Abstract:
System and method for providing a roof ventilation system are disclosed. The roof ventilation system may include a core, a filter, and a spanner. The core may be configured to conform to a roof surface irregularity. The filter may be configured to hinder rain and debris from entering into an attic from ambient yet allow air to flow from the attic to ambient. The spanner may be configured to allow the roof ventilation system of adjust for roof slopes.

Description:
REFERENCE TO CROSS-RELATED APPLICATIONS 
       [0001]    The present application is related and claims priority to U.S. Provisional Patent Application having Ser. No. 60/791,329 having a filing date of Apr. 12, 2006 which is hereby incorporated by reference in its entirety. 
     
     FIELD OF INVENTION 
       [0002]    The present invention generally relates to roof ventilation. More particularly, embodiments of the present invention relate to roof ventilation systems allowing a gas to circulate, between a building attic and ambient. 
       BACKGROUND OF THE INVENTION 
       [0003]    Ventilating attics helps to prolong shingle life, reduce building cooling costs, and help reduce moisture buildup that can lead to mold, mildew, and rot. Current roof ventilation systems, have shortcomings. For example, they suffer from inadequate compression resistance during installation or subsequent use, have poor resistance to intrusion by precipitation, insects, debris, and lack the capability to be rolled up for storage and transportation. Additionally, current roof ventilation systems often are not universal and cannot be effectively used on a broad range of roofing system, i.e., they cannot be used with differing roofing materials. For example, a shingle roof will require a different roof ventilation system than a slate or standing seam metal roof. 
         [0004]    There exists a need for a roof ventilation system that allows for universal application across a broad range of roofing systems. It is also desired that such a system provide compression resistance without substantially reducing airflow. In addition, there exists a need for a roof ventilation system that allows for substantially net free ventilation area optimization while still resisting wind-driven rain. Furthermore, there exists a need for a ridge vent solution that can be rolled-up to facilitate transportation, storage, and installation on roofs, while still having the ability to lie flat on the roof during installation. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    Consistent with embodiments of the present invention a roof ventilation system is disclosed. The preferred systems include a core, a filter, and a spanner. The core preferably conforms to roof surface irregularities. The filter may be configured to hinder rain and debris from entering into an attic while allowing air to flow from, the attic to ambient. The spanner may be configured to allow the roof ventilation system to adjust for varying roof slopes. 
         [0006]    Still consistent with embodiments of the present invention, methods for providing roof ventilation are also contemplated. The methods include providing a core, in which the core provides a space between a ridge cap and a ridge slot, the space allowing air to flow from an attic to ambient. The method may further include providing a barrier allowing air to pass from the attic to ambient yet hindering the passage of rain and debris from passing through the core. 
     
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0007]    Non-limiting and non-exhaustive embodiments are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
           [0008]      FIG. 1  shows a perspective of a roof ventilation system consistent with embodiments of the invention; 
           [0009]      FIG. 2  shows a roof ventilation system consistent with embodiments of the invention for installation on a metal roof; 
           [0010]      FIG. 3  shows a roof ventilation system consistent with embodiments of the invention for installation on a shingle roof; 
           [0011]      FIG. 4  shows a cross-sectional view of the roof ventilation system of  FIG. 3  taken along line  4 - 4 ; 
           [0012]      FIG. 5  shows an embodiment of the invention having a cast monofilament structure; 
           [0013]      FIG. 6  shows a side cross-sectional view of an embodiment of the invention having, a thermoformed structure; 
           [0014]      FIG. 7  shows several core element shapes consistent with embodiments of the invention; and 
           [0015]      FIG. 8  shows several placements of filter elements consistent with embodiments of the invention. 
       
    
    
     GENERAL DESCRIPTION 
       [0016]    Ridge venting is a method of forming a vent opening m a roof during construction (or later cut into the roof) that leaves a vent slot along the roof ridge. A core may be placed atop the vent slot to provide a space to allow air to flow from inside the structure by convection, and drawn from the structure by differential pressure. The core may be provided to elevate a ridge shingle or a ridge cap. A filter connected to the core can be used to hinder moisture, debris, and pests from entering the structure through the vent. 
       DETAILED DESCRIPTION 
       [0017]    Various embodiments are described more My below with reference to the accompanying drawings, which form, a part hereof, and which show specific embodiments of the invention. However, embodiments may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the invention to those skilled in the art. The following detailed description, accordingly, is not to be taken in a limiting sense. 
         [0018]    Reference may he made throughout this specification to “one embodiment,” “an embodiment,” “embodiments,” “an aspect,” or “aspects” meaning that a particular described feature, structure, or characteristic may be included in at least one embodiment of the present invention. Usage of such phrases may refer to more than, just one embodiment or aspect. In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments or aspects. Moreover, reference to a single item may mean a single item or a plurality of items, just as reference to a plurality of items may mean a single item. 
         [0019]    Referring now to the figures,  FIG. 1  shows a perspective of a roof ventilation system  100  consistent with embodiments of the invention. The roof ventilation system  100  has been inverted to show better the underside of a spanning element or spanner  102 , two core elements or cores  104  and  106  and filter elements or filters  108  and  110 . In this perspective view of the roof ventilation system  100 , the spanner  102  may act as a base. The cores  104  and  106  may be attached to the spanner  102 . In addition, the filters  108  and  110  may be attached to either or both the spanner  102  or the cores  104  and  106 . In various aspects of the invention, the spanner  102 , the cores  104  and  106 , and the filters  108  and  110  may have separate materials or design characteristics to best achieve a desired result. The spanner  102  is intended to not only connect the cores  104  and  106 , but also stabilize the roof ventilation system  100  and improve the roof ventilation system&#39;s  100  compression resistance. 
         [0020]    The spanner  102  may he formed of a substantially planar, flexible, thermoplastic, non-woven material, such as COLBACK sold by Colbond Incorporated, Enka, N.C., REEMAY sold by Fiberweb, Old Hickory, Tenn. or Spunbond Polyester sold by Johns Manville, Spartanburg, S.C. The non-woven material may be densified by hot calendering. Hot calendering processes may involve passing the material through two rollers wherein at least one roller is heated. The temperature of the rollers may be above the glass transition temperature of the material and below the melting point of the material. Pressure may be applied to the material at a nip point between the rollers. The required pressure may vary with material characteristics, but generally ranges from 100 to 400 pounds per linear inch. The combination of heat and pressure may produce a thinner, denser material. Calendering of the non-woven not only increases the density by reducing the thickness, but may also increase the stiffness and reduce the material bending radius. 
         [0021]    Connecting the spanner  102  to the cores  104  and  106  improves compression resistance and stability yet have a relatively low basis weight. Furthermore, improved compression resistance and stability may be achieved without a loss in air permeability or without losing the ability to roll up the roof ventilations system  100  for transport prior to installation. 
         [0022]    The cores  104  and  106  preferably allow air flow through the roof ventilation system  100  with little or minimized obstruction, provide compression resistance, and enable the roof ventilation system  100  to be applied to a broad range of roofing system, profiles. The cores  104  and  106  are preferably flexible, which allows the roof ventilation system  100  to be rolled and unrolled prior to installation. A combination of stiffness and flexibility of the core material, however, is important to allow utilization across a broad range of roofing systems. The cores  104  and  106  are preferably formed of a thermoplastic material, such as COLBACK, sold by Colbond Incorporated, Enka, N.C. or Spunbond Polyester, sold by Johns Manville, Spartanburg, S.C. In addition, the cores  104  and  106  are formed by hot calendering the thermoplastic material. Hot calendering may improve the thermoplastic material&#39;s stiffness, and may also reduce its bending radius. Lowering the material&#39;s bending radius allows rolling and unrolling the material without developing cracks or creases to avoid creating permanent deformation. It is desired to avoid permanent deformation is so that the system that will lie substantially flat when unrolled and have improved installation efficiency. 
         [0023]    The cores  104  and  106  may be comprised of a shaped, thermoplastic, and non-woven material. The non-woven may be densified by hot calendering prior to forming cores  104  and  106  into shape. Calendering of the non-woven may increase the stiffness of the non-woven and may enhance the compression resistance. Calendering may also reduce the bending radius of the material allowing the cores  104  and  106  to be rolled and unrolled without permanent deformation. The cores  104  and  106  may be shaped by pleating the calendered or uncalendered material. By way of example and not limitation, the pleating techniques may include score pleating, blade pleating, and gear pleating. The shape of pleated cores  104  and  106  may allow air to escape from inside the building with little or no obstruction, provide enhanced compression resistance, allow the laminate to be tolled and unrolled, and allow the roof ventilation system  100  to be used on a broad range of roofing system profiles (e.g., shingles, metal, slate, etc.). 
         [0024]    The filters  108  and  110  may allow air How from inside the building (e.g., attic) yet hinder intrusion of precipitation, pests, or debris. The filters are preferably formed of Air Lay Nonwoven and sold by Kern-Wove Incorporated, Charlotte, N.C., Spunbond Polyester sold by Johns Manville, Spartanburg, S.C. and Berlin, Germany, REEMAY sold by Fiberweb, Old Hickory, Tenn. and COLBACK sold by Colbond, Incorporated, Enka, N.C. The filters  108  and  110  are preferably conformable to allow the roof ventilation system  100  to adapt to a broad range of roofing system profiles. The filters  108  and  110  may take several, forms, such as a creped pattern. The creping process may compact a substantially planar material and form a plurality of cross-directional folds, or crimps, in the material. The material may be a thermoplastic and may have been, softened by heating. The material may then be allowed to cool under low tension. During the cooling process, the folds may become relatively permanent and may create a stretchable (i.e. elastic) fabric from a formerly planar relatively inelastic fabric. In one aspect of the invention, the filters  108  and  110  may have a 50% to 200% compaction level. In another aspect of the invention, the compaction level may be 75% to 125%. 
         [0025]    The filters  108  and  110  may be formed of a creped or crimped thermoplastic non-woven material. Creping the material may crease an elastic (i.e., stretchable) structure from a formerly planar or inelastic (i.e., non-stretchable structure). The stretchability or extensibility of the creped material may allow it to conform to a broad range of rooting system profiles. Unlike unitary non-woven matting and open-cell foam filters, the filters  108  and  110  may conform to and around roof projections or uneven surfaces. In other words, because the filters  108  and  110  are flexible, they may bend and stretch as needed to conform to roof projections. The creped filters  108  and  110  are less likely to incur a loss of air permeability when installed as compared to other designs. Moreover, by altering the frequency and amplitude of the creped material, it may be possible to increase the net free ventilation area by expanding the materials surface area. For example, by adjusting the frequency of a lightweight thermoplastic non-woven material, to 8-10 crimps per inch and the amplitude to approximately 3 millimeters, the air permeability and net free ventilation area may double. Conversely, increasing the frequency and reducing the amplitude of the creped non-woven material may increase wind-driven rain resistance. 
         [0026]    In connecting the filters  108  and  110  to the cores  104  and  106 , lower levels of compaction may be utilized by attaching the filters  108  and  110  only at selected locations. In other words, the filters  108  and  110  may not be bonded to every core section, that contacts the cores  104  and  106 . By not attaching the filters  108  and  110  to every contact point, additional, material may be available from adjacent sections as needed and the filters  108  and  110  may expand and conform to a roofing system, contour or projection. 
         [0027]    The components (i.e., the spanner  102 , the cores  104  and  106 , and the filters  108  and  110 ) of the roof ventilation system  100  may he bonded to the other components using several different means including, but not limited to, ultrasonic welding, heat bonding, radio frequency welding, mechanical means, and adhesive means. For example, ultrasonic welding, involves converting electrical energy into ultra-high frequency sound waves, creating vibration and frictional beat, within the materials, so that they melt or fuse together. Attachment may also be accomplished by plunge welding or continuous welding the components together. 
         [0028]    Non-woven materials in various aspects of the invention may be broadly classified as bi-component non-woven materials. Bi-component non-woven materials may be formed of two different polymeric materials, in which one component has a substantially lower melting point than the other component. The Bi-component fibers in the non-woven can be formed as core-and-sheath filament, in which the core has the higher melting point component and the sheath has the lower point melting component. In other aspects of the invention, the bi-filament fibers may be made entirely of a higher melting point component and other fibers may be made entirely of a lower melting point component. Other bi-component forms are possible. The lower melting point polymer may serve as an adhesive to bond overlapping or adjacent filaments together while preserving the filament properties of the higher melting point component. The bi-component non-woven material is preferably formed of Spunbond Polyester and sold by Johns Manville, Spartanburg, S.C. and Berlin, Germany, REEMAY sold by Fiberweb, Old Hickory, Tenn. and COLBACK sold by Colbond, Incorporated, Enka, N.C. 
         [0029]    The roof ventilation system  100  cores  104  and  106  and the spanner  102  may have a basis weights between 100 and 550 grams per square meter or, more preferably, between 170 and 250 grams per square meter. The lifters  108  and  110  may have a basis weights between 10 and 150 grams per square meter or, more preferably, between 14 and 100 grams per square meter. 
         [0030]    Turning now to  FIG. 2 , the roof ventilation system  100  is shown being installed on a metal roof  204 . The metal roof  204  may include a decking  202  which may be covered by a sheet  206  formed by a plurality of metal panels  208 . The metal roof  204  comes to a ridge  210  at the top of the rafters  212  and forms a slope defined by raters  212 . 
         [0031]    In vented metal roofing systems, the opposed metal sheets do not extend to contact each other at the peak. The gap formed between the metal sheets forms a vent slot, and the vent slot is covered with the roof ventilation system  100  of the present invention. After the roof ventilation system  100  is installed, a ridge cap  214  is placed on top. 
         [0032]    The metal panels  208  typically extend up to within approximately 18 millimeters to 25 millimeters of the ridge  210 . The termination, of the metal panels  208  may define an open vent slot  216 . The juncture of the metal panels  208  at the ridge  210  and the vent slot  216  may be covered with a ridge cap  214 . The ridge cap  214  typically is formed of similar material as the metal panels  208  and may be installed in sections running along the ridge  210 . 
         [0033]    The metal panels  208  may have a plurality of projections  218  that project up from the decking  202 . Adjacent metal panels  208  may be joined together by overlapping lateral edges  220 . The projections  218  are typically comprised of larger stiffening ribs  224  and smaller squared stiffening ribs  218 . The larger stiffening ribs  224  near the lateral edges  220  of the metal panels  208  may be used to overlap the adjacent metal panel  208 . 
         [0034]    Roof ventilation system  100  may have a conformable lower surface comprised of cores  104  and  106  and a filters  108  and  110  that may readily adapt to the metal panels  208  contours, including any projections  218 . The transversely extending peaks and valleys of the cores  104  and  106  may fit over the projections  218  while the filters  108  and  110  may conform to the metal panels&#39;  208  contours. The roof ventilation system  100  may he secured in proximity to an upper edge  228  of the metal panels  208  and may overlay the projections  218 . The spanner  102  may join spaced-apart cores  104  and  106  located on opposite sides of the vent slot  216 . The roof ventilation system  100  may be secured to the metal panels  208  by adhesive or mechanical means as necessary. In addition, the roof ventilation system  100  may he secured to the underside of the ridge cap  214  by adhesive or mechanical means, as necessary. 
         [0035]    It is contemplated, that the ridge cap may act as the spanner  102 . In other words, the cores  104  and  106  may be secured to the ridge cap  214  during, installation. For example, in  FIG. 2 , the illustrated spanner  102  may be omitted and the ridge cap  214  may act as the spanner  102  instead. In this configuration, the cores  104  and  106  may he secured to the roof adjacent to the ridge  210  and then the ridge cap  214  may be secured to the roof covering the vent opening yet still allowing air flow from to attic to ambient. 
         [0036]    The ridge cap  214  may overlay the roof ventilation system  100  and may be secured to the metal panels  208  by fasteners  222 . The fasteners  222  may be secured into a plurality of large stiffening ribs. As the ridge cap  214  is secured to the metal panels  208 , the cores  104  and  106  and filters  108  and  110  may be compressed and then may expand to fill an opening between the metal panels  208  and the ridge cap  214 . Ultimately, the filters  108  and  110  may suffer little or no air permeability loss. Air may flow from inside the building through the cores  104  and  106  and through the air filters  108  and  110  or vice versa. 
         [0037]      FIG. 3  shows the roof ventilation system  100  consistent with embodiments of the invention for installation, on a shingle roof  302 . The shingle roof  302  may include a decking  204  which, may be covered by a plurality of asphalt shingles  308 . The shingle roof  312  may comprise a ridge pole  320  placed between the upper ends of the rafters  212  and a collar beam  304  extending between rafters  212 . Roof construction methods may not require the ridge pole  320  (e.g., truss systems). 
         [0038]    The roof decking  204  overlies the roof rafters  212 . Typically, at least one layer of building paper or roofing felt  306  is laid onto the decking to provide at least temporary protection during construction. Since shingle roofs are water shedders and not water-proof, the felt  306  also provides some water resistance protection in later use. A vent slot  216  located at the ridge  210  of the roof may permit the upward and outward air flow, as indicated by arrows  310 , from the building interior by convection and differential pressure. A section of the roof ventilation system  100  is shown covering the vent slot  210 . 
         [0039]    As discussed above, the roof ventilation system  100  may have a conformable lower surface comprised of the cores  104  and  106  and the filters  108  and  110  that may adapt to the shingles  308  contours. The roof ventilation system  100  may be secured in proximity to an upper edge of the decking  204  near the vent slot  216 . The spanner  102  may join the cores  104  and  106  located on opposite sides of the vent slot  216 . The roof ventilation system  100  may be secured to the decking  204  by nails  314 , as necessary. Alternatively, the roof ventilation system  100  may be secured to the shingles  308  by adhesive. 
         [0040]    The cap shingles  312  may overlay the roof ventilation system  100  and may be secured to the decking  204  by nails  314 . Two nails  314  may be placed in each cap shingle  312  and covered by an adjacent cap shingle. As the cap shingles  312  are secured to the decking  204 , the cores  104  and  106  and filters  108  and  110  may expand to till the opening between the decking  204  and the cap shingle  312  thus hindering precipitation, pests, and debris intrusion into the attic. Air may flow flora, inside the building through the cores  104  and  106  and the filters  108  and  110 . 
         [0041]      FIG. 4  shows a cross-sectional view of the roof ventilation system  100  of  FIG. 3  taken along line  4 - 4 . The vent slot  216  allows air flow from inside the building space due to convection and differential pressure. The filters  108  and  110  may be bonded to the underside of the spanner  102  and selected valleys of the cores  104  and  106 . The cap shingle  312  may be secured to the roof ventilation system  100  and the decking by a nails  314 . 
         [0042]      FIG. 5  shows an embodiment of the roof ventilation system  100  comprising a cast monofilament structure. Once melted, an extruder develops sufficient pressure to force a molten plastic through a filter and spinnerette or die arrangement. The resulting hot monofilaments are collected, onto a moving die which is shaped in a mirror image of the device. The filaments may be caused to overlap by air currents or by sideways oscillation of the moving die. The shape of the cores  104  and  106  may be spaced apart transversely extending peaks and valleys with overlapping monofilament sidewalls. The spanner  102  may, in an embodiment, be integrated with the cores  104  and  106  and comprised of overlapping monofilaments. The filter  108  may be comprised of a high-loft non-woven. The high loft non-woven material may comprise heavy denier staple fibers such, as 200 to 300 denier per filament staple fiber. The filter  108  may be attached to a planar portion of a cast thermoplastic monofilament structure. 
         [0043]      FIG. 6  shows an embodiment of the roof ventilation system  100  composing a thermoformed structure. The thermoforming may be performed with a pair of matched dies. The thermoplastic material may be preheated before being presented to the dies. The two matched dies may close under pressure to form the spanner  102  and the cores  104  and  106  from a single layer non-woven material. 
         [0044]    The filter  108  may be comprised of open-cell foam. The filter  108  may be attached to a planar portion of the thermoformed structure. The thermoplastic material may be a calendered bi-component non-woven material as described earlier in this specification. The basis weight of the thermoplastic non-woven material may be between 100 grams per square meter and 600 grams per square meter. For example, the basis weight may be between 170 grams per square meter and 350 grams per square meter. The open-cell foam may comprise a polyurethane foam with a porosity of 10 pores per inch to 100 pores per luck. For example, the porosity may be between 20 pores per inch to 50 pores per inch. 
         [0045]      FIG. 7  shows several core shapes that may be used on the roof ventilation system.  100 . All may be shaped to allow the relatively unobstructed airflow from the building inferior, provide structural core compression resistance, allow for universal use on a broad variety of roofing system contours, accept a conformable filter, and allow the roof ventilation system  100  to be rolled and un-rolled, and lie flat prior to installation. The shapes indicated by reference numerals  702 ,  714 , and  710  may be formed by pleating or thermoforming a thermoplastic non-woven material or by casting overlapping monofilaments onto a shaped mold. The shapes indicated by reference numerals  706  and  708  may be formed by thermoforming a thermoplastic non-woven material or by casting overlapping monofilaments onto a shaped mold. 
         [0046]      FIG. 8  shows several placements of the filters  108  and  110  consistent with embodiments of the invention. In each case, the filters  108  and  110  may prevent the intrusion of precipitation, pests, and debris into the building interior through the vent slot. The filters  108  and  110  may be attached to the cores  104  and  106  or the spanner  102  by heat bonding, ultrasonic welding, radio frequency welding, or adhesive means. In  FIG. 8   a,  the filters  108  and  110  may be attached to the underside of the spanner  102  and outboard of the cores  104  and  106 . In  FIG. 8   b,  the filter  108  may be attached to selected valleys of the cores  104  and  106  and may be intended to cross over the vent slot to permit air flow and prevent intrusion into the building interior. The filler  108  may have relatively high frequency and relatively high amplitude to enhance air flow and wind-driven rain resistance.  FIG. 8   c  shows the filters  108  and  110  attached to both the valleys of the cores  104  and  106  and the top side of the spanner  102 . In  FIG. 8   d,  the filters  108  and  110  may be flanked by two core segments  104   a  and  104   b,  The filters  108  and  110  and core segments  104   a,    104   b,    106   a,  and  106   b  may be attached to the spanner  102 . The spanner  102  affords installation efficiency as it covers both sides of the vent slot at one instance. Proper selection of the basis weight, crepe characteristics and air permeability of the filters  108  and  110  allow a superior combination of net free ventilation area and resistance to intrusion by precipitation, pests and debris. 
         [0047]    Reference has been made throughout this specification to “one embodiment,” “an embodiment,” or “embodiments” meaning that a particular described feature, structure, or characteristic is included in at least one embodiment of the present invention. Thus, usage of such phrases may refer to more than, just one embodiment. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. 
         [0048]    One skilled in the relevant art may recognize, however, that the invention may be practiced without, one or more of the specific details, or with other methods, resources, materials, etc. In other instances, well known structures, resources, or operations have not been shown or described in detail merely to avoid obscuring aspects of the invention. 
         [0049]    While example embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise configuration and resources described above. Various modifications, changes, and variations apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present invention disclosed herein without departing from the scope of the claimed invention. 
         [0050]    The above specification, examples and data provide a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.