Patent Publication Number: US-8528269-B2

Title: Fascia vent

Description:
TECHNICAL FIELD 
     This disclosure relates generally to attic ventilation and more specifically to fascia vents. 
     BACKGROUND 
     Modern attic ventilation systems usually include outlet vents high on a roof through which hot air escapes from the attic, coupled with inlet vents in the soffit or eve regions of the roof. The outlet vents might, for instance, comprise ridge vents that extend along and cover a slotted roof ridge while inlet vents might include a plurality of louvered vents covering openings cut in the soffit. As hot air escapes the attic through the outlet vents by means of convection, which may be aided by vent fans in some cases, it is replaced by cooler outside air that is drawn into the attic through the inlet vents. 
     Many styles and configurations of inlet vents for attic spaces have been designed and used in the past. These include independent louvered soffit vents, continuous strips of louvered soffit vent, ventilating material installed behind or atop fascia boards, and complicated louvered fascia vents. A need persists, however, for an inlet vent that is effective, easily installed by the common carpenter, and virtually undetectable when installed. It is to the provision of such an inlet vent that the present invention is primarily directed. 
     SUMMARY 
     Briefly described, a combination fascia board and vent, referred to as a fascia vent, comprises an elongated fascia board having a width appropriate to form the fascia of a gable roof overhang. In one embodiment, the fascia board is fabricated of extruded plastic composite material, which may be formed with a hollow interior having longitudinally extending ribs forming longitudinal channels on the interior of the strip. Other materials, such as, for instance, solid plastics, solid composites, blown and skinned plastics, and wood may be used. In any event, the fascia board is formed on its inside face with a plurality of spaced slots arrayed along a bottom edge and each slot extends laterally only part way across the width of the fascia board. The fascia board is installed by being fastened to the lower ends of the roof rafters with the array of spaced slots facing inwardly and with their bottom ends exposed to ambience along the bottom edge of the fascia board. Soffit boards are installed beneath the overhang between the fascia boards and the outside wall of a dwelling in the traditional way. 
     The exposed bottom ends of the slots in conjunction with the lengths of the slots provide vent paths for outside air to enter the attic. The number and spacing of the slots is selected to provide appropriate ventilating capacity to support the effective replenishment of the attic with fresh outside air as hot air exits the attic through the outlet vents. Thus, circulation is established that helps reduce the temperature within the attic as was as helping to prevent formation of mold and mildew due to trapped stagnant moist air. The fascia vent of this disclosure is thus an effective inlet vent for a variety of roof constructions including any roof with a ridge or gable or power exhaust vents. Further, it requires no special talent or tools to install since it is applied by a carpenter in the same manner as traditional fascia boards. Since the installation of the fascia board and vent are accomplished in a single operation, significant time is saved as compared to installing soffit or eve vents separately and in addition to the installation of fascia boards. 
     In another application, the fascia vent offers the additional benefit of providing for the venting of intake air into a structure that does not have conventional soffits or overhangs. In such installations, the fascia vent is installed against the outside wall of the structure beneath the roof decking. The slots in the back side of the fascia vent provide air passages for the flow in inlet air into the attic above. 
     These and other objects, features, and advantages of the fascia vent disclosed herein will become more apparent upon review of the detailed description set forth below when taken in conjunction with the accompanying drawing figures, which are briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the inside face of a fascia vent that embodies principles of the present invention in one possible configuration. 
         FIG. 2  is a cross sectional view showing the fascia vent of  FIG. 1  installed and operational on a dwelling with a traditional soffit and overhang. 
         FIG. 3  is a view of the underside of the soffit and overhang of  FIG. 2  illustrating how the slots in the fascia board form vents for inlet air to enter the attic space of the dwelling. 
     
    
    
     DETAILED DESCRIPTION 
     Reference is now made in more detail to the drawing figures, wherein like reference numerals refer, where appropriate, to like parts in the several views.  FIG. 1  illustrates a fascia vent that embodies principles of the invention in one possible configuration. The fascia vent  11  comprises an elongated fascia board  12  having an outside face  13  and an inside face  14 . The outside face  13  and inside face  14  are spaced apart from each other and are connected together by a plurality of longitudinally extending internal ribs  18 . The internal ribs  18 , in turn, define a plurality of longitudinally extending interior channels  19  along the length of the fascia board  12 . The fascia board  12  also has a top edge  16  and a bottom edge  17 . At least the bottom edge  17  is shaped to form a drip edge  20  along the bottom of the outside face  13  to inhibit migration of water across the bottom edge  17  to the inside face of the fascia board  12 . 
     In the embodiment of  FIG. 1 , the fascia board  12  is extruded from a plastic composite material which may comprise, for example, polypropylene with fillers that may include wood fiber, sawdust, rice hulls, or any of a number of fillers known to those of skill in the art. Alternatively, the fascia board may be formed from extruded PVC plastic that preferably is blown to provide a lighter weight yet strong structure. Other materials such as other plastics, aluminum or galvanized steel, or even traditional wood may be used to fabricate the fascia boards. In one embodiment, the fascia vent is fabricated from a fire retardant material, preferably a material that meets “class A” fire rating standards. Traditional thermoplastic and composite materials may be rendered fire retardant by including certain additives such as, for example, magnesium trioxide, antimony, alpha-alkyl-D-glucoside, Silica gel combined with potassium carbonate, and other additives generally known to thermoplastic fabricators. The fascia vent also may be fabricated by methods other than extrusion such as, for instance, injection molding, thermoforming, or any other appropriate manufacturing technique. However, an extruded material such as extruded polypropylene with fillers is preferred because it is strong, durable, resistant to deterioration, and permits extrusion of the fascia boards in significantly longer lengths, which reduces installation time and the number of end joints that result when the fascia vent is installed. 
     The fascia board  12  is formed with an array of slots  21  that are spaced apart along the inside face  14  of the fascia board. Each of the slots  21  extends transversely from the bottom edge  17  of the fascia board a predetermined distance to upper ends  23 . In the embodiment illustrated in  FIG. 1 , the slots extend approximately half the width of the fascia board, although longer or shorter slots are possible. The depth of each slot  21  is less than the thickness of the fascia board, the slots extending inwardly in the illustrated embodiment to the inside surface of the outer face  13 . In the embodiment of  FIG. 1 , the slots  21  cut through the support ribs  18  to form air passages that communicate between and among the plurality of slots  21 . Of course, in an embodiment in which the fascia board is solid, such as in a fascia board made of blown PVC or other plastic, or wood, air passages between adjacent slots are not formed when the slots are made. Thus, air passages communicating between and among the slots are not a requirement. The slots  21  may be formed by any appropriate process such as, for example, by being machined with a router or other cutting tool, by being cut out, or by being molded directly into the fascia board as it is extruded or otherwise formed. 
       FIG. 2  shows the fascia vent  11  of  FIG. 1  installed on a dwelling and is a cross section taken through one of the slots  21 . More specifically, an eve  24  is formed from the projecting ends of roof rafters  26 , roof decking  27  and shingles  28  secured atop the roof rafters, and a soffit board  32  enclosing the bottom of the resulting rafter bay. The fascia vent  11  is secured to the ends of roof rafters  26  with appropriate fasteners such as nails, screws, adhesives, hangers, or any other appropriate fasteners (not shown). The outside face  13  of the fascia vent is exposed and presents the appearance of a traditional fascia board secured to the dwelling. In this regard, the outside face  13  in composite or plastic embodiments of the fascia vent may be formed with impressions of wood grain to simulate more closely the appearance of a traditional wooden fascia board. Rain gutters  29  may be secured along the outside face  13  of the fascia vent  11  using fastening devices such as gutter spikes and brackets. The design of the preferred embodiment of the fascia vent with its extruded composite construction and internal support ribs provides rigidity and strength to allow for the penetration and support of gutter fasteners and rain gutters suspended thereon. 
     The slots  21  on the inside of the fascia board  12  are open to and communicate with ambience on their lower ends and extend upwardly above the soffit board  32  so that upper end portions of the slots are exposed to and communicate with the interior of the otherwise enclosed soffit bay. It will thus be seen that the slots together form a vent extending along the entire length of the fascia through which outside air is free to flow, as indicated by arrows  31 , through the bottoms of the slots, into the soffit bay, and thus into the attic of the dwelling. In this way, the attic can be replenished with cool fresh outside air as hot attic air is expelled through ridge vents or other outlet vents higher on the roof. 
     While the fascia vent is illustrated in  FIG. 2  installed along the overhang of a gable roof, it will be understood that it is equally useful for providing attic ventilation for dwellings having roofs without a traditional soffit or overhang. In such installations, the ends of the roof rafters are substantially flush with the outside wall of the dwelling, which is illustrated by phantom line  34  in  FIG. 2 , and the fascia vent is installed against the outside wall. The function of the fascia vent is substantially the same as described above, except that air flows directly into the attic space rather than first into an overhanging soffit bay. 
       FIG. 3  is a view from the bottom of the soffit overhang of  FIG. 1  and illustrates better the open lower ends  22  of the ventilating slots  21 . It can be seen here that the ventilation slots are subtle and aesthetically pleasing and, in fact, are virtually undetectable when viewing a dwelling from a distance. This is an improvement over traditional soffit vents, which can be highly visible along the underside of the soffit and are considered by some to be unsightly. While not illustrated in the figures, the slots preferably are filled or covered with a material designed to prevent insects and moisture from migrating into the attic through the slots. For example, the lower ends  22  of the slots may be covered with an overlapping screen material or a vented strip with openings sized to allow ventilation while preventing insect migration. Alternatively, the slots may be filled with an open weave mesh material such as that used in the fabrication of Cobra® brand rolled ridge vent available from GAF Materials Corporation and described in U.S. Pat. No. 5,167,579. Such material permits air flow while inhibiting migration of insects and moisture through the vent slots. 
     The size and spacing of the vent slots  21  are predetermined to present a total net free ventilating area (NFA) at the soffit areas of a dwelling that compliments that of typical ridge or roof vent products. In this regard, a slot configuration that presents a total NFA of between 6 to 18 square inches for each foot of roof is preferred. In one particular example, a fascia vent according to the invention is provided with six vent slots per linear foot of fascia board. The width of each vent slot is 1 inch, the length of each slot to the semicircular top portion is 2 inches, the radius of the semicircle at the top of each slot is 0.5 inch, and the depth of each slot is 0.5 inch. With this configuration, the final installed NFA presented toward the attic space is about 11.3 square inches per linear foot of fascia vent where a 0.5 inch thick attic board is used for the soffit and about 9.9 square inches per linear foot of fascia vent where a 0.75 inch thick attic board is used. When the fascia on both sides of a roof are considered, these numbers are doubled to about 22.6 and 19.8 square inches for each foot of roof. Also for this example, the NFA per linear foot of fascia vent of the air inlet to the vent (i.e. the exposed bottom ends of the slots) is about 6.1 square inches per foot for a single fascia board and thus about 12.2 total square inches for each foot of roof. It thus will be seen that, for this example, the effective NFA for each foot of roof is about 12.2 square inches, which is within the preferred range and compliments well the NFA of typical ridge and roof vent products. 
     The invention has been described herein in the context of preferred embodiments and methodologies considered by the inventors to represent the best mode of carrying out the invention. It will be understood, however, that various modifications to the illustrated embodiments, both subtle and gross, may be made by skilled artisans without departing from the spirit and scope of the invention. For instance, while preferred materials for the fabrication of the fascia vent have been presented, any material or fabrication process suitable for making the fascia vent is intended to be included herein. Further, the particular configurations or shapes of the slots, their sizes, and their lateral extent all may be modified to meet a particular commercial application or need. The slots need not extend completely through the inside face of the fascia board along their entire lengths, but may, for instance, be enclosed at their bottoms and open within the soffit bay area of a roof. The scope of the present invention is not limited by these and other details but rather is defined and circumscribed only by the language of the following claims.