Abstract:
A metallic T-joint patch is provided for application to intersecting and overlapping portions of a single ply membrane system of different heights. When applied to the joint formed by the intersecting and overlapping membranes, the metallic joint patch having an adhesive layer conforms to the void formed by the joint and assures a water tight seal. A method of making a metallic joint patch and a method of applying a metallic joint patch to a void formed by intersecting and overlapping membranes are also disclosed.

Description:
This application is a continuation-in-part of U.S. application Ser. No. 11/055,148, filed on Feb. 10, 2005 now U.S. Pat. No. 7,638,180, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to roofing materials. More specifically, the present invention is directed to a metallic joint patch to fill voids created by overlapping roofing membranes. 
     BACKGROUND OF THE INVENTION 
     Single ply membranes are roofing membranes that are field applied using just one layer of membrane material (either homogeneous or composite) rather than multiple layers. Oftentimes as a result of the overlapping intersection of two, three or four sheets of the membrane, a joint is created. 
     Current joint patches are either patches of membrane material either heat welded to the intersection of overlapping membranes or pressure sensitive adhesive joint patches of membrane material with the butyl or similar adhesive applied to one side with a release liner. Often, when a patch is applied to intersecting and overlapping portions of a single ply membrane system at the joint (which comprises different heights of overlapping membranes), the adhesive does not conform to the vertical step in height thus causing bridging and leaving a void or channel into which water and debris can enter. 
     Additionally, the membrane material has a memory which results in pull back as the joint patch is rolled or pressed in, keeping the adhesive from effectively filling the void or channel. 
     SUMMARY OF THE INVENTION 
     When roofing membranes intersect or overlap with one another during installation of a roof, joints may be formed at the points of intersection or overlap. A T-joint is a joint formed by the intersection or overlapping of three or four membrane sheets. A butt-joint is a joint formed by adjacent, separate sections of material, such as where two neighboring pieces of roofing membrane abut. The joints formed by the intersection and/or overlapping of roofing membranes can be problematic since the void formed by the joint often permits water to seep into and underneath the roofing membranes, creating a leak in the building envelope. 
     A joint patch is provided to alleviate the problem inherent in the formation of “joints” formed as a result of the overlapping intersection of sheets in the roofing membrane. In one embodiment, the T-joint patch is ribbed and may be circular, oval, square or rectangle. The patch is comprised of a single ply roofing membrane preferably ranging in diameter from approximately 3 inches to 9 inches. Examples of single ply roofing membranes from which the patch is formed includes, but is not limited to, thermoplastic olefin (TPO), polyvinyl chloride (PVC), ethylene propylene diene terpolymer (EPDM) or chlorosulfonated polyethylene (Hypalon®). The joint patch can be injection molded or fabricated by other conventionally known methods, with a rib or similar design having an approximate height of 20-90 mils on the flat plane of the membrane that will receive a butyl rubber or other type of adhesive compound and a release liner. This design will allow for the adhesive to fill in the void created by the overlapping membranes thus assuring a tight seal. 
     In another embodiment, the T-joint is comprised of a metallic foil backed with a polymeric film preferably ranging in length from approximately 3 inches to 9 inches. Examples of metallic foil from which the patch is formed includes, but is not limited to, aluminum, copper, magnesium, zinc, nickel, tin, gold, silver, and alloys thereof. The polymeric film is typically a thermoplastic film that includes but is not limited to polyethylene and polypropylene. Alternatively, the metallic foil may be used without a polymer film applied to it where the adhesive imparts sufficient tear strength to the final product. 
     Accordingly, a roof joint patch is provided, the roof joint patch comprising a flat section of a roofing membrane comprising a metallic foil, the flat section having a first side and a second side, an adhesive waterproofing layer on the first side of the roofing membrane, and a release liner on the adhesive layer. 
     Further, a method is provided of making a roof joint patch, the method comprising coating a first side of a flat section of a roofing membrane comprising a metallic foil with an adhesive layer, and adding a release liner onto the adhesive layer. 
     A method of filling a joint void formed by overlapping membranes is also provided, the method comprising the steps of peeling a release liner off a first side of a flat section of a T-joint patch comprising a metallic foil, the flat section having a first side and a second side, positioning the T-joint patch so as to correspond to a T-joint void formed by overlapping membranes on a roofing surface, and applying pressure on a second side of the T-joint patch such that the T-joint patch fills the T-joint void to form a water tight seal. 
     The joint patch can be fabricated from any commercially available metallic foil with the adhesive applied by a knife over roll coater extruded or by other conventional method, with the adhesive having an approximate thickness of 8-90 mils comprising a butyl rubber or other type of adhesive compound and a release liner. This design will allow for the adhesive to fill in the void created by the overlapping membranes thus assuring a tight seal where the metallic foil will retain the shape of the joint after being rolled in, or alternatively, for the patch to be rolled in so as to kink the metal thereby eliminating pull back due to memory. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  depicts overlapping membranes forming a T-joint or void; 
         FIG. 2  is a perspective view of a circular T-joint patch in accordance with one embodiment of the present invention; 
         FIG. 3  illustrates a top view of the T-joint patch of  FIG. 2  secured in the T-joint formed by the overlapping membranes; 
         FIG. 4  illustrates another top view of the T-joint patch of  FIG. 2  secured in the T-joint formed by the overlapping membranes; 
         FIG. 5  illustrates a view of the roof side of a joint patch having two ribs which segment the patch into four quadrants; 
         FIG. 6  illustrates a top view of the a joint patch in which a single rib, segmenting the patch into halves, is seen in skeletal view; 
         FIG. 7  illustrates a top view of the joint patch of  FIG. 6  secured in the joint formed by the overlapping membranes; 
         FIG. 8  illustrates a top view of a butt-joint patch secured in the joint formed by the overlapping membranes; 
         FIG. 9  depicts overlapping membranes forming a T-joint or void; 
         FIG. 10  is a perspective view of a T-joint patch in accordance with another embodiment of the present invention; 
         FIG. 11  illustrates a top view of the T-joint patch of  FIG. 10  secured in the T-joint formed by the overlapping membranes; and 
         FIG. 12  illustrates another top view of the T-joint patch of  FIG. 10  secured in the T-joint formed by the overlapping membranes. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1 , a joint, commonly referred to as a T-joint, (indicated by the circle denoted X) is formed by the intersection of three (3) membranes  100   a ,  100   b ,  100   c . A first embodiment of the T-joint patch  10  is illustrated in  FIG. 2 . Patch  10  in one embodiment is circular or oval. Patch  10  is planar and has a first side  12  (roof side) and a second side  14  (weather side). A T-shaped rib  16  is positioned on first side  12 . T-shaped rib  16  divides first side  12  of patch  10  into three sections. A layer of adhesive  18  such as a butyl layer or other similar waterproofing adhesive layer, is then coated on T-shaped  16  and first side  12  of patch  10 . A release liner  20  is then positioned on first side  12  of patch  10  and conforms to the shape of patch  10 . Patch  10  is not limited to a circular or oval shape and may also be square or rectangular. 
     In use, release liner  20  is peeled or removed from first side  12  of patch  10 . The T-shaped rib  16  is then positioned to conform with the T-joint formed by the intersection of membranes  100   a ,  100   b ,  100   c  and is fitted in the T-joint. Adhesive layer  18  on first side  12  of patch  10  secures side  12  of patch  10  to membranes  100   a ,  100   b ,  100   c . To provide a water-tight seal, pressure is usually applied to second side  14  of patch  10 . Pressure may be applied by any known means, including the use of a roller or by applying pressure using one&#39;s hands. Heat may also be applied to second side  14  of patch  10  to provide a heat seal.  FIGS. 3 and 4  illustrate patch  10  applied on membranes  100   a ,  100   b ,  100   c . T-shaped rib is positioned in T-shaped joint (not visible), and adhesive layer  12  secures first side  12  of patch  10  to membranes  100   a ,  100   b ,  100   c , leaving second side  14  as the exposed surface. 
     T-joint patch  10 , in one embodiment, is a single ply roofing membrane ranging in size from approximately 3 inches to 9 inches, but the size and shape of the patch is not limited in this respect. Examples of single ply roofing membranes from which patch  10  is formed include thermoplastic olefin (TPO), polyvinyl chloride (PVC), ethylene propylene diene terpolymer (EPDM) or chlorosulfonated polyethylene (Hypalon®). The T-joint patch can be vacuum or injection molded, or fabricated by other conventionally known methods, with a T-shaped rib having an approximate height of 20-90 mils on the flat plane of the membrane that will receive a butyl or other type of adhesive compound and a release liner. 
     In a second embodiment illustrated in  FIG. 5 , joint patch  10  is vacuum or injection molded and segmented (or divided) into four quadrants by intersecting ribs  16 ,  16   b . Each quadrant formed by the intersection of ribs  16   a ,  16   b  have a different height and having the same thickness of butyl or other adhesive layer thereon, along with a release liner (not shown). 
     In a third embodiment, joint patch is segmented into four quadrants as in  FIG. 5 . In this embodiment, the four quadrants formed by intersecting ribs, combined with the butyl layer (or other adhesive layer), and the release liner, all have a different thickness. The difference in the thickness of the quadrants is to accommodate the differences in height of intersecting roofing membranes, which are oftentimes placed on top of one another such that one or more sides of a of a joint may be higher than other sides. 
     In another embodiment illustrated in  FIG. 6 , a joint patch  10  is segmented into two sections  20   a ,  20   b  by a single rib  16 . Sections  20   a  and  20   b  may or may not be equal halves. Each of sections  20   a ,  20   b  are provided with a butyl layer or other adhesive layer, and a release liner. Furthermore, each of sections  20   a ,  20   b  has a different thickness.  FIG. 7  illustrates joint patch  10  of  FIG. 6  applied on membranes  100   a ,  100   b ,  100   c  in a horizontal joint  22 . 
     In another embodiment in accordance with the present invention, patch  10  may be used for sealing a butt joint formed by adjacent, separate sections of material, such as roofing membrane sheets. A butt joint patch generally has a single rib on the deck side of the patch and extending from one side of the patch to the other side, much like patch  10  illustrated in  FIGS. 6 and 7 . The single rib on the deck side of the patch generally splits butt joint patch into two equal sections, however the invention is not limited in this respect, and rib may divide butt joint patch into unequal sections. As with the other joint patches described herein, the butt joint patch will also be provided on its deck side with a butyl layer or other adhesive layer, and a release liner on the butyl or other adhesive layer. The butt joint patch in accordance with the present invention can be vacuum molded, injection molded or fabricated by other conventionally known methods. 
       FIG. 8 , illustrates butt joint patch  10  having a single rib  16  on its deck side positioned in a butt joint  24  formed by the intersection/overlapping of membrane  100   a  and  100   b.    
     In still another embodiment there is provided a butt joint patch having a vacuum or injection molded membrane having a single rib  16  which segments the membrane into two sections of two different heights, each segment having the same thickness of butyl or other adhesive layer thereon, along with a release liner. 
     In  FIG. 9 , a T-joint is shown similar to the T join in  FIG. 1 . Another embodiment of the T-joint patch  10  is illustrated in  FIG. 10 . Patch  10  can be circular or oval. Patch  10  is planar and has a first side  12  (roof side) and a second side  14  (weather side). A layer of adhesive  18  such as a butyl rubber or other similar waterproofing adhesive layer is then coated on first side  12  of patch  10 . A release liner  20  is then positioned on first side  12  of patch  10  and conforms to the shape of patch  10 . Patch  10  is not limited to a circular or oval shape and may also be square or rectangular, or any other shape that may be desired. 
     In use, release liner  20  is peeled or removed from first side  12  of patch  10 . Adhesive layer  18  on first side  12  of patch  10  secures side  12  of patch  10  to membranes  100   a ,  100   b ,  100   c . To provide a watertight seal, pressure is usually applied to second side  14  of patch  10 . Pressure may be applied by any known means, including the use of a roller or by applying pressure using one&#39;s hands. Heat may also be applied to second side  14  of patch  10  to provide a heat seal. 
       FIGS. 11 and 12  illustrate patch  10  applied on membranes  100   a ,  100   b ,  100   c . Adhesive layer  18  secures first side  12  of patch  10  to membranes  100   a ,  100   b ,  100   c , leaving second side  14  as the exposed surface. 
     T-joint patch  10 , in one embodiment, is a metallic foil ranging in diameter from approximately 3 inches to 9 inches, but the size of the patch is not limited in this respect. Examples of metallic foil form which patch  10  is formed include aluminum, copper, magnesium, zinc, nickel, tin, gold, silver, and alloys thereof, with thickness typically in the range of two to eight mils. The T-joint patch can be punched out of metallic sheet, or fabricated by other conventionally known methods, where the butyl or other type of adhesive compound and a release liner are either pre-applied to the sheet or other form on the first side  12  of patch  10 . 
     In another embodiment, T-joint patch  10  is comprised of a metallic foil backed by a polymeric film, preferably a thermoplastic polymeric film, wherein the film thickness is proportional to the foil thickness, the film being made of polyethylene, polypropylene or similar polymer and where the film is bonded to the foil via heating or through other application such as applying a latex coating to the surface. The film thickness can range in gage from 0-4 mils but is not limited to this size. The butyl rubber or other adhesive compound  18  would then be applied to the polymeric film and backed by a release liner  20 . 
     In yet another embodiment, the T-joint patch is comprised of a metallic foil that is colored, preferably in colors matching roof membrane colors, wherein the color is obtained via painting, dyeing, galvanizing, electroplating, anodizing, etching or other surface treatment applied to the metallic membrane. Alternatively, the color may be imparted by applying a colored polymeric film to the second side  14  of the metallic foil rather than or in addition to the polymeric film applied to the first side  12 . 
     While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.