Abstract:
A through-wall flashing device includes a metal exterior surrounding a polymeric core, wherein the metal exterior is substantially non-continuous or otherwise interrupted by thermal breaks disposed about the metal exterior. In assembly, the thermal breaks help to reduce or all together eliminate thermal bridging from an exterior of a building construction to the interior of a building or building wall. The through-wall flashing device is adapted for use with a variety of wall constructions and is specifically configured to provide insulation and moisture sheeting properties around doors, windows and other architectural apertures which may be found in a wall construction.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to a through-wall flashing system for a building, and more specifically, to a through-wall metal flashing system that provides one or more thermal breaks between the exterior and interior conditions of a wall construction of the building. 
       BACKGROUND OF THE INVENTION 
       [0002]    Through-wall flashing systems generally comprise a membrane used in a wall construction for the purpose of preventing the passage of water into a structure from a joint in the wall. Flashing devices can be used anywhere in a building where it is necessary to deflect water away from seams or joints or other areas where water runoff is concentrated. In the past, flashing devices have been comprised of sheet metal such as lead, aluminum, copper, galvanized steel, stainless steel and other architectural metals. These sheet metal components have been primarily used in flashing constructions due to their strength, workability and durability. However, these metal components, when used to connect exterior components of a building directly to interior frame, are at least partially exposed to external conditions and provide direct paths for thermal conductivity from the exterior of a building to an inside portion of a wall construction, or into the interior of the building itself. Such thermal conductivity is known as thermal bridging. Particularly, these metal substances provide negligible thermal resistance, such that hot and cold temperatures from the external environment are easily transferred through these metallic flashing devices. Thus, a need exists for a through-wall flashing system having flashing members with the structural rigidity of continuous metallic flashing members, while greatly reducing, if not eliminating, thermal bridging from exposed portions of the flashing members to internally disposed portions of the flashing members. 
       SUMMARY OF THE INVENTION 
       [0003]    One aspect of the present invention includes a through-wall flashing system for use at an interface between a wall accessory and an exterior wall construction of a building. The flashing system includes at least one flashing strip having a polymeric core, wherein the polymeric core includes an interior flashing portion, an exterior flashing portion and a body portion extending therebetween. An exterior facing is operably coupled to and substantially surrounds the polymeric core, wherein the exterior facing is comprised of a plurality of adjacent surfaces. Thermal breaks are disposed between one or more of the adjacent surfaces of the exterior facing and are adapted to disrupt thermal communication along the exterior facing between the interior flashing portion and the exterior flashing portion of the flashing strip. 
         [0004]    Another aspect of the present invention includes a through-wall flashing system for use in a wall construction. The flashing system includes a flashing member configured to be received within a cavity of the wall construction and includes an external flashing portion disposed along an exterior surface of the wall construction, an internal flashing portion disposed within the cavity of the wall construction, and a web portion extending between the internal and external flashing portions. The flashing member further includes a polymeric core having an upper surface and a lower surface with an exterior facing operably coupled to the upper and lower surfaces. A plurality of thermal breaks are disposed along the exterior facing, thereby separating or dividing the exterior facing into adjacent portions. The thermal breaks are adapted to thermally insulate adjacent portions of the exterior facing from one another, thereby reducing temperature transmission between flashing portions. 
         [0005]    Yet another aspect of the present invention includes a through-wall flashing system for use in a wall construction. The flashing system includes a flashing strip having an interior flashing portion, an exterior flashing portion and a body portion extending between the interior flashing portion and the exterior flashing portion. The flashing strip further includes an exterior facing operably coupled to and substantially surrounding a polymeric core. Thermal breaks are disposed along a length of the exterior facing, and are adapted to disrupt thermal temperature transmission between interior and exterior surfaces of the wall construction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a perspective view of a flashing device according to one embodiment of the present invention; 
           [0007]      FIG. 2  is a cross-sectional view of the flashing device of  FIG. 1  taken at line II; 
           [0008]      FIG. 3  is a fragmentary cross-sectional view of a flashing device according to another embodiment of the present invention shown in an environmental view in a wall construction; and 
           [0009]      FIG. 3A  is a fragmentary cross-sectional view of a flashing device according to another embodiment of the present invention shown in an environmental view in the wall construction of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0010]    For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
         [0011]    Referring to  FIG. 1 , the reference numeral  10  generally designates a flashing member or strip according to one embodiment of the present invention. The flashing member  10  is adapted for use in a flashing system. As shown in  FIG. 1 , the flashing strip  10  includes a plurality of panel portions with a first panel  12 , a second panel  14  and a third panel  16 . The first and third panels  12 ,  16  are generally vertical panels attached to one another by intermediate second panel  14  which, in this embodiment, is substantially horizontal. It is contemplated that in assembly the intermediate panel  14  may have a downward cant from the first panel  12  towards the third panel  16 , thereby providing a gravitational drain for any moisture that comes into contact with the flashings strip  10 . As shown in  FIG. 1 , the flashing strip  10  has an overall stepped configuration, however, other configurations are contemplated for use with the present invention. The first panel  12  defines an interior or internal flashing portion and includes an inner surface  18  and an outer surface  20 . Panel  14  defines a web or body portion and includes an upper surface  22  and a lower surface  24 . The third panel  16  defines an exterior or external flashing portion and includes an inner surface  26  and outer surfaces  28  and  29 . In assembly, the exterior surfaces or skins  20 ,  22 ,  28  and  29  are potentially exposed to environmental conditions A on an exterior side  10 A of the flashing strip  10 . Interior surfaces or skins  18 ,  24 ,  26  are disposed on an interior side  10 B of the flashing strip  10 , and are generally adjacent to the building construction materials which are subject to interior conditions B. Together, the inner and outer surfaces  18 ,  20 ,  22 ,  24 ,  26 ,  28  and  29  of the panels  12 ,  14  and  16  define an exterior facing  32  for the flashing strip  10  which is an exterior shell having thermal breaks as further described below. 
         [0012]    Collectively, the exterior surfaces or skins of the flashing strip  10  are generally comprised of sheet metal made from lead, aluminum, copper, galvanized steel, stainless steel, zinc alloy or lead coated copper. Other sheet metal substrates are also contemplated for use with the present invention. The metal surfaces provide the malleability, strength and durability necessary to prolong the life of the flashing strip  10 . However, in known flashing devices, a continuous or uninterrupted flashing made from a sheet metal material is known to cause thermal bridging from outside environmental conditions to the interior or wall construction of a building. To counter these thermal bridging effects, the flashing strip  10  of the present invention includes thermal breaks disposed on the panel portions  12 ,  14  and  16  of the flashing strip  10 . 
         [0013]    Referring now to  FIGS. 1 and 2 , the flashing strip  10  is shown having a polymeric core  30  disposed within the exterior facing  32  defined by interior and exterior surfaces  18 ,  20 ,  22 ,  24 ,  26 ,  28  and  29  of the panels  12 ,  14  and  16 . In the embodiment shown in  FIGS. 1 and 2 , interior panel portion  12  is a generally upright panel portion and includes interior metal surface  18  and exterior metal surface  20  having a polymeric core portion  30 A disposed there between. Similarly, generally horizontal or downwardly sloping web or body panel portion  14  includes a polymeric core portion  30 B disposed between interior metal surface  24  and exterior metal surface  22 . Finally, in the embodiment shown in  FIGS. 1 and 2 , downwardly facing exterior panel portion  16  includes polymeric core portion  30 C disposed between interior metal surface  26  and exterior metal surface  28 . The polymeric core  30  is generally comprised of an anticorrosive polymeric material that exhibits high insulative qualities or rather, demonstrates high R-value properties such as an R-value in the range of about R.2 to about R8 per inch. Polymeric materials suitable for the polymeric core of the present invention include thermoplastics or thermoset resin materials including for example: acrylonitrile-butadiene-styrene (ABS) copolymers, vinylesters epoxies, phenolic resins, polyvinyl chlorides (PVC), polyesters, polyurethanes, polyphenylsufone resin, polyarylsulfones, polyphthalimide, polyamides, aliphatic polyketones, acrylics, polyxylenes, polypropylenes, polycarbonates, polyphthalamides, polystyrenes, polyphenylsulfones, polyethersulfones, polyfluorocarbons, bio-resins and blends thereof. Other such thermoplastics and thermoplastic resins suitable for the present invention are known in the art which demonstrate high R-values and are thereby heat resistant as well as anticorrosive. Thermoplastics of the present invention are also contemplated to incorporate a recyclable polymer or are made of a polymeric material which is partially comprised of a renewable resource such as vegetable oil or the like. Further, microspheres, such as polymeric or glass nanospheres, can be added to the makeup of the polymeric core  30  to provide further insulative properties and increased R-value expression. When necessary, the polymeric core  30  can also be reinforced or doped with a reinforcing fiber such as fiber glass, carbon fibers, cellulose fibers, aramid fibers, and other such reinforcing agent to provide added structural rigidity to the flashing strip  10 . 
         [0014]    In assembly, the polymeric core  30  forms a thermal break between exterior metal surfaces or skins, such as surfaces  20 ,  22  and  28  shown in  FIGS. 1 and 2 , and interior metal surfaces or skins, such as surfaces  18 ,  24 , and  26  shown in  FIGS. 1 and 2 . Metal surfaces  18 ,  24 , and  26  are commonly in thermal communication with building substrates or wall constructions in assembly, as these surfaces are often disposed directly adjacent to the building substrate in which they are used. In other known flashing systems, this contact between metal surfaces and building substrates creates a thermal path or thermal gradient of least resistance that allows heat (or cold) to enter or escape, thereby creating vulnerability in a wall construction for cold spots and moisture problems. In the present invention, the sandwiched position of the polymeric core  30  between interior and exterior metal surfaces ( 18 ,  24 ,  26  and  20 ,  22 ,  28 ) ensures that heat (or cold) is not transferred to the building substrate in an effort to control the temperature within a building structure. Thus, the polymeric core  30  reduces or altogether eliminates thermal conductivity from the exterior metal surfaces  20 ,  22  and  28  to a building substrate in assembly. 
         [0015]    The flashing strip  10 , as shown in  FIGS. 1 and 2 , of the present invention also combats thermal bridging by incorporating thermal breaks in the exterior facing  32  of the flashing strip  10 . For example, in the embodiment shown in  FIG. 2 , the flashing strip  10  includes exterior metal surface  20  which, in this embodiment, is an L-shaped surface having a generally upright portion  20 A and a generally planar portion  20 B. The portions  20 A and  20 B of metal surface  20  are operably coupled to an upper surface  30 D of the polymeric core  30  along core portions  30 A and  30 B respectively. The metal surfaces of the exterior facing  32  of the flashing strip  10  are generally affixed to the polymeric core at inner and outer core surfaces  30 A,  30 B by continuous bonding. Interior metal surface  18  is also an L-shaped metal surface which includes upright portion  18 A and horizontal portion  18 B which is operably coupled to inner surface  30 E of the polymeric core  30 . Exterior metal surface  22  is a generally planar metal surface that is operably coupled to the outer surface  30 D of the polymeric core  30  and is spaced apart from portion  20 B of exterior metal surface  20  by a gap or spacing  40 A, thereby defining a thermal break  40 A therebetween. Similarly, interior metal surface  24  is operably coupled to inner surface  30 E of the polymeric core  30  and is spaced apart from portion  18 B of interior metal surface  18  at a spacing or gap  40 B disposed on the underside  10 B of the flashing strip  10 . Thermal breaks  40 C and  40 D are also found on panel portion  14  on exterior and interior sides  10 A and  10 B of the flashing strip  10  as shown in  FIG. 2 . Thermal break  40 C is disposed in a spacing between planar portion  28 B of metal surface  28  and metal surface  22 . In the embodiment shown in  FIG. 2 , exterior metal surface  28  includes an upright portion  28 A and a planar portion  28 B, while interior metal surface  26 , disposed on an opposing side of polymeric core portion  30 C relative to exterior metal surface  28 , includes a generally upright portion  26 A and a generally planar portion  26 B. Thermal break  40 D is disposed in a spacing between planar portion  26 B and metal surface  24 . As further shown in  FIG. 2 , a thermal break  40 E is defined in a spacing between upright portion  28 A of exterior metal surface  28  and metal surface  29  disposed on panel portion  16  of the flashing strip  10 . 
         [0016]    Having thermal breaks  40 A- 40 E disposed along the interior surface  10 B and exterior surface  10 A of the flashing strip  10  provides for a break-up in thermal communication between surfaces in contact with a building substrate and interior environment B, and surfaces exposed to exterior environmental conditions A. Thus, the present invention provides a polymeric core  30  sandwiched between interior and exterior metal surfaces, and also provides thermal breaks  40 A- 40 F disposed laterally along the length of exterior facing to adequately reduce thermal communication or temperature transmission into and out of a building interior or a cavity within a wall construction. The thermal breaks  40 A- 40 E provide for a substantially non-continuous exterior facing  32  disposed about the majority of the polymeric core  30 , wherein the non-continuous exterior facing  32  is made up of the interior and exterior metal surfaces disposed on panel portions  12 ,  14  and  16 . Having thermal breaks  40 A- 40 F, which run the entire length of the flashing strip  10 , ensures that thermal bridging does not occur between adjacent metal portions of the exterior facing  32 . Thus, thermal breaks  40 A- 40 F serve to isolate and thermally insulate adjacent portions of the exterior facing  32  from one another, thereby reducing temperature transmission between flashing portions  12 ,  14  and  16  of the flashing strip  10 . It will also be understood that, preferably, the thermal breaks on opposing sides of the polymeric core are offset from each other, that is, the thermal break  40 A is offset from thermal break  40 B so that to provide enhanced rigidity to the flashing. As such, a portion of the metal surface opposes the thermal break  40 B on the other side of the polymeric core. The same is true of the remaining thermal breaks. Additionally, it is preferred that the thermal breaks are spaced apart from the corners or edges where the panel portions meet. 
         [0017]    The configuration and dimensions of the panel portions  12 ,  14  and  16  of flashing strip  10  can be determined by the architectural requirements of the flashing needs for a particular building substrate or wall construction. A typical thermal gap, such as thermal gaps  40 A- 40 E shown in  FIGS. 1 and 2 , may comprise a substantially uniform channel along the length of the flashing strip, and, may be approximately 0.25 mm, but can also be adjusted for architectural specifications. In the embodiment shown in  FIGS. 1 and 2 , it is contemplated that the polymeric core  30  may be dimensioned to have a thickness in a range of about 3 mm to 6 mm to adequately provide interruption of a thermal gradient. The flashing system of the present invention is a customizable flashing system, wherein a plurality of flashing strips or members, such as flashing strip  10  described above, are customized to surround or encase a wall accessory in a wall construction, such as a window, vent, chimney or other like structure. As used throughout this disclosure, panel portions, such as panel portions  12 ,  14  and  16  described above, are flashing portions of a flashing member, wherein an exterior shell, such as exterior shell  32 , provides thermal breaks between the flashing portions. The thermal breaks are suitable to interrupt temperature transmission between adjacent flashing portions, thereby limiting unwanted temperature changes into and out of a building. 
         [0018]    Referring now to  FIG. 3 , a standard window sill detail is shown having a flashing strip  100  according to another embodiment of the present invention. The flashing strip  100  includes panel portions  112 ,  114  and  116  which are similar in configuration to panel portions  12 ,  14  and  16  as described above with reference to flashing strip  10 . The flashing strip  100  includes an upper or outer surface  100 A and a lower or inner surface  100 B. As shown in  FIG. 3 , the flashing strip  100  is disposed between a curtain wall system  60  and a metal stud wall construction  70 . The curtain wall system  60  includes an outwardly facing exterior wall  62  and a bottom wall  64 . In assembly, the bottom wall  64  of the curtain wall system  60  is disposed adjacent the upper side  100 A of the flashing strip  100 . The metal stud wall construction  70  may be an insulated wall construction which includes a weather barrier or exterior sheeting layer  72  coupled thereto using fasteners  74 . The fasteners  74  are further used to couple a polymeric bracket system  76  to the metal stud wall construction  70 . An exterior cladding system includes composite panels  80  and  82  which are coupled to the polymeric bracket system  76  using brackets  81  and fasteners  84 . The wall construction  70  and curtain wall system  60  are representative of assemblies that could be used with the present invention, however, they are not meant to limit the scope of the invention and are exemplary only. As shown in  FIG. 3 , the curtain wall system  60 , the flashing strip  100 , wall construction  70  and exterior cladding units  80 ,  82  are all potentially exposed to an exterior environment A and an interior environment B along portions thereof. 
         [0019]    The flashing unit  100 , as shown in  FIG. 3 , includes a polymeric core  130  surrounded by an interrupted exterior facing  132 . The exterior facing  132  is contemplated to be comprised of a sheet metal material. The exterior facing  132  is considered interrupted, in that the exterior facing  132  includes a plurality of thermal breaks which are identified in  FIG. 3  as thermal breaks  140 A- 140 F. Similar to the thermal breaks noted above, thermal breaks  140 A- 140 F are defined by spacings provided along the entirety of the exterior facing  132  of the flashing strip  100 , such that thermal communication between adjacent portions of the exterior facing  132  is interrupted and non-continuous. 
         [0020]    Referring now to  FIG. 3A , a flashing strip  200  having an upper or outer side  200 A in an inner or underside  200 B is shown disposed between curtain wall system  62  and wall construction  70 . The flashing strip  200  includes panel portions  212 ,  214  and  216 , wherein web panel portion  214  has a downward cant as it extends from panel portion  212  to panel portion  216 . In this way, the flashing strip  200  is disposed between a lower surface  64  of the curtain wall system  60  and an upper wall  78  of the wall construction  70 . The downward cant of web panel portion  214  helps to gravitationally drain moisture from the wall system in assembly. As shown in  FIG. 3A , interior panel portion  212  is disposed within a reglet  66  of the curtain wall system  60 , while exterior panel portion  216  is disposed adjacent to outer cladding unit  80 . The flashing strip  200  includes a substantially non-continuous exterior facing  232  which is generally comprised of a sheet metal material having thermal breaks  240 A- 240 G disposed therealong. Flashing strip  200  further includes a polymeric core  230  similar to cores  30  and  130  described above. The polymeric core  230 , along with the thermal breaks  240 A- 240 G disposed in the exterior facing  232  of the flashing strip  200 , helps to insulate the wall construction from environmental conditions disposed on side A of the wall construction that would otherwise thermally bridge to the interior side B, if the exterior facing  232  were in fact continuous and uninterrupted. 
         [0021]    The flashing members used in the flashing system of the present invention have a universal attachment design for use with virtually any wall construction or stud wall. For instance, the flashing members of the present invention can be used with structures having concrete masonry units (CMU Walls), composite wall panels, brick walls on CMU or stud walls, terra cotta on stud walls, and on stud wall configurations alone. As noted above, heat travels in the path of least resistance such that heat can invade a wall system and affect an interior atmosphere through relatively finite pathways such as fasteners and the like that have metal to metal contact with exterior conditions. Similarly, exterior exposure to cold temperatures can allow for infusion of cold temperatures into a wall construction along highly thermally conductive components. Most applications of metal flashings retain at least some form of metal to metal contact through metal anchors, fasteners, or sill, transition, and window trim. Fasteners used to couple the flashing members of the present invention to a wall construction do not bridge the thermal breaks of the flashing members and therefore do not thermally bridge the exterior conditions A with the interior conditions B. 
         [0022]    It is also to be understood that variations and modifications can be made on the aforementioned structures and methods without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.