Not Applicable.
The present invention relates generally to a system for retrofitting a roof envelope of a building. More particularly, the present invention relates to a system for installing a new roof, formed of new roof decking panels, over an existing roof. Still more particularly, the present invention relates to a clip that enables coupling of a roof subframe system to a span of the new roof decking panels.
Metal roof decking is a building envelope system made from metal decking panels. 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 to form a continuous span. The metal roof decking panels are secured by fasteners to underlying support structures, sometimes referred to as purlins. The metal roof decking panels may also be secured to one another by forming a standing seam at adjacent edges of the roof decking panels.
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 existing roof decking, and then securing 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 roof decking.
In many conventional retrofit roof systems, the new roof system is coupled to the subframe system at discrete locations. For example, the new roof system may include fastener panels coupled by a plurality of fasteners to the subframe system. As another example, the new roof system may include standing seam panels coupled by a combination of fasteners and clips to the roof subframe system. Uplift loads, such as those induced by wind, to the new roof system are resisted by these coupling devices. Thus, the combined cross-section of the coupling devices limits the capacity of the roofing system to withstand uplift loads. Coupling devices located in corner and/or edge zones of the roof envelope may not provide adequate resistance to the uplift loads. This may be because the coupling devices were improperly installed, that there are an insufficient number of them to resist the uplift loads, or a combination of both. Consequently, the coupling devices may fail, allowing a portion of the new roof system to become unattached to the subframe system or removed entirely.
Accordingly, there remains a need for an improved roof system for use in the retrofit of existing roof systems that address certain of the foregoing difficulties. It would be particularly desirable if the roof system enables increased ability of the roof envelope to resist uplift loads and increased thermal efficiency of sheathing ventilation of a building on which the roof system is installed.
Certain of the shortcomings noted above are addressed, at least in part, by a roofing system for retrofitting an existing, or already installed, roof with a new roof and having a coupling member, or clip. In some embodiments, the clip includes a housing adapted for slideable engagement with a subframe coupled to an installed roof panel and a rail adapted to couple with a new roof panel. The housing has a slot extending therethrough. The rail extends through the slot and is slideable relative to the housing within the slot.
In some embodiments, the roof system includes a roof panel installed on a building, a subframe coupled to the roof panel, and the coupling member slideably interlocked with the subframe. Further, in some embodiments, the roof system includes a subframe, the coupling member slideably interlocked with the subframe, and a roof panel supported by the coupling member.
Thus, the embodiments disclosed herein comprise a combination of features and characteristics that are directed to overcoming various shortcomings of prior roofing systems. 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:
The following description is directed to exemplary embodiments of a retrofit roof system. The embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. One skilled in the art will understand that the following description has broad application, and that the discussion is meant only to be exemplary of the described embodiments, and not intended to suggest that the scope of the disclosure, including the claims, is limited only to those embodiments.
Certain terms are used throughout the following description and the claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features and components described herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to. . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, the connection between the first device and the second device may be through a direct connection, or through an indirect connection via other intermediate devices and connections.
Referring now to
Existing roof system 110 includes a plurality of purlin supports 140 supporting a plurality of overlapping, existing roof deck panels 145. Referring to
Roof subframe system 105 includes a plurality of subframes 150. Referring to
Subframe 150 includes a base portion 205 that is spaced apart from two opposing surfaces, first longitudinal flange 210 and second longitudinal flange 215. First and second longitudinal flanges 210, 215 are generally coplanar and oriented in a generally horizontal plane that is parallel to a plane including base 205. Further, flanges 210, 215 are substantially symmetric about the longitudinal axis 220 of subframe 150. A first lip 235 extends from a first edge of first longitudinal flange 210 at an angle 217 extending between interior surfaces of first longitudinal flange 210 and first lip 235, as shown. Similarly, a second lip 240 extends from a first edge of second longitudinal flange 215 at an angle 219 extending between interior surfaces of second longitudinal flange 215 and second lip 240, as also shown. In some embodiments, including those illustrated by
A first wall 225 and a second wall 230 extend vertically downward from a second edge of first longitudinal flange 210 and a second edge of second longitudinal flange 215, respectively. First and second walls 225, 230 are normal to first and second longitudinal flanges 210, 215 in this embodiment. However, in other embodiments, first and second walls 225, 230 may extend from first and second longitudinal flanges 210, 215 in other angular orientations. First and second walls 225, 230 are coupled to and interconnected by base 205. As shown, base 205 is the lowermost portion of subframe 150 and extends horizontally between respective ends of first and second walls 225, 230. In some embodiments, base 205 includes one or more throughbores 250 that enable coupling of subframe 150 to existing roof system 110, as will be described. A channel 245 is formed by first wall 225, base 205, and second wall 230.
A void, or punch out, 255 is created in subframe 150. Punch out 255 extends along a central axis 260 that is generally perpendicular to the longitudinal axis 220 of subframe 150. Punch out 255 passes through corresponding sections of first wall 225, second wall 230, and base 205. Punch out 255 is configured to matingly receive, or fit over, a rib 190 of the existing roof deck panel 145 when subframe 150 is installed over the existing roof deck panel 145, as illustrated in
Referring still to
To couple roof subframe system 105 to existing roof system 110, as shown in
Each clip 125 includes a base 130 and a rail 135 coupled thereto. Referring to
In the illustrated embodiment shown in
As best viewed in
Each end 275 also extends downwardly from top 285. Each end 275 includes a vertical portion 340 coupled between edges of top 280 and bottom 345. A flanged portion 350 extends downwardly from bottom 345 and substantially parallel to sides 270 of base 130. Flanged portion 350 has a width 355 configured to enable insertion of flanged portion 350 within channel 245 of subframe 150 when clip 125 is coupled to roof subframe system 105, as will be described.
Surfaces 335, 330 of sides 270 and bottom 345, including flanged portion 350, bound an interior region 360 of base 130. As illustrated by
Turning now to
Lateral portion 380 has an interior width 390 and an exterior width 392. End portion 387 has a height 395. An interior region 430 is formed between end portion 387, lateral portion 380, and the upper end of vertical portion 375. Vertical portion 375 has an interior height 377.
Cross-section 370 of rail 135 is configured to enable rail 135 to be received through punch outs 295 of base 130 of clip 125 and extend through slot 285 of base 130, as shown in
When rail 135 is inserted through punch outs 295 and slot 285 of base 130, as illustrated by
Length 365 of rail 135 is selected to enable continuous coupling of clip 125 to new roof system 115, as will be described. In some embodiments, length 365 is selected to enable rail 135 to extend between two adjacent clips 125 spaced some distance apart, as illustrated by
Referring next to
New roof system 115 includes a plurality of overlapping, new roof deck panels 425. Turning finally to
Still referring to
In the illustrated embodiment of new roof deck panel 425, edge portion 440 has a vertical portion 460 extending upward from base portion 435, and a lip 465 extending laterally therefrom. Lip 465 has a width 470, and vertical portion 460 has a height 462. Edge portion 445 has a vertical portion 475 extending upward from base 435, a lateral portion 480 extending therefrom, and a lip 485 extending downward from lateral portion 480 along its edge distal vertical portion 475. Lip 485, lateral portion 480, and the upper end of vertical portion 475 bound interior region 450. Lip 485 has a height 490, and lateral portion 480 has a width 495.
Each rail 135 is configured such that interior width 390 (
Once so positioned, as illustrated in
Thus, in accordance with the principles disclosed herein, rails 135 of clips 125 are configured to enable edge portions 440, 445 of adjacent new roof panel deck panels 425 to be inserted within and over, respectively, rails 135, as illustrated by
The embodiment of new roof deck panel 425 described and illustrated with reference to
Returning to
Consequently, when new roof system 115 displaces, for example, due to thermal expansion or contraction of new roof deck panels 425 in response to changing ambient temperature and/or radiant loads, new roof system 115 is permitted limited displacement relative to subframe system 105 and existing roof system 110, while remaining coupled thereto. Enabling limited displacement of new roof system 115 in this manner reduces stresses levels to new roof system 115, roof subframe system 105, and the coupling between the two, namely clips 125. Reduced stresses, in turn, enable reduced fatigue damage to and longer service life of the affected components.
In many conventional retrofit roof systems, the new roof system is coupled to the roof subframe system at discrete locations, for example, by a plurality of clips and/or fasteners. Uplift loads to the new roof system are resisted by these clips and fasteners. Thus, the combined cross-section of the clips and fasteners limits the capacity of the roofing system to withstand uplift loads.
In contrast, uplift loads to new roof system 115 of retrofit roof system 100 are resisted by clips 125, which provide a significantly broader cross-section than that of conventional fasteners. First, the coupling between new roof system 115 and rails 135 of clips 125 is continuous across the span of roofing system 100, rather than discrete. Second, when rails 135 are pulled vertically relative to bases 130, loads to rails 135 are resisted by bases 130 over the engagement area between lateral portions 380 of rails 135 and tops 280 of bases 130. Third, roof subframe system 105 resists load from bases 130 over the continuous engagement area between lips 235, 240 of subframes 150 and angled portions 320 and vertical portions 315 of bases 130. Thus, the cross-section of the coupling between new roof system 115 and roof subframe system 105 is significantly broader than that of conventional roofing systems. Hence, uplift loads are distributed across greater area, thereby enabling clips 125, and therefore retrofit roof system 100, to withstand higher uplift loads, as compared to their conventional counterparts.
Additionally, coupling new roof system 115 to roof subframe system 105 via clips 125 provides gap 160 therebetween. The width of gap 160 is controlled by the dimensioning of clips 125, in particular bases 130 of clips 125. Preferably, bases 130 of clips 125 are sized such that gap 160 is up to four inches in width. In some embodiments, however, gap 160 may be in excess of four inches deep.
Retrofit roof system 100 enables air to pass through gap 160 between new roof system 115 and existing roof system 110. In hot environments, such air flow enables removal of a portion of the heat transferred from the surrounding environment through new roof system 115, thereby eliminating the transfer of that heat through existing roof system 110 into the interior of a building coupled thereto. This enables the building interior to remain cooler. In cold environments, the opposite is true. Thus, gap 160 enables improved thermal efficiency of the building upon which retrofit roof system 100 is installed.
In embodiments of retrofit roof system 100 having support bridging panels 170, such panels 170 provide structural support to new roofing system 115. This enables new roofing system 115 to resist loads and prevent accompanying damage from, for example, snow, ice, fallen tree branches, and human traffic during installation. Further, panels 170 restrain insulation 175, if present, and prevent insulation 175 from expanding into gap 160, where insulation 175 may impede air flow.
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.
This application claims benefit of U.S. Provisional Application Serial No. 61/173,848 filed on Apr. 29, 2009, and entitled “Retrofit Roof System and a Clip Therefor,” which is hereby incorporated herein by reference in its entirety for all purposes
Number | Date | Country | |
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61173848 | Apr 2009 | US |