The present invention relates to a roof ventilation system, and specifically to venting located at a bottom edge of the roof to allow air flow to a separately provided ridge vent in order to provide a complete ventilation system.
It has been known to ventilate attics under gable roofs by running a vent along the roof ridge. Such vents are created during construction by sizing the uppermost row of sheathing panels to leave an open slot running along the ridge essentially the length of the roof. The slot creates effective heat ventilation by convection flow and suction caused by wind across the roof ridge.
One known ridge vent that has proven to be very successful is described in the inventor's prior U.S. Pat. No. 5,167,579. This roof vent is formed using a non-woven synthetic fiber mat having randomly aligned fibers located over a vent slot at the roof ridge. Cap shingles are then installed over the non-woven synthetic fiber mat. The synthetic fiber mat allows for air flow through the slot at the roof ridge, while preventing the ingress of moisture and debris. Other known ridge vents by the inventor are disclosed in U.S. Pat. No. 8,393,943 and U.S. Patent Application Publication No. 2013/0324030. Each of these references are incorporated herein by reference as if fully set forth.
Soffit ventilators that are used in conjunction with such ridge vents are typically perforated or louvered openings located along the eaves of an overhanging roof. The vents allow fresh ambient air to flow into the attic to equalize attic temperature and pressure with the outside. This equalization inhibits moisture from condensing on insulation and wood roofing materials which causes mildew and rot, prevents build-up of ice dams which could buckle shingles and gutters, and reduces air-conditioning costs when hot attic air is replaced by cooler ambient air.
A soffit ventilation system works in conjunction with a ridge vent to provide passive ventilation. As hot stale air is withdrawn from the ridge slot vent by convection and/or wind suction, it is replaced by fresh ambient air through the soffit vents.
There is, however, a problem in construction with no soffit or a very narrow soffit with no vent openings, or where the use of a soffit vent would adversely affect an exterior appearance of a building. In order to address this, the present inventor had previously proposed a solution as disclosed in U.S. Pat. No. 5,560,157, which is incorporated herein by reference as if fully set forth. In this arrangement, a non-woven strip of material was proposed to be installed behind the fascia board, providing sufficient ventilation with only a small shadow line (less than 1 inch). This solution was not adopted in the industry due to various issues, including difficulty of installation.
It is thus desired to have a roof construction that allows for ventilation and fresh air flow through the attic without the need for a soffit or cutting vent holes into a soffit, and which is easy for a contractor to handle and install.
Briefly stated, a building structure is provided that is adapted to allow for ventilation of vapors from within the structure so as to retard deterioration of the structure. The building structure has a roof extending over one or more vertical side walls. An attic space is enclosed between the roof and an internal ceiling. The roof is constructed on a plurality of parallel rafters. The rafters are supported by a vertical side wall. The roof has a roof sheathing member overlying the roof rafters. A fascia is secured to the outer ends of the roof rafters and at least one portion of the fascia is spaced from the outer ends of the rafters. A fascia vent strip is interposed between the fascia and the outer ends of the rafters to provide for the flow of vapor therebetween and into the attic. The fascia vent strip includes a series of parallel grooves spaced apart at 16″ or 24″ on center. The grooves are adapted to receive the outer ends of the rafters with an interference fit to at least temporarily hold the fascia vent strip to the ends of the rafters during installation. Optionally, an adhesive is provided in each groove.
In another aspect, a building structure is provided that is adapted to allow for ventilation of vapors from within the structure so as to retard deterioration of the structure. The building structure has a roof extending over one or more vertical side walls. An attic space is enclosed between the roof and an internal ceiling. The roof is constructed on a plurality of parallel rafters. The rafters are supported by a vertical side wall. The roof has a roof sheathing member overlying the roof rafters. A fascia is secured to the outer ends of the roof rafters and at least one portion of the fascia is spaced from the outer ends of the rafters. A fascia vent strip is interposed between the fascia and the outer ends of the rafters to provide for the flow of vapor therebetween and into the attic. The fascia vent strip includes a series of parallel glue stripes spaced apart at 16″ and 24″ on center (i.e., 0″, 16″, 24″, 32″, 48″, etc.). The glue stripes are adapted to contact the outer ends of the rafters to at least temporarily hold the fascia vent strip to the ends of the rafters during installation.
The present invention will be explained in more detail in connection with the drawings in which presently preferred embodiments are shown.
Certain terminology is used in the following description for convenience only and is not considered limiting. Words such as “front,” “back,” “top,” and “bottom” designate directions in the drawings to which reference is made. This terminology includes the words specifically noted above, derivatives thereof and words of similar import. Additionally, the terms “a” and “one” are defined as including one or more of the referenced item unless specifically noted.
The preferred embodiments of the present invention will be described with reference to the drawing figures where like numerals represent like elements throughout.
The studs 14 and top plate 16 frame the vertical walls 26. Referring to
A ceiling 38 underlying the ceiling joist 18 divides the interior 32 from an attic 40. A batten-type insulation 28 is preferably laid between the ceiling joists 18. Plywood roof sheathing 42 overlies the roof rafter 20, with roofing paper 44 and shingles 46 or another type of exterior roofing covering sheathing 42. In conventional construction of building structures of this type, the structure has a board or boards secured to the vertical edge 24 of the rafters, called an eave fascia, or simply the fascia 50.
The fascia vent strip 52 is preferably an air permeable resilient strip that is sandwiched between the vertical edge 24 of the roof rafters and the fascia 50 that allows for soffit ventilation of the attic in building structures that have little or no eave, and therefore essentially no soffit area.
The fascia 50 and the fascia vent strip 52 are secured to the rafters by fasteners extending through the fascia 50 and strip 52 into the vertical edge 24 of the roof rafters 20. As seen most clearly in
A rain gutter 54 is secured to the fascia 50, and a drip edge 56 underlies the shingles 46 at the lower outer end of the roof sheathing 42, projecting over the fascia 50 and into the rain gutter 54.
In a preferred embodiment, the fascia vent strip 52 is formed of individual strips that are preferably 3 inches wide and 50 feet long with a thickness of 1 or 1½ inches. The strip 52 can be manufactured in various colors to blend with the fascia 50 and/or the siding 36, and is preferably made of a non-woven air permeable and resilient material made of synthetic fibers (usually nylon or polyester) which are opened and blended, then randomly aligned into a web by an airflow. The web is treated with bonding agents of water-based phenolics and latexes. The treated web is then oven-cured to bind the fabrics into a relatively rigid mat having a significant porous area between these random fibers. U.S. Pat. No. 5,167,579 describes such an air permeable and resilient material or member being used in conjunction with a ridge vent and is incorporated herein by reference.
As shown in
As shown in
The fascia vent strip 52 can be installed on new construction before the fascia 50 is installed, or in renovating a pre-existing building structure by first removing the existing fascia boards 50 from the rafters 20. With the fascia 50 not installed, the lower surface 60 of the air permeable and resilient strip 52 is placed flush with the bottom of the ceiling joist 18 and the horizontal edge 22 of the roof rafters 20 with the strip 52 extending 3 inches upward, and then pressed onto the ends of the rafters 20 so that the grooves 72, and optionally the glue 74, at least temporarily hold the fascia vent strip 52 in position.
With the strip 52 held in place, the fascia 50 is then placed and secured by driving fasteners through the fascia and strip 52 into the vertical edge 24′ of the roof rafters 20. The rain gutter 54 and drip edge 56 are installed in a conventional manner afterwards, with the shape of the drip edge 56 fashioned to conform with the movement outboard of the fascia 50.
Referring now to
The roof rafters 20′ each have a lower outer end 21′ which is cut to form a horizontal edge 22′ and a vertical edge 24′. In conventional construction of this style roof, the soffit 70 underlies and is secured to the horizontal edge 22′ of the roof rafters 20′. The fascia 50′ in this illustration is a metal plate and is secured to the vertical edge 24′ of the roof rafters 20′.
In this embodiment, similar to the first embodiment, the insulation 28′ is located between the ceiling joists 18′ and ends above the top plate 16′. The drip edge 56′ underlies the shingles 46′ at the lower end of the roof sheathing 42′, projects over the fascia 50′ and into the rain gutter 54′.
In this type of structure, a fascia vent strip 52′ is located in proximity to the fascia 50′ in a notch 76 cut in each of the roof rafters 20′. The air enters from the outside through the lower surface 60′ of the air permeable and resilient strip 52′ and flows through the strip 52′ to both the upper surface 62′ and the side surface 64′. Unlike conventional soffit vents where insulation 28′ could fall into the area above the soffit 70 and block the vent, if insulation 28′ falls into the area above the soffit 70 in this invention, the insulation 28′ will not block the ventilation.
The fascia strip 52′ is shown in detail in
Similar to the first embodiment, the fascia vent strip 52′ can be installed on new construction before the fascia 50′ is installed, or in renovating a pre-existing building structure by first removing the existing fascia boards 50′ from the roof rafters 20′.
Each rafter 20′ is cut to form a notch 76 of the same height as the width of the resilient strip 52′ and of the same depth as the thickness of the strip 52′. The strip 52′ is set into the notches 76 is at least temporarily held by the glue stripes or plugs 74′ to the ends of the rafters 20′. The lower surface 60′ of the air permeable and resilient strip is placed flush with the bottom of the ceiling joist 18 and the horizontal edge 22′ of the roof rafters 20′ and extends upward in the notch 76. The fascia 50′ is then placed and secured by driving fasteners through the fascia 50′ and strip 52′ into the vertical edge 24′ of the roof rafters 20′.
In typical renovation, the gutter 54′ and the drip edge 56′ are also removed in order to facilitate the cutting of the notch 76 in the rafters 20′ and then reinstalled.
Those skilled in the art will recognize that the first embodiment of the fascia vent strip 52 could also be used in this application. In this case the notches 76 would not need to be as deep and would be reduced by the depth of the grooves 72.
Referring to
Each of the fascia vent strips 52, 52′, 52″ is preferably made of the non-woven air permeable and resilient material made of synthetic fibers that are opened and blended, and then bonded together, as discussed above. This non-woven air permeable and resilient material has sufficient stiffness to prevent over-compression as the fascia board 50, 50′, 50″ is installed. To the extent that glue is provided on the fascia vent strip 52, 52′, 52″, a release paper can be used on the glue that is removed prior to installation.
While the preferred embodiments of the invention have been described in detail, the invention is not limited to these specific embodiments described above which should be considered as merely exemplary. Further modifications and extensions of the present invention may be developed and all such modifications are deemed to be within the scope of the present invention as defined by the appended claims.
The following documents are incorporated herein by reference as if fully set forth: U.S. Provisional Patent Application No. 62/365,674, filed Jul. 22, 2016.
Number | Date | Country | |
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62365674 | Jul 2016 | US |