Patent Application
20130020796
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1. Field of the Invention
The present invention relates, in general, to roofing of buildings, and in particular, to a so-called “roof flashing” for preventing moisture from passing between a vent pipe and a roof where the vent pipe passes through the roof.
2. Information Disclosure Statement
When a vent pipe passes through a roof of a building, such as a roof of a residential home or other building, it is necessary to prevent water and moisture from passing between the vent pipe and the roof in the region where the vent pipe passes through and emerges upwardly from a hole in the roof. It is well-known to use a prior art “roof flashing” to accomplish this, which may be done for new home construction or for remedial re-roofing of a residential home. While it would be desirable that an installed roof flashing last forever, in practice the roof flashing only needs to function properly without deterioration for a period of time that is longer than the life of the roof's shingles because the roof flashing can and often must be replaced when new shingles are installed onto the roof. Prior art roof flashings that use rubber materials are known to deteriorate and leak before the roof shingles need to be replaced.
Often, the orientation of the roof at the roof hole is pitched at a roof pitch angle with respect to the horizontal plane, and the pitch of the roof can vary from roof to roof. Furthermore, the vent pipe can pass through the roof at a somewhat arbitrary vent pipe angle with respect to the upper surface of the roof. While it is desirable that the vent pipe be vertical, often the vent pipe will be non-vertical, with the vent pipe being oriented at a non-zero polar angle as measured with respect to the vertical plane along the direction of the roof's rise. This combination of differing roof pitch angles from roof to roof, and somewhat varying vent pipe angle and vent pipe polar orientation from roof to roof, mandates that a roof flashing must accommodate both the roof pitch angle and the vent pipe angle and polar orientation for a given roof. Still furthermore, the vent pipe projection height, defined as the distance that the distal end of the vent pipe extends above the upper surface of the roof, may vary from one vent pipe to another, and this height variation often must be accommodated when installing a roof flashing.
Many approaches have been tried by prior art roof flashings. The majority of prior art roof flashings installed on new homes or for re-roofing of a residential dwelling are necessarily of a two-piece construction, such that a flexible rubber boot spherical cap, having a centrally-disposed first hole for sealingly fitting around the upwardly-extending vent pipe, is placed atop an upwardly-extending spherical cap on a generally planar base of the roof flashing, in which the spherical cap of the base of the roof flashing has an enlarged second hole therethrough, such that the interface between the rubber boot spherical cap and the spherical cap of the base of the roof flashing may be adjustably oriented to accommodate varying roof pitches and vent pipe angles. While such prior art two-piece roof flashings with a rubber boot spherical cap may initially provide a good watertight seal between the sides of the vent pipe and the base of the roof flashing, over time the rubber deteriorates due to age and heating, and the boot begins to crack and thus leak around the vent pipe. It is known in the prior art to retrofit such aged and leaking rubber boot spherical caps by installing a so-called “repair collar” atop the leaking rubber boot spherical cap, in which the repair collar is simply yet another flexible rubber boot cap with a centrally-disposed hole through which the vent pipe passes, and, because of the relative lack of aging of the repair collar as compared to the leaking rubber boot spherical cap therebeneath, the flexibility of the rubber of the repair collar can seal to the vent pipe and thus stop the leaking of the aged roof flashing. Of course, over time, the rubber of the repair collar will also deteriorate, causing the repaired roof flashing to leak as time passes.
To address the deterioration of rubber boots of prior art roof flashings, it is known to make roof flashings out of metal, such as lead or aluminum. One prior art approach is to provide a roof flashing made of lead or aluminum having a “pre-bent” upstanding sleeve that is welded or otherwise sealed to the base plate flange at a pre-determined angle chosen for a certain roof pitch. Often the top of the upstanding sleeve is sealed to the vent pipe using caulking, which causes the seal between the sleeve of the roof flashing and the vent pipe to deteriorate over time. Another approach for such metal roof flashings with a “pre-bent” upstanding sleeve is to have a top cap or “counter flashing” that is received atop the sleeve of the roof flashing, with an outer sleeve of the counter flashing being received about the outer sleeve of the roof flashing, and with a downwardly-depending inner sleeve of the counter flashing extending into the top of the vent pipe, the outer sleeve of the counter flashing being sealed to the inner sleeve of the counter flashing by an annular ring at the top of the counter flashing cap. Such a prior art “counter flashing” cap is sold by FlashCo Manufacturing, Inc., 1452 Industrial Ave., Sebastopol, Calif. 95472, for use with a fixed-angle all-lead roof flashing that is sold by FlashCo Manufacturing under the trademark L-SERIES flashing. Still another approach for all-lead roof flashings with a “pre-bent” upstanding sleeve is to fold over the top of the upstanding sleeve into the top of the vent pipe during installation of the roof flashing, thereby preventing moisture from passing between the exterior of the vent pipe and the roof through the hole in the roof through which the vent pipe emerges. Such an approach, while durable because the lead roof flashing does not deteriorate, has a disadvantage of using lead, which is detrimental to the health when ingested, and also somewhat constricts the air flow through the vent pipe due to the lead flashing being folded down into the top of the vent pipe, often leaving projecting crimps and folds that restrict air flow through the vent pipe. Because all “pre-bent” roof flashing solutions only accommodate a single roof pitch, it is necessary to inventory a variety of such fixed-angle roof flashings so that the correct pitch angle of roof flashing can be used for a given roof pitch.
One piece prior art flexible all-rubber roof flashings are also known that have a corrugated section to allow the roof flashing to flex and accommodate a range of roof pitches, with the vent pipe sticking out a centrally-disposed hole in the rubber roof flashing, and in which the centrally-disposed hole in the rubber roof flashing seals to the outer surface of the vent pipe. Like other prior art rubber boots used with two-piece roof flashings, these all-rubber roof flashings deteriorate over time and leak.
Another all-metal (aluminum) two-piece roof flashing is described in Poitras, U.S. Pat. No. 6,163,960 (issued Dec. 26, 2000), and sold under the trademark VENT 2000 by that inventor's company. To allow that all-metal two-piece roof flashing to accommodate a range of roof pitch angles, the upstanding sleeve of this roof flashing is joined by a corrugated metal portion to the metal base plate. A bending tool (the so-called “Folding Machine 2000”) is used during installation of the VENT 2000 product, and grips the base plate of the VENT 2000 product while bending force is applied to a lever arm inserted into the top of the upstanding sleeve and engaging the interior wall of the upstanding sleeve, thereby causing the angle of the upstanding sleeve to change as the corrugated metal portion becomes bent due to the force applied to the lever arm, while the engagement of the lever arm with the interior wall of the upstanding sleeve prevents buckling of the upstanding sleeve during the bending process. After the upstanding sleeve has been bent to the desired angle and the VENT 2000 product is removed from the bending tool, the VENT 2000 roof flashing is then installed over a vent pipe and a sleeve cap, similar to the counter flashing top cap sold by FlashCo Manufacturing, Inc., as discussed above, is placed over the top of the upstanding sleeve to prevent moisture and water from flowing down the exterior surface of the vent pipe and through the vent pipe's roof hole. The two-piece construction of the VENT 2000, with a removable top cap, is necessary so that the lever arm of the Folding Machine 2000 installation tool can be inserted into the top of the upstanding sleeve and forceably engage the inner walls of the upstanding sleeve, thereby preventing buckling of the upstanding sleeve, during the bending procedure prior to installation of the roof flashing.
In addition to the Poitras patent, mentioned above, the following patents disclose various approaches used by prior art roof flashings: Kifer, U.S. Pat. No. 4,526,407 (issued Jul. 2, 1985); Kifer, U.S. Pat. No. 4,903,997 (issued Feb. 27, 1990); and Rodriguez et al., U.S. Pat. No. 5,588,267 (issued Dec. 31, 1996).
None of these references or prior art devices, either singly or in combination, discloses or suggests the present invention.
The present invention is an integral one-piece roof flashing for preventing moisture and water from passing between a vent pipe and a roof where the vent pipe passes through the roof at a vent pipe angle with respect to an upper surface of the roof. The roof flashing includes a base plate having an aperture therethrough with a laterally-extending planar flange around the base plate's aperture, an upstanding outer sleeve defining a first longitudinal passage therethrough and with the outer sleeve having a proximal and a distal end, and a corrugated portion defining a second longitudinal passage therethrough, in which the corrugated portion flexingly and sealingly joins the proximal end of the outer sleeve to the base plate about the aperture. The corrugated portion is intermediate the base plate and the proximal end of said outer sleeve. The aperture, the second longitudinal passage, and the first longitudinal passage are adapted for mutually receiving the vent pipe thereinto with the planar flange resting upon the upper surface of the roof. As the roof flashing is dropped onto the vent pipe, the corrugated portion flexes to align the outer sleeve at the vent pipe angle with respect to said planar flange. The corrugated portion allows the outer sleeve to flex front to back, side to side, and up and down to accommodate different vent pipe heights and roof pitch angles. The roof flashing further includes a downwardly-depending inner sleeve having a top end integrally and immovably joined to the distal end of said outer sleeve. The inner sleeve is adapted for being received into a top end of the vent pipe with the planar flange resting upon the upper surface of the roof.
The planar flange of the base plate preferably includes measurement indicia thereon for measuring the length of the vent pipe to ensure that the top end of the vent pipe is within a minimum and maximum length above the upper surface of the roof so that successful installation can be accomplished. Preferably, the roof flashing is molded from a plastic.
It is an object of the present invention to provide a roof flashing that is more durable than prior art roof flashings, and which does not leak after the roof flashing has been installed on a roof during the life of the roof. It is a further object of the present invention to provide a roof flashing that can accommodate a wide angles of roof pitches and vent pipe heights, and which does not require bending tools during installation. It is a still further object of the present invention to provide means for determining whether the vent pipe height is within acceptable limits prior to installation of the roof flashing.
Referring to the figures of the drawings, two preferred embodiments of the present invention are shown. There are many similarities between the various embodiments, and only the differences between the embodiments will be discussed in detail, it being understood that similar structure for the various embodiments serves similar purpose. The reference numerals for the various parts of the embodiments shall be understood to have a prefix identifying the particular embodiments (e.g., “1.”, “2.”) and a suffix identifying the particular structure (e.g., “20”, etc.), such that reference numerals with the same suffix are understood to be similar structure particular to each of the different embodiments (e.g., “1.20”, “2.20”). Reference numerals without a prefix (e.g., “22”) shall be understood to indicate environmental structure that is substantially the same for all embodiments.
Referring to
Vent pipes such as vent pipe 22 are typically provided in a number of standard diameters such as 1.5 or 2.0 inches (3.81 or 5.08 cm) that must be accommodated by roof flashings such as that of the present invention. Because roof pitches vary from building to building and roof to roof, the vent pipe 22 emerges through the roof at a vent pipe angle 34 with respect to the upper surface 36 of the roof 24.
As contrasted with prior art roof flashings, both embodiments 1.20 and 2.20 of the roof flashing of the present invention are of an integral one-piece construction, and lack any interface or seam between parts of the roof flashing from the engagement of the roof flashing with the vent pipe to the base plate of the roof flashing. Unlike the VENT 2000 roof flashing product, no bending tool is required for installation of the present invention, which simply drops over the vent pipe onto the roof surface and becomes self-aligning. Both embodiments 1.20 and 2.20 of the present invention are preferably formed from plastic, preferably polypropylene, as by being moldedly formed, but other plastics could be used instead, such as, for example, polyethylene, flexible polyvinylchloride (“PVC”), polyurethane, or polyethylene terephthalate (“PET”). The two desirable qualities of the material from which the roof flashing of the present invention is made are (1) the material should be somewhat flexible so that the roof flashing may flex to accommodate a range of vent pipe angles with respect to the upper surface of the roof, in a manner hereinafter described in detail, and (2) the material should be durable and preferably not crack or deteriorate due to heat and age after the roof flashing is installed on a roof, at least not before replacement roof shingles need to be installed on the roof.
Roof flashing 1.20 comprises a base plate 1.38, an upstanding outer sleeve 1.40, and a corrugated portion 1.42. It should be understood that the term “corrugated portion”, as used herein, broadly encompasses similar structure and construction such as a pleated portion or an accordion portion, the essential function being performed by portion 1.42 being the flexing of portion 1.42 to accommodate different angles of vent pipe and roof pitches by a single roof flashing 1.20. Additionally, as hereinafter described in detail, corrugated portion 1.42 also permits the outer sleeve 1.40 to extendingly move in a longitudinal direction therealong to accommodate a range of heights for the vent pipe 22.
Base plate 1.38 has an aperture 1.44 therethrough and includes a laterally-extending substantially planar flange 1.46 around aperture 1.44 so that planar flange 1.46 may rest upon the upper surface 36 of roof 24. Preferably, planar flange 1.46 may have a plurality of transverse holes or depressions 1.48 through which roofing nails 1.50 may respectively be nailed into the roof 24 during installation of the roof flashing 1.20 so as to secure the roof flashing 1.20 to the roof 24.
Upstanding outer sleeve 1.40 defines a first longitudinal passage 1.52 therethrough, and outer sleeve 1.40 has a proximal end 1.54 and a distal end 1.56.
Base plate 1.38 preferably includes a raised center portion 1.58 that is raised above the plane of planar flange 1.46 and surrounding aperture 1.44. The center portion may have a low profile and be only slightly raised, as shown by center portion 2.58 of the second embodiment 2.20 of the present invention, or it may have a higher profile and be substantially raised, as shown by center portion 1.58 of the first embodiment 1.20 of the present invention. Center portion 1.58 may have a downwardly-sloping peripheral wall 1.60 that joins with planar flange 1.46, just as center portion 2.58 has a smaller downwardly-sloping peripheral wall 2.60 that joins with planar flange 2.46 of the second embodiment 2.20.
The interior of corrugated portion 1.42 defines a second longitudinal passage 1.62 therethrough, and corrugated portion 1.42 flexingly and sealingly joins proximal end 1.54 of outer sleeve 1.40 to center portion 1.58 of base plate 1.38 about aperture 1.44, with corrugated portion 1.42 being intermediate base plate 1.38 and proximal end 1.54 of outer sleeve 1.40. Aperture 1.44, second longitudinal passage 1.62, and first longitudinal passage 1.52 are adapted for mutually receiving vent pipe 22 thereinto with planar flange 1.46 resting upon the upper surface 36 of roof 24, with corrugated portion 1.42 flexing as needed to align outer sleeve 1.40 at vent pipe angle 34 with respect to planar flange 1.46.
Roof flashing 1.20 further comprises a downwardly-depending inner sleeve 1.64 having a top end 1.66 that is integrally and immovably joined to distal end 1.56 of outer sleeve 1.40. Inner sleeve 1.64 is adapted for being received into a top end 68 of vent pipe 22 with planar flange 1.46 resting upon the upper surface 36 of roof 24. The inner diameter 1.70 of outer sleeve 1.40 determines the largest-diameter vent pipe 22′ that can be accommodated by roof flashing 1.20 (see
Downwardly-depending inner sleeve 1.64 is preferably tapered slightly inwardly toward the bottom to ease insertion into the vent pipe during installation of the roof flashing.
The bottom corrugation 1.78 of corrugated portion 1.42 is seen to define a bottom corrugation plane 1.80 that establishes a nominal or starting angle orientation 1.82 of outer sleeve 1.40 with respect to planar flange 1.46. Starting angle orientation 1.82 of outer sleeve 1.40 with respect to planar flange 1.46 is defined as the planar angle between bottom corrugation plane 1.80 and planar flange 1.46, and defines the nominal orientation of outer sleeve 1.40 before front to back flexing of corrugated portion 1.42 occurs, where the “front” 1.84 of roof flashing 1.20 is oriented “down” the roof and the “back” of roof flashing is oriented “up” the roof. As corrugated portion 1.42 flexes front to back in response to front to back angular movement of outer sleeve 1.40 to match the orientation of the vent pipe, outer sleeve 1.40 moves through a first range of angles from a backmost angle 1.88, preferably of at least +45 degrees, to a frontmost angle 1.90, preferably at least −45 degrees, with respect to its starting angle orientation 1.82. By comparison of the first embodiment 1.20 of the roof flashing as shown in
By comparison of the first embodiment 1.20 of the roof flashing as shown in
It will be further understood, as best seen in
It should be noted from
Referring to
Other aspects of the second embodiment need not be described in detail because the description of similar structure for the first embodiment will suffice for both embodiments.
To install either embodiment of the roof flashing of the present invention, the installer should first use the measurement indicia 1.96, 2.96 to ensure that the vent pipe height is within acceptable limits above the upper surface of the roof. The roof flashing 1.20, 2.20 is then dropped over the vent pipe, and roofing nails 1.50 are nailed through holes 1.48, 2.48 to anchor the base plate 1.38, 2.38 to the roof with planar flange 1.46, 2.46 resting upon the upper surface 36 of the roof, and with inner sleeve 1.64, 2.64 extending into the vent pipe in a manner hereinbefore described. As the planar flange 1.46, 2.46 comes to rest on the upper surface of the roof, the corrugated portion 1.42, 2.42 of the roof flashing will flex to allow the outer sleeve 1.40, 2.40 to become aligned with the vent pipe. Overlapping shingles may now be installed on the roof surface and overlapping the base plate 1.38, 2.38.
Although the present invention has been described and illustrated with respect to a preferred embodiment and a preferred use therefor, it is not to be so limited since modifications and changes can be made therein which are within the full intended scope of the invention.
