Patent Application
20220162857
This invention relates to a wood or cellulosic structural or roof sheathing panel with rigid foam insulation with ventilation channels.
Current roof assemblies are typically multiple layers of several materials, each performing a single function, that are installed separately on the site in which the building is being constructed. In many roofing systems, there is a deck, an underlayment barrier on top of the deck, covered by a surface layer of shingles (e.g., asphalt, ceramic, metal, and the like). Compatibility between the various layers creates challenges not only for the designer, but also for the installers. In addition, a varied and large amount of materials are required during the installation, as well as during maintenance (e.g., re-roofing).
A central layer in most such assembles in a wood panel product, or an integral composite engineered panel product, including, but not limited to, engineered wood composite products formed of lignocellulosic strands or wafers (sometimes referred to as oriented-strand board, or OSB). Products such as fiberboard and particleboard have been found to be acceptable alternatives in most cases to natural wood paneling, sheathing and decking lumber. Fiberboard and particleboard are produced from wood particles bonded together by an adhesive, the adhesive being selected according to the intended use of and the properties desired for the lumber. Often times, the adhesive is combined with other additives to impart additional properties to the lumber. Additives can include, but are not limited to, fire retardants, insect repellants, moisture resistant substances, fungicides and fungal resistant substances, and color dyes. A significant advantage of fiberboard and particleboard lumber products is that they have many of the properties of plywood, but can be made from lower grade wood species and waste from other wood product production, and can be formed into lumber in lengths and widths independent of size of the harvested timber.
A major reason for increased presence in the marketplace of the above-described product alternatives to natural solid wood lumber is that these materials exhibit properties like those of the equivalent natural solid wood lumber, especially, the properties of retaining strength, durability, stability and finish under exposure to expected environmental and use conditions. A class of alternative products are multilayer oriented wood strand particleboards, particularly those with a layer-to-layer oriented strand pattern, such as OSB. Oriented, multilayer wood strand boards are composed of several layers of thin wood strands, which are wood particles having a length which is several times greater than their width. These strands are formed by slicing larger wood pieces so that the fiber elements in the strands are substantially parallel to the strand length. The strands in each layer are positioned relative to each other with their length in substantial parallel orientation and extending in a direction approaching a line which is parallel to one edge of the layer. The layers are positioned relative to each other with the oriented strands of adjacent layers perpendicular, forming a layer-to-layer cross-oriented strand pattern. Oriented, multilayer wood strand boards of the above-described type, and examples of processes for pressing and production thereof, are described in detail in U.S. Pat. Nos. 3,164,511, 4,364,984, 5,435,976, 5,470,631, 5,525,394, 5,718,786, and 6,461,743, all of which are incorporated herein in their entireties by specific reference for all purposes.
Roof ventilation is an important part of the building process and service life of a house. A roof without good airflow can result in mold and other wood decay organisms growing under it, due to the increased temperature and moisture content of the environment in the area under the roof, which generates optimal growth conditions for the aforementioned organisms. In contrast, however, a roof with excessive ventilation can cause energy loss by not providing effective temperature regulation (i.e., by letting too much cold and/or hot air escape from the house), thus requiring HVAC and/or AC systems to operate more frequently and increase their energy consumption.
Present methods to ventilate the roof include leaving a gap between the roof sheathing and the edge of the ridge. This gap is then covered with a felt fabric and a ridge cap (some products have the felt integrated with the ridge cap). The ridge cap might have channels to promote air movement. Another method comprises the installers cutting rectangle shaped sections (i.e., exhaust vents) at the ridge of the roof, then covering them with felt and a ridge cap. This latter method relies on the accuracy and experience of the roofer, as the size of the cut off will affect the roof ventilation.
In various exemplary embodiments, as seen in
A plurality of parallel air channels extend vertically in the rigid foam insulation sheet, providing a pathway for air to pass up and out of the eave space. In one exemplary embodiment, some or all of the air channels are disposed on the surface of the foam layer that is laminated or attached to the panel's inner face, so that part of the air channel is formed at the interface. In this configuration, the upper part of the air channel is formed by the inner face of the panel.
In several embodiments, the base or core panel comprises an oriented strand board (OSB) or other manufactured wood panel. The panel may be of any size suitable for the roofing installation, and a common size is 4 feet wide by 8 feet long, with a thickness ranging from ⅜″ to 19/32″. The rigid foam insulation panel comprises expanded polystyrene (EPS), extruded polystyrene (XPS), graphite polystyrene (GPS), or polyisocyanurate (Poly-Iso), or other rigid foam insulation, with air channels carved or formed in the foam layer upper surface (i.e., the surface that interfaces with the inner or lower face of the panel). The air channels generally extend in an upward direction (i.e., from the eaves to the crown of the roof).
In various exemplary embodiments, as seen in
A plurality of parallel air channels 22 extend vertically in the rigid foam insulation sheet, providing a pathway for air to pass up and out of the eave space 8. In one exemplary embodiment, some or all of the air channels 22 are disposed on the surface of the foam layer that is laminated or attached to the panel's inner face, so that part of the air channel is formed at the interface. In this configuration, the upper part of the air channel is formed by the inner face of the panel.
In several embodiments, the base or core panel 10 comprises an oriented strand board (OSB) or other manufactured wood panel. The panel may be of any size suitable for the roofing installation, and a common size is 4 feet wide by 8 feet long, with a thickness ranging from ⅜″ to 19/32″. The rigid foam insulation panel 20 comprises expanded polystyrene (EPS), extruded polystyrene (XPS), graphite polystyrene (GPS), or polyisocyanurate (Poly-Iso), or other rigid foam insulation, with air channels 22 carved or formed in the foam layer upper surface (i.e., the surface that interfaces with the inner or lower face of the panel). The air channels generally extend in an upward direction (i.e., from the eaves to the crown of the roof). In the embodiment with 4×8 panels, the 4-foot edge is the side that extend upward, so the air channels are parallel, or generally parallel, with the 4-foot side of the of the panel.
The integrated roofing product (panels with foam insulation layer, and possibly with a radiant barrier layer, as described below) are installed across support or roof rafters such that the 8-foot edge is perpendicular to these supports. In general, the first course of panels is installed along the bottom edge of the roof along the eave, with subsequent panels installed in an offset pattern (similar to bricks) to provide stability to the roof system. The base form of the integrated roofing product has one or more channels (four channels are shown in
Once the entire roof has been sheathed, facial openings 28 may be cut into the foam layers at the area of the bottommost panels that extend over the eave, allowing air to travel up from the ventilated eave space into the air channels, through the sheathing to the ridge vent, and thence out into the open atmosphere. In some embodiments, the openings may be pre-formed or pre-cut at the factory during the manufacturing process, so that products with the facial openings may be installed as the bottommost panel row without the need to do so at the site.
In several exemplary embodiments, a radiant barrier (RB) layer 50 (typically a form of metallic foil) may be used in the present invention. In one embodiment, the RB may be attached to the inner surface of the foam insulation layer (i.e., opposite the sheathing panel), which is the side of the foam facing into the attic space, as seen in
The present invention helps reduce attic temperatures in warm climates, while also providing additional air flow through the roofing system to cool the exterior roofing materials and thereby extend their life. Greater ventilation through attic spaces also facilitates faster drying and reduces the risk of moisture buildup and its resulting problems.
The present invention possesses several advantages over prior art roof insulation systems such as that disclosed in Dysart, U.S. Pub. No. 2018/0087280 (application Ser. No. 15/330,278), which is incorporated herein by specific reference for all purposes. The present invention is manufactured as an integrated product at a factory, with the foam insulation layer laminated or attached to the inner side of the base/core panel. The combined product thus, in several embodiments, may act as the roof deck, with the inner face of the foam insulation layer (opposite the base/core panel) facing the attic space, and possibly exposed thereto. The foam insulation layer is not placed over the top of the roof deck, as described in Dysart. Further, when used with a radiant barrier on the inner face of the foam insulation layer, the radiant barrier is then exposed to the open air space in the attic, as necessary for proper function of a radiant barrier. That is, the inner face of the radiant barrier is not covered by another layer. Radiant barriers function by reducing heat transfer by radiation (as opposed to conduction and convection), and thus the radiant barrier must face an air space to function properly as radiation moves through space. A radiant barrier that is sandwiched between two panels or solid surfaces will simply conduct heat, and cannot act as a radiant barrier.
The present invention also can be configured so that the radiant barrier is on the inner face of the base/core panel, with exposure to the open air space formed by the air channels. In this configuration the radiant barrier is still on the inner side of the base/core panel, and thus continues to be located on the underside of the base/core panel. This is in sharp contrast to Dysart where the radiant barrier is located on the upper/outer side of the roof decking layer.
Thus, it should be understood that the embodiments and examples described herein have been chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited for particular uses contemplated. Even though specific embodiments of this invention have been described, they are not to be taken as exhaustive. There are several variations that will be apparent to those skilled in the art.
This application claims benefit of and priority to U.S. Provisional App. No. 63/117,513, filed Nov. 24, 2020, which is incorporated herein in its entirety by specific reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63117513 | Nov 2020 | US |
