Patent Application
20080163573
Not Applicable.
1. Field of Art
The present invention relates generally to a system and method for retrofitting a roof envelope of a building. More particularly, the present invention relates to a system and method for installing a new metal roof over an existing metal roof. Still more particularly, the present invention relates to a roll formed metal roof subframe system which enables installation of a span of new metal roof decking panels over a span of existing metal roof decking panels.
2. Description of Related Art
Metal roof decking is a building envelope system made from metal decking panels or sections. Each metal decking panel is secured by fasteners to the support structure (typically made of steel) of the building on which the roof is located Metal roof decking is inherently strong and lightweight, and thus offers several advantages over other types of roofing (i.e., asphalt shingles, etc.), such as increased durability, energy efficiency, resistance to weather damage, and ease of installation, as well as being comparatively economical and having low maintenance requirements. Also, metal roof decking may be designed for use with pitched, flat, or arched construction, and may be applied to nearly all types of buildings.
Standing seam metal roofs are also popular on virtually all types of buildings due to their weather-tightness, durability, and flexible design. Additionally, standing seam metal roofs are more energy efficient and cost effective than many non-metal counterparts, and have an additional desired characteristic of allowing for thermal movement within the roof system.
Metal roof decking products have a number of shapes, materials, and aesthetic variations that can be used in constructing roof decking for buildings. One common type of metal roof decking is known as a fluted, or ribbed, roof decking. Ribbed metal roof decking includes a plurality of ribbed metal roof decking panels, each panel characterized by a sequence of alternating upper and lower surfaces that extend the length of the panel. The upper surfaces, or ribs, are found substantially in an upper plane, and are substantially parallel to each other. Likewise, the lower surfaces, or valleys, are found substantially in a lower plane, one that is generally parallel to and spaced vertically apart from the upper plane. The upper and lower surfaces are connected by a series of vertical or sloped walls which also extend the length of the panel. The upper, lower and vertical or sloped walls define flutes, or channels. When installed to form metal roof decking, the ribbed metal roof decking panels typically overlap one another, and span over and are secured by fasteners to underlying support structures, sometimes referred to as purlins. In this configuration, the ribbed metal roof decking panels are connected to form a continuous span to create the roof envelope of a building.
For various reasons, the metal roof decking of a building, in part or whole, may be in need of repair, replacement, upgrade, or a general retrofit. Due to the lightweight qualities of some metal roof decking, an existing roof may be retrofit by installing a system of subframes over the original roof decking, and securing the new roof decking to the subframe system. The use of subframe systems in this manner provides additional support and points of attachment for the new metal roof decking panels. In some instances, however, conventional subframe systems cannot be used to transition from an older roof configuration in need of retrofit to a new metal roof decking that complies with new construction practices and roof uplift requirements. Additionally, conventional subframe systems may not provide the necessary strength over a long roof span, and may require inefficient production and time-consuming installation processes.
Accordingly, there remains a need for new and improved metal roof subframing systems for use in the retrofit of metal roof decking that address certain of the foregoing difficulties.
Certain of the shortcomings noted above are addressed, at least in part, by a subframe. In embodiments, the subframe includes an elongate base portion, a first wall extending between the portion and a first longitudinal flange, a second wall spaced apart from the first wall and ng between the base and a second longitudinal flange, and a punch out passing traversely the base, the first wall and the second wall.
Some roof system embodiments include a first roof panel, a second roof panel and a subframe therebetween. The first roof panel is supported by a support member and has at least one raised rib. The subframe positioned between the first roof panel and the second roof panel. The punch out of the subframe matingly receives the raised rib of the first roof panel, with the upper surface of the subframe engaging and supporting the second roof panel.
Some embodiments of a subframing system include a deflection limiter of a given length configured to overlay a first rib of a first roof. The deflection limiter includes a first foot extending from a first angled wall, a second foot extending from a second angled wall, and a rib wall coupled between the first angled wall and the second angled wall. The subframing system also includes a first subframe member generally disposed normal to the length of the deflection limiter and configured to couple to the deflection limiter.
Some roof system embodiments include a first roof on a building. The first roof has a first roof panel having a plurality of parallel ribs and supported by a support member. The roof system embodiments also include a second roof panel, a deflection limiter overlaying a first rib of the first roof panel and extending in a direction parallel to the ribs, and a first subframe member engaging the deflection member. A first punch out of the first subframe member receives the rib of the deflection limiter and a second punch out of the first subframe member receives the rib of the first roof panel.
Some methods include positioning a first subframe member over a rib of a first roof, coupling the first subframe member to a support member of the first roof, overlaying a second roof on the first subframe member, and coupling the first subframe member to the second roof. These methods may also include positioning a deflection limiter over a rib of the first roof, positioning a second subframe over the deflection limiter and substantially at a right angle to the deflector limiter, coupling the second subframe to the deflection limiter and the deflection limiter to the support member, overlaying the second roof on the second subframe, and coupling the second subframe to the second roof. The first subframe is substantially identical to the second subframe.
Thus, the embodiments disclosed herein comprise a combination of features and characteristics that are directed to overcoming various shortcomings of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
For a more detailed description of the preferred embodiment of the present invention, reference will be made to the accompanying drawings, wherein:
In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, certain embodiments of, the present invention, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to these embodiments illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results.
Referring now to
First and second walls 106, 108 are coupled to and interconnected by base 107. As shown, base 107 is the lowermost portion of subframe 100 and extends horizontally between respective ends of first and second walls 106, 108. Channel 10 is formed by first wall 106, base 107, and second wall 108. A void, or punch out 109, is created in subframe 100. Punch out 109 extends along a central axis “C” that is generally perpendicular to the longitudinal axis “I,” of subframe 100. Punch out 109 passes through corresponding sections of first wall 106, second wall 108, and base 107. When subframe 100 is installed over an existing roof panel, punch out 109 is configured to matingly receive or fit over a rib of the existing roof panel. In the embodiment shown in
Subframe 100 may be created by a rollformed manufacturing process. With this process, the length of subframe 100 can easily be controlled and tailored to the desired span of existing metal roof decking to be retrofit. Moreover, with rollformed manufacturing, any length of subframe 100 is obtainable, allowing subframe 100 to be used on any span of existing roof decking.
To couple subframe 100 to the existing roof system 200, subframe 100 is positioned over a section 220 in alignment with a purlin support 210 such that longitudinal flanges 102, 104 extend generally perpendicular to the direction of ribs 230 of existing roof system 200. When aligned with purlin support 210, base 107 of subframe 100 rests on valley 240 of existing roof section 220 with punch out 109 positioned over a rib 230, Fasteners 300 are then inserted through base 107 and valley 240 and into purlin support 210 at intervals along the length of subframe 100 to couple subframe 100 to top flange 212 of purlin support 210. In some embodiments, the respective heights of subframe 100 and ribs 230 may be chosen such that first and second lips 103, 105 extend so as to rest in contact with an upper surface of ribs 230, as shown in
After subframe 100 is secured to a purlin support 210 of an existing roof system 200, retrofit of the roof may proceed by installing new roof decking panels or sections over subframe members 100 and above the existing roof system 200, Referring to
When subframe 100 is coupled to new roof deck section 400, channel 110 of subframe 100 is enclosed by first wall 106, base 107, and second wall 108 of subframe 100 and by new roof deck section 400. Thus, the coupling of new roof deck section 400 to subframe 100 creates an enclosed, self-supporting tubular structure that has greater structural capacity and stability in comparison to other structures which are not self-supporting, such as a subframe member having only a single support wall coupled between the old roof and a new roof deck section 400. As used herein, “self-supporting” is used to describe a subframe support member that, in end view or cross-section, has a channel or trough that, once closed by attachment to new roof sections 400, forms a closed conduit or tubular structure, regardless of the cross-sectional shape of the conduit. Moreover, in embodiments, including those depicted by
The self-supporting structure formed by subframe 100 and new roof deck section 400 allows subframe 100, specifically first and second walls 106, 108 and base 107, to better support the weight of new roof deck section 400, as well as other loads applied to section 400, such as the weight of accumulated snow. Moreover, torque applied to new roof sections 400, by, for example, wind loads, is reacted in both first and second walls 106, 108 of subframe 100 and (in the embodiments depicted by
Buildings located in some geographical regions, such as coastal areas, experience high wind loads. For this reason, buildings in these regions may be required to satisfy more stringent design standards. This may necessitate roofs constructed prior to the adoption of the stringent design standards to be retrofit in compliance with the newer standards. For instance, in metal roofs constructed using one common construction practice, the main supporting structural members are typically placed at 5 feet on center throughout the building roof span. New constructions practices and uplift requirements, particularly in geographic regions experiencing high wind loads, such as coastal regions, may now require much closer spacing than 5 feet over some or all of the roof envelope. To enable compliance with new construction practices and uplift requirements, the retrofit of an existing roof system 200, as described above, may be supplemented with the installation of a plurality of structural members that are positioned between the existing roof panels and the subframe members 100. These structural members, referred to herein as deflection limiters, are positioned over existing roof system 200 such that the combination of the deflection limiters and subframes 100 forms a support structure for a new roof system 400 that satisfies the spacing requirement dictated by the new construction practices and uplift requirements.
In more detail and referring now to
A new roof system 400 may be retrofit to existing roof system 200 using a support structure formed by a plurality of deflection limiters 500 and subframes 100 such that the support structure conforms to new construction practices and satisfies new uplift requirements. In some embodiments, retrofit of new roof system 400 to existing roof system 200 proceeds as follows.
The roof envelope 600 of existing roof system 200 is conventionally known to be divided into two zones, an edge zone 605 and a field zone 610, as shown in
First, a plurality of subframes 100 are installed within field zone 610. Each subframe 100 is installed using methodology previously described with reference to
Next, a plurality of deflection limiters 500 and subframes 100 are installed within edge zone 605. Each deflection limiter 500 is positioned over a rib 230 of existing roof section 220 within edge zone 605, as shown in
A subframe 100 is then positioned across at least some deflection limiters 500 such that subframe 100 is normal to deflection limiters 500, and such that punch out 109 of subframe 100 receives deflection limiters 500, as shown in
Alternatively, it may be desirable, or new construction practices and uplift requirements may dictate, that the support structure of new roof system 400 has smaller spacing 620 in regions in addition to edge zone 605, for example, throughout the entire roof envelope 600. Therefore, in other embodiments, a plurality of deflection limiters 500 and subframes 100 are installed, as described above, within both edge zone 605 and field zone 610. In this manner, an enhanced support structure meeting the new spacing requirement 620, as shown in
The systems and methods for a subframing system having a plurality of subframes 100 disclosed herein enable retrofit of an existing roof with new roof. Due to the nature of its design, the subframing system is, in many instances, independent of the existing roof configuration, and thus may accommodate a large number of existing roof configurations. The subframing systems described herein also offer increased structural capacity and stability over that of certain conventional subframing systems. Where new construction practices and uplift requirements necessitate a new roof having a support structure with spacing less than that of roofs built using conventional construction practices, the subframing system may be supplemented using a plurality of deflection limiters 500 and subframes 100. The deflection limiters 500 may be positioned only within certain regions of a roof envelope, such as within the edge zone, or throughout the roof envelope, depending on the uplift requirements, to further enhance the structural capacity and stability of the new roof.
While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching herein. The embodiments described herein are exemplary only and are not limiting. It will be appreciated that many other modifications and improvements to the disclosed embodiments may be made without departing from the inventive concepts herein disclosed. Because many varying and different embodiments may be made within the scope of the present inventive concept, including equivalent structures or materials hereafter thought of, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.
The present application claims the benefit of, and incorporates by reference, provisional application Ser. No. 60/878,559, filed Jan. 4, 2007, and entitled “Roof Runner Subframe System.”
| Number | Date | Country | |
|---|---|---|---|
| 60878559 | Jan 2007 | US |
