Patent Document

BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention pertains generally to an article of manufacture which facilitates the application and sealing of sheet-like membranes, such as rubberized roofing materials, to the outside edges of buildings; more particularly, to a sheet metal mini-wall parapet which replaces prior art parapets which are labor intensive to make and install, and are not as sturdy and long lasting as our invention. The mini-wall parapet of this invention also allows it to be fully prefabricated in the shop of sheet metal, such as galvanized steel, aluminum, stainless steel, or other corrosion resistant metal, without the use of any wood or masonry in the structure. 
         [0003]    2. Discussion of the Background of the Invention 
         [0004]    Roof edge sealing constructions are referred to in the literature by several names such as mini-wall parapets, coping structures, roof edge assemblies, gravel stop assemblies, water dams, and the like. These devices are provided for the purpose of sealing the outer edges of roof construction components by anchoring the sheet-like roofing membranes to the roof edges. They also serve to retain ballasts, control water drainage, or for supporting fascia members at the interfaces between various constructions and structures. For purposes of this disclosure, we will refer to these devices as mini-wall parapets. In the description of the drawings which follows, all elements in common with prior art  FIGS. 1A and 1B , will include the same numbering system insofar as possible. Also, the dimensions of the various elements are not true to scale, and certain portions of the drawings may be depicted as exaggerated in thickness or thinness to facilitate their disclosure. 
         [0005]    As indicated by prior art  FIG. 1A , edge sealing mini-wall parapet  1 , is fabricated on the site at the edge of the roof deck  2  by layering a plurality of wood planks  3  (such as 2×6&#39;s or 2×8&#39;s), as shown at interface  17 . Such a mini-wall parapet  1  is typically formed from so-called pressure treated wood so that it is assured of moisture and insect resistance, but untreated wood can be utilized as well, provided that the wood is well-sealed from moisture and insects by the rest of the structure. If the deck  2  is of concrete or masonry construction, the lowermost wood plank  3  is secured to roof deck  2  by anchor bolts or masonry fasteners  4 . If the deck  2  is of wood or metal construction, the lower layer  3  is screwed to the deck. In that case, the fastening elements  4  are screws. Each of the subsequent wood layers  3  are securely nailed to the next lower layer by nails  5 . The number of layered planks  3  required is determined by the thickness of the insulation layer  6 , whereby the mini-parapet is at least a minimum height above the insulation layer  6 . 
         [0006]    At the outside top of the typical wood mini-parapet  1 , there is provided a triangular element  8  with the hypotenuse of the triangular shape facing the inside of the mini-parapet. Member  8  is also of pressure treated wood, and is nailed (toenail fashion) to the upper wood layer  3  by nails  9 . The triangle shaped member  8  is provided as a gravel stop where a gravel ballast is used, and/or to deflect water back toward the roof so that it does not drip excessively over the outside wall of the building. 
         [0007]    The roof deck  2  is shown over a conventional outside wall  18 , which may be of brick or block or a combination thereof. The roof deck  2  is attached to the outside wall  18  at interface  19  in the conventional manner. 
         [0008]    The roof membrane  7  is glued or otherwise installed over the roof insulation layer  6 , and continues to lap over the mini-wall parapet  1 , over the gravel stop  8 , and partially down the outside of the mini-wall parapet as shown. An elongated cleat  11  of corrosion resistant sheet metal is either nailed or screwed by elements  12  laterally along the length of the mini-wall parapet into the lower wood layer  3 . The elements  12  can also be masonry attachments if the elongated cleat  11  is installed laterally along the length of concrete roof deck  2  into the outside edge of roof deck  2 . See prior art  FIG. 1B . 
         [0009]    The bottom of the cleat  11  is bent outward slightly as shown at  13 , so that a finishing cap or coping member  10  can be resiliently installed. The coping member  10  is also of corrosion resistant sheet metal and includes an inverted flange  16  which snuggly engages the outwardly bent bottom edge  13  of the cleat  11  when installed. The coping member  10  is prefabricated by bending its sheet metal in the shape shown. The coping member  10  and the cleat  16  are sufficiently flexible so that they can be elastically deformed when the coping member  10  is snapped over the top of member  8  when final installation is made. The upper end of the coping member  10  is downwardly bent at  14  so that the upper end fits snuggly over the element  8 . The coping member  10  may have an outwardly bent lip  15 . This lip minimizes the possibility that the coping member  10  might snag or even cut the roof membrane  7  when the coping member is installed. The lip  15  also minimizes injury to the installer when the coping member  10  is installed. As noted above, the coping member  10  and the cleat member  11  are sufficiently flexible so that they can be elastically deformed (see dotted depiction) when the coping member  10  is installed over the top of the mini-wall parapet, without exceeding the elastic limit of any of the bends in the coping member  10  or of the cleat  11 . Thus when installed, the coping member  10  snaps snugly and permanently over the elements of the mini-wall parapet  1  and the sealed edge of the roof membrane  7 . Therefore, the mini-wall parapet  1  is fully protected from weather and moisture. In all of these embodiments, elements are shown with exaggerated spacing between the elements for clarity of disclosure. In actual structure, such spacing would be minimized. 
         [0010]    Prior art  FIG. 1B  discloses a sheet metal variation of the mini-wall parapet  1 . The wood planks  3  of  FIG. 1A  have been eliminated and replaced by the one-piece, generally U-shaped sheet metal structure  3 . U-shaped sheet metal structure  3  can be prefabricated in the shop prior to installation at the site. The gage of the generally U-shaped structure  3  is chosen to have sufficient vertical strength to easily function as a mini-wall parapet. At the first step in its installation, the U-shaped member is still open at the top, whereby the structure can be easily attached along the roof edge at  17 . As shown in  FIG. 1B , the bottom wall member  22  is attached to the roof deck  2  by screws or masonry anchors  4 , depending on the composition of deck  2 . The lower left hand corner of the U-shaped member  3  is folded over on itself to form a double layer, and the double layer extends generally downwardly to form the cleat  11 , Cleat  11  functions in the same manner as the cleat of prior art  FIG. 1A . The cleat  11  is bent slightly outwardly at its lower edge as shown by element  13  in the same manner as in prior art  FIG. 1A . If deemed necessary, cleat  11  can be further adhered to the edge of the roof deck  2  by the lateral fasteners  12 . 
         [0011]    At the top, opposite ends of the U-shaped element  3  are two staggered end elements  20  which are folded over as shown. The two folded over elements  20  are staggered vertically in height and sloped to receive the top member  8 . The slope allows for the drainage of water toward the roof. Thus, when the top member  8  is installed, it performs the same general function as element  8  performs in prior art  FIG. 1A . Top member  8  is attached to the U-shaped elements by screws  5 . The top member  8  is of pressure treated plywood, and, although it can be prefabricated in the shop, it should be installed in the field to allow access to the interior of the U-shaped element  3  when it is fastened to the roof deck  2 . The top member  8  can also be horizontal if desired, but such a configuration would not positively cause drainage toward the roof. The top member  8  can also be prefabricated of sheet metal, but plywood is preferred. Once the top member is installed, it provides even greater rigidity to the mini-wall parapet assembly. Further, the inner cavity of the mini-wall parapet  1  of prior art  FIG. 1B  can be filled with fiber glass, foam, mineral wool, or other insulation  27  to provide further thermal insulation if that is deemed necessary. 
         [0012]    Thereafter, the membrane  7  and the coping member  10  are installed in the same manner as in  FIG. 1A . The coping member  10 , although of different shape from that used in  FIG. 1A , is installed and functions in the same manner as coping member  10  in prior art  FIG. 1A . The outward appearance of the mini-wall parapet of  FIG. 1B  from the ground, from an aesthetic standpoint, is virtually identical to that of  FIG. 1A . 
       SUMMARY OF THE INVENTION 
       [0013]    The object of this invention is to provide a sheet metal mini-wall parapet for sealing the roof membrane to the edge of a building which can be fully and inexpensively prefabricated off site which thus minimizes installation time and expense, whereby a superior seal is obtained while at the same time providing that seal for far less cost than conventional mini-wall parapet structures. 
         [0014]    It is a further object of this invention to replace conventional wood plank mini-wall parapets with a sheet metal structure which is of much simpler construction, which is a much less expensive structure to manufacture and which is much quicker to install, and which provides a long-lasting and superior seal over conventional structures 
         [0015]    It is a further object of this invention to provide a mini-wall parapet which is not only inexpensive to make, it is easier to install, and it is aesthetically indistinguishable from conventional prior art mini-wall structures when viewed from the ground. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIGS. 1(A-B)  are directed to conventional prior art wood plank or sheet metal mini-wall parapets. 
           [0017]      FIGS. 2(A-B)  are directed to the first embodiment of our invention including sheet metal construction which can be fully prefabricated at the shop, and requires minimal installation time and expertise when installed at the roof site. 
           [0018]      FIGS. 3(A-B)  are directed to a second embodiment which is a variation of the embodiment of  FIGS. 2(A-B) . This embodiment allows for thicker insulation layers. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]      FIG. 2A  is a cross-sectional end view of the first embodiment of our invention prior to installation as indicated by the element  1   a.  An end view of our sheet metal structure  1   a  is generally a four sided box shape in construction. Beginning at the bottom outside corner, a cleat  11  is shown which has a lower end which is bent out slightly at  13 . The cleat  11  performs the same function that it performed in the prior art devices. The top of the cleat is bent 90 degrees to the right to form the horizontal bottom member  22  of our device. The bottom member  22  extends beyond the inside wall  3 , and is folded over on itself to form a double layered extension  23 . The double layered extension  23  provides the element used to attach the whole device to the roof deck. Therefore, layer  23  will be hereafter referred to as the attachment layer  23 . The attachment layer  23  can be made as wide or as narrow as needed for proper attachment to the roof deck  2 . See the dotted extension  30 . Since the roof deck composition may vary, i.e., concrete, wood, or slotted steel, different widths for the attachment layer  23  may be necessary to assure a firm roof base for attachment. 
         [0020]    The top folded over layer of the attachment layer  23 , is bent upwardly at 90 degrees at the appropriate point to form the inside right side wall  3  of the structure  1   a.  The sheet metal is again bent 90 degrees to the left at the appropriate height to form the top wall  24  of the structure  1   a.  At the appropriate point, the top wall is bent upwardly at an obtuse angle  25  to a point  28 , where it is bent downwardly at an acute angle  27  to form the outer wall  26  which lines up with the bottom outside layer  11 . The triangle  8  portion is not closed, but its upstanding generally triangular shape forms a gravel block  8  which functions in the same fashion as the gravel block  8  in  FIG. 1A . 
         [0021]    Outer wall  26  extends downwardly until it reaches point  29  where it is again bent 90 degrees to the right to form the lip  21 . Lip  21  is of sufficient width so that it cannot be flexed past the bottom wall  22  when the coping member  10  (see  FIG. 2B ) is ultimately installed. Lip  21  is also spaced from the bottom member  22 , as indicated by the gap  20 , to provide room for a small amount of flexure when the coping member  10  is installed (again see  FIG. 2B ). Since, apart from the coping member  10 , our device is of one-piece construction, the fabrication and installation procedures are minimal as compared with the prior art devices, above. 
         [0022]      FIG. 2B  discloses the sheet metal device  1   a  of  FIG. 2A  after it has been installed as the mini-wall parapet  1 . The device  1   a  of  FIG. 2A  is attached to the roof deck  2  at the attachment layer  23  by the standard attachments  4 , which can be either masonry attachments or screws dependent upon the composition of the roof deck  2 . The structure  1  can be further secured through the cleat  11  laterally along the edge of the roof deck  2  by the attachments  12  in the same way that the prior art cleats were attached by the elements  12 . The roof insulation layer  6  is installed on the roof deck  2  in the same manner as the prior art installations. Note that the folded attachment member  23  is shown in exaggerated thickness in  FIG. 2B  for purposes of disclosure, but its actual thickness is such that it does not significantly distort the insulation layer  6  when it is installed. The roof membrane  7  is installed over the device  1   a  of  FIG. 2A  in the same fashion as in the prior art devices, and it laps over the gravel guard  8 , and partially down the outer wall  26  in the same manner as in the prior art. However, since the metal surfaces forming our mini-wall parapet are smooth, when the membrane is glued, it adheres more strongly in our structure than structures of the prior art. Thus, our fully metal structure resists tearing or separation from the structure as compared with the wood or partial wood devices of the prior art. As in the prior art, our void  27  can be filled with insulation if necessary. 
         [0023]    Finally with respect to  FIG. 2B , our coping member  10  is installed in the same manner as with the prior art devices. As noted above, the gap  20  is provided to allow a slight flexure of the device when the coping member  10  is installed. In summary, therefore, our device is easier to make, easier to install, is more durable, adheres more strongly to the roof membrane, and thus, is an all around more desirable device as compared with the prior art. 
         [0024]      FIGS. 3(A-B)  disclose variations of our mini-wall parapet over the invention of  FIGS. 2(A-B) . Specifically, these embodiments accommodate those situations where the roof insulation layer  6  is made thicker for a variety of reasons. For example, in this environmentally sensitive day and age, it may be desired by certain “green” thinking people that the insulation must be thicker than usual so that energy loss through the roof is additionally minimized. Further, a second layer  6  may be recommended where extremely hot or extremely cold climates exist. Still further, it is often desirable to drain water toward roof drains that are not adjacent to the mini-wall parapet so that the roof does not collect water in long-standing ponds near the parapet. Such ponds may promote insect growth or roof leakage that would not occur with a well drained roof. Well drained roofs also minimize ice dams that may develop in freezing temperatures. And, ice dams can also cause such long-standing ponds to collect. Therefore, roof drainage systems often use a tapered insulation layer (as indicated at  35  in  FIG. 3B ) to accomplish drainage. 
         [0025]    In any case, the insulation layer may be much thicker next to the mini-wall parapet structure to facilitate draining water away from the mini-wall parapet. In those situations, the mini-wall parapet structure must be of increased height than those of  FIGS. 2(A-B) . In  FIG. 3A , the structure of such an embodiment is disclosed as being quite similar to that of  FIG. 2A . But note, that in this embodiment, two insulation layers  6  are shown so that the body of the structure must be at least that much taller than  FIG. 2A . The coping member  10  of such a structure would have to have greater height as well. If it were simply a matter of making the coping member  10  taller, there would be no problem; but, since the coping member  10  may also be used as the decorative exterior facade for the mini-wall parapet, a problem arises which is termed in the art as “oil-canning.” Oil-canning occurs when a tall, relatively thin layer of sheet metal is supported such that the weight of the metal itself causes it to sag minutely. Apparently, when viewed in the lateral direction, this minute sag causes the sheet metal to look uneven and unsightly. Therefore, oil-canning is undesirable from an aesthetic point of view. To obviate the oil-canning problem, the coping member  10  must be made shorter because oil canning does not noticeably occur when shorter coping members  10  are used. Clearly however, when significantly shorter coping members  10  are necessary, they will not reach between the cleat  11  and the gravel stop  8 . Therefore, the metal forming the lip  13  is continued and doubled over to extend up the outside wall  26  as shown by the extension  29 . (The doubled over cleat increases the strength of the cleat as well.) The top of this extension  29  is bent over again by an angle of approximately 135 degrees, forming a new cleat shown by the numeral  30 . The new cleat  30  allows the coping member  10  to be the same, or near the same, height as used in  FIGS. 2(A-B) ; and the coping member  10  operates in the usual fashion without experiencing oil canning. 
         [0026]      FIG. 3B  discloses and solves a further problem which may occur with the structure of  FIG. 3A . When the coping member  10  is formed from a coated decorative metal, a mismatch may occur between the exterior coating on the coping member  10 , and the exterior surface of extended wall  29 . This mismatch may be unsightly. Therefore, a facade member  31  is provided. The facade member  31  is fabricated from the same material as the coping member  10 , with the same matching exterior as the coping member  10 . The bottom of the facade member  31  is bent into a hook  32  which engages the original cleat lip  13 . The top of the facade member  31  is further bent downwardly to form a new lip  33  that it fits snuggly behind the new cleat  30  of the extension member  29 . Thereafter, when the coping member  10  is installed, the bottom lip  16  of the coping member  10  engages both the facade lip  33  and the cleat  30  simultaneously. When the coping member  10  is resiliently snapped over the gravel stop  8 , as in the prior art, the matching facade member  31  is also locked into place. If this installation proves awkward to assemble, a double sided tape layer  34  under lip  33  can be used to temporarily hold the facade member  31  in place under the cleat  30  until the coping member  10  is snapped into place. In all other respects, the tall mini-wall parapet structure  1  is installed in the same fashion as in  FIGS. 2B and 3A . 
         [0027]    Each of the sheet metal structures in  FIGS. 2(A-B)  and  3 (A-B) are fabricated in the lateral direction as elongated sheet metal structures which are of fixed length, but which may be fabricated of various lengths, dependent upon the needs of the installers. Alternatively, the various lengths can also be cut to length in the field as necessary. Further, the elongated sheet metal structures may be miter cut as needed, in the shop or in the field, to form either inside or outside corners as required. Finally, while the four walls of the sheet metal structure are generally fabricated as perpendicular, different angles other than strictly 90 degrees are contemplated. within the scope of the claimed invention Also, rounded corners, or even rounded sides, are also contemplated within the scope of the claimed invention. Finally, the vertical walls of these embodiments as recited in the claims are designated as “left hand” or “right hand” walls or “inside” or “outside” for ease of description, but these designations may be reversed dependent on from which end the structure is viewed. 
         [0028]    Without further analysis, the foregoing so fully reveals the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of the prior art, fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art, and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.

Technology Category: 0