
     The process  1300 , vis-à-vis the two-step determination of temperature and moisture/precipitation, can reduce the amount of power consumed by the heating system  400  to prevent the formation of ice dams. If the temperature is above the freezing point in step  1310 , e.g., 50 degrees Fahrenheit, then there is little concern that snow or melt-water will freeze at overhang  120 , forming an ice dam. Therefore, the continuous sheet heater does not need to be operated. Turning the sheet heater on or off can be accomplished by simply providing power to the heating system  400  or preventing power from being supplied to the heating system  400 , in accordance with the sensed conditions as described above. Further, if the temperature is determined to be at or below 35° F. in step  1310 , no ice or water will freeze to form an ice dam, if no precipitation and/or moisture is detected in step  1320 . Accordingly, heating system  400  should not be active. In the event that the temperature is at or below the freezing point and moisture is detected, than the formation of an ice dam is possible. To prevent the formation of the ice dam, the heating system  400  can be activated by control unit  1205 . 
     The process  1300  and the controller  1200  are preferably configured to operate without any intervention by a user. For example, a homeowner can configure the controller  1200  once, and can the controller  1200  can preferably function without any further input by the homeowner. 
     In some embodiments, the heating system  400  can be installed on top of standard ice and water shield using adhesive and/or nails before the starter course of shingles is applied. Subsequent courses of the heating system can then be installed as desired. 
     Other embodiments are within the scope and spirit of the invention. For example, while the foregoing description has focused on the heating system  400  being used to prevent/remove ice dams, the heating system  400  can also be configured to melt snow off of an entire roof (e.g., when snow weight is a concern). In addition, instead of using the process  1300 , the heating system  400  can be controlled manually. 
     The subject matter described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. The subject matter described herein can be implemented as one or more computer program products, such as one or more computer programs tangibly embodied in an information carrier (e.g., in a machine-readable storage device), or embodied in a propagated signal, for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). A computer program (also known as a program, software, software application, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file. A program can be stored in a portion of a file that holds other programs or data, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub-programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. 
     The processes and logic flows described in this specification, including the method steps of the subject matter described herein, can be performed by one or more programmable processors executing one or more computer programs to perform functions of the subject matter described herein by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus of the subject matter described herein can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). 
     Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processor of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks, (e.g., internal hard disks or removable disks); magneto-optical disks; and optical disks (e.g., CD and DVD disks). The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. 
     To provide for interaction with a user, the subject matter described herein can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, (e.g., a mouse or a trackball), by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, (e.g., visual feedback, auditory feedback, or tactile feedback), and input from the user can be received in any form, including acoustic, speech, or tactile input. 
     The subject matter described herein can be implemented in a computing system that includes a back-end component (e.g., a data server), a middleware component (e.g., an application server), or a front-end component (e.g., a client computer having a graphical user interface or a web browser through which a user can interact with an implementation of the subject matter described herein), or any combination of such back-end, middleware, and front-end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet. 
     It is noted that one or more references are incorporated herein. To the extent that any of the incorporated material is inconsistent with the present disclosure, the present disclosure shall control. Furthermore, to the extent necessary, material incorporated by reference herein should be disregarded if necessary to preserve the validity of the claims. 
     To the extent certain functionality or components “can” or “may” be performed or included, respectively, the identified functionality or components are not necessarily required in all embodiments, and can be omitted from certain embodiments of the invention. 
     Further, while the description above refers to the invention, the description may include more than one invention. Upon review of the description and embodiments provided herein, those skilled in the art will understand that modifications and equivalent substitutions may be performed in carrying out the invention without departing from the essence of the invention. Thus, the invention is not meant to be limiting by the embodiments described explicitly above.