Patent Application
20120233949
Metal roofing systems are often sought for their durability, affordability, and aesthetics. In some cases, metal roofing systems are installed directly on top of a previously finished roof, for example, on top of shingles. Although it is relatively simple to install a metal roofing structure directly on top of a finished roof, problems may arise over time as the roof is exposed to various thermal and environmental conditions. For example, the exposure of the roof to changing temperatures can result in cycles of thermal expansion and contraction of the metal roofing material that can cause the fasteners securing the metal roofing material to the building structure to become loose, particularly when fastened to wood rafters or decking, which have a different thermal expansion coefficient from that of the metal roof. The roof may also be exposed to wind conditions that cause the metal roofing material to be pulled away from the building structure. This may be particularly problematic for residential structures located in coastal areas. Accordingly, it would be desirable to provide a secure metal roofing system suitable for withstanding changing thermal and environmental conditions.
Some or all of the above needs and/or problems may be addressed by certain embodiments of the present application. Disclosed embodiments may include systems and methods for a secure metal roofing system for attachment to a roof structure. The secure metal roofing system may include one or more elongate bars. The elongate bars may include a number of slots spaced apart from one another in a longitudinal direction. Fasteners may be disposed within the respective slots for securing the elongate bars to the roof structure. In this manner, the slots may be sized and shaped to accommodate a difference in thermal expansion between the elongate bars, the fasteners, and the roof structure so as to minimize or prevent the fasteners from backing out of the roof structure due to changes in thermal and/or environmental conditions. The secure metal roofing system may also include one or more roofing panels and a number of fasteners configured to secure the roofing panels to the elongate bars. Further, a moisture barrier may be disposed between the roof structure and the elongate bars and the roofing panels.
Other embodiments, aspects, and features of the invention will become apparent to those skilled in the art from the following detailed description, the accompanying drawings, and the appended claims.
The appended drawings are not necessarily drawn to scale.
Systems and methods for the installation of secure metal roofing systems on building structures, particularly roof structures, are provided. In some embodiments, the roofing system may be installed directly on top of an existing finished roof, for example, on top of shingles. In other embodiments, the secure metal roofing system may be installed on top of an unfinished roof. For example, the secure metal roofing system may be installed on top of a plywood roof structure or any other wood deck structure or may be installed to rafters with proper wood battens void of inside insulation, such as barns, storage buildings, garages, and other non-occupied structures. In certain embodiments, a moisture barrier may be installed between the existing finished or unfinished roof and the secure metal roofing system.
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Generally speaking, the metal roofing system 100 may include one or more elongate bars 108, one or more roofing panels 110, and a moisture barrier 112. The elongate bars 108 may be positioned directly on top of the shingles 104 and oriented generally transverse to the rafters 106. In some embodiments, the elongate bars 108 may be secured directly to each of the rafters 106 at each location where the elongate bars 108 intersect the rafters 106. For example, fasteners 109, such as wood screws, may be used to secure the elongate bars 108 to the surface of the finished roof 102 via the rafters 106. In other embodiments, the elongate bars 108 may be secured directly to the roof deck 113, the rafters 16, or a combination thereof. After the elongate bars 108 have been secured to the rafters 106 and/or roof deck 113, the roofing panels 110 may be secured to the elongate bars 108. For example, fasteners 111, such as metal screws, may be used to secure the roofing panels 110 directly to the elongate bars 108 at locations between the rafters 106. In this manner, the elongate bars 108 may be fastened directly to the surface of the finished roof 102 via the rafters 106 and/or roof deck 113, and the roofing panels 110 may be fastened directly to the elongate bars 108. That is, the elongate bars 108 may be fastened directly to the roof structure using wood screws, and the roofing panels 110 may be fastened directly to the elongate bars 108 using metal screws. Such a configuration is advantageous because the roofing panels 110 and the elongate bars 108 are directly fastened together and generally comprise the same or similar thermal expansion coefficients. In some instances, the roofing panels 110 may be fastened directly to the elongate bars 108 and partially fastened to the rafters 106 and/or roof deck 113.
In some instances, prior to installation of the elongate bars 108 and roofing panels 110, a moisture barrier 112 may be disposed in overlying relation to the surface of the finished roof 102 so as to cover the shingles 104. The moisture barrier 112 may prevent water, such as rain, from penetrating the finished roof 102. The moisture barrier may include any underlayment known in the art, including, but not limited to, polyethylene film or the like.
As depicted in
Still referring to
In certain embodiments, the slots 114 are spaced apart to correspond with the spacing of the rafters 106. In this manner, the slots 114 are used to fasten the elongate bars 108 directly to each of the rafters 106 at each location where the elongate bars 108 intersect the rafters 106. In other embodiments, the roofing panels are not fasted to the slots but instead fastened directly to the elongate bars 108 via, for example, a metal screw.
In certain aspects, the roofing panels and elongate bars may comprise materials having the same or similar coefficients of thermal expansion. In other aspects, the roofing panels and the elongate bars may comprise materials having the same or similar electrode potentials to reduce or prevent galvanic corrosion. For example, the roofing panels and elongate bars may comprise the same material.
The elongate bars may be any type of metal roofing material suitable for installation on a building structure. For example, the elongate bars may comprise rectangular strips of metal. The rectangular strips of metal may include, but are not limited to, galvanized steel, stainless steel, and aluminum. Similarly, the roofing panels may be any type of metal roofing material suitable for installation on a building structure. For example, the roofing panels may comprise sheets of metal. The metal sheets may include corrugations or ridges for increased strength and/or rigidity. The roofing panels may be made of various metals, including, but not limited to, galvanized steel, stainless steel, and aluminum.
As discussed above, the metal roofing system may also include one or more different types of fasteners. For example, the roofing system may employ a first type of fastener for fastening the elongate bars to the roof structure, for example the roof deck or rafters, and a second type of fastener for fastening the roofing panels to the elongate bar extending between the rafters. For example, wood screws may be employed for attaching the elongate bar to the wooden roof structure, and metal screws may be employed for attaching the roofing panels to the elongate bars between the rafters.
It should be noted that in some embodiments the metal roofing system may be made of materials other than metal. For example, the roofing panel and elongate bars may be made of a polymeric or plastic material or a composite material. In such embodiments, the roofing panels and the elongate bars may comprise materials having the same or similar coefficients of thermal expansion. Similarly, the one or more different types of fasteners may be made of materials other than metal.
In certain aspects, the elongate metal bars may comprise a generally rectangular strip of metal. In other aspects, the elongate metal bars may be approximately ⅛ inch thick and approximately 1.5 inches wide. In yet other aspects, the elongate metal bars may be approximately 16, 18, or 20 gauge thick. One will appreciate, however, that the elongate metal bars may be any thickness. In certain embodiments, a plurality of holes or slots may be provided in the elongate metal bars. In this manner, the slots may be employed to accommodate a difference in thermal expansion between the elongate bar, the wood screw, and the wooden rafters of the building structure. For example, the slots may be elongated in the longitudinal direction of the elongate metal bar. In certain embodiments, the slots may be approximately 0.75 inch long. The holes or slots may be separated by spans of about 8 inches. Such a span may advantageously allow the elongate bar to be employed in building structures that employ 16-inch spans between rafters and in building structures that employ 24-inch spans between rafters.
Before installing the metal roofing system, the roof surface may first be prepared for the installation. Generally, this involves removing debris and loose materials from the surface and then, optionally, laying down a moisture barrier underlayment. If the metal roofing system is to replace an existing roof, the existing roof surface (e.g., shingles) may be maintained on the roof or removed.
In certain embodiments, one or more elongate metal bars may then be placed on the shingle roof or deck on top of the moisture barrier underlayment. In an exemplary embodiment, the elongate metal bars extend in a horizontal direction, i.e., generally parallel to the roof line. Each of the elongate bars may then be installed with fasteners, such as wood screws. Each fastener may be placed at locations corresponding to where the elongate bars and rafters intersect so that each fastener extends through the elongate bars, into the roof surface, and into the rafters. For example, wood screws may be fastened into the elongate bars every 16 inches or 24 inches, depending on the distance between the rafters in the roof structure. In some embodiments, the wood screws may pass through preformed holes or slots in the elongate bars.
Metal screws may be employed at intermediate locations between the rafters to fasten the roofing panels to the elongate bars. In this manner, the elongate bars may be fastened directly to the surface of the roof structure via the rafters, and the roofing panels may be fastened directly to the elongate bars. Such a configuration may minimize or prevent the effects of thermal and/or environmental conditions on the metal roofing system.
Although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments.
The present application claims the benefit of U.S. Provisional Patent Application No. 61/452,855, filed Mar. 15, 2011, entitled “SECURE METAL ROOFING SYSTEM,” which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61452855 | Mar 2011 | US |
