Patent Application
20050055932
The present invention relates generally to roofing membranes.
A roof system generally includes a roof deck that comprises the structural supporting surface of a building extending between the surrounding exterior walls of the building. The roof deck may be constructed from plywood, metal decking or concrete or any other suitable material. Depending upon the construction, the roof deck may extend over the surrounding exterior walls or the roof deck may be exposed short of the exterior walls thereby forming a parapet wall, i.e., a low retaining wall at the edge of the roof deck. If desired, the roof system may also include an insulation barrier formed from polyisocyanarate or any other suitable material applied over the roof deck.
To make the roof deck and building weather resistant, a roofing membrane is installed over the roof deck. One typical way of securing a roofing membrane to a roof deck is to use nails or screws that extend through small metal plates that are manually spaced apart in rows on the roofing membrane. The metal plates are covered by overlapping roofing membranes.
One problem encountered when installing roofing membranes is accounting for the wind uplift forces. The wind uplift forces are not evenly distributed across the roof deck and the perimeter of the roof deck, particularly next to a parapet wall which encounters greater wind uplift forces than are encountered on the other areas of the roof deck. Failure to adequately secure the roofing membrane to the roof deck at the parapet wall or anywhere on the roof deck may cause the roofing membrane to separate from the roof deck and/or parapet wall resulting in roof failure and possible damage to the building structure and building interior.
Another problem with most existing methods of installing roofing membranes is that these methods require manually aligning the securing devices on the roofing membrane. This increases the time and labor cost for the installer.
The present invention overcomes the shortcomings of prior devices and methods by providing a roofing product with one or more layers of thermoplastic having a batten strip integral therein. In addition, a roofing product may also have a layer of fabric between the layers of thermoplastic. A batten strip may have built-in spaced openings for securing a roofing product to a roof deck. In addition, a batten strip may include two or more catch cords for engaging securing devices extending through the batten strip. The structure and features of the roofing product provides improved performance against weather conditions, such as wind and moisture. The roofing product may be made from polymer materials that include flame retardants, UV absorbers or UV screeners to improve weatherability. One advantage of the present invention is that the installing a roofing product to a roof deck that is simple and economical. Another advantage is that the present invention eliminates a substantial amount of labor required to place batten strips and securing device on a roofing product.
According to a first broad aspect of the present invention, there is provided a roofing product comprising: a flexible roofing membrane comprising a first layer, the first layer being comprised of a first thermoplastic; and a batten strip integral with the roofing membrane, wherein the roofing product is flexible.
According to a second broad aspect of the present invention, there is provided a method for securing a first roofing product to a roof deck comprising the steps of: providing a flexible roofing membrane comprising at least one batten strip integral with the roofing membrane; and securing the first roofing product to the roof deck by using securing means that extends through the batten strip into the roof deck, wherein the roofing membrane includes a first layer comprised of a first thermoplastic.
According to a third broad aspect of the present invention, there is provided a method of making a roofing product comprising the steps of: integrally bonding at least one batten strip to a first thermoplastic layer; integrally bonding a fabric layer to the first thermoplastic layer; and integrally bonding a second thermoplastic layer to the fabric layer.
According to a fourth broad aspect of the present invention, there is provided a method of making a roofing product comprising the steps of: forming a batten strip on at least a first side of a fabric layer; integrally bonding the first side of the fabric layer to a first thermoplastic layer; and integrally bonding a second side of the fabric layer to a second thermoplastic layer.
Other objects and features of the present invention will be apparent from the following detailed description of the preferred embodiment.
The invention will be described in conjunction with the accompanying drawings, in which:
It is advantageous to define several terms before describing the invention. It should be appreciated that the following definitions are used throughout this application.
Where the definition of terms departs from the commonly used meaning of the term, applicant intends to utilize the definitions provided below, unless specifically indicated.
For the purposes of the present invention, the term “flexible” refers to any material that is capable of being bent, twisted, bowed, curved, etc. For example, a flexible material may be a material that is capable of being formed into a coil and capable of being unrolled from a coil to lie substantially flat. A flexible material may have the capability to be coiled in any direction. Alternatively, a flexible material may be a material that is capable of being repeatedly folded and unfolded.
The term “roofing membrane” refers to the conventional meaning of the term roofing membrane, i.e. a water impermeable sheet of polymeric material that is secured to a roof deck. A roofing membrane may use polymeric materials such as ethylene propylene diene terpolymer rubber (EPDM), chlorinated polyethylene, PVC, chlorosulfanated polyethylene, TPO, etc. The roofing membrane may be made from a blended composite polymer having additives, such as UV screeners, UV absorbers, fire retardants, etc. to improve weatherability.
The term “roof deck” refers to the conventional meaning of the term roof deck, i.e. a structural supporting surface of a building extending between the surrounding exterior walls of the building. The roof deck may be constructed from plywood, metal decking or concrete or any other suitable material.
The term “batten strip” refers to any piece of material used in connection with a roofing membrane used to reinforce a region of the roofing membrane so that a fastening device such as a nail, screw etc. that extends through the roofing membrane does not pull through the roofing membrane when the fastening device is used to secure the roofing membrane to a roof deck. The batten strip may be a conventional batten strip that extends the entire width of a roofing membrane or may be a piece of material that acts as a localized reinforcement of the roofing membrane. For example, a batten strip may be one of several circles, squares, etc. of reinforcing material integrally bonded on or within a roofing membrane as shown in
The term “upper side” refers to a side of a layer of a roofing membrane that does not face a roof deck when the roofing membrane is secured to the roof deck.
The term “bonded side” refers to the side of a layer of a roofing membrane that is bonded to another layer of the roofing membrane. The bonded side may or may not face a roof deck when secured to another layer of roofing membrane, depending on its orientation. A single layer in the roofing membrane may have two sides that are both bonded sides, each bonded side being bonded to an additional layer in the roofing membrane.
The term “lower side” refers to the side of a layer of a roofing membrane or batten strip that faces toward a roof deck when the membrane is secured to the roof deck.
The term “upper layer” refers to a layer of a roofing membrane that is on top when the roofing membrane is secured to a roof deck. An upper layer may be partially overlapped by one or more roofing products.
The term “lower layer” refers to the layer of a roofing membrane that is nearest to a roof deck when the membrane is secured to the roof deck. The lower layer of one roofing membrane may overlap the upper layer of another roofing membrane.
The term “thermoplastic” refers to the conventional meaning of thermoplastic i.e. a compound substance that exhibits the property of a material, such as a high polymer, that softens when exposed to heat and generally returns to its original condition when cooled to room temperature. Examples of thermoplastics suitable for use include thermoplastics such as: PVC and thermoplastic polyolefins such as polyethylene (PE), linear polyethylene (LPE), polybutenes (PB), polypropylene (PP), co-polymers of polyolefins, ethylene-propylene rubber (EPR), ethylene-propylene copolymer (EPM), EPDM blended with PP or PE or copolymer, etc.
The term “thermoplastic polyolefin (TPO)” refers to the conventional meaning of the term “thermoplastic polyolefin” i.e. polyolefins that are thermoplastics. Examples of TPO's that are suitable for use include linear polyethylene, polyethylene, polybutenes, polypropylene, co-polymers, EPR or EPDM blended with PP or PE or copolymer, etc.
The term “UV absorber” refers to any conventional additive blended into a polymer to stabilize the adverse effects of light exposure, such as a loss of strength, degradation and decoloration. The use of a UV absorber may allow at least one layer of roofing membrane to exhibit good weathering characteristics. Examples of preferred UV absorbers additives include benzotriazole, benezophenones, hindered amine light stabilizers (HALS), non-interacting HALS (NOR-HALS), etc.
The term “UV screener” refers to a conventional additive blended into a polymer to reflect ultraviolet rays. Examples of preferred UV screener additives include TiO2, carbon black, zinc oxide, etc.
The term “fire retardants” or “FRs” refer to a conventional additives blended into a polymer to reduce the flammability of a polymer by slow down the rate of combustion. Examples of preferred FRs include magnesium hydroxide, brominated FR, SbO3, etc.
The term “integral” refers to a material that is of one piece or in which two or more materials are permanently bonded together to form a single material. Methods for making a batten strip integral with a roofing membrane, may include coextruding one or more layers of the membrane with the batten strip, welding, chemical bonding, adhesive, weaving, etc. A material is integral when that material is on, within, part of, etc. a second material to form a combined or composite material.
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A batten strip may be bonded to an upper side of an upper layer of a roofing membrane or may be co-extruded with the upper layer of a roofing membrane. Although a batten strip, as shown in
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The roofing product, including the roofing membrane and batten strip, is preferably flexible and more preferably is capable of being rolled and unrolled. A flexible roofing product may allow an installer to position the flexible roofing product in any desired position on a roof deck. In addition, a roofing product that may be rolled into a roll of material allows easier transportation from the manufacturer to the on-site installer.
The roofing product may consist of any number of layers, including a single layer. Preferably, a roofing product may have at least three or more layers. The multiple layers of the roofing product may consist of similar materials or different materials.
A preferred thickness for the roofing product may be 0.001 to 8.0 cm, more preferably be 0.01 to 3.0 cm, and even more preferably 0.0889 to 0.2286 cm. A roofing product should have at least the minimum thickness required for the flute span of the roof when applied to a metal roof.
Upper and lower layers of the roofing membrane may be composed of a thermoplastic polyolefin (TPO). A preferred TPO for the present invention is EPR, PP, or a combination of EPR and PP. Other suitable polymer resins may be used to form the roofing membrane layers. The polymer composition of at least one roofing membrane layer may be blended composition including one or more additives prepared by conventional methods, such as an extrusion process. Such a blended composition may include conventional ultra-violet (UV) absorbers, UV screeners, fire retardants, and other weatherability modifiers. One or more UV absorbers and/or screeners may improve the weatherability of the roofing membrane by preventing a loss of strength, degradation, or discoloration of the roofing membrane. FRs may be added to the polymer to slow down polymer combustion of the roofing membrane when exposed to flames.
A preferred thickness of a layer of roofing membrane may be 0.001 to 8.0 cm. A more preferred thickness of such a layer may be 0.01 to 3.0 cm. Yet another more preferred thickness of such a layer may be 0.0889 to 0.2286 cm.
The width of the roofing product is preferably 0.3 to 3.81 m, more preferably 1.9 to 3.81 m. It should be appreciate that the width of the roofing product may vary depending on the requirements of the manufacturer or installer. In addition, the layers within a roofing product, i.e. roofing membrane layers, will generally have a substantially similar width as the roofing product.
A preferred thickness of the fabric layer is 0.001 to 3.0 cm, more preferably 0.001 to 1.27 cm, and even more preferably 0.015 to 0.066 cm. A preferred woven fabric may have 2-12 threads per cm (5-30 threads per in.) and a thread thickness of 100-3000 denier, and more preferably 4 threads per cm (10 threads per in.) and a thread thickness of 1000 denier.
The batten strip may be a flexible strip having preferred dimensions of 1.27 to 5.1 cm wide and 0.025 to 0.254 cm thick and more preferably 2.54 cm wide and 0.127 cm thick, as described in U.S. Pat. No. 5,469,671, the entire contents and disclosure of which is hereby incorporated by reference. The batten strip may consist of the following materials, fabric, cloth, nylon, metal, PP, PE and PVC. A polymer used in a batten strip may be a blended composition including fire retardants and UV modifying agents as additives. A preferred material for the batten strip is described in U.S. Pat. No. 4,963,430, the contents and disclosure of which is hereby incorporated by reference. As set forth in U.S. Pat. No. 4,963,430 the composition of the batten strip may be from about 80% to 97% by weight of polyethylene terephthalate and from about 3% to 20% by weight of a polyolefin and wherein the polyolefin may be PP.
A batten strip made of fabric may be composed of woven, non-woven or composite fabric materials, either natural or synthetic. Preferably, a fabric batten strip is made of a suitable material to withstand a typical force on a roof deck by having a larger load pull through strength. For example, a typical fabric batten strip is 2.54 cm wide and 0.1016 cm thick, which preferably has a load pull through strength of at least 635 pounds. However, the fabric batten strip may require less pull through strength if more fasteners are used per unit area of roofing membrane to mount a roofing membrane on the roof deck. And conversely, more pull through strength may be required if fewer fasteners are used per unit area of roofing membrane. The load pull through strength of the fabric layer may increase once the fabric layer is integrally bonded within the roofing membrane. In general, fabric batten strips having a high pull through strength are desirable, because they require fewer fasteners and, therefore, less labor to install.
A batten strip may be integrally bonded to, on, or within one side of a roofing membrane layer. The integral relationship between the materials in the roofing product of the present invention is preferred over prior methods of laying a batten strip on top of a roofing product, which is done during the installation of the roofing product. The prior methods required precise alignment that required more time when installing. However, the integral bond between the batten strip and roofing membrane, which may be done during the manufacture of the roofing product, may reduce the time to install the roofing product. The roofing product of the present invention is able to eliminate much of the effort to manually place a batten strip on a roofing membrane.
It should be appreciated that a layer of insulation may be located between a roof deck and lower layer of roofing membrane. An example of an insulation layer is described and disclosed in U.S. Pat. No. 6,238,502, the entire contents and disclosure of which is hereby incorporated by reference. Examples of insulation materials include polyurethane, polystyrene, wood fiberboard, polyisocyanarate, etc. One or more additional layers of insulation may be located between a roofing product and roof deck. Preferably, when a layer of insulation is present a fastener may extend through the layer of insulation into a roof deck.
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Catch cords 752 and 754 may be embedded in batten strip 702 in a parallel configuration as illustrated in
Whether in a parallel or helical configuration, preferably the two cords are of equal length are spaced at a width sufficient to catch or grab the head of the securing device inserted between the cords.
The catch cords may each be a string of woven natural or synthetic fabric, such as cotton or nylon, flexible plastic or other suitable material, such as flexible metal wire. The catch cords may be used in various roofing products. The catch cords may be located anywhere within the batten strip. The catch cords may be mounted on or within the batten strip. One or more of the catch cords may extend the entire length of a batten strip. Alternatively, the catch cords may be present in particular portions of a batten strip, such as in the portion where the opening is located.
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An overlapping roofing product may be secured to an overlapped roofing membrane by various convention methods such as by hot-welding, using an adhesive, etc.
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Although particular types of roofing products of the present invention are shown in
In an alternative embodiment of the present invention, the batten strip may be located on top of both overlapping roofing membranes. This arrangement may allow a screw to extend through two overlapping roofing membranes.
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A preferred spacing of openings is 5 to 40 cm apart, more preferably about 15 cm apart. Preferably the openings are at substantially regular intervals. The spacing of the openings may vary depending on the flute span of the roofing deck. Also, instead of the pre-made openings shown in
Preferably, there should be little gap between the roofing products in the region where two roofing products overlap each other and where the batten strip is located. The bottom roofing product may be fastened used the batten strip and securing device. The top roofing product may be hot-welded directed on top of the bottom roofing product to substantially cover the batten strip. This configuration may create an airtight seal between overlapping roofing products.
It should be appreciated that a roofing product of the present invention may be secured to a parapet wall in addition to being secured to a roof deck.
A securing device may be any type of conventional securing device, such as screws, bolts, nails, seam discs, etc. for securing the roofing membrane to the roof deck, a plurality of conventional screw type securing devices and one or more batten strips or, if desired, a suitable combination of the foregoing. A washer may be used with various embodiments of the present invention in addition to the embodiments in which a washer is shown in the drawings.
The screw type securing devices may be conventional screws of the type commercially available from Olympic Securing devices, ITW Buildex, SFS Stadler and Tru-Fast. Similarly, the batten strips and seam discs may also be of a conventional design and of the type commercially available from Olympic Securing devices, ITW Buildex, SFS Stadler, Tru-Fast and Talan Products Inc.
There may be an anchor means that attaches to the securing device on the interior side of the roof deck. The anchor means may further secure the roofing product to the roof deck when the roof deck is made of a thin or weak material.
Although roofing products shown in the drawing figures have one or three layers, the roofing membrane of the present invention may have any number of layers including two layers or more than three layers. For example, a roofing product may have just two layers of TPO without a layer of fabric.
The roofing membrane is positioned to lay flat against the roof deck so that an edge of the roofing membrane is aligned with an edge of the roof deck. This edge may be bounded by a parapet wall or similar edge. The roofing membrane has a batten strip located near the edge for securing the edge of the roofing membrane to the roof deck. In addition, the roofing membrane may a batten strip that is positioned on a parapet wall to further secure the roofing membrane.
A batten strip is preferably located approximately 1.0 cm to 10 cm from an edge of the roofing membrane and more preferably approximately 6.35 cm from one edge of the roofing membrane. However, the batten strip may be located anywhere on a roofing membrane and a roofing membrane may include more than one batten strip.
A roofing product may cover the entire field of the roof deck. In such a case, one roofing product may have at least two batten strips located at opposing edges of the roofing product for securing to the roof deck. Additional batten strips may be used to further secure the roofing product to the roof deck. These batten strips may be positioned on every edge, or spaced within a single roofing product. The arrangement of batten strips at every edge may improve the roofing product's performance against weather conditions.
The integral placement of the batten strip in relationship to the roofing membrane provides good weather performance against wind, temperature, and moisture. The integral relationship prevents the roofing membrane from sliding or slipping out from underneath the batten strip or other attachment means. In preventing sliding or slipping, the integral design also prevents any enlargement of the openings in the batten strip. In addition, the further support of the cords may prevent any gaps or unfilled holes that may surround the screw in the batten strip.
The batten strips may have various sizes and shapes. For example, batten strips may be rectangular, square, round, oval, or any other shape.
Although in the roofing product of
The roofing product of the present invention may be made in a variety of ways. For example,
Although only two methods of making a roofing product are described above, other methods of making roofing product may be used. For example, the batten strip may be sewn onto a fabric material and the fabric material and integral batten strip then laminated between two thermoplastic layers.
Although in the methods described above, both thermoplastic sheets are made from the same thermoplastic, different thermoplastics may be used for each thermoplastic sheet. Also, although the thermoplastic layers in the methods described above are made from two resins, a thermoplastic layer may be made from a single resin.
Preferably, a feeder may be a gravimetric feeder or similar feeder. A screw extruder may be a twin-screw extruder or similar extruder.
It should be appreciated that a single layer of resin may be combined with a batten strip using a similar method as described above. In addition, more layers of resin and/or fabric may be added as necessary. Multiple batten strips may be integral with the layers of material in the roofing product.
Another method for forming a helical pattern of catch cords within a batten strip is to provide each hollow needle with a ball inset similar to a ball valve which would allow the hollow needles to be pivoted in opposite horizontal directions. Other conventional methods for controlling the motion of hollow guide needles may also be employed.
All documents, patents, journal articles and other materials cited in the present application are hereby incorporated by reference.
Although the present invention has been fully described in conjunction with the preferred embodiment thereof with reference to the accompanying drawings, it is to be understood that various changes and modifications may be apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom.
