AU2017200910A1 - End lap sealing strip - Google Patents

Abstract

The invention resides in an end lap sealing device for cladding sheets used in roofing comprising a stiffening plate shaped to match a profile of the cladding sheets and an elongate compressible strip moulded around the 5 stiffening plate. A cavity is formed in the elongate compressible strip for receiving a joining clip fixable to a lower cladding sheet and for fixing an upper cladding sheet. The joining clip comprises an upper part to which the upper cladding sheet is fixed and a lower part to which the lower cladding sheet is fixed, wherein the two parts are able to slide relative to each other allowing movement to 10 account for thermal expansion. 3062771v 3067071v1..

Description

1 2017200910 10 Feb 2017

TITLE

END LAP SEALING STRIP

FIELD OF THE INVENTION 5 The present invention relates to the field of construction. More particularly, the invention relates to roofing formed from cladding sheets in long spans and more specifically to roofing formed from insulated roof cladding sheets.

BACKGROUND TO THE INVENTION 10 Modern building techniques have developed that allow the construction of large open buildings which require large roof areas. The preferred roofing material for these buildings is profiled steel roofing sheets. A typical roof may be over 50 meters long, perhaps up to 100 meters. Such a roof is referred to in the roofing industry as a “long run” roof. To enable rainwater run-off the slope will be 15 determined by the roof length, the cross sectional area of the roof tray and the specific rainfall intensity at the location. The industry generally agrees on an absolute minimum pitch of about 1 degree depending on the selected roof profile. Suppliers of steel roofing sheets for long run roofs provide tables of maximum span, maximum purlin spacing and minimum pitch for various 20 applications.

It is possible to construct a long run roof from continuous lengths of roofing sheets. This requires very large rolls of flat steel sheeting to be delivered to a site and for the profile to be pressed into the sheet as it is removed from the roll. On-site rolling adds considerable cost and risk. Production quality in an 25 uncontrolled environment is difficult while handling excessively long sheets presents added danger to installers. In locations that experience significant thermal changes there can also be problems with thermal expansion with single sheet long run roofing. Due to workplace health and safety issues, the problems 3062771vl 2 with handling and thermal expansion, and the high cost, single sheets are not the preferred approach for long run roofing in most situations.

Unlike single skin roofing profiles, insulated roofing panels (regularly referred to as sandwich panels) cannot be rolled formed on site. Factory production is required as more complex roll-forming & steel to core lamination is required

The preferred approach to constructing long run roofing, whether single skin or sandwich panels, is to use shorter sheet lengths that overlap side-to-side and end-to-end. While this reduces cost, eases handling and minimises thermal expansion problems, it introduces a potential problem of water ingress at the end-to-end overlap of the sheets. End- lapping of roofing sheets/panels can lead to problems associated with contact corrosion, accelerated corrosion due to water being trapped in the lap assembly & leaks associated with sealant failures. These issues with end-lapping are well documented by Bluescope Steel in their Technical Bulletin CTB 8. Bluescope Steel do not cover conventional endlapping techniques in their roofing warranties. These end-lapping techniques do not allow the lower level sheet to be “weathered” (turned up) so wind driven rain cannot pass over the upper end of the sheet).

Installers of roofing sheets or panels in long run applications have either applied a waterproof flexible sealant (such as the silicone product known as Silastic®) or a flexible butyl tape (such as Bostik®). The seal meant to be provided by the sealant or tape can be compromised during construction. Even if the seal is good it can fail due to thermal movement in the lap joint or otherwise break down over time. As a result of these shortcomings, difficult to handle, failure due to thermal cycling, breakdown over time, the flexible sealant or tape approach is not preferred. A more successful approach is to provide a sealing device constructed to achieve waterproof sealing for a time that is at least comparable to the life of the roof. One such system is described in Australian patent application number 2009202866 assigned to Stramit Corporation Pty Ltd. This application describes 306277lvl 3 a device that provides a seal between the ends of overlapping profile roofing sheets which comprises an elongate body that matches the profile of the overlapping sheets. The device provides a weatherproof seal and engages with the profile of the lower and upper sheets to stay in place. A similar solution is described in international patent publication number WO2014/075149 assigned to Bluescope Steel Limited. This application describes a clip formed to fit over and lock onto a rib of a lower cladding sheet and to retain an upper cladding sheet on the clip in an end lap arrangement. The innovation includes an elongate weather strip formed of compressible material that compresses between the upper and lower cladding sheets. The content of this application is incorporated herein by reference.

Both of these solutions are designed for single sheet roofs. A different solution is needed for rooves made from insulated panel sheets such as those produced by Metecno Pty Ltd and known as Metecnospan® and Solarspan®. (see www.bondor/com.au/products/roofing), the content of which is incorporated herein by reference). Furthermore, even for single sheet rooves, the existing solutions have handling difficulties in laying out the clips and compressible insulation.

SUMMARY OF THE INVENTION

In one form, although it need not be the only or indeed the broadest form, the invention resides in an end lap sealing device for cladding sheets comprising: a stiffening plate shaped to match a profile of the cladding sheets; an elongate compressible strip moulded around the stiffening plate; a cavity formed in the elongate compressible strip for receiving a joining clip fixed to a lower cladding sheet and to which an upper cladding sheet is fixed.

Suitably the invention further comprises, in combination, the end lap sealing device and a joining clip wherein the joining clip comprises an upper part to which the upper cladding sheet is fixed and a lower part to which the lower 3062771vl 4 2017200910 10 Feb 2017 cladding sheet is fixed, wherein the two parts are able to slide relative to each other. The relative sliding allows for movement due to thermal cycling.

Preferably the cladding sheets are insulated roof sheets.

The elongate compressible strip is preferably moulded above and below 5 the stiffening plate and is shaped and sized to match the profile of the cladding sheets. The strips suitably nest and compress into the trays and ribs of each sheet/panel.

The stiffening plate is preferably made from steel or stiff plastic. The elongate compressible material is suitably an open cell foam material. 10 Each elongate compressible strip suitably terminates in a connector to facilitate connection to an adjacent elongate compressible strip. The connector is preferable a male/female connector, most preferably a tongue and groove connector.

In a further form the invention resides in a method of constructing a long 15 run roof with end lap sealing by fixing an end lap sealing device and joining clip to a lower cladding sheet and then fixing an upper cladding sheet to the joining clip and end lap sealing device such that the lower cladding sheet and the upper cladding sheet overlap and are held with a fixed vertical spacing but allowing for small longitudinal movement. 20 Further features and advantages of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in 25 the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, in which: FIG 1 is a perspective view of an end slap sealing device according to one embodiment; 306277lvl 5 FIG 2 is the stiffening strip of the end lap sealing device of FIG 1; FIG 3 is a perspective view of the end slap sealing device of FIG 1 together with a lower cladding sheet, an upper cladding sheet and a joining clip; FIG 4 is an enlarged view of a part of FIG 3; FIG 5 is an end view of a part of FIG 3; FIG 6 is a perspective view of a joining clip; and FIG 7 is a perspective view of an end slap sealing device according to another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention reside primarily in an end lap sealing device and a method of end lapping cladding sheets or panels using the end lap sealing device. Accordingly, the elements and method steps have been illustrated in concise schematic form in the drawings, showing only those specific details that are necessary for understanding the embodiments of the present invention, but so as not to obscure the disclosure with excessive detail that will be readily apparent to those of ordinary skill in the art having the benefit of the present description.

In this specification, adjectives such as first and second, left and right, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. Words such as “comprises” or “includes” are intended to define a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a process, method, article, or apparatus. A reference to a cladding sheet also includes an insulated panel and vice versa. Insulated panels include insulated composite roofing panels such as, but not limited to, the MetecnoSpan® and SolarSpan® products mentioned previously.

Referring to FIG 1 there is a shown an end lap sealing device 1 3062771vl 6 comprising an elongate compressible strip 10 shaped to match the profile of roof cladding sheets. The strip 10 includes cavities 12 adapted to receive joining clips, described further below. The strip 10 has a number of plane sections 14 either side of the cavities 12. The cavities 12 are offset with respect to the plane sections and thereby match the ribs of the cladding sheets. It will be appreciated that the specific shape of the strips 10 is dependent on the profile of the cladding sheets being end lapped.

At each end of the strip 10 is a connector, which is suitably either a male connector 151 or complimentary female connector 152. In one preferred form the connectors 151,152 are tongue and groove connectors, although the invention is not limited to this particular form. There are numerous other suitable connector profiles such as finger joint, miter joint, splice, etc. In use, strips 10 are laid end to end to form one continuous strip across the width of the roof. FIG 2 shows a stiffening plate 20. The stiffening plate 20 provides a degree of rigidity to the strip 10 so that it remains in place during assembly. In the absence of the stiffening plate 20 the strip 10 is floppy and difficult to handle. It also tends to move rather than remain in place on a lower cladding sheet until fixed. As with the strip 10, the stiffening plate 20 comprises plane sections 21 either side of ribs 22. Each rib 22 includes an aperture 23 that receives a fixing element (not shown).

Referring to FIG 3, there is a shown an elongate compressible strip 10 in place between a lower cladding sheet 30 and upper cladding sheet 31. As can be seen from FIG 3, the profile of the strip 10 matches the profile of the lower cladding sheet 30 and the upper cladding sheet 31 so that when assembled the strip 10 provides a seal between the cladding sheets 30, 31. As can be seen most clearly in the enlarged view of FIG 4, a joining clip 40 is located in the cavity 12. The stiffening plate 20 provides a firm platform to support the joining clip 40 during assembly. The joining clip 40 is attached to the rib of the lower cladding sheet 30 by a fixing element that passes through the aperture 23 in the stiffening plate 20. The upper cladding sheet 31 is fixed to the joining clip 40.

The structure of the end lap sealing device 1 and joining clip 40 can be 3062771vl 7 seen most clearly in the end view of FIG 5. It is clearly shown in FIG 5 that the elongate compressible strip 10 is moulded around the stiffening plate 20. The joining clip 40 is located in the cavity 12 and sits on the rib 22 of the stiffening plate 20. There are multiple joining clips 40 per end lap sealing device 1. In the embodiment shown there are four but for convenience the number will be selected to match the size of cladding sheet being used.

The stiffening plate 20 is made from steel but could alternatively be made from suitably rigid plastic. The elongate compressible strip 10 is made from an open cell foam or other similar material that can be moulded around the stiffening plate and that has the appropriate degree of compressibility for the application. A suitable structure for the joining clip 40 is shown in FIG 6. The joining clip 40 consists of an upper part 44 that is able to slide in a lower part 43. The lower part 43 is fixed to the lower cladding sheet 30 as described above. This is most suitably done using a conventional roofing screw (not shown) that passes through the lower part 43, through the lower cladding sheet 30 and into a purlin (not shown). A hole 46 is provided in the top part 44 of the joining clip 40 for the roofing screw to pass through. It will be appreciated that this also fixes the end lap sealing device 1 in position.

The upper cladding sheet 31 is then fixed to the upper part 44. It would be usual to use a pair of roofing screws to fix the upper cladding sheet 31 to the upper part 44 of the joining clip 40. As clearly shown in FIG 6 the upper part 44 has a pair of flanges 441 that slide in corresponding slots 431 formed in the lower part 43. This arrangement allows for a degree of relative movement between the upper part 44 and lower part 43. When the lower part 43 is fixed to the lower cladding sheet 30 and the upper cladding sheet 31 is fixed to the upper part 44, the relative movement between the parts allows for movement due to thermal expansion.

In use, a roof is assembled by constructing a frame with purlins in conventional manner. A first row of lower cladding sheets are fixed to the purlins. A number of end lap sealing devices are laid at the end of the first row of sheets 3062771vl 8 and clipped together using the male/female connectors. Joining clips are then placed into the cavities and fixed through to the purlins. A next row of cladding sheets are put in place and sequentially fixed to the joining clips. The sheets are fixed to the purlins and the process is repeated at the end of the second row of sheets, etc.

Persons skilled in the art will understand that this process results in a step joint at the end lap.

As an alternative the joining clips may be pre-positioned in the cavities so that a roofer can lay the end lap sealing device as a single action. The inventors envisage this to be a quicker and therefore preferable approach.

As mentioned above, the shape of the end lap sealing device will depend on the cladding sheets being used. Another embodiment of an end lap sealing device 70 is shown in FIG 7. The embodiment of FIG 7 has the same basic structure as the embodiment of FIG 1 but with a higher ridge 71 and a longer plane section 72. Other variations of specific shapes and sizes are possible.

The embodiments of the end lap sealing device have been described with respect to the primary application of long run roofing. It will be appreciated that the structure of the invention is not limited by the application. Thus, it is conceivable that the invention may find other uses, such as wall construction.

The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention. 3062771vl

Claims (19)

1. An end lap sealing device for cladding sheets comprising: a stiffening plate shaped to match a profile of the cladding sheets; an elongate compressible strip moulded around the stiffening plate; and a cavity formed in the elongate compressible strip for receiving a joining clip fixable to a lower cladding sheet and for fixing an upper cladding sheet.

2. The end lap sealing device of claim 1 wherein the cavity is formed above the stiffening plate such that, in use, the stiffening plate provides a firm platform for the joining clip.

3. The end lap sealing device of any preceding claim wherein the stiffening plate is made from steel or stiff plastic.

4. The end lap sealing device of any preceding claim wherein the elongate compressible strip is made from an open cell foam material.

5. The end lap sealing device of any preceding claim wherein the elongate compressible strip is moulded above and below the stiffening plate and is shaped and sized to match the profile of the cladding sheets.

6. The end lap sealing device of any preceding claim wherein each elongate compressible strip nests and compress into the trays and ribs of adjacent sheets above and below the end lap sealing device.

7. The end lap sealing device of any preceding claim wherein the cladding sheets are insulated roof sheets.

8. The end lap sealing device of any preceding claim wherein each elongate compressible strip terminates in a connector to facilitate connection to an adjacent elongate compressible strip.

9. The end lap sealing device of claim 8 wherein the connector is a male/female connector.

10. The end lap sealing device of claim 9 wherein the connector is a tongue and groove connector.

11. A joining clip comprising an upper part to which an upper cladding sheet is fixed and a lower part to which a lower cladding sheet is fixed, wherein the two parts are able to slide relative to each other, the joining clip being of a size and shape to fit in the cavity of the end lap sealing device of claim 1.

12. In combination, the end lap sealing device of claim 1 and the joining clip of claim 11.

13. A method of constructing a long run roof with end lap sealing by fixing an end lap sealing device of claim 1 and joining clip of claim 11 to a lower cladding sheet and then fixing an upper cladding sheet to the joining clip and end lap sealing device such that the lower cladding sheet and the upper cladding sheet overlap and are held with a fixed vertical spacing but allowing for small longitudinal movement.

14. The method of claim 13 wherein the end lap sealing device is fixed to the lower cladding sheet before the joining clip is inserted into the cavity.

15. The method of claim 13 wherein the joining clip is inserted into the cavity before the end lap sealing device is fixed to the lower cladding sheet.

16. The method of claim 13 wherein adjacent end lap sealing devices are connected by connectors on each end of the end lap sealing devices.

17. The method of claim 16 wherein the connectors are complimentary male and female connectors.

18. The method of claim 17 wherein the connectors are tongue and groove connectors.

19. A long run roof comprising a plurality of overlapping cladding sheets and end lap sealing devices arranged between overlapping portions of a lower cladding sheet and an upper cladding sheet, each end lap sealing device comprising: a stiffening plate shaped to match a profile of the cladding sheets; an elongate compressible strip moulded around the stiffening plate; and a cavity formed in the elongate compressible strip; and a joining clip located in the cavity, the joining clip comprising: an upper part to which the upper cladding sheet is fixed; and a lower part to which the lower cladding sheet is fixed; wherein the two parts are able to slide relative to each other.