The present invention relates to sealant assemblies and methods, and more particularly, to sealant assemblies and methods adapted to seal an interface between a surface and a projection extending from the surface.
The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Buildings commonly incorporate roof surfaces designed to repel water and prevent water from leaking into interior areas of the building. Frequently, roof surfaces are also designed to accommodate one or more roof projections extending from the roof surface. For example, it is known to penetrate a roof surface with an exhaust pipe to allow venting of gases generated within the building. When roof projections are necessary, special care must be taken to avoid leak paths at the interface between the roof surface and the roof projection.
In an effort to prevent leaks, it is known to treat the interface area between the exhaust pipe and the roof surface with a sealant assembly. Conventional sealant assemblies are typically formed by circumscribing the exhaust pipe with a curb element to create a roof pocket about the exhaust pipe. Once the roof pocket is formed, a filling sealant is introduced into the roof pocket to complete the sealant assembly.
While frequently useful in various applications, conventional sealant assemblies may fail due to environmental exposure. For example, conventional sealant assemblies include a curb element and a filling sealant that comprise different materials. Using different materials may result in an insufficient bond between the curb element and the filling sealant, leading to separation of the curb element and the filling sealant. Furthermore, different materials often have substantially different coefficients of expansion. The differing coefficients of expansion can result in fracture of the interface between the curb element and the filling sealant as components of the assembly expand and contract at different rates during heating and cooling cycles. Moreover, forming the curb element and the filling sealant from different materials may discourage or prevent integral bonding that may further contribute to failure of any attachment interface between the curb element and the filling sealant. Separation at the interface limits the benefits of the curb element, leaving the filling sealant to seal the projection and the roof.
Conventional pocket sealant assemblies typically have a solid and inflexible curb element. When a roof is not perfectly flat the solid and inflexible curb element will not conform to the roof and may leave gaps between the inflexible curb element and the roof. These gaps may leave a leak path. For example, U.S. Pat. No. 5,768,838 issued to Georgeau discloses a solid thermosetting polyurethane curb element and U.S. Publication No. 2003/0014926 issued to Champa discloses a curb or structural section having vertical and horizontal portions. However, Georgeau and Champa do not teach that the polyurethane curb element and the structural section are flexible. In addition, Georgeau and Champa do not disclose a chemical composition that allows the curb to conform to irregularities on a roof.
The side walls of many conventional pocket sealant assemblies contribute to water pooling at the juncture between the outer edge of the curb element and the roof. Vertical or nearly vertical lower portions of the outer edge of the curb element allow water to flow down to the roof with little or no lateral momentum. Without lateral momentum, the water often pools next to the sealant pocket, increasing the chances of a leak.
For the reasons set forth above, conventional sealant assemblies may eventually degrade such that the curb element and the filling sealant are disassociated from one another. Such disassociation can contribute to leak-path formation that can lead to unnecessary and potentially catastrophic water damage within the building. Disassociation of the curb element can also introduce a loose object on the roof surface that might introduce a tripping hazard. A disassociated curb element may also tumble from the roof and thereafter present a dangerous falling object.
Accordingly, it is an aspect of the present invention to obviate problems and shortcomings of conventional sealant assemblies and methods. More particularly, it is an aspect of the present invention to provide sealant assemblies and methods that discourage disassociation between a flexible member and the filling sealant of the sealant assembly.
In accordance with one aspect, a sealant assembly is provided for sealing an interface between a surface and a projection extending from the surface. The sealant assembly includes a flexible member circumscribing an area to form a sealant pocket. The sealant assembly further includes a filling sealant at least partially filling the sealant pocket. The filling sealant and the flexible member comprise substantially the same material.
In accordance with another aspect, a method of sealing an interface between a surface and a projection extending from the surface is provided. The method includes the step of positioning a flexible member on the surface with the flexible member circumscribing the projection and the projection extending through a sealant pocket defined by the flexible member and the surface. The method further includes the step of adding a filling sealant into the sealant pocket, wherein the filling sealant subsequently solidifies such that the flexible member and the solidified filling sealant form a solid sealant assembly with the flexible member and the solidified filling sealant comprising substantially the same material.
In accordance with still another aspect, a sealant assembly is provided. The sealing assembly includes a flexible member circumscribing an area to form a sealant pocket and a solidified filling sealant within the area and filling at least a portion of the sealant pocket. Sufficient plasticizer is included in the formulation to ensure that there is adequate flexibility in the flexible member such that it can conform to a slightly irregular roofing surface. The sealant assembly is formed by a process including the step of positioning the flexible member on a surface with the flexible member circumscribing a projection extending from the surface. The process further includes the step of adding a filling sealant into the sealant pocket, wherein the filling sealant is substantially contained within the sealant pocket. Still further, the process includes the step of permitting the filling sealant to solidify such that the flexible member and the solidified filling sealant form a solid sealant assembly with the flexible member and the solidified filling sealant comprising substantially the same material.
The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:
Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. Further, in the drawings, the same reference numerals are employed for designating the same elements, and in order to clearly and concisely illustrate the present invention, certain features may be shown in somewhat schematic form.
Sealant assemblies herein include a flexible member that may circumscribe a single projection or any plurality of projections in accordance with aspects of the present invention. Flexible members may be provided in a wide variety of shapes and/or sizes depending on the particular application. Moreover, the flexible member is formed as a single piece. However, the present invention also contemplates that the flexible member is formed from a plurality of pieces that can be assembled together to circumscribe the one or more projections. For example, in an embodiment of the present invention, the flexible member includes a continuous ring in a variety of shapes such as a continuous circular, oval, square, triangular, rectangular, or other continuous shape that can circumscribe a projection. The continuous ring can be placed over the top of the projection to circumscribe the projection adjacent the interface. In further embodiments, the ring may be split so that it is not necessary to place the ring over the top of the projection. For example, the ring may be split at a single location wherein the projection may be laterally inserted through the slit to enter the interior area of the ring. In another example, the ring may be split at two locations, wherein the ring halves may be closed around the projection to circumscribe the projection.
In still further examples, the flexible member has a plurality of corner elements adapted to at least partially circumscribe the projection. For example, as shown in
The illustrated corner element is shown to include relatively sharp corners. In further embodiments, the corner elements may comprise rounded corners to reduce stress points. For example, the corner element can comprise a first and second extension arm together with a rounded corner portion positioned between the first and second extension arm. In further embodiments, the entire corner element may comprise a rounded corner portion.
As shown in the illustrated embodiment, the extension arms 42, 44 comprise the same length. It is contemplated that the extension arms, if provided, may be longer or shorter than the relative length illustrated in the figures. Moreover, it is contemplated that the extension arms might comprise different lengths in further embodiments.
In accordance with exemplary embodiments of the present invention, the first extension arm 42 can include a first end portion 46a with a first substantially flat surface 48a that is substantially perpendicular to the first extension axis 42a. Similarly, the second extension arm 44 can include a second end portion 46b with a second substantially flat surface 48b that is substantially perpendicular to the second extension axis 44a. Providing the end portions with a substantially flat surface that is substantially perpendicular to the respective extension axis can facilitate connection of flexible member elements. For example, end portions with perpendicular surfaces can allow compression of the end portions without significant development of shear stress and without deforming the end portions away from the extension axis. In contrast, compression of diagonal surfaces can develop significant shear stresses and might wedge against each other to deform the end portions away from the extension axis and therefore interfere with the fastening process.
In further examples, end portions of body components may have alternative configurations to facilitate connection of the components to one another. For example,
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The intermediate segments, if provided, can include a wide variety of sizes to customize the size of the sealant pocket 134. For example, the first pair of intermediate segments 50a, 50b may have a first length and the second pair of intermediate segments 52a, 52b may have a second length. The first and second lengths may be equal or different from one another depending on the desired size of the flexible member 130. For example, the intermediate segments 50a, 50b, 52a, 52b can have substantially identical lengths to form a substantially square shaped flexible member 130. In still further examples, the first pair of intermediate segments 50a, 50b may have a different length than the second pair of segments 52a, 52b to form a substantially rectangular shaped sealant pocket 134. In still further examples, only one pair of segments is used to extend the length of the sealant pocket 134 in a single desired direction. In further examples, the flexible member 130 may be provided as a kit with four relatively long intermediate segments. The relatively long intermediate segments may be cut on site to provide a customized flexible member having an appropriate size. Customizing the flexible member can reduce the overall size of the flexible member wherein less filling sealant is necessary to fill the sealant pocket.
The intermediate segments may also have various shapes in accordance with aspects of the present invention. As shown in
An exemplary method of sealing an interface between a surface and a surface projection extending from the surface is described with respect to
The flexible member 30 may also be sealed or fastened with respect to the surface 200. Providing a seal between the flexible member 30 and the surface 200 may help contain filling material within the sealant pocket as the filling material solidifies. Fastening the flexible member 30 to the surface 200 can also help maintain the sealant pocket 34 in the desired location with respect to the one or more surface projections 202. In the illustrated example, tape 36, such as a Butyl tape, can be used to form a seal the flexible member 30 to the surface 200 and/or can help fasten the flexible member 30 with respect to the surface 200. In further examples, an adhesive layer or other sealant layer may be used to aid in sealing and/or fastening of the flexible member.
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Accordingly, the corner elements, intermediate segments (if provided), and the filling material comprise substantially the same material to form a solid, sealed block around the roof protrusions 202. Being formed from the same material, the assembled flexible member and the filling material have the same coefficient of expansion and therefore resist cracks or other failures that may otherwise occur due to temperature fluctuations. Still further, forming the assembled flexible member and the filling material from substantially the same material can facilitate integral bonding at the interface between the flexible member and the filling sealant to further resist cracks or other failures of the connection between the flexible member and the filling sealant.
A wide range of materials may be used as the common material to form the corner elements, intermediate elements (if provided), and the filling material. For example, the common material can comprise a wide variety of polymers, such as polymers and copolymers EPDM, Butyl rubber, Neoprene, SSBS, SEBS, Hypalon, Acrylic elastomers, CPE, PVC, CPVC, epichlorohydrin, ethylene acrylic elastomers, EPR, PIB, polybutadiene rubbers, polynorbomenes, polysulfide, one and two part urethane elastomers, and the like. Other materials may be used as the common material to provide a sealant assembly with components having the same coefficient of expansion or components that form an integral bond with the filling material. Preferably, the flexible member and the filling sealant are formed of materials that include renewable polyols.
In a preferred embodiment, the filling sealant and the flexible member are each composed of a two part composition, a part A and a part B, as shown below in Table 1. More specifically, Table 1 lists each of the components of the composition and provides a percent by weight of each component in part A and in part B, respectively. Additionally, a preferred range of percents by weight of each component is shown. Part A and part B are each pre-mixed separately, and are blended together in substantially equal portions before application.
Examples of commercially available polyols for use in part A or part B include JEFFOL® PPG-400, JEFFOL® PPG-2000, JEFFOL® G31-23 (JEFFOL® products available from Huntsman Petrochemical Corporation of Austin, Tex.), PLURACOL® P-410, PLURACOL® P-726, PLURACOL® P-2010 (PLURACOL® products available from Wyandotte Chemical Corp. of Wyandotte, Mich.), and VORANOL® 220-56 available from Dow Chemical Company of Midland, Mi. Examples of renewable polyols include SOYOL® R2-052-G available from Urethane Soy Systems Company of Volga, S. Dak., and POLYCIN® GR 53 available from Baker Castor Oil Company of Bayonne, N.J.
Examples of adhesion promoters include amino silanes. Commercially available amino silanes include AP-32 and AP-33 available from Advanced Polymer, Inc. of Carlstadt, N.J., and DOW CORNING Z-6020® available from Dow Chemical Corporation of Midland, Mi. Examples of UV stabilizers include hindered amines and substituted benzophenones. Commercially available UV stabilizers include TINUVIN® 292 and TINUVIN® 328 available from Ciba-Geigy Corporation of Ardsley, N.Y., and CYASORB® UV-9, CYASORB® UV-24, and CYASORB® UV-531 available from Cytec Industries, Incorporated of West Paterson, N.J. Examples of metal catalysts include dibutyltin dilaurate and dibutyltin diacetate, both available from Air Products and Chemicals Inc. of Allentown, Pa. Examples of desiccants include molecular sieves (commercially available from W. R. Grace of Columbia, Md.), oxazolidenes (available from Dow Chemical Corp. of Midland, Mich.) and calcium oxide (commercially available from Mississippi Lime of St. Louis, Mo.).
Sufficient plasticizer is included in the formulation to ensure that there is adequate flexibility in the flexible member such that it can conform to a slightly irregular roofing surface. Examples of plasticizers include dioctyl phthalate (DOP), diisodecyl phthalate (DIDP), and diisononyl phthalate (DINP), available from Alfa Aesar, of Ward Hill, Mass. Examples of isocyanates include allophanate-modified MDI, uretonimine-modified MDI, dimer-modified MDI, and mixed isomers of MDI, available from Bayer, BASF, Huntsman Chemical, and Dow Chemical.
In a preferred embodiment, part A and part B each contain a different color dye or pigment in a range of up to 4% by weight. Upon mixing part A and part B, the two pigments create a new color indicative of proper blending of part A and part B. The new color of the filling sealant is preferably substantially the same as a color of the flexible member. Preferably, a primary color pigment and a secondary color pigment are used, or a secondary or a primary color pigment may also be used with white pigment. Primary color pigments in subtractive color systems are typically cyan, magenta, and yellow. Secondary color pigments in subtractive color systems are typically violet, orange, and green. For example, part A may contain a red pigment and part B may contain a white pigment and upon mixing the composition has a pink color. It should be appreciated that other colors may be employed without departing from the scope of the present invention.
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A method of sealing an interface between a roof projection and a roof using a flexible member including a unitary body piece will now be described. The roof is first cleared of loose gravel, dirt, granules, or other foreign substances that may interfere with adhesion between a filling sealant and the roof. A first mating surface and a second mating surface of the unitary body piece are separated by an amount corresponding to a dimension of the projection. The unitary body piece is placed around the roof projection by passing the roof projection between the first mating surface and the second mating surface. Preferably, there is at least one inch between the roof projection and each side of the unitary body piece. A mark is traced around the edges of the unitary body piece, and the unitary body piece is removed from around the roof projection. An interface between the roof projection and the roof is sealed with a sealant, and a bead of sealant is applied to the inside of the traced mark. A bead of sealant is then applied within a recess of the second mating surface. The unitary body piece is then placed around the roof projection, and a projection on the first mating surface is engaged with the recess on the second mating surface. The engaged unitary body piece is then placed onto the bead of sealant on the roof and pressure is applied. Preferably, excess sealant is removed from the outside of the unitary body piece. A test amount of a filling sealant is preferably dispensed to confirm a proper mix of components comprising the filling sealant. The sealant pocket created by the unitary body piece is then filled with the filling sealant.
From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.
While the best modes for carrying out the invention have been described in detail, it is to be understood that the terminology used is intended to be in the nature of words and description rather than of limitation. Those familiar with the art to which this invention relates will recognize that many modifications of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced in a substantially equivalent way other than as specifically described herein.
The present application is a continuation-in-part of U.S. application Ser. No. 11/128,779, filed on May 13, 2005. The disclosure of the above application is incorporated herein by reference.
Number | Date | Country | |
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Parent | 11128779 | May 2005 | US |
Child | 12503757 | US |