Patent Publication Number: US-2010109318-A1

Title: Zinc flashing for roof penetrations

Description:
The present invention claims priority on U.S. Provisional Application Ser. No. 61/109,641 filed Oct. 30, 2008 entitled “Zinc Flashing for Roof Penetrations,” which is incorporated fully herein by reference. 
     The present invention is generally directed to flashing for roofing systems, more particularly to flashing that is used about roof penetrations, and even more particularly to zinc flashing that is used about roof penetrations. 
    
    
     BACKGROUND OF THE INVENTION 
     Currently, soft lead flashing is the common choice for flashing materials. Lead flashing is used because it is malleable, thus is easy to form the lead flashing to the surface of a roofing system and about various structures on the surface of the roofing system. As such, lead flashing is relatively easy to integrate between layers of roofing material and the lead flashing also easily conforms to irregular shapes on the surface of the roofing system. Roof flashing can also be formed by other materials such as stainless steel or galvanized sheet metal. This non-lead flashing is much more rigid than lead flashing, thus typically requiring the flashing to be anchored (e.g., nailed, riveted, screwed, etc.) to the surface of the roofing system. The anchoring of such flashing to a roofing system typically adds to the cost and time for assembling the roofing system. Furthermore, the arrangements required to anchor such non-lead roof flashing to the roofing system can adversely affect the sealing properties of the roofing system. As such, lead flashing is the preferred choice of flashing in the roofing industry. Lead flashing generally does not require special anchoring arrangements on the roofing system, and lead flashing is easy to bend. Lead flashing also is slow to corrode and does not form unsightly oxides and discoloration during corrosion. 
     Although lead flashing is a desirable roof flashing for purposes of installation on roofing systems, lead materials are of a health concern in many countries since lead can leach into water that contacts the lead material. As such, lead materials have fallen out of favor in many communities. Consequently, stainless steel flashing and galvanized flashing have grown in popularity in the roofing industry, even though such materials are more costly and expensive to use, and can result in an inferior roofing system. 
     In view of the current problems in the roofing industry, there is a need for a flashing product that has similar malleability properties as lead, has corrosion resistant properties, is not considered harmful to humans and the environment, and which can be effectively used as flashing on a roofing system. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to flashing, and more particularly to flashing that can be used on roofing systems, and more particularly to flashing that can be used to seal the area about penetrations in a roofing system. In accordance with one non-limiting embodiment of the invention, the flashing is formed of a metal material that primarily constitutes zinc. In one non-limiting aspect of this embodiment, the zinc content of the metal material is over 95 weight percent. In another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99 weight percent. In still another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99.1 weight percent and has about 0-0.9 weight percent alloying metals and impurities. In still yet another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99.2 weight percent and has about 0-0.8 weight percent alloying metals and impurities. In another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99.3 weight percent and has about 0-0.7 weight percent alloying metals and impurities. In still another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99.4 weight percent and has about 0-0.6 weight percent alloying metals and impurities. In yet another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99.5 weight percent and has about 0-0.5 weight percent alloying metals and impurities. In yet another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 99.6 weight percent and has about 0-0.4 weight percent alloying metals and impurities. In another and/or alternative non-limiting aspect of this embodiment, metal material is not formed of a titanium zinc alloy. Titanium zinc alloys are known as zinc alloys that certain amounts of copper and titanium. Typically, titanium zinc alloys include about 0.75-1.1 weight percent copper and about 0.13-1.7 weight percent titanium and the balance zinc with minor impurities of no more than 0.05 weight percent. Titanium zinc alloys are not suitable for the zinc flashing of the present invention since such zinc alloys are too rigid. Titanium zinc are less malleable than the zinc alloy used in the present invention, thus flashing formed of titanium zinc alloy will not easily conform to roof surfaces in a manner similar to lead flashing. Indeed, flashing formed of titanium zinc alloy exhibits the same malleability problems as flashing formed of stainless steel and galvanized steel. In still another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 91.1 weight percent and the copper content of the metal material is less than 0.75 weight percent and the titanium content is less than 0.13 weight percent. In yet another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 91.2 weight percent and the copper content of the metal material is less than 0.7 weight percent and the titanium content is less than 0.1 weight percent. In still yet another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 91.2 weight percent and the copper content of the metal material is less than 0.6 weight percent and the titanium content is less than 0.075 weight percent. In another and/or alternative non-limiting aspect of this embodiment, the zinc content of the metal material is over 91.2 weight percent and the copper content of the metal material is less than 0.5 weight percent and the titanium content is less than 0.05 weight percent. In still yet another and/or alternative non-limiting aspect of this embodiment, the metal material of the present invention is not pure zinc. As such, limited amounts of alloying agents are included in the metal material to improve the physical characteristics of the metal material; however, it can be appreciated that the metal material can be formed of pure zinc. Generally, the alloy content of the metal material is at least about 0.005 weight percent, typically at least about 0.01 weight percent, more typically at least about 0.05 weight percent. Furthermore, the alloy content of the metal material is generally less than about 1 weight percent, typically less than about 0.9 weight percent, and even more typically less than about 0.8 weight percent. Typically alloy metal content of the metal material is about 0 01-0.9 weight percent, more typically about 0.05-0.85 weight percent, and even more typically about 0.05-0.8 weight percent. The alloying components that can be used in the metal material include aluminum, cadmium, chromium, copper, iron, lead, magnesium, nickel, tin, titanium, and any combination thereof. Generally the alloying metals include copper, cadmium, iron and/or titanium. The metal material can include various impurities (e.g., carbon, oxygen, nitrogen, etc.). Generally the impurity content of the metal material is less than about 0.05 weight percent, typically less than about 0.01 weight percent, and more typically less than about 0.005 weight percent. 
     It has been found that relatively pure zinc and certain zinc alloys form a durable and malleable material that can be easily formed into various shapes. As such, when these types of metals are formed into flashing, the zinc flashing does not require special attachment arrangements as is require for stainless and galvanized flashing materials. The average thickness of the metal material that forms the zinc flashing of the present invention is generally less than 0.25 inches, typically less than about 0.125 inches, more typically less than about 0.1 inches, even more typically about 0.005-0.05 inches, and still even more typically about 0.01-0.03 inches. The zinc flashing in accordance with the present invention provides a flash system that is compatible in utility to the current standard roof flashing products, such as lead flashing products. The zinc flashing of the present invention can be used to waterproof roof penetrations through a roof system that cannot be sealed using the primary roofing material. For instance, primary roofing materials may be too rigid (e.g., concrete, tile, sheet metal, etc.) and/or experience significant shrinkage (e.g., asphalt built up roofing, etc.) during the useful life of the roofing materials, thus cannot be used in-of-themselves to waterproof the region about a roof penetration (e.g., round cast iron plumbing vent pipe, round PVC plumbing vent pipe, etc.). In such instances, flashing is typically used to form the waterproof seal about the roof penetration. Lead flashing is typically used since such material is soft and easily conforms to the shape of the roof penetration and has a life that is generally longer than the life of the primary roofing materials. The zinc flashing of the present invention can be used to replace standard lead flashing without requiring increased costs or labor. The malleability properties of the zinc material of the present invention are similar to lead materials and the life of the zinc material is generally the same as or longer than the life of the primary roofing materials. Flashing that is made of soft and/or malleable materials is important as a waterproofing component of roofing systems. The flexibility of the of the zinc material of the present invention enables the flashing made from such zinc material to facilitate in waterproofing roofing systems, especially around penetrations in a roofing system. As such, the zinc flashing of the present invention can be used on standard roofing systems, can be conformed to roof penetrations, and can be conformed to the shape of the roofing system layers. 
     In another and/or alternative non-limiting aspect of the present invention, the zinc flashing of the present invention can have a specific configuration for use with roof penetrations. In one non-limiting embodiment, the zinc flashing includes a generally flat planar base plate with an aperture in the base plate. As can be appreciated, the base plate is not required to be flat and planar. A vertical tube structure extends upwardly from the base plate and at least partially encircles the aperture in the base plate. The vertical tube structure can extend upwardly at an angle perpendicular to the upper surface of the base plate; however, the vertical tube structure can extend upwardly at an angle of 30°-90° from the upper surface of the base plate. The non-perpendicular angle of the upwardly extending vertical tube is generally used on sloped roof surfaces. The vertical tube structure can be a separate piece of material from the base plate, thus requiring the vertical tube to be connected to the base plate by 1) a mechanical attachment arrangement (e.g., rivets, clamps, mechanical seam, etc.), 2) use of solder, 3) use of a weld bead, and/or 4) use of an adhesive. Alternatively, the vertical tube structure and base plate can be formed from a single piece of material. The vertical tube structure is designed to fit about vertical penetrations that are extending upwardly from the roofing surface. In another and/or alternative non-limiting embodiment, the aperture in the base plate has a generally circular cross-sectional shape; however, other cross-sectional shapes such as a polygonal shape (e.g., square-shaped, rectangular-shaped, etc.), oval shaped and the like can be used. In yet another and/or alternative non-limiting embodiment, the vertical tube can have a constant cross-sectional shape and/or constant cross-sectional area along the longitudinal length of the vertical tube; however, this is not required. In one non-limiting aspect of this embodiment, the vertical tube has a circular cross-sectional shape along the complete longitudinal length of the vertical tube. In another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a circular cross-sectional shape along the complete longitudinal length of the vertical tube and the cross-sectional area remains generally constant along the complete longitudinal length of the vertical tube. In still another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a circular cross-sectional shape along the complete longitudinal length of the vertical tube and the cross-sectional area changes along at least a portion of the longitudinal length of the vertical tube (e.g., cone-shaped vertical tube, etc.). In yet another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a polygonal cross-sectional shape along the complete longitudinal length of the vertical tube. In still yet another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a polygonal shape along the complete longitudinal length of the vertical tube and the cross-sectional area remains generally constant along the complete longitudinal length of the vertical tube. In still yet another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a polygonal shape along the complete longitudinal length of the vertical tube and the cross-sectional changes along at least a portion of the longitudinal length of the vertical tube (e.g., pyramid-shaped vertical tube, etc.). 
     As described above, the zinc flashing of the present invention can be used as a substitute for prior art lead flashing and create water-proofing about roof penetrations. For example, in asphalt built-up roofing systems, the roof is built-up through the application of layers of felt material and liquid asphalt. The solidified asphalt does not have the flexibility over time that is required to maintain a seal about a roof penetration (e.g, a cast iron plumbing vent pipe, etc.) for more than a few years. The roof penetration generally expands and contracts as the ambient temperature changes. Over time, this expansion and contraction will cause the seal between the asphalt and the roof penetration to break, thereby compromising the water-proofing of the roofing system. Typically, the watertight warranty for built-up asphalt roofing systems is at least 10 years. As such, metal flashing has been used to form a water-proof seal about roof penetrations. In practice, roofers lay down two or three plys of felt up to the region of the roof penetration and then apply the metal flashing about the roof penetration. The metal flashing is then set in a bed of asphalt mastic and subsequently pressed down onto the roof to then be sealed by the first few layers of roofing. The top side of the flashing is then generally primed and two additional layers of roofing felt and liquid asphalt are applied over the felt layers on the metal flashing. After application of the felt layers and the asphalt, the base plate of the metal flashing is sandwiched between the layers of the built-up roofing system. The vertical tube that extends upwardly from the base plate of the metal flashing can then be sealed at the top region of the roof penetration by compressing the top portion of the vertical tube with a mechanical drawband or the like and then applying a sealant to the drawn portion of the vertical tube and the roof penetration. Alternatively, the top portion of the vertical tube can be bent down into the roof penetration and/or a roof cap can be installed over the top of the vertical penetration to create a watertight condition. In the past, lead flashing has been used as the metal flashing to form the water-tight seals for roof penetrations as set forth above. The zinc flashing of the present invention is designed to be a replacement of the lead flashing that is used to seal roof penetrations. The zinc flashing can also have additional uses and can be used in flashing applications that are illustrated in U.S. Pat. No. 7,114,301; U.S. Pat. No. 7,059,086; U.S. Pat. No. 6,503,601; U.S. Pat. No. 5,913,779; U.S. Pat. No. 5,605,020; U.S. Pat. No. 5,344,062; U.S. Pat. No. 5,317,845; U.S. Pat. No. 4,977,721; U.S. Pat. No. 4,700,512; U.S. Pat. No. 4,102,090; US 2007/0101664; US 2005/0252111; US 2005/0055889; US 2004/0255523; EP 1424455; GB 2,386,135; GB 2,355,471; GB 1,429,022; WO 2006/02629; WO 2004/051026; WO 2004/007864; and WO 2003/074812; all of which are fully incorporated herein by reference. The zinc flashing of the present invention has been designed to be substituted for prior lead flashing materials without sacrificing ease of installation and durability and longevity of the life of the flashing. Indeed, the zinc flashing will far outlast the useful life of a built-up roofing system and many other types of roofing systems. 
     In still another and/or alternative non-limiting aspect of the present invention, the zinc flashing of the present invention has an important advantage over current lead flashing in that zinc and zinc alloys are considered to be a much safer material to handle than lead. Zinc can be handled by humans without skin protection. Lead, on the other hand, can be dangerous for humans to directly contact. Indeed, many government agencies are attempting to reduce the amount of lead and lead exposure in workplaces. Roofing work is considered by many a low skill trade wherein workers may have minimal education and may not speak or read English, therefore, exposing workers to the harmful effects of lead. Lead flashing is commonly handled without any protection to the skin. Furthermore, respirators are generally not used when lead based solders (60% lead) are used. The use of zinc flashing in accordance with the present invention overcomes such problems associated with the handling and soldering of lead flashing. The zinc flashing of the present invention also can be used on a variety of types of roof systems such as, but not limited to, asphalt built up roof, modified bitumen roofing, single ply membrane roofing, fluid applied roofing, asphalt shingles, clay tiles, concrete tiles, slate, galvanized steel sheet metal roofing, aluminum sheet metal roofing, zinc sheet metal roofing, and the like. The zinc alloy used on the zinc flashing of the present invention is formulated to be soft enough and malleable enough to conform to the surface of many types of roofing systems and/or roofing structures on the roofing system (e.g., roof penetrations, roof vents, etc.) and the zinc flashing can be integrated into such roofing systems without the use of mechanical fasteners, thus such zinc flashing has significant advantages over stainless steel, galvanized, and tin flashing. 
     In yet another and/or alternative non-limiting aspect of the present invention, the bottom surface and/or upper surface of the base plate can include an adhesive that can be used to secure to the bottom surface and/or upper surface of the base plate to a roofing surface; however, this is not required. Various types of adhesives can be used (e.g., urethane adhesive, epoxy adhesive, methacrylate adhesive, methacrylate adhesive, isocyanate adhesive, cyanoacrylate adhesive, etc.). In one non-limiting embodiment of the invention, the adhesive can be a pre-applied adhesive layer that includes a removable protective film. The removable protective film, when used, can be designed to be removable so as to expose the layer of adhesive prior to contacting the bottom face of the adhesive to a roofing surface; however, this is not required. The adhesive, when used, is designed to at least partially maintain the zinc flashing in position on the surface of the roofing system. The type of adhesive and thickness of the adhesive layer is non-limiting. 
     In still yet another and/or alternative non-limiting aspect of the present invention, at least a portion of the zinc flashing can be coated with a material that inhibits or prevents oxidation of the zinc material that can form on the zinc flashing when exposed to the environment; however, this is not required. In one non-limiting embodiment, the complete zinc flashing is coated with a material that inhibits or prevents oxidation of the zinc material. The type and thickness of the material coated on the zinc material is non-limiting. 
     In another and/or alternative non-limiting aspect of the present invention, a portion of the zinc flashing includes a protective layer that creates a barrier layer between the zinc flashing and one or more components of a roofing system; however, this is not required. It has been found that when zinc metal directly contacts certain metals (e.g., iron, iron alloys, etc.), the contact point can result in accelerated corrosion of the contacted metal and/or zinc flashing. The protective layer is designed to inhibit or prevent the direct contact of the zinc flashing with a potentially reactive metal material. The protective layer can be in the form of a coating and/or a material that is inserted between the zinc flashing and the potentially reactive metal material. In one non-limiting embodiment, the protective layer is a coating material that is applied to one or more regions of the zinc flashing. In one non-limiting aspect of this embodiment, the coating material is a polymer coating, bitumen coating and the like. In still another and/or alternative non-limiting aspect of this embodiment, the coating material has a thickness of less than 0.25 inches, typically less than about 0.1 inches, and more typically greater than about 0.0001 inches. In still yet another and/or alternative non-limiting aspect of this embodiment, the coating material is coated on the complete surface of the zinc flashing. In another and/or alternative non-limiting aspect of this embodiment, the coating material is coated only on the bottom surface of the base plate of the zinc flashing. In still another and/or alternative aspect of this embodiment, the coating material is coated only on the interior surface of the vertical tube that extends upwardly from the base plate of the zinc flashing. In yet another and/or alternative non-limiting aspect of this embodiment, the coating material is coated only on the exterior surface of the vertical tube that extends upwardly and/or downwardly from the base plate of the zinc flashing. In yet another and/or alternative non-limiting aspect of this embodiment, the coating material is coated only on the bottom surface of the base plate of the zinc flashing and the interior and/or exterior surface of the vertical tube that extends upwardly and/or downwardly from the base plate of the zinc flashing. In another and/or alternative non-limiting embodiment, the protective barrier is a material that is positioned between the zinc flashing and one or more components of a roofing system. In one non-limiting aspect of this embodiment, the protective barrier is a material that is adhesively or mechanically connected to the zinc flashing. In another and/or alternative non-limiting aspect of this embodiment, the protective barrier is a natural or man-made rubber material, a polymer material, a bitumen material and the like. In still another and/or alternative non-limiting aspect of this embodiment, the protective barrier has a thickness of at least 0.02 inches and generally less than about 0.5 inches; however, it can be appreciated that thicker protective barriers can be used. In yet another and/or alternative non-limiting aspect of this embodiment, the protective barrier is only positioned on the bottom surface of the base plate of the zinc flashing. In still yet another and/or alternative non-limiting aspect of this embodiment, the protective barrier is only positioned on the interior surface of the vertical tube that extends upwardly from the base plate of the zinc flashing. In another and/or alternative non-limiting aspect of this embodiment, the protective barrier is positioned only on the exterior surface of the vertical tube that extends upwardly and/or downwardly from the base plate of the zinc flashing. In another and/or alternative non-limiting aspect of this embodiment, the protective barrier is only positioned on the bottom surface of the base plate of the zinc flashing and the interior and/or exterior surface of the vertical tube that extends upwardly and/or downwardly from the base plate of the zinc flashing. In this arrangement, the protective barrier can be a single piece of material or multiple pieces of material that can be formed of the same type or different types of materials and can have the same or differing thicknesses. 
     In still yet another and/or alternative non-limiting aspect of the present invention, the zinc flashing can include a sealing gasket used to facilitate in forming a water-tight seal between the zinc flashing and the roofing system; however, this is not required. The sealing gasket, when used, is generally positioned at least partially about the outer surface of the vertical tube. In one non-limiting embodiment, the sealing gasket, when used, is positioned at least partially about the outer surface of the vertical tube and at or near the base of the vertical tube that is connected to the base plate. In still another and/or alternative non-limiting embodiment, the sealing gasket, when used, is positioned at least partially about the outer surface of the vertical tube and at or near the top end of the vertical tube. In yet another and/or alternative non-limiting embodiment, the sealing gasket can be formed of a variety of materials such as, but not limited to, a polymer material, rubber material, and the like. In still yet another and/or alternative non-limiting embodiment, the gasket material is generally a flexible and/or stretchable material; however, this is not required. In another and/or alternative non-limiting embodiment, the sealing gasket can be secured to the zinc flashing by the use of a friction connection, mechanical connection, hot melt connection, and/or adhesive connection. In another and/or alternative non-limiting embodiment, the sealing gasket can including an aperture that is designed to at least partially fit about a roof penetration and at least partially form a water-tight seal with the roof penetration. 
     In another and/or alternative non-limiting aspect of the present invention, the zinc flashing can include a split to enable the zinc flashing to be fitted about a structure on a roofing system such as a roof penetration; however, this is not required. When the zinc flashing includes a split, the split can be closed and/or sealed by one or more of the following arrangements: use of mechanical devices (e.g., rivets, clamping bands, clips, latches, etc.), by use of a mechanically formed seal (e.g, bending together of the edges, etc.), by use of a solder, by use of a weld bead, by use of an adhesive, by use of a sealing gasket, by use of a sealing sleeve, etc. 
     In still another and/or alternative non-limiting aspect of the present invention, the zinc flashing can be used to facilitate in forming a water-tight seal about a roof drain; however, this is not required. The zinc flashing includes a base plate that has an aperture. The base plate can be a generally flat planar plate; however, this is not required. The bottom surface of the base plate can include a downwardly extending vertical tube; however, this is not required. The downwardly extending vertical tube, when used, is designed to fit at least partially in the roof drain so as to facilitate in the formation of a water-tight seal. As can be appreciated, the edges of aperture can be bent down to form the downwardly extending vertical tube or a preformed downwardly extending vertical tube can be included on the base plate. The vertical tube structure at least partially encircles the aperture in the base plate. The vertical tube structure can extend downwardly at an angle perpendicular to the bottom surface of the base plate; however, the vertical tube structure can extend at an angle of 30°-90° from the bottom surface of the base plate. The non-perpendicular angle is generally used on sloped roof surfaces. The vertical tube structure can be a separate piece of material from the base plate, thus requiring the vertical tube to be connected to the base plate by 1) a mechanical attachment arrangement (e.g., rivets, clamps, mechanical seam, etc.), 2) use of solder, 3) use of a weld bead, and/or 4) use of an adhesive. Alternatively, the vertical tube structure and base plate can be formed from a single piece of material. In another and/or alternative non-limiting embodiment, the aperture in the base plate has a generally circular cross-sectional shape; however, other cross-sectional shapes such as a polygonal shape (e.g., square-shaped, rectangular-shaped, etc.) can be used. In yet another and/or alternative non-limiting embodiment, the vertical tube can have a constant cross-sectional shape and/or constant cross-sectional area along the longitudinal length of the vertical tube; however, this is not required. In one non-limiting aspect of this embodiment, the vertical tube has a circular cross-sectional shape along the complete longitudinal length of the vertical tube. In another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a circular cross-sectional shape along the complete longitudinal length of the vertical tube and the cross-sectional area remains generally constant along the complete longitudinal length of the vertical tube. In still another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a circular cross-sectional shape along the complete longitudinal length of the vertical tube and the cross-sectional area changes along at least a portion of the longitudinal length of the vertical tube (e.g., cone-shaped vertical tube, etc.). In yet another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a polygonal cross-sectional shape along the complete longitudinal length of the vertical tube. In still yet another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a polygonal shape along the complete longitudinal length of the vertical tube and the cross-sectional area remains generally constant along the complete longitudinal length of the vertical tube. In still yet another and/or alternative non-limiting aspect of this embodiment, the vertical tube has a polygonal shape along the complete longitudinal length of the vertical tube and the cross-sectional changes along at least a portion of the longitudinal length of the vertical tube (e.g., pyramid-shaped vertical tube, etc.). 
     In still another and/or alternative non-limiting aspect of the present invention, the zinc flashing can at least partially form a pitch pocket about a roof penetration; however, this is not required. In such an arrangement, the vertical tube has a cross-sectional area that is greater than the cross-sectional area of the roof penetration. A water-tight seal is formed between the vertical tube and the roof penetration by inserting a sealant (e.g., asphalt, polymer, pitch, etc.) into the space between the inner surface of the vertical tube and the outer surface of the roof penetration. In common practice, grout can be first inserted into the space between the inner surface of the vertical tube and the outer surface of the roof penetration prior to adding the sealant; however, this is not required. When a grout is used, the grout is generally a non-shrinkable grout; however, this is not required. 
     In yet another and/or alternative non-limiting aspect of the present invention, the zinc flashing can be used in conjunction with a cap, which cap is used to prevent liquids from entering the top opening of a roof penetration; however, this is not required. The cap can be formed of the same or similar material as the zinc flashing, however, this is not required. The cap, when used, can be connected to the exterior surface of the vertical tube of the zinc flashing; however, this is not required. When the cap is connected to the exterior surface of the vertical tube of the zinc flashing, the connection can be formed by use of 1) a mechanical attachment arrangement (e.g., rivets, clamps, mechanical seam, etc.), 2) a solder, 3) a weld bead, and/or 4) an adhesive; however, this is not required. 
     In still yet another and/or alternative non-limiting aspect of the present invention, the vertical tube of the zinc flashing can include a fluted portion or corrugated portion; however, this is not required. The fluted portion or corrugated portion, when used, can be used to adjust the longitudinal length of the vertical tube to accommodate differing lengths of roof penetrations; however, this is not required. 
     In one non-limiting object of the present invention, there is provided a zinc flashing material that can be used to replace standard types of flashing materials formed of lead, tin, galvanized steel and stainless steel. 
     In another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that has the same or similar malleability as lead flashing. 
     In still another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that is formed of pure zinc or a certain type of zinc alloy. 
     In still another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that is coated with a protective layer to inhibit or prevent reaction of the zinc flashing with other components of a roofing system. 
     In yet another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that is used with a protective barrier to inhibit or prevent reaction of the zinc flashing with other components of a roofing system. 
     In still yet another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that includes an adhesive layer to facilitate in securing the zinc flashing to a roofing system. 
     In another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that is coated with a material that inhibits or prevents corrosion of the zinc flashing material. 
     In still another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that includes a vertical portion that is fluted or corrugated so that the zinc flashing can be adjusted relative to roof penetrations. 
     In still yet another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that includes a sealing gasket used to at least partially form a seal with a roof penetration. 
     In another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that can be used to least partially form a pitch pocket about a roof penetration. 
     In still another and/or alternative non-limiting object of the present invention, there is provided a zinc flashing material that can be used to form water-tight seals about roof drains and/or roof penetrations. 
     These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference may now be made to the drawings, which illustrate several non-limiting embodiments that the invention may take in physical form and in certain parts and arrangements of parts wherein; 
         FIG. 1  illustrates a zinc flashing in accordance with the present invention that includes a zinc base plate and a vertical tube extending upwardly form the top surface of the zinc base plate; 
         FIG. 2  is a modification of  FIG. 1  wherein the zinc flashing includes a split in the base plate and the vertical tube; 
         FIG. 3  illustrates the installation of the zinc flashing of  FIG. 1  on a roof membrane and which zinc flashing includes the use of a cap; 
         FIG. 4  is a cross-sectional view of the zinc flashing of  FIG. 1  that includes a protective layer in the form of a coating on the bottom surface of the zinc base plate and the inside surface of the vertical tube; 
         FIG. 5  is a cross-sectional view of the zinc flashing of  FIG. 1  that includes a protective layer in the form of the coating on the bottom and top surface of the zinc base plate and the inside and outside surface of the vertical tube; 
         FIG. 6  is a cross-sectional view of the zinc flashing of  FIG. 1  that includes a protective layer in the form of a sleeve on the inside surface of the vertical tube; 
         FIG. 7  is another modification of  FIG. 1  wherein the vertical tube includes a fluted portion to adjust a longitudinal length of the vertical portion; 
         FIG. 8  illustrates the installation of the zinc flashing of  FIG. 7  on a roof membrane and which zinc flashing includes the use of a cap; 
         FIG. 9  is another modification of  FIG. 1  wherein the vertical tube is connected to the baseplate at a non-perpendicular angle; 
         FIG. 10  illustrates the installation of the zinc flashing of  FIG. 7  on a roof membrane; 
         FIG. 11  is another modification of  FIG. 1  wherein the vertical tube is connected to the baseplate at a non-perpendicular angle and the vertical tube is generally cone-shaped; 
         FIG. 12  illustrates the installation of the zinc flashing of  FIG. 11  on a roof membrane; 
         FIG. 13  is a modification of  FIG. 1  wherein a rubber sealing sleeve is positioned on the top portion of the vertical tube; 
         FIG. 14  illustrates the installation of the zinc flashing of  FIG. 13  on a roof membrane; 
         FIG. 15  is another modification of  FIG. 1  wherein the vertical tube has a polygonal cross-section shape along a longitudinal length of the vertical portion; 
         FIG. 16  is a modification of  FIG. 15  wherein the zinc flashing includes a split in the base plate and the vertical tube; 
         FIG. 17  illustrates the installation of the zinc flashing of  FIG. 15  on a roof membrane; 
         FIG. 18  illustrates a zinc flashing in accordance with the present invention that includes a zinc blase plate and a vertical tube extending downwardly from the bottom surface of the zinc base plate; and, 
         FIG. 19  illustrates the installation of the zinc flashing of  FIG. 18  on a roof membrane. 
     
    
    
     NON-LIMITING EMBODIMENTS OF THE INVENTION 
     Referring now to the drawings wherein the showings are for the purpose of illustrating non-limiting embodiments of the invention only and not for the purpose of limiting same,  FIGS. 1-19  illustrate several non-limiting configurations of the zinc flashing in accordance with the present invention. The zinc flashing is formed of a malleable zinc alloy that includes over 99 weight percent zinc. The zinc flashing can be formed of pure zinc or a special zinc alloy The zinc alloy generally contains at least about 0.01 weight percent alloying agent and less than about 0.7 weight percent alloying agents. The alloying agents typically include one or more metal alloy agents selected from the group of aluminum, cadmium, chromium, copper, iron, lead, magnesium, nickel, tin, and titanium. The alloying agent content in the zinc alloy is maintained at small quantities so that the malleability of the zinc alloy is not adversely affected. Non limiting examples of zinc alloys that can be used in the present invention are set forth below in the following examples: 
     EXAMPLE A 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Component 
                 Weight Percent 
               
               
                   
                   
               
             
            
               
                   
                 zinc 
                 91.1-99.99% 
               
               
                   
                 aluminum 
                 up to 0.9% 
               
               
                   
                 cadmium 
                 up to 0.9% 
               
               
                   
                 chromium 
                 up to 0.9% 
               
               
                   
                 copper 
                 up to &lt;0.75% 
               
               
                   
                 iron 
                 up to 0.9% 
               
               
                   
                 lead 
                 up to 0.9% 
               
               
                   
                 magnesium 
                 up to 0.9% 
               
               
                   
                 nickel 
                 up to 0.9% 
               
               
                   
                 tin 
                 up to 0.9% 
               
               
                   
                 titanium 
                 &lt;0.13% 
               
               
                   
                 Impurities 
                 &lt;0.05% 
               
               
                   
                   
               
            
           
         
       
     
     EXAMPLE B 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Component 
                 Weight Percent 
               
               
                   
                   
               
             
            
               
                   
                 zinc 
                 91.1-99.9% 
               
               
                   
                 aluminum 
                 up to 0.7% 
               
               
                   
                 cadmium 
                 up to 0.7% 
               
               
                   
                 chromium 
                 up to 0.5% 
               
               
                   
                 copper 
                 up to 0.7% 
               
               
                   
                 iron 
                 up to 0.5% 
               
               
                   
                 lead 
                 up to 0.7% 
               
               
                   
                 magnesium 
                 up to 0.5% 
               
               
                   
                 nickel 
                 up to 0.5% 
               
               
                   
                 tin 
                 up to 0.7% 
               
               
                   
                 titanium 
                 up to 0.12% 
               
               
                   
                 Impurities 
                 &lt;0.05% 
               
               
                   
                   
               
            
           
         
       
     
     EXAMPLE C 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Component 
                 Weight Percent 
               
               
                   
                   
               
             
            
               
                   
                 zinc 
                 91.2-99.9% 
               
               
                   
                 aluminum 
                 up to 0.5% 
               
               
                   
                 cadmium 
                 up to 0.5% 
               
               
                   
                 chromium 
                 up to 0.3% 
               
               
                   
                 copper 
                 up to 0.5% 
               
               
                   
                 iron 
                 up to 0.3% 
               
               
                   
                 lead 
                 up to 0.5% 
               
               
                   
                 magnesium 
                 up to 0.3% 
               
               
                   
                 nickel 
                 up to 0.3% 
               
               
                   
                 tin 
                 up to 0.5% 
               
               
                   
                 titanium 
                 up to 0.1% 
               
               
                   
                 Impurities 
                 &lt;0.05% 
               
               
                   
                   
               
            
           
         
       
     
     EXAMPLE D 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Component 
                 Weight Percent 
               
               
                   
                   
               
             
            
               
                   
                 zinc 
                 92-99.9% 
               
               
                   
                 aluminum 
                 up to 0.2% 
               
               
                   
                 cadmium 
                 up to 0.2% 
               
               
                   
                 chromium 
                 up to 0.2% 
               
               
                   
                 copper 
                 up to 0.2% 
               
               
                   
                 iron 
                 up to 0.2% 
               
               
                   
                 lead 
                 up to 0.2% 
               
               
                   
                 magnesium 
                 up to 0.2% 
               
               
                   
                 nickel 
                 up to 0.2% 
               
               
                   
                 tin 
                 up to 0.2% 
               
               
                   
                 titanium 
                 up to 0.08% 
               
               
                   
                 Impurities 
                 &lt;0.05% 
               
               
                   
                   
               
            
           
         
       
     
     EXAMPLE E 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Component 
                 Weight Percent 
               
               
                   
                   
               
             
            
               
                   
                 zinc 
                 94-99.9% 
               
               
                   
                 aluminum 
                 up to 0.1% 
               
               
                   
                 cadmium 
                 up to 0.2% 
               
               
                   
                 chromium 
                 up to 0.1% 
               
               
                   
                 copper 
                 up to 0.2% 
               
               
                   
                 iron 
                 up to 0.1% 
               
               
                   
                 lead 
                 up to 0.2% 
               
               
                   
                 magnesium 
                 up to 0.1% 
               
               
                   
                 nickel 
                 up to 0.1% 
               
               
                   
                 tin 
                 up to 0.1% 
               
               
                   
                 titanium 
                 up to 0.05% 
               
               
                   
                 Impurities 
                 &lt;0.01% 
               
               
                   
                   
               
            
           
         
       
     
     The zinc or zinc alloy materials can be formed into the zinc flashing in a variety of ways. For example, the zinc flashing can be at least partially stamped or cut (e.g., mechanical cutting, water cutting, laser cutting, etc.) from a sheet or strip of zinc, cast from molten zinc, etc. One or more portions of the zinc flashing can be connected together by use of a solder (lead/tin mix, lead free, etc.), weld bead, adhesive (e.g., urethane, epoxy, methacrylate, meth methacrylate, isocyanate, cyanoacylate, etc.), and/or by forming a mechanical seam. When one or more portions of the zinc flashing are coated, the coating can be applied by any number of techniques (e.g., dip coating, brush coating, spray coating, electroplating, air knife coating, etc.). The coating, when used on the zinc flashing, is used to protect the zinc material from corroding and/or to inhibit or prevent the zinc materials from directly contacting another material, which contact could result in accelerated corrosion of the zinc material and/or material in direct contact with the zinc material. When one or more portions of the zinc flashing including the use of a barrier layer (e.g., rubber sleeve, etc.), the barrier layer can be connected to one or more portions of the zinc flashing by use of an adhesive (e.g., urethane, epoxy, methacrylate, meth methacrylate, isocyanate, cyanoacylate, etc.), and/or by a mechanical connection arrangement (e.g., clamp, friction fit, rivet, tape, etc.). 
     The zinc flashing of the present invention can have many shapes. Several of these shapes are described in more detail below (e.g., base plate plus vertical tube, base plate plus fluted base portion plus vertical tube, base plate plus vertical tube plus cap, split base plate plus split vertical tube, base plate plus vertical tube plus flexible sleeve, etc.). Several of these shapes are described in more detail below. 
     Referring again to  FIGS. 1-19 , several non-limiting embodiments of zinc flashing in accordance with the present invention are illustrated. In general, the zinc flashing illustrated in  FIGS. 1-19 , that are suitable for use with penetrations in a roofing system. In each of the illustrated embodiments, the zinc flashing  100  includes a base plate  110  that includes an opening or aperture  120 . The base plate is illustrated as having a planar shape; however, this is not required.  FIGS. 1-17  illustrate a vertical tube  130  that extends upwardly from the top surface  112  from the base plate and which encircles opening  120  in the base plate. The vertical tube is generally formed of the same material as the base plate, but this is not required. The vertical tube is generally a separate component from the base plate that is connected to the base plate; however, it can be appreciated that the base plate and vertical tube can be a one piece unit that is formed from the same piece of material. 
     The cross-sectional size and shape of opening  120  is selected to enable a roof penetration to pass through the opening when the zinc flashing is secured to a roofing system. The longitudinal length of the vertical tube can be the same or greater length as the longitudinal length of the roof penetration; however, this is not required. As illustrated in  FIG. 1 , vertical tube  130  has a generally circular cross-sectional shape; however, this is not required.  FIG. 1  also illustrates that the vertical tube has a generally constant cross-sectional shape and size along the longitudinal length of the vertical tube; however, this is not required.  FIG. 1  also illustrates that the vertical tube is generally perpendicular from the top surface of the base plate; however, this is not required. 
     Referring to  FIGS. 4-6 , the zinc flashing can include a protective barrier to inhibit or prevent direct contact between the zinc or zinc alloy of the zinc flashing with the roofing system and/or roof penetration; however, this is not required. Referring now to  FIG. 4 , there is illustrated a coating  140  that is positioned on the inside surface  132  of the vertical tube and a coating  150  that is positioned on the bottom surface  114  of the base plate. Coatings  140 ,  150  can be formed of the same or different material and have the same or different thickness. Coatings  140 ,  150  can be applied to the zinc flashing in a variety of ways (e.g., spray coating, dip coating, brush coating, etc.). The method of coating for coatings  140 ,  150  can be the same or different. Non-limiting examples of compositions of coatings  140 ,  150  include plastisol, PVC, vinyl, etc. As mentioned above, coatings  140 ,  150  provide a physical barrier between the zinc or zinc alloy of the zinc flashing and the roofing system and roof penetration. Coating  140 ,  150  is generally used to inhibit or prevent corrosion from being initiated by or accelerated by the contact of the zinc or zinc alloy with the roofing system and/or the roof penetration. Coating  150  can also be used to improve adhesion of the base plate  110  with the surface of the roof system; however, this is not required. Coatings  140 ,  150  can also or alternatively be used to inhibit or prevent the zinc or zinc alloy from oxidizing in the environment; however, this is not required. 
     Referring now to  FIG. 5 , there is illustrated a coating  140  that is positioned on the inside surface  132  of the vertical tube, a coating  160  positioned on the outside surface  134  of the vertical tube, a coating  150  that is positioned on the bottom surface  114  of the base plate, and a coating  170  that is positioned on the top surface  112  of the base plate. Coatings  140 ,  150 ,  160 ,  170  can have the same or different formulation and/or have the same or different thickness. The method of applying these coatings to the zinc flashing can be the same or different. The function of coatings  140 ,  150 ,  160 ,  170  can be the same or different from coatings  140 ,  150  as described in  FIG. 4 . 
     Referring now to  FIG. 6 , there is illustrated a sleeve  180  that is positioned on the inside surface  132  of the vertical tube and a portion on the outside surface  134  of the vertical tube. As can be appreciated, sleeve  180  does not need to extend to the outside surface  134  of the vertical tube. The sleeve can be connected to the vertical tube in a variety of ways (e.g., adhesive, melt connection, mechanical connection, etc.). As can be appreciated, a sleeve can also or alternatively be positioned on the complete outside surface  134  of the vertical tube, positioned on the bottom surface  114  of the base plate, and/or positioned on the top surface  112  of the base plate. Sleeve  180  is generally used to inhibit or prevent corrosion from being initiated by or accelerated by the contact of the zinc or zinc alloy with the roofing system and/or the roof penetration. As can be appreciated, the zinc flashing can include both a coating and a sleeve; however, this is not required. 
     The coatings and/or sleeve as described above in  FIGS. 4-6  can be used on any of the zinc flashing arrangements illustrated in  FIGS. 1-3  and  7 - 19 ; however, this is not required. 
     Referring now to  FIG. 2 , there is illustrated a zinc flashing similar to the zinc flashing of  FIG. 1  that includes a split  200  in the base plate and a split  210  in the vertical tube. The split in the base plate and the vertical tube enables the zinc flashing to be fitted about a roof penetration. As illustrated by the arrows, the zinc flashing can be opened along the side of the zinc flashing so that the zinc flashing can be fitted about a roof penetration. Once the zinc flashing is fitted about a roof penetration, the split is closed by moving the zinc flashing in a direction that is opposite of the arrow. The split can then be closed in a variety of ways (e.g., adhesive, weld, solder, rivet, etc.). 
     Referring now to  FIG. 3 , there is illustrated a roofing system  300  that includes a roof penetration  400  that extends through the surface of the roofing system and a zinc flashing  100  that is positioned on the roofing system and about the roof penetration. The roofing system illustrated in  FIG. 3  is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 3 , the base plate  110  is positioned between two layers  310 ,  320  of roofing system  300 .  FIG. 3  also illustrates a vent cover  500  that is positioned on the top of the roof penetration. The use of a vent is not required. The vent can be made of the same or different materials than the zinc flashing. The vent can include a coating or sleeve as described above with regard to  FIGS. 4-6 . The vent can be connected to the roof penetration and/or vertical tube of the zinc flashing is a variety of ways. As can be appreciated, vent cover  500  can be eliminated. As also can be appreciated, the top edge of vertical tube can be bent into the roof penetration; however, this is not required. 
     Referring now to  FIG. 7 , there is illustrated another modified version of the zinc flashing. The zinc flashing is similar to the zinc flashing of  FIG. 1  except that the base portion  136  of the vertical tube includes a fluted or corrugated portion  600 . The fluted portion enables the longitudinal length of the vertical tube to be adjusted to accommodate various longitudinal lengths of roof penetrations. The fluted portion can also or alternatively enable the angle of the vertical tube that extends from the base plate  110  to be adjusted to accommodate various orientations of the roof penetration extending from the surface of a roofing system. Generally the fluted portion  600  forms less than 60% of the longitudinal length of the vertical tube, and typically less than 50% of the longitudinal length of the vertical tube, and more typically less than 40% of the longitudinal length of the vertical tube, and more typically less than 30% of the longitudinal length of the vertical tube, and more typically less than 25% of the longitudinal length of the vertical tube. 
     Referring now to  FIG. 8 , there is illustrated the zinc flashing of  FIG. 7  that is connected to a roofing system  300  in a manner similar to the connection of the zinc flashing illustrated in  FIG. 3 . The roofing system  300  includes a roof penetration  400  that extends through the surface of the roofing system and a zinc flashing  100  that is positioned on the roofing system and about the roof penetration. The roofing system is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 8 , the base plate  110  is positioned between two layers  310 ,  320  of roofing system  300 .  FIG. 8  also illustrates a vent cover  500  that is positioned on the top of the roof penetration. The use of a vent is not required. The vent can be made of the same or different materials than the zinc flashing. The vent includes a coating or sleeve as described above with regard to  FIGS. 4-6 . The vent can be connected to the roof penetration and/or vertical tube of the zinc flashing in a variety of ways. As can be appreciated, vent cover  500  can be eliminated. As also can be appreciated, the top edge of vertical tube can be bent into the roof penetration; however, this is not required. The fluted potion  600  on the vertical tube enables the longitudinal length of the vertical tube and the angle of the vertical tube that is extending from the base plate to be adjusted for a particular roof penetration while the zinc flashing is being installed on the roofing system. 
     Referring now to  FIG. 9 , there is illustrated a modification of the zinc flashing illustrated in  FIG. 1  wherein the vertical tube  130  is connected to the base plate at a non-perpendicular angle. Such zinc flashing can be used on sloped roofing systems. 
     Referring now to  FIG. 10 , there is illustrated the zinc flashing of  FIG. 9  that is connected to a roofing system  300  in a manner similar to the connection of the zinc flashing illustrated in  FIGS. 3 and 8 . The roofing system  300  includes a roof penetration  400  that extends through the surface of the roofing system and a zinc flashing  100  that is positioned on the roofing system and about the roof penetration. The roofing system is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 10 , the base plate  110  is positioned between two layers  310 ,  320  of roofing system  300 .  FIG. 10  also illustrates a vent cover  500  that is positioned on the top of the roof penetration. The use of a vent is not required. The vent can be made of the same or different materials than the zinc flashing. The vent can include a coating or sleeve as described above with regard to  FIGS. 4-6 . The vent can be connected to the roof penetration and/or vertical tube of the zinc flashing in a variety of ways. As can be appreciated, vent cover  500  can be eliminated. As also can be appreciated, the top edge of the vertical tube can be bent into the roof penetration; however, this is not required. The angled relationship of the base plate to the vertical tube enables the vertical tube to accommodate roof penetrations extending upwardly from sloped roofing systems while the zinc flashing is being installed on the sloped roofing system. 
     Referring now to  FIG. 11 , there is illustrated a modification of the zinc flashing illustrated in  FIG. 1  wherein the vertical tube  130  has a cone shape. The cone-shaped vertical tube is also illustrated as being connected to the base plate at a non-perpendicular angle; however, this is not required. Such zinc flashing, similar to the zinc flashing illustrated in  FIG. 9 , can be used on sloped roofing systems. Although the vertical tube is illustrated as being cone-shaped, it will be appreciated that the vertical tube can have other shapes. The cross-sectional area of the cone-shaped vertical tube is illustrated as being greater at the base of the vertical tube where the vertical tube begins to extend upwardly from the base plate; however, this is not required. 
     Referring now to  FIG. 12 , there is illustrated the zinc flashing of  FIG. 11  that is connected to a roofing system  300  in a manner similar to the connection of the zinc flashing illustrated in  FIGS. 3 ,  8  and  10 . The roofing system  300  includes a roof penetration  400  that extends through the surface of the roofing system and a zinc flashing  100  that is positioned on the roofing system and about the roof penetration. The roofing system is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 12 , the base plate  110  is positioned between two layers  310 ,  320  of roofing system  300 . A vent cover, not shown, can be positioned on the top of the roof penetration; however, this is not required. The top edge of the vertical tube is illustrated as only partially extending up the side of the roof penetration; however, it can be appreciated that the top edge of the vertical tube can extend to the top edge or beyond the top edge of the roof penetration. A sealant, not shown, can be positioned about the top edge of the vertical tube to form a water tight seal between the top edge of the vertical tube and the roof penetration; however, this is not required. As also can be appreciated, the top edge of vertical tube can be bent into the roof penetration; however, this is not required. The angled relationship of the base plate to the vertical tube enables the vertical tube to accommodate roof penetrations extending upwardly from sloped roofing systems while the zinc flashing is being installed on the sloped roofing system. 
     Referring now to  FIG. 13 , there is illustrated a modification of the zinc flashing illustrated in  FIG. 1  wherein the vertical tube  130  has a cone shape. Connected to the top edge of the vertical tube is a sealing gasket  600  that can be made of a variety of materials (e.g., plastic, rubber, EPDM, silicone, etc.). The gasket can be formed of a rigid or flexible material. Generally, the gasket is formed of a flexible material. The cone-shaped vertical tube is illustrated as being connected to the base plate at a non-perpendicular angle; however, this is not required. Such zinc flashing, similar to the zinc flashing illustrated in  FIGS. 9 and 11 , can be used on sloped roofing systems. Although the vertical tube is illustrated as being cone-shaped, it will be appreciated that the vertical tube can have other shapes. The cross-sectional area of the cone-shaped vertical tube is illustrated as being greater at the base of the vertical tube where the vertical tube begins to extend upwardly from the base plate; however, this is not required. The gasket  700  includes a slot  710  that is designed to receive the top edge of the vertical tube; however, this is not required. The slot  710  is used to facilitate in securing the gasket to the vertical tube. As can be appreciated, other or additional arrangements can be used to secure the gasket to the vertical tube (e.g., adhesive, melted connection, friction fit, etc.). The top  720  of the gasket  700  generally includes a cross-sectional shape and size that is the same or similar to the cross-sectional shape of the roof penetration so that a seal can be formed between top  720  and the outer surface of the roof penetration; however, this is not required. 
     Referring now to  FIG. 14 , there is illustrated the zinc flashing of  FIG. 13  that is connected to a roofing system  300  in a manner similar to the connection of the zinc flashing illustrated in  FIGS. 3 ,  8 ,  10  and  12 . The roofing system  300  includes a roof penetration  400  that extends through the surface of the roofing system and a zinc flashing  100  that is positioned on the roofing system and about the roof penetration. The roofing system is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 14 , the base plate  110  is positioned between two layers  310 ,  320  of roofing system  300 . A vent cover, not shown, can be positioned on the top of the roof penetration; however, this is not required. The top edge of the vertical tube  130  and the top  720  of the gasket  700  is illustrated as only partially extending up the side of the roof penetration; however, it can be appreciated that the top  720  can extend to the top edge or beyond the top edge of the roof penetration. A sealant, not shown, can be positioned about the top  720  of the gasket to form a water tight seal between the top of the gasket and the roof penetration; however, this is not required. The angled relationship of the base plate to the vertical tube enables the vertical tube to accommodate roof penetrations extending upwardly from sloped roofing systems while the zinc flashing is being installed on the sloped roofing system. 
     Referring now to  FIG. 15 , there is illustrated a modification of the zinc flashing illustrated in  FIG. 1  wherein the vertical tube  130  has a polygonal cross-sectional shape (e.g., square-shaped, rectangular-shaped, etc.). The vertical tube is illustrated as being connected to the base plate at a perpendicular angle; however, this is not required. The cross-sectional area of the polygonal-shaped vertical tube is generally greater than the cross-sectional area of the roof penetration; however, this is not required. 
     Referring now to  FIG. 16 , there is illustrated a zinc flashing similar to the zinc flashing of  FIG. 15  that includes a split  200  in the base plate and a split  210  in the vertical tube. The split in the base plate and the vertical tube enables the zinc flashing to be fitted about a roof penetration. As illustrated by the arrows, the zinc flashing can be opened along the side of the zinc flashing so that the zinc flashing can be fitted about a roof penetration. Once the zinc flashing is fitted about a roof penetration, the split is closed by moving the zinc flashing in a direction that is opposite of the arrow. The split can then be closed in a variety of ways (e.g., adhesive, weld, solder, rivet, etc.). 
     Referring now to  FIG. 17 , there is illustrated the zinc flashing of  FIG. 15  or  16  that is connected to a roofing system  300  in a manner similar to the connection of the zinc flashing illustrated in  FIGS. 3 ,  8 ,  10 ,  12  and  14 . The roofing system  300  includes a roof penetration  400  that extends through the surface of the roofing system and a zinc flashing  100  that is positioned on the roofing system and about the roof penetration. The roofing system is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 17 , the base plate  110  is positioned between two layers  310 ,  320  of roofing system  300 . A vent cover, not shown, can be positioned on the top of the roof penetration; however, this is not required. The top edge of the vertical tube  130  is illustrated as only partially extending up the side of the roof penetration; however, it can be appreciated that the top edge can extend to or beyond the top of the roof penetration. As illustrated in  FIG. 17 , the cross-sectional area of the vertical tube is greater that the cross-sectional area of the roof penetration. Positioned between the inside surface  132  of the vertical tube and the outer surface of the roof penetration is a sealing arrangement  800 . The sealing arrangement  800  is formed of two layers, a bottom layer that is formed of a non-shrinkable grout  810  and a top sealant layer  820  (e.g., asphalt, polymer, pitch, etc.). As can be appreciated, may other or additional sealant arrangement can be used. 
     Referring now to  FIG. 18 , there is illustrated zinc flashing  100  that is used to form a seal about a drain in a roofing system. The zinc flashing includes a base plate  900  and a downwardly extending tube  950  that is connected to the bottom surface  910  of the base plate. The base plate is illustrated as having a planar shape; however, this is not required. The downwardly extending tube  950  extends downwardly from the bottom surface  910  from the base plate and which encircles opening  920  in the base plate. The downwardly extending tube is generally formed of the same material as the base plate, but this is not required. The downwardly extending tube is generally a separate component from the base plate that is connected to the base plate; however, it can be appreciated that the base plate and downwardly extending tube can be a one piece unit that is formed from the same piece of material. 
     The cross-sectional size and shape of opening  920  is selected to enable the downwardly extending tube to extend into a roof drain when the zinc flashing is secured to a roofing system. As illustrated in  FIG. 18 , downwardly extending tube  950  has a generally circular cross-sectional shape; however, this is not required.  FIG. 18  also illustrates that the downwardly extending tube has a generally constant cross-sectional shape and size along the longitudinal length of the downwardly extending tube; however, this is not required.  FIG. 18  also illustrates the downwardly extending tube generally perpendicularly from the bottom surface  920  of the base plate; however, this is not required. The base plate and/or downwardly extending tube can include a coating or sleeve as described above with regard to  FIGS. 4-6 ; however, this is not required. 
     Referring now to  FIG. 19 , there is illustrated a roofing system  300  that includes a roof drain  1000 . The roofing system is a built-up roofing system; however, it will be appreciated that the zinc flashing can be used on other types of roofing systems. As illustrated in  FIG. 19 , the baseplate  110  is positioned between two layers  310 ,  320  of roofing system  300 . A drain cover  1100  is positioned over drain  1000 . The drain cover  1100  is not required. The top edge of the downwardly extending tube extends only partially into drain  1000 . As illustrated in  FIG. 19 , the cross-sectional area of the downwardly extending tube is less than the cross-sectional area of the interior of drain  1000 . A sealing arrangement, not shown, can be used to form a seal between the roofing system and the zinc flashing; however, this is not required. Clamping rings, bolts, etc. can also be used to secure the zinc flashing in position relative to the drain; however, this is not required. 
     It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. The invention has been described with reference to preferred and alternate embodiments. Modifications and alterations will become apparent to those skilled in the art upon reading and understanding the detailed discussion of the invention provided herein. This invention is intended to include all such modifications and alterations insofar as they come within the scope of the present invention. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.