Abstract:
A metal-foil-containing flashing laminate is disclosed which laminate is for flashing cavity walls. The laminate has at least one layer of an elastomeric composite over which is placed a hot melt adhesive layer, a metal foil lamina, and another hot melt adhesive layer. In this embodiment the metal foil is encapsulated by the adhesive layers. In application this laminate used with a release paper forms a peel-and-stick product and is suitable for surface mounting. Also to the basic laminate an additional elastomeric composite layer is placed above the metal foil lamina sandwiching the foil and forming a through-wall mountable product. A termination bar for use with surface mounted flashing with a polymeric foam coating is also disclosed. The peel-and-stick flashing may be lap-mounted at the seams between adjacent strips without caulks or sealants.

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of a patent application entitled Masonry Flashing System bearing Ser. No. 10/143,484 and filed May 10, 2002 now U.S. Pat. No. 6,584,746. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an improved flashing system for cavity wall structures, and more specifically to metal foil masonry flashings and a termination bar therefor. 
     2. Description of the Prior Art 
     In the past, investigations relating to cavity wall flashing systems for brick veneer masonry construction have been conducted. While strides have been made in flashing-related technologies, including metal foils, elastomeric materials and hot melt adhesives, there still remain several areas where continued development is ongoing. 
     The inventors&#39; patents and their assignee&#39;s product line are all related to accessories for cavity wall structures and include insulation, and anchoring and seismic devices, and are sold under the trademarks of Seismiclip®, Byna-Tie®, and DW-10-X®. These products, which are manufactured by Hohmann &amp; Barnard, Inc., Hauppauge, N.Y. 11788, have become widely accepted in the industry and have provided the inventors with particular insight into the technological needs of this marketplace. 
     Masonry walls with brick veneer are designed with an inner and an outer wythe and a cavity therebetween. The masonry block inner wythe and insulation thereon isolates the interior of the building from the environment, while the brick veneer outer wythe provides an aesthetic finish to the building. The walls of a building are constructed to exclude water and water vapor from the interior. Since the presence of excessive levels of water or water vapor in the cavity hastens the deterioration of building materials, various masonry flashing systems have been proposed. 
     Because of widespread usage and familiarity with bitumenous and asphaltic products in roofing applications, when masonry flashing systems were first designed, the building construction industry adopted the familiar copper and asphalt products. At that time the technology of pressure-sensitive hot melt adhesives needed for peel-and-stick applications was insufficiently developed. Some critics indicated that the adhesive quality was insufficient for the rough masonry block surfaces. Because of the presence of plasticizers, others were apprehensive about the available hot melt adhesives meeting the requisite fire retardancy standards. Also, to provide fire retardancy, some pressure-sensitive products were marketed for building construction use with inorganic fillers, such as alumina trihydrate, antimony oxide or calcium carbonate. However, these filled pressure-sensitive products had disadvantages, such as application problems, phase separation, toxicity, and reduced adhesion upon activation. 
     Prefabricated peel-and-stick flashing materials have been proposed, such as those shown in Harkness, U.S. Pat. No. 4,775,567 (see infra). These materials have included layers of bitumen and of compound bitumen for adhering the materials to the exteriors of masonry walls. While, under ideal circumstances, these peel-and-stick materials were easy to apply, the patent literature indicates that these materials did not conform well to irregular surfaces. Thus, the prior art bitumens used to secure these flashing materials to masonry walls often lacked the tackiness to bond tightly and durably to the wall surfaces. On occasion, when circumstances were not ideal, the bitumenous materials drooled marring the aesthetics of the brick veneer. 
     In the past, the previously mentioned assignee hereof has distributed, under the Copper Aqua Flash membrane name, a line of composite flexible flashings. The composite, in one form thereof, is 50 mil. thick and consists of a 3-ounce, solid sheet of annealed copper laminated on one side to a polyester film and bonded on the other with a highly adhesive SBS modified bitumen (rubberized asphalt) with a peel-and-stick silicone top sheet. By completely encapsulating the copper in the polyester film on one side and rubberized asphalt on the other, the copper is protected from corrosion by alkaline or acidic solutions. Although the rubberized asphalt virtually eliminated the possibility of non-adhered areas, the Copper Aqua Flash membrane still had some of the previously described disadvantages of a bitumen-based flashing system. 
     Despite these early efforts, developing the right combination of materials and methods for flashing cavity walls in a fast and efficient manner has proved elusive. In addition to the above described technical problems, because there is frequently a delay in erecting the inner wythe and the outer wythe, the flashing installed in the inner wythe is often exposed to substantial ultra-violet radiation. Thus, standards similar to ASTM Specification G154 for nonmetallic materials need to be met by masonry flashing systems. 
     As flashing for cavity walls involves numerous technological considerations, including, but not limited to, tensile strength, puncture- and tear-resistance, UV exposure, water absorption, pliability, peel and lap adhesion, and flammability, various industry standards under ASTM have arisen which serve as a guide to flashing manufacturers, architectural engineers, and and others preparing and meeting construction specifications. Among the relevant ASTM standards are ASTM D 624, Standard test method for tear strength of . . . thermoplastic elastomers; ASTM D 412, Standard test method for . . . thermoplastic elastomers—tension; ASTM D 2240, Standard test method for rubber property—durometer hardness (applies to thermoplastic elastomers); and, ASTM G 154, Standard practice for operating fluorescent light apparatus for UV exposure of nonmetallic materials. 
     In preparing for this application the following patents came to the attention of the inventors and are believed to be relevant to the further discussion of the prior art: 
     
       
         
               
               
               
             
           
               
                   
               
               
                 U.S. Pat. No. 
                 Inventor 
                 Issue Date 
               
               
                   
               
             
             
               
                 6,224,700 
                 Oakley 
                 May 1, 2001 
               
               
                 6,035,582 
                 Pacific 
                 Mar. 14, 2000 
               
               
                 5,870,864 
                 Snyder 
                 Feb. 16, 1999 
               
               
                 5,860,259 
                 Laska 
                 Jan. 19, 1999 
               
               
                 4,910,931 
                 Pardue 
                 Mar. 27, 1990 
               
               
                 4,775,567 
                 Harkness 
                 Oct. 4, 1988 
               
               
                 4,775,409 
                 Harkness 
                 Jul. 5, 1988 
               
               
                 4,295,911 
                 Haage et al. 
                 Oct. 20, 1981 
               
               
                 4,239,795 
                 Haage et al. 
                 Dec. 16, 1980 
               
               
                   
               
             
          
         
       
     
     Oakley—U.S. Pat. No. 6,224,700—Issued May 1, 2001 
     Oakley in U.S. Pat. No. 6,224,700 (assigned to Mar-Flex Systems, Inc., Middletown, Ohio) describes a method of applying a composite material to an above-grade building component to form a tacky non-swelling elastomeric membrane. Thereafter, a flexible, non-porous polymeric sheet is pressed onto the tacky exterior of the elastomeric membrane. The polymeric sheet is stronger than the elastomeric membrane and protects the elastomeric membrane from punctures or tears. Here, in situ construction is both labor intensive and requires special equipment for installation. 
     Pacific—U.S. Pat. No. 6,035,582—Issued Mar. 14, 2000 
     Pacific describes a flashing material which includes a sheet layer of copper, aluminum or other metal or a thin sheet of unreinforced plastic. Here it appears that in situ adhesives are applied. 
     U.S. Pat. No. 5,870,864—Snyder—Issued Feb. 16, 1999 
     Snyder describes a drainage system employing water collection pans which for insertion into the interior cavities of masonry block units over the length of a selected block wall course for collecting the water drained through the interior cavities of the upper courses and directing water to the exterior of the wall. 
     U.S. Pat. No. 5,860,259—Laska —Issued Jan. 19, 1999 
     Laska describes an insulated drainage panel for use in cavity wall or veneer wall construction which panel includes a planar insulating board with a porous structure thereof. 
     U.S. Pat. No. 4,910,931—Pardue—Issued Mar. 27, 1990 
     In the Pardue patent, a water collection and drainage system is described for a masonry block wall having bond beam block courses and intervening standard block courses. A system of upper water collection pans is supported along each upper bond beam course. Downspouts leading from drain openings in the upper collection pans drain collected from the pans through the vertical block cavities in lower block courses to the next lower series of collection pans. Weeping spouts lead laterally from the base collection pans to the exterior of the wall to continuously drain collected water from the interior wall cavities. 
     U.S. Pat. Nos. 4,775,567 and 4,775,409—Harkness—Issued Oct. 4, 1988 and Jul. 5, 1988, Respectively. 
     A waterproofing laminate suitable for use in roofs, floors or other surfaces where waterproofing is desired contains a reinforcing sheet, first and second bitumen layers secured to opposite surfaces of the reinforcing sheet, first and second compound bitumen layers secured to the bitumen layers, an elastomeric sheet secured to the first compound bitumen layer and a release sheet secured to the second compound bitumen layer. Certain preferred materials for use in the laminate are recited. 
     U.S. Pat. Nos. 4,295,911 and 4,239,795—Haage et al.—Oct. 20, 1981 and Dec. 16, 1980, Respectively. 
     A protective covering for the protection of surface seals against mechanical damage in building constructions and other civil engineering constructions which comprises a composite of an elastic, waterproof thermoplastic synthetic resin film sheet and/or synthetic resin layer and a lattice-like fabric having knot couplings or points of intersection of the threads that yield under the effect of a load. 
     The use of a masonry flashing system of this invention includes a polymeric membrane with hot melt adhesive thereon, release paper, and drip plates for brick veneer facing, as described infra, has also been found to obviate the difficulties discussed and provides other advantages set forth herein. 
     SUMMARY 
     In general terms, the masonry flashing system disclosed hereby includes a laminate for flashing. The laminated flashing is particularly applicable to cavity walls such as a wall with an inner wythe of masonry block and an outer wythe or veneer of brick. The masonry flashing laminate also includes a hot melt adhesive which encapsulates a metal foil layer and/or coats a surface of the laminate. In some embodiments, the adhesive is selected for compatibility with a peel-and-stick installation. When, for instance, during surface mounting, the laminate with hot melt adhesive thereon is pressed against the rough surface of the masonry block, the pressure activation creates a durable bond. The elastomeric portion of the laminate is constructed on a polymeric substate which in large part is a mixture of polyvinyl chloride and ethylene acetate carbon monoxide terpolymer. For purposes of improving puncture and tear resistance, a fibrous mat—either woven or non-woven—is embedded under a second elastomeric layer or cover. 
     Other components of the system include a stainless steel drip plate with a hot melt adhesive coating and a termination bar. The drip plate adhesive coating enables the installer to accurately position the plate and, during construction, maintain the alignment thereof. Optionally, a foam layer is placed on the lower surface of the drip plate and on the termination bar so as to improve the sealing of the installation. 
     The peel-and-stick technology shown herein enables quick and sure flashing of cavity walls which was unavailable prior to the advances in the materials of both elastomeric membranes and hot melt adhesives. The detailed description of these materials is provided hereinbelow. Preparing surfaces with adhesives and foams enables installation without additional caulking compounds and sealants. 
     OBJECTS AND FEATURES OF THE INVENTION 
     It is an object of the present invention to provide, for cavity wall construction, a metal-foil-containing masonry flashing system. 
     It is a further object of the present invention to laminate at least on the exterior surface of the metal foil a polymeric membrane and to coat the flashing with hot melt adhesive which, upon pressure activation, strongly adheres to the rough and porous surfaces of masonry block and brick. 
     It is another object of the present invention to provide in a masonry flashing system for cavity wall construction, combining metal foil and polymeric membrane technologies in system free of bituminous or asphaltic coatings, which flashing resists tearing and puncturing. 
     It is yet another object of the present invention to provide labor-saving metal foil masonry flashing system which utilizes peel-and-stick components that are easy and economical to install in cavity wall constructs having a masonry block inner wythe and a brick outer wythe. 
     It is still yet another object of the present invention to provide a metal foil masonry flashing system which operates cooperatively with present flashing accessories such as mortar guards and weep hole fittings. 
     It is a feature of the present invention that the hot melt adhesive hereof is compatible with flashing membranes containing ketone ethylene ester and meets industry flammability standards. 
     It is another feature of the present invention that the polymeric membrane hereof is highly, ultra-violet resistant and the membrane includes an embedded woven or non-woven fiber layer to enhance tear and puncture resistance. 
     It is yet another feature of the present invention that the termination bar has a foam layer thereon for sealing upon installation and obviate the use of sealants and caulks during the installation of the flashing system. 
     Other objects and features of the present invention will become apparent upon reviewing the drawing and reading the detailed description which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following drawings, the same parts in the various views are afforded the same reference designators. 
         FIG. 1  is a perspective view of a first embodiment of a metal foil masonry flashing system of this invention and shows a cavity wall with an interior wythe of masonry block and an exterior wythe of brick having a through-wall-mounted flashing membrane installed in the cavity thereof; 
         FIG. 2  is a perspective view of the uninstalled peel-and-stick flashing membrane of  FIG. 1  with successive laminae partially broken away to show details of the structure thereof; 
         FIG. 3  is a cross-sectional view of the flashing membrane of  FIG. 2 ; 
         FIG. 4  is a perspective view of the uninstalled peel-and-stick drip plate of  FIG. 1  with release sheets partly peeled back to show details of the structure thereof; 
         FIG. 5  is a perspective view of a second embodiment of a metal foil masonry flashing system of this invention and shows a cavity wall with an interior wythe of masonry block and an exterior wythe of brick having a surface-mounted flashing membrane installed in the cavity thereof; 
         FIG. 6  is a perspective view of the uninstalled peel-and-stick flashing membrane of  FIG. 5 , similar to  FIG. 2  but having a single layer of polymeric membrane; 
         FIG. 7  is a cross-sectional view of the flashing membrane of  FIG. 6 ; 
         FIG. 8  is a perspective view of the termination bar for use with the surface-mounted flashing membrane; 
         FIG. 9  is a perspective view of a third embodiment of a metal foil flashing of this invention and is an uninstalled flashing membrane suitable for through-the-wall mounting; and, 
         FIG. 10  is a cross-sectional view of the flashing membrane of  FIG. 9 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the metal foil masonry flashing system of this invention, in contradistinction to the parent case, hot melt adhesives are used to attach polymeric flashing material to at least one side of the metal foil and to the cavity face of the masonry inner wythe. The masonry flashing is emplaced behind the insulation which, in turn, serves to protect against thermal losses, to reduce sound, and to prevent water vapor condensing on colder surfaces. The metal foil increases the longevity of the flashing by enhancing the tensile strength and by improving tear and puncture resistance. 
     Referring now to  FIGS. 1 through 4 , the first embodiment of this invention in which a masonry flashing system, referred to generally by the reference designator  10 , is shown. In this embodiment, a cavity wall structure  12  is shown having an inner wythe  14  of masonry blocks  16  and an outer wythe  18  of facing brick  20 . Between the inner wythe  14  and the outer wythe  18 , a cavity  22  is formed. Successive bed joints  24  and  26  are formed between courses of blocks  16  and the joints are substantially planar and horizontally disposed. Also, successive bed joints  28  and  30  are formed between courses of bricks  20  and the joints are substantially planar and horizontally disposed. For the through-wall flashing installation of this embodiment bed joint  26  and bed joint  28  are employed. 
     For purposes of this discussion, the exterior surface  32  of the interior wythe  14  contains a horizontal line or x-axis  34  and an intersecting vertical line or y-axis  36 . A horizontal line or z-axis  38  also passes through the coordinate origin formed by the intersecting x- and y-axes. In the discussion which follows, it will be seen that the masonry flashing system  10  of this invention is constructed to completely seal the cavity, to drain water therefrom and to permit air and water vapor to enter and exit through weep holes  40  that are in communication the masonry flashing system  10 . 
     Across the cavity  22 , in this embodiment, a through-the-wall installation of the masonry flashing system is shown. The system  10  includes a composite flashing membrane  42  having polymeric and metal foil laminae. The flashing membrane  42  is constructed for embedment in bed joint  26  in an x-z plane, for adherence to surface  32  in an x-y plane, for extending across and into bed joint  28  thereby sealing cavity  22 , and for embedment in bed joint  28  in an x-z plane. In this preferred mode, it is seen that the polymeric membrane  42  is installed behind insulation  44 . 
     Between the membrane  42  and the brick  20 , a drip plate  46 , preferably of stainless steel, is constructed to improve the communication between the masonry flashing system  10  and weep holes  40 . Weep holes  40  permit any moisture or condensate to drain away from and out of the cavity  22 . 
     Referring now to  FIGS. 2 and 3  the laminar structure of the uninstalled peel-and-stick flashing membrane  42  is shown. The membrane  42 , while being shown in  FIG. 1  as a through-wall mounted system, is suitable for either through-wall or surface mounting and utilizes the hot melt adhesive technology for both construction and application. The laminar structure consists of a seven-layer arrangement. When viewing the uninstalled membrane  42  from the exposed surface and proceeding toward the mounted surface these layers are:
         a. elastomeric composite-Elvaloy KEE;   b. hot melt adhesive—APC #915;   c. metal foil—copper;   d. hot melt adhesive—APC #915;   e. elastomeric composite—Elvaloy KEE;   f. hot melt adhesive APC #915; and   g. release sheet;
 
and each layer is described in further detail below. The elastomeric composite  50  is, in turn, a laminar structure.
       

     Each elastomeric composite  49  layer is comprised of a first elastomeric sheet or carrier  50  which serves as a base layer upon which is disposed a fibrous mat  52 . The fibrous mat  52  is constructed to enhance the tear and puncture resistance of the overall composite. The fibrous mat  52  may be a woven or nonwoven technical textile or may be filaments randomly arranged upon membrane  42 . In this embodiment, a second elastomeric sheet  54  is disposed on the fibrous mat  52  sandwiching and sealing the laminae together. 
     In general, it is preferred that the elastomeric sheets  50  and  54  contain at least one material selected from the group consisting of ethylenepropylene diene monomer, polyisobutylene, chlorinated polyethylene, natural rubber, polyvinyl chloride, ethylene vinyl acetate, and chlorosulfonated polyethylene. A specifically preferred formulation for the elastomeric sheet includes about 10 to 40 percent by weight of unplasticized polyvinyl chloride, and about 10 to 40 percent by weight of an ethylene vinyl acetate carbon monoxide terpolymer. The elastomeric sheet may also contain up to about 15 percent of primary or secondary plasticizer with, or without, up to about 10 percent of processing aids or stabilizers. 
     In the elastomeric sheets  50  and  54  the amount of polyvinyl chloride is preferably in the range of about 20 to 30 percent by weight of the entire composition and may advantageously be provided as a suspension or emulsion grade of polyvinyl chloride. The ethylene vinyl acetate carbon monoxide terpolymer may contain about 15 to 85 percent ethylene, about 5 to 60 percent vinyl acetate, and about 0.5 to 30 percent carbon monoxide, all on a weight basis. A suitable terpolymer for use in this context is that marketed by E. I. du Pont de Nemours &amp; Company under the trademark Elvaloy, with the preference being for Elvaloy KEE or, in the alternative, Elvaloy 742. It is within the contemplation of this invention that elastomeric carrier  50 , fibrous mat  52 , and elastomeric sheet  54  may be replaced by a suitable long-fiber reinforced elastomeric body having, when formed into a membrane, similar flexibility and toughness. 
     Referring again to  FIG. 2 , the peel-and-stick polymeric membrane  42  further includes several hot melt adhesive layers  55  which are formulated for pressure activation and compatibility with the elastomeric composites  56 , the metal foil  57 , and the release sheet  58  adhered thereto. The adhesives described herein are particularly useful for peel-and-stick applications in building construction industry as such adhesives are readily pressure activated after the release paper is removed. The adhesive is formulated so that, in case of fire, the coatings thereof will not contribute to smoke or accelerate flame spreading and thus do not require inorganic fillers which are known to interfere with the adhesive function. Also, the adhesives are formulated to have sufficient tackiness so that a durable bond between the membrane and the rough and porous surface of the masonry block is experienced. The adhesive on the through-wall flashing permits lapping of the widths of flashing precluding the use of caulks and sealants at the lapped joints  59 . 
     Incorporating by reference the Di Rado et al. patent, U.S. Pat. No. 5,106,447, the hot melt adhesive compositions of hot melt layer  56  may be prepared from 10 to 50 weight percent of an isotactic thermoplastic polybutene-1/ethylene copolymer containing from about 5.5 to about 10% by weight ethylene (polybutylene); 20 to 50 percent of a tackifier; 15 to 50 percent of an amorphous diluent having a softening point greater than 90 degrees C.; 0 to 2 percent of a stabilizer; and 0 to 5 percent wax. 
     The polybutylene copolymers employed herein are copolymers of polybutene-1 and ethylene wherein the ethylene content varies from about 5.5 to about 10% by weight of the copolymer. The applicable isotactic polybutylenes are relatively rigid while in their plastic form but flow readily upon being heated. Expressing molecular weight in terms of melt index, the applicable isotactic polybutylenes to be used in the present adhesive should exhibit a melt index in the range of from about 5 to 2000 dg/min and preferably from 400 to 700 dg/min. The latter melt flow values are determined by the method described in ASTM D1238 and are inversely related to molecular weight, i.e., the lower the melt index, the higher the molecular weight. These copolymers are available from Shell Chemical Company under the Duraflex trademark as Duraflex 8310, 8410, 8510 and 8910, with the 8910 having a melt index of about 700, a grade preferred for use herein. Mixtures of these copolymers may also be used. 
     The tackifying resins which may be used to extend the adhesive properties of the isotactic polybutylene include: (1) hydrogenated wood rosin or rosin ester; (2) polyterpene resins having a softening point, as determined by an ASTM method E28-58 T, of from about 80 degrees C. to 150 degrees C., the latter polyterpene resins generally resulting from the polymerization of terpene hydrocarbons in the presence of Friedel-Crafts catalysts at moderately low temperatures and including the latter resins which are aromatically modified; examples of commercially available resins of this type being the Nirez resins sold by Reichhold Chemical, the Zonatac resins sold by Arizona, and the Piccolyte S-10, S-25, S-40, S-85, S-100, S-115, S-125 and S-135 resins as sold by Hercules Chemical; (3) aliphatic petroleum hydrocarbon resins having a Ball and Ring softening point of from about 80 degrees C. to 160 degrees C., resulting from polymerization of monomers consisting primarily of 5 carbon atom olefins and diolefins, and including the latter resins which are aromatically modified, examples of commercially available resins of this type being Wingtack 95 and Wingtack Extra as sold by the Goodyear Tire and Rubber Company and the Escorez 1000 series of resins sold by the Exxon Chemical Corporation; and (4) partially and fully hydrogenated hydrocarbon resins such as Resin H-130 from Eastman, Escorez 5000 series from Exxon, and Regalrez from Hercules. The amorphous diluents which are needed and present in the adhesive composition include (atactic) amorphous polypropylene or other similar high softening point (i.e. greater than 90 degrees C.), low crystalline diluent, (e.g. amorphous polyalphaolefins). These diluents, are used at levels of 20 to 50% by weight, preferably about 20 to 25% by weight. 
     To test the degree of tackiness of the above-described flashing structure, a pull test is performed. An Elvaloy 742 (see paragraph 052, above) 8-inch by 12-inch sample is coated with a hot melt adhesive, namely, APC #915, manufactured by Adhesive Products Company, Indianapolis, Ind. 46235 which hot melt adhesive formulation includes one or more of the aforementioned tackifying resins. A suitable release paper is applied thereover. After a prescribed cure period, the release paper is removed and the flashing of this invention is applied to the surface of a concrete block. The application to the concrete block is at room temperature utilizing a hand-operated laminating roller to provide the pressure activation. A spring scale is then attached to the masonry flashing and a 65 lb. force is required to peel the flashing from the block. Repeating the test for SBS-modified, peel-and-stick flashing, a force of 27 lb. (max.) is required to peel the flashing from the block. 
     Among the applicable stabilizers or antioxidants utilized herein are included high molecular weight hindered phenols and multifunctional phenols such as sulfur and phosphorous-containing phenols. Representative hindered phenols include: 1,3,5-trimethyl 2,4,6-tris (3,5-di-tert-butyl-4-hydroxy-benzyl)benzene; penta-erythrityl tetrakis-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate; 4,4′methylenbis(2,6-tert-butyl-phenol); 4,4′-thiobis (6-tert-butyl-o-cresol); 2,6-di-tertbutylphenol; 6-(4-hydroxy-phenoxy)-2,4-bis (n-octyl-thio)-1,3,5-triazine; di-n-octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate; and sorbitol hexa [3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate]. 
     The performance of these antioxidants may be further enhanced by utilizing, in conjunction therewith known synergists such, for example, as thiodipropionate esters and phosphites. Particularly useful is distearylthiodipropionate. These stabilizers are generally present in amounts of about up to 2 weight percent, preferably 0.25 to 1.0%. It is also possible to add minor amounts (i.e. less than about 5% by weight of the formulation) of other diluents such as (1) waxes including petroleum waxes such as a paraffin wax having a melting point of from about 50 degrees C. to 75 degrees C. and microcrystalline wax having a melting point of from about 60 degrees to 90 degrees C.; the latter melting points being determined by ASTM method D127-60; (2) low molecular weight (600 to 3000) liquid polybutene; (3) polyethylene greases having a softening point of from about 80 degrees C. to 100 degrees C. and a hardness value, as determined by ASTM method D-1321, of from about 60 degrees C. to 120 degrees C.; (4) hydrogenated animal, fish and vegetable fats and oil such as hydrogenated tallow, lard, soya oil, cottonseed oil, castor oil, menhaden oil and cod liver oil; and (5) synthetic waxes made by polymerizing carbon monoxide and hydrogen, such as Fischer-Tropsch wax. 
     In addition, relatively small amounts (less than about 5%) of isotactic polypropylene may be employed as a reinforcing agent. Other additives such as flow modifiers, pigments, dyestuffs, etc., which are conventionally added to hot melt adhesives for various end uses may also be incorporated in minor amounts into the formulations of the present invention. 
     Referring again to  FIG. 2 , a metal foil or copper layer  57  is shown. A metallic layer is provided to enhance the tensile strength and puncture- and tear-resistant characteristics of the flashing. As with copper and bitumen flashing combinations any of the commonly used weights of copper sheeting may be used, including, but not limited to, 2 oz/ft 2 , 3 oz/ft 2 , 5 oz/ft 2  and 7 oz/ft 2 . The selection of copper sheeting weight is determined by the parameters of the application and by the desired pliability of the end product. Other metal foils or sheeting may be used and may be selected from aluminum, stainless steel, copper, lead-coated copper, galvanized steel, terne-coated metal, epoxy-coated metal foil, and other metal foils. 
     Referring now to  FIG. 4 , an uninstalled drip plate assembly  46  is shown in detail. The drip plate  60 , preferably constructed of stainless steel, Type 304SS, has a hot melt adhesive layer  62  on one surface thereof which, after removal of release sheet  64 , is activated by being pressed onto the facing brick  20  of outer wythe  18 . Holding the drip plate  60  securely in place by the adhesion of the drip plate to the brick, ensures the alignment of the masonry flashing system  10  components during and after the application of mortar to the bed joint. On the surface opposite the captured surface, the drip plate  60  also has another hot melt adhesive layer  66  which, after removal of release sheet  68 , is activated by flashing, in this embodiment the polymeric membrane  42 , being pressed thereon. Upon installation of the masonry flashing system  10 , the drip plate  46  secures the edge of membrane  42  and directs water draining therefrom to weep holes  40 . 
     Referring now to  FIGS. 5 through 8 , the second embodiment of this invention in which a surface-mounted masonry flashing system, referred to generally by the reference designator  110 , is shown. In this embodiment, similar parts to those of the first embodiment are referred to by reference designators  100  units higher than a similar part in the first embodiment. Thus, for example, the masonry block  16  in the first embodiment has an analogous masonry block  116  in the second embodiment. Here a cavity wall structure  112  is shown having an inner wythe  114  of masonry blocks  116  and an outer wythe  118  of facing brick  120 . 
     Between the inner wythe  114  and the outer wythe  118 , a cavity  122  is formed. Successive bed joints  124  and  126  are formed between courses of blocks  116  and the joints are substantially planar and horizontally disposed. Also, successive bed joints  128  and  130  are formed between courses of bricks  120  and the joints are substantially planar and horizontally disposed. For purposes of this discussion, the exterior surface  132  of the interior wythe  114  contains a horizontal line or x-axis  134  and an intersecting vertical line or y-axis  136 . A horizontal line or z-axis  138  also passes through the coordinate origin formed by the intersecting x- and y-axes. In the discussion which follows, it will be seen that the metal foil masonry flashing system  110  is constructed to completely seal the cavity and to drain water and water vapor therefrom through weep holes  140  that are in communication the flashing system  110 . 
     Across the cavity  122 , in this embodiment, a surface-mounted installation of the metal foil masonry flashing system is shown. The system  110  includes a polymeric membrane or a composite elastomeric sheet  142  constructed for adherence to surface  132  in an x-y plane, for extending across and canted slightly downwardly from an x-z plane into bed joint  128  sealing cavity  122 , and for embedment in bed joint  128  where the membrane thereby is adhered to drip plate  146 . In this preferred mode, it is seen that the polymeric membrane  142  is installed behind termination bar  144  secured by attaching hardware  145 . Between the membrane  142  and the brick  120 , a drip plate  146 , preferably of stainless steel, is constructed to improve the communication between the masonry flashing system  110  and weep holes  140 . 
     Referring now to  FIGS. 6 and 7  the laminar structure of the peel-and-stick flashing membrane  142  is shown in greater detail. The membrane  142  is suitable for surface mounting and utilizes the hot melt adhesive technology for both construction and application. The laminar structure consists of a five-layer arrangement. When viewing the uninstalled membrane  142  from the exposed surface and proceeding toward the mounted surface these layers are:
         a. elastomeric composite-Elvaloy KEE   b. hot melt adhesive—APC #915   c. metal foil—stainless steel—304SS   d. hot melt adhesive—APC #915   e. release sheet
 
The elastomeric composite and the hot melt adhesive have been described in detail above.
       

     Each elastomeric composite layer is comprised of a first elastomeric sheet or carrier  150  which serves as a base layer upon which is disposed a fibrous mat  152 . The fibrous mat  152  is constructed to enhance the tear and puncture resistance of the overall composite. The fibrous mat  152  may be a woven or nonwoven technical textile or may be filaments randomly arranged upon membrane  142 . In this embodiment, a second elastomeric sheet  154  is disposed on the fibrous mat  152  sandwiching and sealing the laminae together. 
     Referring again to  FIG. 6 , a metal foil or stainless steel layer  157  is shown. The metallic layer is provided to enhance the tensile strength and the puncture- and tear-resistant characteristics of the flashing membrane  142 . As in the first embodiment, the metal foil thickness is determined by desired pliability and strength. Here, the preferred material is from the 300-series stainless steels, usually 304SS, and may be 22 ga. to 32 ga. thick (in the example 24 ga. material). 
     Referring now to  FIG. 8 , a stainless steel termination bar and hardware  144  and  145 , respectively, is shown. The termination bar  144  includes a polymeric foam layer or lamina  170  to enhance the sealing between the system and the cavity. The use of the same metal for the metal foil, the termination bar and the hardware prevents galvanic corrosion. The foam layer is placed between the termination bar and exterior polymeric layer of the metal foil flashing membrane  142 . 
     Referring again to  FIG. 6 , the peel-and-stick polymeric membrane  142  further includes two hot melt adhesive layers  155 -one on either side of metal foil  157 , which adhesives are formulated for pressure activation and compatibility with the elastomeric composites, the metal foil  157 , and the release sheet  158  adhered thereto. The adhesives described herein are particularly useful for peel-and-stick applications in building construction industry as, after the release paper is removed, such adhesives are readily pressure activated. 
     As in the first embodiment, the adhesive is formulated so that, in case of fire, the coatings thereof will not contribute to smoke or accelerate flame spreading and thus do not require inorganic fillers which are known to interfere with the adhesive function. Also, the adhesives are formulated to have sufficient tackiness so that a durable bond between the membrane and the rough and porous surface of the masonry block is experienced. Upon application to the backup wall, the adhesive on the surface-mounted flashing permits lapping of widths of the flashing obviating the use of caulks and sealants at the lapped joints. 
     Referring now to  FIGS. 9 and 10 , the third embodiment of this invention in which an uninstalled metal foil masonry flashing referred to generally by the reference designator  242 , is shown. In this embodiment, a cavity wall structure identical to that in the second embodiment is employed. Here, only the uninstalled metal flashing  242 , an alternative to that in  FIGS. 6 and 7 , is shown and parts similar to those in the second embodiment are referred to by reference designators  100  units higher than a similar part in the second embodiment. Thus, for example, the elastomeric sheet  150  has an analogous elastomeric sheet  250  in the second embodiment. 
     Referring now to  FIGS. 9 and 10  the laminar structure of the metal foil flashing membrane  242  is shown. The membrane  242 , while being shown in  FIGS. 9 and 10  is suitable for through-wall mounting only and shows internal use of the hot melt adhesive technology. The laminar structure consists of a six-layer arrangement. When viewing the uninstalled membrane  242  from the exposed surface and proceeding toward the mounted surface these layers are:
         a. elastomeric composite—long-fiber reinforced ( 250 ,  FIGS. 9 and 10 )   b. hot melt adhesive—APC #915 ( 255 ,  FIGS. 9 and 10 )   c. metal foil—stainless steel ( 257 ,  FIGS. 9 and 10 )   d. hot melt adhesive—APC #915 ( 255 )   e. elastomeric composite—long-fiber ( 250 ) reinforced ( 251 )   f. polymeric foam—closed-cell neoprene
 
The elastomeric composite  250  is a long-fiber reinforced polymeric structure.
       

     Referring now to  FIGS. 9 and 10  the polymeric membrane  242  of this embodiment is shown in greater detail. The membrane  242  is comprised of an elastomeric sheet or carrier  250  into which is admixed a long-fiber or filamentous reinforcement material  252 . The admixture of the filamentous material  252  is constructed to enhance the tear and puncture resistance of the overall composite. 
     Throughout the flashing system described herein, a polymeric foam lamina or layer  251  is optionally employed to enhance the sealing between the system and the cavity wall components. This has been found to enhance the sealing of the cavity. Suitable polymeric foams include both cross-linked and non-cross-linked polyethylene and closed-cell neoprene sponge. 
     Because of environmental and flammability concerns with traditional solvent-based adhesives and an invested position in bitumen-containing materials, the building construction industry has been slow to adopt hot melt adhesive compositions for masonry flashing applications. Now, with the recent advances in hot melt adhesives technology incorporated into the above application advantages over solvent-based or bitumen systems are created hereby. Thus, because the polymeric membranes described above have the requisite tear and puncture resistance and the hot melt adhesives meet the fire retardancy and adhesiveness requirements, the previous barriers to use have been removed. It is further appreciated that the advance in the art is remarkable as the hot melt adhesives hereof do not contain organic solvents and thereby do not cause the environmental concerns of the solvent-based systems. 
     The masonry flashing system of this invention exhibits temperature stability superior to that of bitumen materials and do not break down at high ambient temperatures. In addition, as hot melt adhesives are pressure activated, they set up immediately and reduce the time required for installation. Thus, the bonding of hot melt adhesives to masonry surfaces is immediate and unlike bitumen materials are not dependent on ambient temperatures for cure purposes. This translates into greater quality construction and easier assurance thereof. Another advantage of hot melt adhesives is their economy and applicability to peel-and-stick structures.