Abstract:
A precipitation resistant ventilator for a structure enclosing an interior space. The ventilator encloses a space that is in communication with the structure interior space. A thin sheet of air permeable water resistant material is disposed within the ventilator interior. The thin sheet of air permeable water resistant material forms a barrier that excludes the entry of precipitation and other foreign matter into the roof structure while still allowing air exchange.

Description:
RELATED APPLICATION 
   This application is a continuation of application Ser. No. 10/209,851 filed Jul. 31, 2002 now U.S. Pat. No. 6,623,354 and application Ser. No. 09/651,071 filed Aug. 30, 2000 now U.S. Pat. No. 6,450,882. 

   FIELD OF THE INVENTION 
   The present invention relates to roof ventilators folded from a blank of corrugated plastic sheet material having a top panel and two vent panels. More particularly, it relates to a roof vent of corrugated construction including an internal filtering material to exclude precipitation, debris and vermin from entry into the vented roof. 
   BACKGROUND OF THE INVENTION 
   It is a common practice in the construction of structures to ventilate gable roofs by providing a vent along the roof ridge. Ventilation apertures are formed in the construction process by leaving or cutting an open slot along the ridge through the sheathing material covering the roof. Heated air rises and escapes at the ridge taking with it moisture that may have accumulated within the roof. The flow of wind over the ridge of the roof assists in the extraction of moisture and heated air by creating a zone of relatively reduce pressure as it crosses the ridge. Soffit vents enable the entry of fresh exterior air into the roof to replace air that has left through the ridge vent. Soffit vents are openings in the soffit material covering the undersides of the overhanging eaves of the roof. 
   Ideally, a ventilated roof provides for an unrestricted outflow of air through the ridge vent and inflow through the soffit vents. However, without protection of the ventilating openings, wind blown precipitation, debris and insects enter the roof and encourage damage to the structure through mildew, rot and infestation. A ventilated cap is therefore placed over the open slot in the ridge and attached to the roof along each side. 
   Therefore, many types of vent caps have been developed in an effort to provide free flow of air while excluding rain, snow and insects. Louvers, baffles and screens have been standard features of roof vents for decades. 
   Snow, in particular, is a great concern. It has a small particle size and is lightweight. Wind can carry snow upward and into roof vents readily. Snow particles may bypass louvers and deflectors that prevent the entry of most rain. As much as two feet of wind driven snow has been reported to have passed through roof vents and accumulated inside roof structures. 
   A number of ridge vent caps employ filtering material to restrict the entry of precipitation and foreign matter. Filtering materials include porous foams and fibrous materials. Examples of the use of porous foams include U.S. Pat. No. 5,830,059 issued to Sells, U.S. Pat. No. 5,673,521 issued to Coulton et al. and U.S. Pat. No. 4,876,950 issued to Rudeen. Both closed cell foams and open cell foams have been utilized. Open cell foams have the benefit of allowing greater airflow but tend to absorb a substantial amount of water. Closed cell foams absorb little water but restrict airflow to a greater degree. Foam products, in general, tend to deteriorate with age and exposure to the elements. 
   Fibrous materials enjoy wider use as roof vent filters. Examples include U.S. Pat. No. 5,902,432 issued to Coulton et al., U.S. Pat. No. 5,830,059 issued to Sells, U.S. Pat. Nos. 5,561,953, 5,425,672, 5,352,154, 5,167,579 all issued to Rotter. These patents and others disclose the use of mats of randomly aligned synthetic fibers to exclude vermin and the elements from roof vents. The Rotter patents disclose roof vents made entirely from mats of randomly aligned synthetic fibers. Fiber mats may suffer from compression, for example, under a snow load, and add expense and complexity to the construction of roof vents. 
   Another approach to preventing the entry of precipitation and foreign matter into vents is to employ check valves structured to close at a predetermined wind speed so as to stop the inflow of air and precipitation. Check valves have moving parts and are prone to the possibility of wear and blockage and when they operate ventilation is restricted. They also complicate the manufacturing process. U.S. Pat. No. 5,803,805 to Sells discloses a check valve ridge vent. 
   In recent years the use of corrugated plastic sheet materials to manufacture roof vents has presented to the marketplace a variety of inexpensive, strong, durable ridge vents which may be applied in sections or as a continuous roll. Ridge vents of this type are typically applied along the peak of a roof and covered by a row of shingles. They are thus referred to as “shingle over roof vents.” Some have sufficient structural integrity such that they can be fastened to the roof with a pneumatic nail gun without crushing the vent. 
   Examples of corrugated plastic ridge vents include U.S. Pat. No. 5,651,734 issued to Morris, U.S. Pat. No. 5,934,995 to Morris, Kasner and Stoll and U.S. Pat. No. 5,947,817 to Morris, Gosz and Stoll which are incorporated herein in their entirety by reference. 
   Wind deflectors are sometimes installed along with the vent in order to restrict the entry of rain and snow into the vent. The installation of wind deflectors requires an additional step in the installation process with an attendant increase in time and expense. 
   The applicant is aware of a single example of a corrugated ridge vent employing a filtering material to exclude precipitation and the like. U.S. Pat. No. 5,704,834 issued to Sells discloses the use of a flexible, air permeable, moisture repelling, woven or nonwoven fabric covering the outer side of the vent passages to resist the penetration of moisture into the vent passages. The fabric filter is held in place by a perforated metal flashing attached either to the roof or to the vent. 
   Considerable complexity is added to the manufacturing process in order to incorporate the flashing into the vent. The presence of a rigid or semi rigid flashing may also prevent or complicate the rolling of the vent for transport and reduce ease of application. Additionally, the filtering fabric is exposed to the elements. Sun and wind may accelerate its deterioration. 
   It would be desirable to produce a ridge vent of folded corrugated plastic construction that effectively excludes wind blown precipitation and other foreign matter. The process of manufacturing the ridge vent should be as simple as possible. It would be preferable for such a ridge vent to require no flashing to support the filtering material. The ridge vent would ideally be possible to produce either in a continuous roll or in discrete sections. It would be preferable that filtering material be protected from exposure to the elements to maximize its life. 
   SUMMARY OF THE INVENTION 
   The present invention largely solves the above problems by providing a shingle over ridge vent that effectively excludes the entry of precipitation and foreign matter into the roof space. The ridge vent is sturdy, easily manufactured and readily installed. In addition, the filtering material that excludes precipitation is protected from factors that speed its deterioration. 
   The ridge vent is constructed of corrugated weather resistant material having a convoluted intermediate ply. Airflow passages in the convoluted layer are linearly oriented generally perpendicular to the long axis of the ridge vent. 
   The material is cut and scored so that it may be folded to have a single top panel extending its entire length. At either side of and below the top panel a plurality of folds create a plurality of stacked layers of the corrugated material with a plurality of airflow passages therethrough. A routed groove may extend the length of the bottom side of the top panel of the ridge vent to facilitate bending the ridge vent to conform to different roof pitches and to provide an additional exit path for air flowing out of the ridge vent. 
   A sheet of air permeable, water resistant, woven or nonwoven fabric or other membrane is applied to the bottom side of the vent. The filtering fabric is bonded to the corrugated material in the vicinity of the peak of the vent and on the bottom sides of the stacked, corrugated vent material. When the ridge vent is applied to the roof ridge the filtering fabric forms a tent like structure such that any accumulated rainwater drains out through the bottommost layer of the stacked side vent portions of the ridge vent. 
   The enclosure of the filtering fabric inside the ridge vent protects the fabric from exposure to sunlight and other factors that encourage deterioration. 
   The ridge vent may be produced in lengthy continuous rolls or discrete sections for installation. Discrete sections of ridge vent may be stacked flat or folded then stacked for shipping and handling. Multiple sections may be butted together end to end to cover a lengthy ridge application. 
   The vent material is unrolled or unfolded and disposed along the roof ridge so as to straddle the precut slot in the roof sheathing. The ridge vent may then be secured to the roof ridge with fasteners such as nails. It may be caulked as necessary. An individual skilled in the art will appreciate that if a roof is substantially irregular such as a corrugated metal roof or a tiled roof that a resilient conforming material may be placed beneath the ridge vent to provide a tight seal between the ridge vent and the roof. An end plug of resilient foam or other appropriate material may be inserted and secured in the end of the roof vent to close off the opening there. The ridge vent then may be covered with shingles nailed directly through the ridge vent into the roof sheathing. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a fragmentary elevated perspective view of a ridge vent in accordance with the present invention being installed on a roof; 
       FIG. 2  is a side plan view of a three ply weatherproof material that may be used in the construction of the present invention; 
       FIG. 3  is a side plan view of two layers of a three ply weatherproof material that may be used in the construction of the present invention; 
       FIG. 4  is a side plan view of two layers of an alternate three ply weatherproof material that may be used in the construction of the present invention; 
       FIG. 5  is an end plan view of the ridge vent of  FIG. 1  depicting a folding scheme for the hinge panels forming the lateral vents of the present invention; 
       FIG. 6  is an end plan view of an embodiment of the present invention as stored and shipped in a flat configuration; 
       FIG. 6   a  is an end plan view of an alternate embodiment of the present invention as stored and shipped in a flat configuration; 
       FIG. 6   b  is an end plan view of another alternate embodiment of the present invention as stored and shipped in a flat configuration; 
       FIG. 7  is an end sectional view an embodiment of the ridge vent installed on a roof ridge; 
       FIG. 7   a  is an end sectional view an alternate embodiment of the ridge vent installed on a roof ridge; and 
       FIG. 8  is an end sectional view of an alternate embodiment of the present invention as installed on a shed roof abutting a vertical exterior wall. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  depicts the precipitation resistant ridge cap roof vent  10  being installed on a roof  12 . The roof depicted is a rafter roof, though the ridge vent  10  may be installed on many other types of roofs to provide ventilation. The roof  12  depicted includes rafters  14  secured to a ridge board  16 . Rafters  14  support sheathing  18 . Sheathing  18  may be of plywood, oriented strand board, planks or other suitable material secured to rafters  14 . Generally sheathing  18  is overlaid with tarred felt paper  20  which is in turn overlaid with shingles  22 , though other roofing materials may be employed. A cutout slot  24  is provided along the ridge  26 . Slot  24  may terminate some distance from the end  28  of the ridge  26 . 
   The ridge vent  10 , as depicted in  FIGS. 1 ,  5 ,  6 , and  7 , broadly includes a top panel  30 , a plurality of vent panels  32  and filtering fabric  34 . Top panel  30  presents a long axis  36  aligned generally parallel with the ridge  26  of the roof  12  when ridge vent  10  is installed. Top panel  30  and vent panels  32  are constructed of a weatherproof three ply material  38  including a generally planar top ply  40 , a generally planar bottom ply  42  and an intermediate ply  44 . The intermediate ply  44  defines a multiplicity of airflow passages  46  extending generally transversely to long axis  36  and entirely across top panel  30  and vent panels  32 . Plug  47  may be inserted in the end of the ridge vent  10 . 
     FIGS. 2 ,  3  and  4  depict several possible configurations of the three ply material  38 .  FIG. 2  depicts a three ply material  38  whose intermediate ply is comprised of a series of cross walls  39  connecting the top ply  40  to bottom ply  42  and defining a plurality of airflow passages  46  therebetween.  FIGS. 3 and 4  depict an intermediate ply  44  of one or several convoluted or fluted layers  48  defining a plurality of airflow passages  46 .  FIGS. 3 and 4  also show how multiple layers of three ply material  38  may be stacked to provide many generally parallel airflow passages  46  therethrough. 
   Top panel  30  also presents an exterior surface  50  and an interior surface  52 . Interior surface  52  may include a routed groove  54  usually extending generally parallel to long axis  36 . Routed groove  54  extends through bottom ply  42  and into intermediate ply  44  defining inner openings  56  of airflow passages  46 . The outer edges  58  of top panel  30  define the outer openings  60  of airflow passages  46 . 
   Vent panels  32  are disposed under the outer edges  58  of top panel  30  in a stacked fashion. They contain a multiplicity of airflow passages  46  oriented generally transverse to long axis  36 . Vent panels  32  may be formed by scoring and folding a sheet of three ply material  38  as depicted in FIG.  5 . Vent panels  32  may then be secured to top panel  30  by the use of adhesives or fasteners  62  such as staples. 
   Alternately, vent panels  32  may by cut separately and stacked beneath the outer edges  58  of top panel  30  and secured together and to top panel  30  with fasteners  62  or adhesive. Thus airflow passages  46  are formed extending from exterior edges  64  to interior edges  66  of vent panels  32 . 
   Filtering fabric  34  is secured along the interior surface  52  of top panel  30 , preferably in the region of the routed groove  54 , and on the bottom side  68  of the lowermost vent panel  32  extending the length of the ridge vent  10 . Adhesives, fasteners, heat fusing or any other suitable technique may secure filtering fabric  34  to the ridge vent  10 . 
   Filtering fabric  34  may be of any thin, air permeable, water resistant, sheet material. Woven or nonwoven fabrics may be employed as well as air permeable water resistant membranes that are not of fabric. Preferably, filtering fabric  34  allows passage of about 75 percent of the air that would flow were it not present. The filtering fabric  34  may be a nonwoven spunbonded material of randomly arranged synthetic polymer fibers. 
   Referring to  FIGS. 6   a  and  7   a , in an alternate embodiment of ridge vent  10  filtering fabric  34  may be applied directly over inner openings  56  of airflow passages  46 . Filtering fabric  34  may cover only interior edges  64  of vent panels  32 . 
   Alternately, as depicted in  FIG. 6   b  filtering fabric  34  may extend from bottom side  68  of vent panels  32 , up over inner openings  56 , across interior surface  52  of top panel  30 , down over inner openings  56  on the opposite side and onto bottom side  68  on the opposite side. The filtering fabric  34  may be secured to interior edges  64 , bottom side  68  of vent panels  32  and interior surface  52  of top panel  30  as required. 
     FIG. 8  depicts an alternate embodiment of the ridge vent  10  adapted for use where it is desire to ventilate a shed style roof  70  in contact with an exterior wall  72 . Shed roof vent  74  generally includes a generally planar top panel  76 , vent panels  32  and filtering fabric  34 . Planar top panel  76  includes flange panel  78  extending along its length. Vent panels  32  are disposed beneath top panel  76  and are stacked and secured in a similar fashion to ridge vent  10 . Filtering fabric  34  is attached along the bottom side  68  of the lowermost vent panel  32  and to planar top panel  76  on or near flange panel  78 . Filtering fabric  34  may also be attached to cover the interior edges  66  of vent panels  32  alone. Fasteners, adhesives, heat fusing or other suitable techniques may secure filtering fabric  34  to planar top panel  76  and vent panel  32 . Flashing  80  may overlie the shed roof vent  74 . 
   Referring to  FIG. 1 , in operation, ridge vent  10  is applied to the ridge  26  of a roof  12  over a previously made cutout  24  extending the length of the ridge  26  except for a small portion left uncut at each end of the roof  12 . The cutout  24  may be larger than a cutout that would be used with a non-filtering ridge vent in order to compensate for the restriction of airflow caused by the filtering fabric  34 . The ridge vent  10  is unrolled or unfolded if it is received packaged in either of these forms. The roof vent  10  is disposed so that the routed groove  54  is generally centered over the cutout  24  and the vent panels  32  are generally parallel to the shingles  22  or other roof surface. It will be appreciated by those skilled in the art that a resilient or conforming piece of material may be placed between the ridge vent  10  and the roof  12  to fill in any gaps that may be present due to any substantial irregularities in the roof structure. This may be helpful in the case of a corrugated metal or tiled roof. 
   Once in place, the ridge vent  12  may be secured to the roof  12  by fasteners such as nails or by adhesives. Nails may be applied directly through top panel  30  where it overlies vent panels  32  and into roof sheathing  18 . A ridgeline (not shown) of shingles  22  may be applied directly over ridge vent  10 . 
   As can be seen in  FIGS. 1 , and  7 , when the ridge vent is installed the filtering fabric  34  forms a tent like structure. Wind blown precipitation such as rain or snow may be carried into the interior of the ridge vent  10  through airflow passages  46  but it is stopped from traveling further by the water resistant filtering fabric  34  while air may still pass. Liquid rain or melted snow that accumulates on top of the filtering fabric  34  drains from the ridge vent  10  through the lowermost layer of airflow passages  46  in vent panels  32  onto the roof  12  where it may run off shingles  22 . 
   In the embodiment depicted in  FIGS. 6   a  and  6   b , wind blown precipitation may be carried into airflow passages  46  but is prevented from proceeding further by filtering fabric  34  and may drain back out. 
   Referring to  FIG. 8 , shed roof vent  74  is applied at the top of a shed style roof  74  where it abuts an exterior wall  72 . Flange panel  78  may be bent downwardly and secured to exterior wall  72  by fasteners or adhesive. Alternately, the flange panel  78  may be bent upwardly and secured to the wall  72 . Flashing  80  may be applied on top of the shed roof vent  74 . Vent panels  32  may be nailed or otherwise secured to sheathing  18  through shingles  22 . Any wind blown precipitation that enters the shed roof vent  74  is prevented from entering the space beneath the roof by filtering fabric  34 . Rain or melted snow that accumulates on top of filtering fabric  34  drains from the shed roof vent  74  through the airflow passages  46  in the bottommost vent panel  32 . 
   The present invention may be embodied in other specific forms without departing from the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.