1. Field of the Invention
The present invention relates to a roof assembly for a building structure, and more particularly, but not by way of limitation, to roof assembly improvements providing greater load bearing and water tightness capabilities.
2. Discussion
Numerous types of roof assemblies have been proposed for pre-engineered buildings to provide adequate load resistance and watertightness, while expanding and contracting to accommodate variations in weather conditions. Typical of such roof assemblies, the standing seam roof assembly has become popular in recent years.
The panel members of a standing seam roof assembly are joined along lapped together side edges forming the standing seams and are secured to secondary structural members either by fasteners, such as screws, that extend through the panels (often referred to as ‘through fasteners’), or by clips. Through fasteners, when used, extend through flat portions of the panels to attach to the underlying support structure to substantially lock the panels and support structure together, limiting differential movement between the panels and support structure. Clips used with standing seam roof assemblies connect to the panel edges and are either floating (one or two piece moveable) or fixed (single piece with no movement allowed between the panel and the supporting structure).
Roofs are generally classified either as shed roofs or low slope gasket roofs. Shed roofs are designed to shed water by gravity pulling the water down and away from panel joints more effectively than wind or capillary action propel water through the joints, and such roofs generally have slopes of three to twelve or greater. Gasket roofs, on the other hand, are generally low sloped and have roof joints that are made watertight by sealant material in the panel joints. Securing the sealant material in place is accomplished, for example, by encapsulating or by exerting pressure on a gasket material, such as by seaming. Generally, low slope gasket roofs have slopes as low as one quarter to twelve.
Heretofore, field seamed gasket joints in large roofs have generally been limited to two-piece clips in which movement between the roof and the underlying structure occurred within the clip. The reason for this is that, in the past, the top hook portion of the clip intersected the gasket sealant, and if the clip hook moved in relation to the panel which held the sealant, the movement of the clip hook deformed and destroyed the gasket seal. Single piece clips have been used freely in shed roofs where gasket sealing is not required.
Standing seam metal roof panels exhibit considerable diaphragm strength, and it is desirable to use this strength by interconnecting the panels side to side so that adjacent panels do not slide relative to each other; further, the panels are connected to the support frame to stabilize the support frame, rather than bracing and stabilizing the support frame by other means. In the past, stabilization of the support frame has been achieved by means of separate bracing. On gasket roofs, two-piece floating (moveable) clips, in some instances, have been used to permit the brace and frame to remain fixed while permitting panel movement relative to the frame, such as due to temperature and other gradients. Alternatively, when fixed clips are used, the length of the panel run is limited to about 40 feet so that the expansion and contraction of the panel does not damage the connections to the underlying support structure.
The desirable result of eliminating detrimental differential movement between the panels of the roof assembly and the support structure on large roofs can also be achieved by constructing the underlying support structure with the capability to move slightly to accommodate expansion and contraction of the roof assembly. One means of achieving this is exemplified by the Flex Frame™ support system produced by ReRoof America, Inc. of Tulsa, Okla.
The interconnected panel members of a standing seam roof assembly lend stiffness and strength to a flexible roof structure, while allowing the roof structure to expand and contract as a function of the coefficient of expansion of the panel material and the temperature cycles of the roof panels.
If floating clips or flexible framing are not used, the repeated action of expansion and contraction of the panel member will, in time, weaken the panel-to-panel lap joints and the panel to framing connection, causing separation, structural failure and roof leakage. Leaks are generally caused by the weakening of the fastening members and working or kneading of the sealant disposed at the joints. Thus, prior art sealants for standing seam roof assemblies have required the qualities of adhesion, flexibility and water repellence. Further, in many instances the pressure on the sealant can vary greatly throughout the length of the panel sidelap and end lap joints, resulting in uneven distribution and voids in the joint sealant.
Many problems encountered with prior art standing seam roofs, such as structural failures and leaks, are overcome by the standing seam floating roof assembly taught by U.S. Pat. No. 5,737,894 issued to Harold G. Simpson. Adjacently disposed panels are joined by interlocking female and male sidelap members to form a standing seam assembly, or joint, and clips connect the standing seam joints to underlying building support structure, with upper portions of the clips hooked over the male sidelap members and the lower portions attached to the underlying building supporting structure, such as a purlin or joist.
Floating clips of the sliding type permit clip hook portions to move relative to clip base portions connected to the underlying building supporting structure, while the clip hook portions are secured to the panel sidelaps. A sealant material is positioned between the interlocking joints of interlocked female and male sidelap portions of the panels, forming a sealant dam to make the joints watertight.
In addition to new construction, standing seam roof assemblies are also finding increased usage in another segment of the roofing industry, the replacement of built-up roofs. Generally, a built-up roof is formed of a plurality of interconnected sections that are sealed by a watertight over-coat of asphaltic composition. Built-up roofs have generally performed well, but problems occur with age, with building settlement and with standing water pockets resulting from construction errors. Standing water causes roof deterioration, resulting in leaks and other problems.
A need has long existed for replacing a roof without making substantial modifications to the existing roof. In addition to economy of fabrication and ease of on-site construction, it is desirable that a newly erected roof assembly present a new roof surface independent of the variations in the surface of the preexisting roof Past roof replacements, especially those capable of altering the roof slope to improve drainage, are excessively time consuming and require both substantial destruction of the original roof and extensive custom construction, exposing the building and its contents to damage by the elements roof replacement.
The process of manufacturing standing seam panels results in dimensional variations occurring in such panels, and this is especially of concern when the width of the panels vary significantly beyond specified tolerance limits. Since the edges of the panels that form the male and female sidelaps are interconnected and mechanically joined, the standing seams of interlocked adjacent roof panels must accommodate panel width variations. This is especially true when the width dimension of panels exceed the specified maximum permitted width, as the excess material can cause difficulty in joint formation. That is, when the edge of the panels extend beyond the design specification, the extra long leg components of a sidelap in the standing seam can interfere with uniform joint closure and sealing, resulting in poor quality seams.
In addition to the other deficiencies of the prior art mentioned above, there is a need for accommodation of dimensional variations of roof panels used to form standing seam roof assemblies.
The present invention provides a standing seam roof assembly in which adjacent roof panels are supported by underlying support structure in overlapping edge relationship to form a standing seam between adjacent roof panels. The assembly comprises a first roof panel having a female sidelap portion that forms a male insertion cavity and a second roof panel having a male sidelap portion engagable in the male that forms a standing seam assembly when the male sidelap portion is inserted into the female insertion cavity to form the standing seam assembly. Restraining means are provided to prevent relative in-plane movement between the first and second sidelaps, including connecting a selected ones of the male and female leg members to prevent in-plane movement there between.
In a preferred embodiment, the female sidelap has a hook portion forming a female retaining groove and the male sidelap has a male tab member. In the assembled mode, the male tab member is disposed in the female retaining groove, and the female and male sidelaps are folded or seamed so a hook portion of the female sidelap and the male tab member are tightly brought into adjacency to form the standing seam between the first and second panels.
The objects, features and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the drawings and appended claims.
The embodiments of the present invention will be described with reference to the drawing figures that are included herewith, and certain terminology will be utilized insofar as practical and consistent with that which is familiar to those skilled in the pre-engineering building industry.
Whether in a new roof installation, or in a reroof installation, the roof panels of a standing seam metal roof are secured at the interlocking sidelap joints and at the end overlap of contiguous panels. Fastener penetration of the roof panels, except at the end overlaps and roof perimeters, is avoided to minimize leakage points. To maintain water tightness at points of attachment to underlying structure, the roof panels are permitted to expand and contract in relation to the underlying structure, or the roof panels and the underlying structures must be permitted to move in unison without unduly straining or fracturing the panels. This can be accomplished by limiting the length of the roof panels, or by utilizing support structures sufficiently flexible to allow the attachment means to move with the expansion and contraction of the panels. The flexibility of the support structurals must be greater for longer panel runs because, other factors being equal, the expansion and contraction of the panels will be greater.
Past practice has been common for non-penetrating fasteners to use either a fixed or a sliding clip with a minimum length contact surface between the hold-down portion of the clip and the top of the male leg of the seam. The length of the clip has been held to a minimum, resulting in stress concentrations in the panel at the point of attachment, leading to severe distortion in the panel joints as the panels are subjected to wind uplift.
In conventional standing seams, the standing seam clips engage the male sidelap portions, and the female sidelap portions are field clamped over the male sidelap portions and the clips; thus, the load transferred from the female sidelap portions must pass through the male sidelap portions to the clips where the load, in turn, passes to the building support structures. In this arrangement, there is a tendency for the panel joints to unravel, or unzip, leading to distortions over the short panel portions retained by the clips, potentially resulting in premature panel failure from wind uplift.
A roof panel is usually attached to the underlying building structurals in a manner that causes the roof panel to act as a three or four span continuous beam. This arrangement substantially reduces the maximum moment occurring at any one point compared to the moment that would occur in a simple beam, other factors being equal. However, this can cause a negative moment to occur at the attachment point. This negative moment peaks and drops off very quickly as the panel section moves from the center line of the attaching clips toward the point of inflection (P.I.), the P.I. being where the moment in the panel changes from positive to negative. This being the case, it is advantageous to reinforce the panel corrugations for a major portion of the distance from the point of support to the P.I., because the small amount of material required to reinforce this short distance is more than compensated for by the increased overall strength of the panel.
Past center hold-down practice has been to coordinate usage of floating clips with eave and ridge hold-down means so that, if floating clips are used to attach the center of the panel to the building structural, then fixed clips are used to attach the eave or ridge portions of the panel to the underlying structural. Conversely, if the panel edge attachment consists of floating, (two-piece, moveable) non-penetrating attachment means, such as clips, then the center hold-down is fixed. Even so, non-penetrating floating hold-down devices have heretofore been largely complex and expensive.
The effectiveness of non-penetrating center hold-down devices is influenced by the number and height of corrugations formed in the panel, and by the width, thickness and strength of the metal laterally separating the corrugations. The configuration and number of panel corrugations in turn has a direct impact on the efficiency of material utilization, which is a primary cost factor. Conventional standing seam roofs may only achieve a flat-width-to-coverage ratio as low as 1.25:1 where through fasteners exist only at panel end laps and do not occur at the panel centers. On the other hand, non-standing seam panels with penetrating hold-down fasteners are commonly thirty six (36) inches wide and may achieve flat-width-to-coverage ratios as low as 1.17:1.
Roof panels have a substantially flat pan profile with an upstanding female sidelap portion along one longitudinal edge, and an upstanding male sidelap portion along the opposite edge. The medial portion of the profile usually will have a number of medial corrugations to stiffen the panels. Adjacent roof panels are interlocked with the female sidelap portion wrapped around the male sidelap portion, as will be depicted in several figures included herewith.
Referring to the drawings generally, and more particularly to
The pre-engineered structure 12 comprises a primary structural system 14 which consists of a plurality of upwardly extending column members 16 rigidly connected to a foundation (not shown). Also, the primary structural system 14 has a plurality of generally sloping primary beams 18 which are supported by the column members 16.
A secondary structural system 20 comprises a plurality of open web beams 22, also called bar joists, supported by the primary beams 18 generally in horizontal disposition. It will be understood that cee or zee purlins, or wood beams, can be used as the secondary structurals in lieu of the bar joists 22 in the practice of the present invention.
A plurality of roof panels 24 are supported over the secondary structural assembly 20 by a plurality of panel support assemblies 26 and are attached to the upper flanges of the bar joists 22. The roof panels 24, only portions of which are shown, are depicted as being standing seam panels with interlocking standing seams 25 connected by clip portions of the panel support assemblies 26.
The present invention can as well be used in a re-roof installation.
Whether in a new roof as depicted in
This can be accomplished by limiting the length of the roof panels 24 or by utilizing support structures sufficiently flexible to allow the attachment means to move with the expansion and contraction of the panels. The flexibility of the support structural will be greater for longer panel runs as the expansion and contraction of the panels will be greater.
In
The drawings that accompany the following description will disclose and describe the various embodiments of the present invention. It should be noted that the numerical designations will be the same for identical components.
The reader's attention is now invited to
A pair of adjacently disposed, side overlapped roof panels 12A, 12B are shown as exemplary of the standing seam configurations of the present invention. Each of the roof panels 12A and 12B has a female sidelap portion 14 formed along one edge and a male sidelap portion 16 formed along the opposite edge thereof. Each standing seam is formed by the joining of a female sidelap and a male sidelap, and for the purpose of describing the standing seam 10, the roof panel 12A contributing the female sidelap 14 to the standing seam 10 will be referred to as the female roof panel 12A, and the roof panel 12B contributing the male sidelap 16 to the standing seam 10 will be referred to as the male roof panel 12B.
The female sidelap portion 14 has a substantially vertical, or angularly, positioned leg that is formed into a hook 20 at its distal end (edge) for engagement of the male sidelap 16 as the two adjacent roof panels 12A, 12B are joined. In
The clips 24 are positioned at spaced apart intervals along the standing seam 10, with the tabs (the upper portions of the clips 24) sandwiched between the female and male sidelaps 14, 16. In
The female side lap 14 has a female first leg 26, a female first radius portion 28, a female second leg 30, a female second radius portion 32, a female third leg 34, and the hook portion 20. These together form a female first cavity 36 (sometimes herein referred to as the first male insertion cavity 36), and a female second cavity 38 (sometimes herein referred to as the second male insertion cavity 38). The male side lap 16 is inserted into these first and second male insertion cavities 36, 38.
A female retaining groove 40 is formed at the distal end of the female third leg 34 in the hook 20 extending from the female third leg 34 and nested within the hook portion 20 of the female sidelap 14.
The male side lap 16 has a male first leg 44, a male first radius portion 46, a male second leg 48, a male second radius portion 50 and a male third leg 52 (sometimes herein referred to as the male tab member 52). The male second radius portion 50 is positioned in the female second cavity 38, and a distal (outer) end (or edge) of the male tab member 52 is positioned in the female retaining groove 40. Mastic 54 is placed in the depth of the female retaining groove 40 to seal the standing seam 10 against moisture migration between the female and male sidelaps 14, 16.
Each clip 24 is seamed with the panel sidelaps 14, 16 so that upward, downward and shear loads are transferred from the panels 12A, 12B into the clips 24 to pass to the building support structure. Each clip 24 is configured to grip both the male second leg 48 and the male tab member 52 when the roof panels 12A, 12B are subjected to either downward or upward loading.
The clip 24 has a clip first leg 24A; a clip second leg 24B; and a clip third leg 24C (sometimes referred to herein as the clip tab 24C). The clip 24 also has a clip first radius portion 25A and a clip second radius portion 25B (and in
In
In the installed mode of the standing seam 10 following field seaming, as depicted in
In addition to the aforementioned locking engagement, the male tab member 52 acts as a locking tab that engages the female retaining groove 40 to resist unfurling, or unzipping, by uplift forces. When the panels 12A, 12B are subjected to uplift forces, such as by wind, pivoting disengagement is attempted by the separation by these members, and as this occurs, the male tab member 52 and the female retaining groove 40 permit some upward flexing of the adjacent roof panels 12A, 12B, while maintaining the latching integrity of the side lap portions 14, 16 and closure of the standing seam 10.
It should be noted that, as shown in
In
This can be accomplished in a factory forming roll process if adequate roll material edge placement in the roll former can be obtained and maintained, or accomplished on the field site, so long as the field-seamer is configured to accommodate the particular shape of the seam hook; however it is usually simpler to achieve the proper final shape if field reforming of hook 20 can be avoided.
More complete seams are shown in
In
As discussed herein, it is preferable that the hook 20, during factory forming, be angled such that its distal hook end 21 extends substantially parallel to the leg 34 generally as depicted in
Continuing with the disclosure of the structural features of the present invention, the profile of standing seam assembly 10 provides for ease of initially assembling and interlocking the male sidelap 16 with the female sidelap 14, as the female sidelap 14 can be positioned above and dropped or rolled onto the male sidelap 16 to position the sidelaps 14, 16 together as depicted in
As mentioned, one edge of the uncoiling material being passed through the roll forming machine will be selected to accommodate the material “run-out.” Since the width of the coiled sheet material will of course vary within set tolerance limits, as the coiled material is formed by the forming rollers one edge is maintained at a set datum line while the material's opposing edge will not be fixed; rather, the opposing edge will float, or run-out. Accordingly it follows that this dimensional run-out will case the hook 20 on the female sidelap 14 to vary in dimensional length.
The length and configurations of the hook end portion 21 of the female sidelap 14 is critical in field assembly seaming, affecting load and water tightness performances of the standing seam, because if the hook 20 is improperly formed, the panel seam will not seam and perform correctly. One means of insuring the hook 20 folds into the cavity properly as the final stages of field seaming forms the correct configuration is to form the hook end 21 substantially parallel to the male third leg 52 before folding the female third leg 34, clip third leg 46C and the male third leg 52 into the male cavity 36. One problem is the width tolerance of the raw material coil used to roll form the panel is difficult to control, coil manufacturers often allow coil width to exceed the desired or specified width.
To accommodate this extra width the hook 20 may be angled outward from leg 34 and made long enough to accommodate excess coil width and form an effective hook, but this can result in the hook end 21 being so long that it prevents proper forming of the finished standing seam. A second problem is that the resultant angle of hook 20 relative to female leg 34 of the female sidelap portion 14 can cause difficulties in field seaming the sidelap. When the field seaming process is performed, forming the panel as shown in
The proper shape and length of the hook 20 required to place it in position for proper field assembly and seaming can be achieved in a number of ways. Proper hook shape and length may be obtained by:
1) by forming the hook at a wide angle, thus accommodating a wide coil, and then reforming the hook after seam assembly and before final seaming; (However, in this situation, it will be noted that leg 34 of the female sidelap portion 14 and male tab portion 52 of male sidelap 16 are close to being parallel to each other, but hook 20 is generally inclined at an angle from leg 34 of the female sidelap portion 14. Since the length of hook 20 varies to accommodate variable material widths used in the formation of the panel 12 and thus the female sidelap 14, by having the hook at an angle from leg 34 of the female sidelap portion 14 a greater width range of panel material can be accommodated than if the hook 20 were formed parallel to leg 34. But, if the panel width is excessive, it can prevent field placement of the female sidelap over the male sidelap 16.)
2) by controlling the width of the coil and forming the hook 20 to the proper shape and length before field assembly of the seam;
3) by developing tooling with an adjustable spacer in the shaft between the main roll form tools, the variance in coil width can be controlled so that proper material edge placement is attained and maintained so that the length of the hook 20 is kept within acceptable limits, assuring that the material forming the hook 20 runs out properly and accommodates any scalloping (described below with reference to
4) by crimping or bending the normally straight female third leg 34 into an angled leg as depicted in
As discussed above, the female third leg 34 of the female sidelap portion 14 and the tab portion 52 of the male sidelap 16 are close to being parallel to each other, but the hook end 21 may not be parallel. The hook end 21 may be inclined at an angle to accommodate variations in the width of raw material used to form the female sidelap 14, and if the width of the panel is excessive, the length of hook end 21 is extended, causing the hook end 21 to contact the under side of the male sidelap 16 during seaming, thereby likely preventing proper field assembly. If the hook end 21 is formed at an improper angle, or if it is too long, the hook end 21 can prevent proper forming of the final seam profile, resulting in premature up-loading failure.
In order to overcome the problem of improper hook formation and obtain a tight seam, it is sometimes necessary to pre-form the hook 20 into the proper profile by pre-seaming after initial panel positioning. This can be accomplished during factory forming if adequate roll adjustment and material edge placement in the roll former can be obtained and maintained. It can also be accomplished at an installation site by a field seamer having appropriate capability to properly form the hook prior to final seaming.
Mention should now be made of a phenomenon referred to as scalloping, an effect depicted in, and described further with reference to,
In sum, the control of the length and angular disposition of the hook 20 is important for field seaming, not only to avoid unnecessary mechanical interference, and assembly, but also as it affects load capacity and watertightness of the panel sidelaps. Good practice will form the hook 20 at an angle sufficient to accommodate coil width tolerances, while assuring that the length of the hook is not so excessive as to interfere with the field seaming required to achieve acceptable loading capacity and weather tightness performances of the finally formed standing seam. In fact, if the length of hook 20 is not controlled by limiting raw material tolerances or by varying shims, and the hook 20 is too long, proper forming of the finished sidelap will probably not be achieved.
Having above described the particulars of the standing seam 10 as depicted in
As with the above described standing seam 10 of
The crimped female third leg 34, when flexed inwardly in the seaming operation, allows the distal ends of the male tab 52 and the clip third leg 24C to be extended further into the female retaining groove 40; then, as the seaming operation releases the inward pressure on angled bend 61, the female third leg 34 tends to return to its original shape, bringing the female cavity closer to the distal ends of the included members, such as the male tab 52 and/or the clip third leg 24C, increasing the resistance to unfurling and failure.
The crimp 61, accomplished by factory forming or field formed at the jobsite, will serve to locate where the seaming break is to be located and reduces the field seaming force required to further form it. Furthermore, as the included angle at 61 increases there will be a tendency for the hook 20 to rotate counterclockwise (as viewed), making it easier to close the included angle of hook 20. As the angle of the break at crimp 61 is increased, there will be a tendency for the hook 20 to close and to be forced against the distal end of the clip 24, or in the spacings between the clips 24 and the distal end of the male third leg 52. If sufficient seaming pressure is applied, the clip third leg 24C and the female third leg 34A will also be deformed, thereby further tightening the seam 10.
In this embodiment, the clip 24 has a clip fourth leg 24D, and the hook end 21 is positioned adjacent to the end of the clip fourth leg 24D; mastic 54 is placed as shown to seal the ends of the female side lap 14 and the male tab member 52 (in addition to, or in lieu of, mastic in the clip retaining groove 60).
In
The clip hook 24 serves an important feature in that one of the failure modes of a standing seam roof under uplift failure conditions is that the clip tab which counters roof uplift load is in tension and sometimes tends to deform (straighten out) to pull out from between the male and female sidelaps. The clip hook, which is usually formed of stronger metal than the panel sidelap, is wrapped around the male sidelap end (or edge) and provides a much more secure lock, especially when the tab is lengthened as described herein and wherein the female sidelap wraps around the clip to further restrain the clip fourth leg 24D. Furthermore, as the second male leg 48 begins to unfurl, it exerts pressure on the hook 20 to restrain both the clip fourth leg 24D and the hook 20.
With regard to the standing seam 10B depicted in
The clip 24 as configured in
The standing seam 10C separates the engagement of the clip 24 from the edges of the male sidelap 16 and the female sidelap 14 that are sealed by the mastic material 54. This separation provides for transfer of uplift forces from the clip 24 into the male seam as depicted in
All of the standing seams discussed above have the female sidelap 14 which forms the female retaining groove 40 that lockingly engages the male tab 52 of the male sidelap 16. This engagement drives the male tab 52 into ever more pressing engagement with the retaining groove 40 as uplift forces tend to separate the female first leg 26 of the female sidelap 14 from the male first leg 44 of the male sidelap 16. The locking characteristic of this seam is not limited to seams having female sidelaps which form the female retaining groove 40, for an equivalent embodiment would be to have the male sidelap 16 form the retaining groove 70, as shown in
In the standing seam 10D, the female sidelap 14 has the female first leg portion 26, the female first radius portion 28, the female second leg portion 30, the female second radius portion 32, the female third leg portion 34, the female third radius portion 72, and the female fourth leg portion 74; the female fourth leg portion 74 also is referred to herein as the female tab member 74. The mastic material 54 is appropriately disposed to sealingly engage the ends (or edges) of the female sidelap 14 and the male sidelap 16, and the clip 24 is formed to have the clip fourth leg 24D that wraps around the male tab 52 for locking engagement therewith.
In the seamed configuration depicted in
It should be noted that sealant 54 can be moved into male retaining groove 70 and clip fourth leg 24D extended to lock in the male retaining groove 70, thus increasing the resistance of failure at a clip location.
Having discussed the configuration of the characteristic locking engagement of the tab members and the retaining grooves of the several standing seam embodiments of the present invention, the reader's attention will now be directed to the method of field seaming the standing seam and of attaching the standing seam to the underlying building support structure.
The clip 24 as shown in
In the seaming operation, it is necessary to prevent the edge of the hook 20 of the female sidelap 14 from distorting in a manner that creates a scalloped edge, such as depicted in
To prevent this scalloped edge interference, it is possible to pre-form the hook 20 or to crimp the hook 20 against the male tab member 52 before forming the desired included angle within the female second radius portion 32. While
Similarly,
Seaming further partially straightens female tab 74A as shown in
More particularly, the hold down clip tab 101 has a first tab member 110 that slidingly engages an inside surface 112 of the beam section 104, and a pair of second tab members 114 that slidingly engage an opposing outer surface 116. A pair of third tab members 118 extend from the first tab member 110 and slidingly engage the top flange surface 108. In this manner, the top flange surface 108 provides a track on which the hold down clip 101 slides in a longitudinal direction.
During seaming of the standing seam 10 when connected to the underlying support structure by the clip 100, the female seam 14 and the clip 100 are pulled tighter over the male sidelap 16, and collapsing these members occurs into the notches 120 create the indentures 124. As the sidelaps 14, 16 are seamed, it is this tightening and stretching of the female sidelap 14 creating the slight indentures 124 into the notches 120 that add to the locking integrity of the standing seam 10.
Modifications to the clip 100 can be as that depicted in
The clip base 102 can be formed from a single piece of sheet metal configured as shown so to include rib sections 123 and embossments 124 to provide additional strength and resistance to distortional forces upon the clip base 102. The clip base 102 is anchored to the underlying support structure, such as a purlin, as depicted in
Finally,
Having discussed the standing seam 10 along with several modifications thereof, and as well, alternative sidelap portion configurations and clip configurations, attention will now be directed to a method of seaming the standing seam 10 during the second stage of forming which usually occurs during field installation of a standing seam roof. As discussed above, the standing seam 10 requires a pre-crimping operation of the hook 20 of the female sidelap 14 prior to jointly forming the male tab member 52 of the male sidelap 16 and the female third leg 34 of the female sidelap 14 to the desired angle at the female first radius portion 28 and female second radius portion 32. This prevents scalloping of the edge of the hook 20 as discussed above and shown in
In use, the seamer 134 with the pre-crimping assembly 140 mounted thereon is placed in the open position (
In use, the crimping roller assembly 184 is similarly set up as the pre-crimping assembly 140 discussed previously. By lifting the latch 148, the handle 144 can be lowered to bring the die crimping roller assembly 184 into operable engagement with the standing seam 10. The eccentric bushing 146 is rotated to align the roller flanges with the seam. The latch plate 182 is adjusted to place the roller assembly 184 to the proper depth of engagement with the seam 10, and the pre-crimping assembly 184 is then moved along the seam 10 to achieve the desired field seaming.
In the above discussion, the merits of a standing seam roof with few or no fasteners penetrating the sheet metal panels at medial portions thereof has been recognized. Generally, applications of standing seam roof panels with floating clips have capitalized on reducing the center or medial panel penetrations in order to minimize leak paths through the roof. At times, however, the lack of medial fixed panel attachment to underlying support structure can result in an undesirable reduction in diaphragm strength of the roof or wall, resulting in a need for additional bracing.
In order to achieve adequate diaphragm strength, the panels making up the roof or wall must possess a number of qualities. One such quality is resistance of a panel sliding in relation to adjacent panels. This quality is referred to as in-plane panel sidelap shear capacity. Sidelap shear capacity, or resistance to panel sliding, can be achieved in a number of ways.
A sufficient diaphragm strength is necessary to prevent the panels from “saw-toothing” when subjected to a lateral “racking” load. The panel must also possess sufficient in-plane strength such that the panel does not buckle as load is applied. The panel may be strengthened by adding ribs or corrugations and by attaching floating clips to a substrate with sufficient rigidity to hold the panel and panel roof in place so it cannot develop major buckles involving multiple panels.
Sidelap shear is illustrated in
For the panels 12 to resist the diaphragm load, among other things, the panels must resist movement, or sliding, or adjacent panels. To illustrate the shearing movement under such load, a pair of marks 210A and 210B are depicted at the edges of the adjacent panels in
Standing seam diaphragm strength benefits a building structure in several ways. It can serve to stiffen the structural members when the roof is appropriately secured and it can also serve to transfer roof applied loads to the parallel shear walls. Standing seam panel roofs possessing adequate diaphragm strength can also transfer horizontal load, such as from wind or earthquake loads applied to the roof, to the shear walls that are capable of resisting loads in a parallel direction. In this situation, the connections between the roof and the supporting structurals may or may not transfer shear load. However, the connections can stiffen the roof and the plane of the roof. To effectively transfer such loads, the roof must be adequately attached to the shear walls as in
In order to achieve the structure stability illustrated in
The present invention increases the diaphragm strength of a standing seam roof by attachment of a backer plate on the upstanding portions of the sidelaps, as illustrated in
Preferably, the brace plates 220, 222 are used in protected areas of the roof, such as the ridge of a building that is protected by ridge trim, so that the through fasteners 224 are not visible and are not exposed to the weather elements.
Other embodiments of the present invention that increase the resistance of the female sidelap 14 to sliding in relation to the clip 24 and the male sidelap 16 are shown in
Another embodiment of the present invention that can be used to increase the diaphragm strength of a standing seam roof is a backer and optional cinch plate assembly that can be installed at a panel endlap, a ridge or an eave location.
The backer member 234 can be made up of a series of pieces, a partial one being a channel member 238 joined by a vertically and horizontally moment and shear connection plate 240 to make the channel member 238 into one substantially continuous backer member 234. The backer member 234 extends under, and bridges between, adjacent panels 12, which are similarly attached to the backer member 234 via additional cinch plates 230 and fasteners 236. Thus, the multiple cinch plates 230 and fasteners 236 sandwich the panels 12 to the underlying backer member 234. The tightened fasteners 236 also increase the lateral resistance to sliding of end-to-end overlapped panels and the backer member 234 extending between adjacent panels.
The fasteners 236 increase shear resistance to prevent sliding between adjacent panels 12 in the vicinity of their panel endlap portions. The beam and shear strength of the backer member 234 serves to prevent adjacent panels from sliding in relation to each other.
The strengthening beam 250 has an upstanding web portion 254 and an upper ledge portion 256. The strengthening beam 250 has a supporting flange 258 at the lower end of the web portion 254. In practice, the strengthening beam 250 is a unitary sheet metal member that is formed so that the upper ledge portion 256 and the supporting flange 258 extend in opposite directions and normal to the middle web portion 254.
The strengthening beam 250 is configured so that the upper ledge 256 fits over the top of the male sidelap 16 and the web portion 254 fits against the upstanding male first leg 44. Thus, when the female sidelap 14 is positioned over the male sidelap 16, the upper ledge 256 and the web portion 254, and these are seamed together to form the standing seam 10, the strengthening beam 250 serves to increase the load capacity thereof. Optionally, the strengthening beam 250 can be attached to the underlying backer member 234 by fasteners 260 extending through the supporting flange 258.
Another way of increasing the diaphragm strength of the roof panels 12, often in combination with the other means disclosed hereinabove, is to utilize fasteners 236 to secure the eave row (not shown) of the panels. That is, fasteners 236 can be used to attach the ends of the roof panels 12 directly to an eave strut or to a support member that is itself fastened to an eave strut, thus often serving as a shear wall.
The amount of deflection illustrated by the uplift forces in
Further, it will be noted that, from
With reference to
One such change is that there has been an increasing appreciation that diaphragm strength directly impacts the structural strength of zee purlins that support roof panels. Technical requirements relating to the stability of zee purlins are becoming much more rigorous, as is the demand for stability of the overall building structure. Diaphragm strength can contribute directly to both of these, thus mitigating the objections mentioned above.
In the use of the backer member 234 of
Mention should also be made that an “acorn” nut can be used with the fastener 224. An acorn nut is one that covers the end of the bolt so that there is no leaking between the bolt threads and the nut threads from the outside end of the bolt. For an acorn nut, the bolt must be coordinated with the thickness of the material in the bolt grip after the nut has been applied, so that the depth of the bolt does not penetrate the full depth of the acorn nut. This will enable the nut and the bolt head to force the material gripped between them to form a watertight, structurally sound, aesthetically acceptable joint. These may be located at a panel clip, in between panel clips or periodically spaced throughout the length of the panel standing seam at critical locations, such as at panel endlap splices, the ridge and/eave structures or other locations.
The embodiment of
Several embodiments of the present invention relating to increasing diaphragm load bearing ability have been disclosed herein:
These diaphragms strengthening means may be used separately or in combination at specific areas of building roof or wall portions, such as at particular areas more likely to sustain diaphragm shear loading as required in the various zones thereof. U.S. Pat. No. 6,588,170 entitled Zone Based Roofing Systems, issued Jul. 8, 2003, discusses such zones, and the disclosure of this patent is hereby incorporated herein by reference for such purposes as may be necessary.
With regard to the brace plates 220, 222 of
Another device that will increase the frictional resistance between adjacent panels, thereby increasing the resistance to shear forces, is a U-shaped member (not shown) having a slot into which the standing seam can be received, and having threaded apertures through which threaded rods can extend to exert closing pressure on the joined panels as the elements of the seam are brought together. Since frictional resistance is normally proportional to applied pressure, the sectional resistance and resistance to shear movement between adjacent panels is increased. These pressure apparatuses can be used in conjunction with the serrated plate of
Importantly, the overlap of the backup plate of
The female sidelap 14 comprises the female first leg 26, the female first radius portion 28, the female second leg 30, the female second radius portion 32 and a female third leg 34A, which form the female first cavity 36 and the female second cavity 38 (the first and second male insertion cavities, respectively), for receiving the male sidelap 16. The female retaining groove 40 is disposed at the edge of the female third leg 34A, the female fourth leg portion 42 extending from the female third leg 34A to form the female retaining groove 40.
The male sidelap 16 comprises the male first leg 44, the male first radius portion 46, the male second leg 48, the male second radius portion 50 and the male third leg 52 (the male tab member) disposed in the female first cavity 36. The male second radius portion 50 is disposed in the female second cavity 38, and the edge of the male tab member 52 is disposed in the female retaining groove 40.
The clip radius portion 25A is shaped to conform to the curvature of the female first radius portion 28 and the male first radius portion 46. The clip second radius portion 25 lockingly engages the male second radius portion 50 in the female second cavity 38.
The end of the clip third leg 24C is lockingly engaged in the female retaining groove formed by the female third leg 34A and the hook 20. The hook 20 wraps the male tab 52 and the clip third leg 24C. A mastic material 54 is disposed in the female retaining groove 40 to seemingly engage the distal end of the male tab 52, providing a water tight seal for the standing seam 10.
Having above described the particulars of the standing seam 10 as depicted in
As described above, the standing seam 10 has a multiple lock integrity, whereby standing seam 10 is secured by the male first portion 46 in the female first radius portion 28; the male second radius portion 50 in the female second radius portion 32; and the male third leg 52 (the male tab) in the female retaining groove 40.
The male tab 52 acts as a locking tab engaging the female retaining groove 40 to resist unfurling, or unzipping, by uplift forces. When the panels 12 forming the standing seam 10 are subjected to uplift load, such as by wind, pivoting disengagement is attempted by the separation of these members, and as this occurs, the male tab 52 and the female retaining groove 30 permits some upward flexing of the adjacent roof panels 12, while maintaining the latching integrity of the sidelap portions 14, 16 and closure of the standing seam. Furthermore, the hook 20 wraps around and secures the male tab 52 and the clip third leg 24C.
The crimped female third leg 34A, when flexed as in a wind uplift condition, serves as a back wound, flexed spring that further resists unfurling, or unzipping, at the standing seam 10. Thus, the multiple lock integrity is enhanced as the standing seam 10 resists not only unfurling under uplift loading, but also gravity, shear and rotation forces applied thereto.
As with the above described standing seam 10 of
The crimped female third leg 34A when flexed inwardly in the seaming operation allows the distal ends of male third leg 52 and clip leg 24C to be extended further into female retaining groove 40 then as the seaming operation release the inward pressure on angled bend 61, female third leg tends to return to its original shape thus bringing the female cavity closer to the distal ends of included members such as male third leg 52 and/or clip third leg 24C and increases the corrugations' resistance to unfurling and failure.
The truncated clip portion 294 may be flexed inwardly in the seaming operation in the same manner as the female third leg 34A, and after release of the seaming pressure, it tends to return to its original shape, bringing the female retaining cavity 40 closer to the third female leg 52. The force of the truncated clip 294 adds to the force of the third female leg 34A, thus increasing the resistance of the standing seams to unfurling and failure.
In
In the art of constructing metal buildings, metal roof panels are supported at spaced apart support points, that is, with the panels spanning between two and twelve feet; and the metal roof panels are strengthened with longitudinal ribs or corrugations. Thus, the panels can be considered as acting as continuous beams when design loading calculation is undertaken. For example, under uniform loading, continuous beams spanning three or more points of support possess moment and shear curves that are maximum at the points of support, and they are subject to failure at the point of attachment.
It should be noted that moment drops off very quickly away from the support points, while shear diminishes more gradually and is significantly less as the distance from the support increases. Because of this, a standing seam metal roof panel develops high stress at its support points, and the present invention recognizes that it would be desirable to reinforce the panel, particularly the panel seam, at these points and at points of discontinuity, such as at panel endlaps.
Panel reinforcement can be accomplished in a number of ways, but an effective way is by using longer length, multiple strength panel clip tabs and reinforcing beams that fold into the seam and serve to strengthen the seam at these critical points. In tight fitting seams, the sidelap of the panel can be wrapped around a long clip/beam that will connect the clip/beam to the panel seam so that the clip/beam becomes integral with the seam.
In this regard, it is preferable to select a clip tab length and strength that is appropriate to achieve the desired panel strength required for a particular span, load, location and related variants that are factors under the specific conditions. In all, with other things being equal, a longer, stronger clip tab or beam placed at a critical location is desirable for greater loads and longer panel spans.
The present invention (long tab) is particularly beneficial in strengthening panels in high wind uplift load zones such as disclosed in U.S. Pat. Nos. 6,823,642; 6,588,170, wherein the long tab disclosed herein, forms a part of a roof demand and zone based roofing method for constructing a roof of metal panels for a building having a roof support structure, the roof having a plurality of demand zones, the method comprising: (a) identifying and mapping the plurality of demand zones of the roof; (b) installing the panels on the roof support structure thereby covering the roof support structure with the metal panels; (c) choosing a long tab clip from a plurality of other processes for joining side-adjacent panels to form joints there between, wherein the joining process chosen for each demand zone to form a joint between the side-adjacent panels in that demand zone at least satisfies the performance requirements of that particular demand zone, and whereby the chosen joining process for that demand zone differs from the joining process chosen for at least one other demand zone; and (d) installing the metal panels according to the joining process chosen for each demand zone in step (c).
In many instances utilizing the long tab clip will eliminate the need for many additional purlins thus substantially reducing the cost of the building structure. Among other things, the reason for this is that the end bay on many buildings is twenty to forty feet long, the high wind zone at the end of the building is normally only ten to fifteen feet wide, if the distance between purlins is reduced to enable a panel with more limited spanning capability to meet the high wind load for this end zone the additional purlins, required only for the building end high load area (usually ten to fifteen feet) must continue on over to the first frame in from the end wall, thus in effect wasting these purlins from the end of the high wind zone to the first frame in from the end wall. However, if the long tab clip is used to strengthen the panel in the high wind zone the extra purlins do not need to need to be added and they do not need to continue to the first building frame from the end wall.
The panel clip 300 has a hook portion 306 configured to fit over a similarly configured male sidelap, and it has a plurality of spaced apart notches 308 like the notches of, and for the purpose discussed above for, the clip 100 (
The strength of the panel clip 300 can be varied by modifying the tab cross-section configuration, material strength and thickness such as shown in
Specific panel and clip strengths and configurations can be determined by accepted panel test procedures. The accepted practice is to test certain tab lengths and strengths, and then interpolate the strength of intermediate length and strength clip tabs.
In considering the suitability of a metal panel roof to sustain the wide range of loading conditions that can be expected in its area of service, the controlling engineering design principles will now be reviewed for such roof. The longitudinally extending metal panels of the roof, presumably being well seamed at the standing seam sidelaps, as well as the panel corrugations, act as multi-span continuous structural beams that are alternately subjected to inwardly directed live loading (such as the weight of snow) and outwardly directed live loading (such as upwardly directed forces imposed by wind). The total beam strength of the panel corrugation seam is substantially proportional to the strength of the corrugation plus any beam reinforcing applied to it.
The roof should also withstand shear and torsional loads when the building is subjected to horizontal loading, such as that imposed by an earthquake, and it will be capable of withstanding such horizontal loading if properly anchored to the underlying building structurals. When attached by floating clips, the roof can be attached to the building perimeter structure so that the roof will transfer loading perpendicularly to a shear wall.
In the case of roof panels with substantially flat sections between spaced apart corrugations, these can be strengthened by applying additional corrugations, generally from about one inch wide and one fourth deep, in various shapes to reinforce the panel areas between corrugations for shear and torsional strength and stability, so that these areas are commensurate in strength to that of the panel interconnected sidelaps.
As will be understood by one skilled in the art of pre-engineered building construction and design, the design specifications will first consider the roof under typical uniform loading, and shear and moment diagrams (not shown) will be undertaken to predict the operational performance. When roof panels are resisting inward or outward loading, peak moment and sear occur at inboard support points (medial to the panel lengths), and moment stress drops off very rapidly as the point of inflection (P.I.) is approached. Shear stress likewise drops off rapidly. Because of this, it is desirable that the strength of the panel be varied, particularly at the standing seams, as the shear and moment stress increase; this means that the location of any splice that may be necessary should be located in close proximity to the minimum stress points as feasible.
Prior art panel splice points (particularly at endlaps) can constitute moment and shear splices, or hinge point splices, that are capable of transferring shear, but which do not transfer substantial moment force. It is preferable to locate moment hinge (splices) point as near as possible to the point in the panel where moment stress drops to zero and bending stress changes from positive to negative, even though shear stress or force are not minimum at that point, it being often more difficult to transfer moment stress than shear stress in a standing seam panel; however, it is often not possible to locate either moment or shear splices at points of zero stress because of other considerations relating to erection, shipping or manufacturing limitations. The shear at the points of zero moment stress, commonly referred to as points of inflection (P.I.), is normally less than maximum.
Physical testing by standards established for metal roof panels has demonstrated that the endlap connection portions of many metal roofs is weaker than the other portions of the roofs, thereby presenting the potential, and probably the likelihood, of premature panel failures from wind uplift at the endlaps. One reason for such failure is that the panel center (the substantially flat portion) tends to bow up under wind uplift loading. When this occurs, unless the back-up plates at the endlaps bridge between standing seams and are connected to adjacent panels, the standing seams at the endlaps tend to separate, or pull apart, at the panel standing seams, further stressing the panel sidelap connections and increasing the probability of failure.
Reinforcing beams, such as the strengthening beam 250 of
The elongated, variable length of the panel clip 300 (
It is often not possible to locate a panel endlap at the most desirable location, and it is desirable to transfer both shear and moment through the slice at the endlap. Shear can be transferred through a relatively short splice such as shown in
Another embodiment of the long clip 300 may be used at points where it is desirable to splice the panel at endlaps located between supports. This embodiment of the clip may eliminate the base portion and optionally the lower part of the clip tab may be reinforced with various beam strengthening bends such as shown in
It is clear that the present invention is well adapted to carry out the objects and to attain the ends and advantages mentioned as well as those inherent therein. While presently preferred embodiments of the invention have been described in varying detail for purposes of the disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention disclosed and as defined in the above description and in the accompanying drawings.
The present application claims priority to U.S. Provisional Application No. 60/848,502 filed Sep. 29, 2006, entitled “Roof Assembly Improvements Providing Increased Load Bearing.”
Number | Name | Date | Kind |
---|---|---|---|
3998019 | Reinwall, Jr. | Dec 1976 | A |
4213282 | Heckelsberg | Jul 1980 | A |
4269012 | Mattingly et al. | May 1981 | A |
4435937 | Stone | Mar 1984 | A |
4497151 | Simpson et al. | Feb 1985 | A |
4522005 | Seaburg et al. | Jun 1985 | A |
4570404 | Knudson | Feb 1986 | A |
4575983 | Lott et al. | Mar 1986 | A |
4602468 | Simpson | Jul 1986 | A |
4694628 | Vondergoltz et al. | Sep 1987 | A |
4807414 | Krause | Feb 1989 | A |
4987716 | Boyd | Jan 1991 | A |
5001882 | Watkins et al. | Mar 1991 | A |
5012623 | Taylor | May 1991 | A |
5038543 | Neyer | Aug 1991 | A |
5134825 | Berridge | Aug 1992 | A |
5181360 | Shingler | Jan 1993 | A |
5201158 | Bayley et al. | Apr 1993 | A |
5222341 | Watkins et al. | Jun 1993 | A |
5241785 | Meyer | Sep 1993 | A |
5379517 | Skelton | Jan 1995 | A |
5606838 | Hughes et al. | Mar 1997 | A |
5685118 | Simpson | Nov 1997 | A |
5737894 | Simpson et al. | Apr 1998 | A |
6301853 | Simpson et al. | Oct 2001 | B1 |
6889478 | Simpson | May 2005 | B1 |
7574839 | Simpson | Aug 2009 | B1 |
20020035812 | Simpson et al. | Mar 2002 | A1 |
20030145548 | Mitchell | Aug 2003 | A1 |
20050055903 | Greenberg | Mar 2005 | A1 |
20050193644 | Simpson et al. | Sep 2005 | A1 |
20050204674 | Marshall | Sep 2005 | A1 |
20050246992 | Rood, Jr. | Nov 2005 | A1 |
20090044477 | Simpson et al. | Feb 2009 | A1 |
20090126303 | Ferge et al. | May 2009 | A1 |
Number | Date | Country | |
---|---|---|---|
60848502 | Sep 2006 | US |