AU713521B2 - Cladding panel - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Application Number: Lodged: Class Int. Class Complete Specification Lodged: Accepted: Published: Priority Related Art: Applicant: STRAMIT CORPORATION LIMITED 005 010 195)

FLOOR

390 ST KILDA ROAD -TvoCS Iee' MELBOURNE VIC- 304 CA '-=Cooa. Co-

AUSTRALIA

Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street MELBOURNE 3000 AUSTRALIA Complete Specification for the invention entitled: CLADDING PANEL Our Reference: IRN 416587 The following statement is a full description of this invention, including the best method of performing it known to applicant:

RNC:CAP.DOC

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pp p p 4 p p 2 CLADDING

PANEL

This invention relates to a cladding panel for buildings.

The panel of the invention is of sheet material and primarily is for use in an array of a plurality of the panels for external wall cladding for a building. However, the panel can be used for other purposes, such as for internal wall or ceiling cladding. Where used for wall cladding, successive panels typically are interlocked at overlapping, top and bottom horizontally extending side margins, but also overlap without interlocking at vertically extending end margins, with successive panels built up bottom to top, or top to bottom. However, the panels can be disposed in an array in which the interlocking side margins extend other than horizontally.

With panels of a type to which the present invention relates, successive l ae seu~ued to a building structure, such as a wall frame, by means of fasteners. Typically, the fasteners comprise screws, although they may comprise pop rivets or clouts where the building structure is respectively steel or timber.

Panels of that type can be adapted for securement to the building structure S in an arrangement in which the fasteners are concealed such as at the interlocking margins This is more aesthetically pleasing to designers or architects and their clients. However, with some panels, the nature of interlocking can provide 20 inadequate securement of the panels, particularly in geographical areas prone to high prevailing wind forces or to cyclones. In other cases, the interlocking can provide adequate securement against high wind forces, including those experienced during a cyclone, but clients require the psychological assurance provided by exposed fasteners along overlapping and/or interlocking margins of 25 the panels of an array. Such panels can provide bracing for the support structure, as well as cladding over such structure.

An object of the present invention is to provide a panel which is suitable for securement in an array of the panels, by either exposed or concealed fasteners at interlocking margins.

A cladding panel for a building, wherein the panel has opposite, first and second side margins which are separated by a main body-portion of the panel and which extend between respective ends thereof; wherein the margins are formed such that each has a configuration which is at least partly complementary to the other, to provide for interlocking between the first margin of the panel and the eu-a Ci j RN 4I416357 d- O111MQg second margin of an adjacent like panel; and wherein the configuration of said margins enables securement of like panels in an array with the first margin of one panel overlapping, and interlocking with, the second margin of a laterally adjacent panel, the second margin having an inner edge adjacent to the body portion and an outer edge and, intermediate of its inner and outer edges, a longitudinal groove or trough,, such that with the panel applied to a building structure, a base surface of the groove or trough engages the structure and the panel can be secured to the structure by a respective fastener through the base at intervals therealong, and the body portion having at least one groove or channel which is substantially parallel to the margins and has a base surface which is aligned with the base surface of the second margin; whereby the panels of the array can be secured to the building structure by a concealed fix arrangement where fasteners are applied through the ,,1U ,,gno eachll panel or by a revealed fix arrangement where fasteners are applied through the first margin of each panel and the second margin of a laterally adjacent panel and through the base surface of the body portion.

In the course of securement of a plurality of the panels to a building structure in an array, the successive panels are secured in turn by fasteners applied through at least the second margin of each panel. The panels are built-up in rows in which they overlap end-to-end. After the first row, the first margin of 0 0 20 each of the successive panels of a next row is overlapped, and inter-locked, with the second margin of a respective panel of the preceding row. Application of fasteners through a second margin of a panel precedes or follows overlapping and i~ interlocking of the first margin of a panel of a next row depending respectively on whether the fasteners are to be concealed or revealed. When the fasteners are to be concealed, they are applied only through the second of overlapping margins.

Where the fasteners are revealed, they preferably are applied through both margins together. However, in the latter case, some fasteners can be applied only through the second margins, with others applied through both overlapping margins.

With the panels disposed in a substantially vertical array in which the margins extend substantially horizontally, it is usual for the second margin to be uppermost. For ease of description, but without any intention of limiting the S invention, the first and second margins therefore are distinguished as being lower nd upper margins, respectively.

C-\J 'C NCIRN41657b doc 0110/99 Also for ease of further description, opposite sides of each margin are respectively identified as inner and outer sides. An inner side is that by which each margin merges with the main body of the panel, whereas the outer side is that which is remote from the main body and defines an edge of the panel. In this context, the margins of the panel preferably are configured such that the lower margin is able to interlock with the upper margin of an adjacent panel at the inner side of the lower margin and the outer side of the upper margin. Also, the panel has front and rear surfaces which, when the panel is applied to a building structure, such as a wall frame, respectively face away from and towards the structure. Terms used herein such as forwardly or rearwardly are used relative to this context of front and rear surfaces.

With a lower margin overlapping and interlocked with an upper margin of an l"r tc 1U1,-il ,u Iuvv IrMargin extends across the groove in spaced relationship to the base of the groove. This spacing defines a cavity which, between the base of the groove and the lower margin, has a depth sufficient to accommodate the heads of fasteners applied through the base of the groove, where concealment of I: the fasteners is required. The lower margin preferably has a width sufficient to at least substantially cover the groove, and most preferably the outer edge of the lower margin is closely adjacent to the inner edge of the upper margin when the :20 margin are overlapped and interlocked.

In a first form, the upper margin may be such that, with a lower margin interlocked therewith, the lower margin abuts against a respective land of the upper margin at each side of the groove. The depth of the groove preferably is such that the heads of fasteners to be concealed are able to be substantially fully accommodated therein, and covered by the lower margin. Preferably interlocking between the margins is along at least part of the width of the outer land, such as by an outer portion of the upper margin extending forwardly and at least partly over the outer land to define an interlock groove therewith.

In that first form, inner land preferably is recessed rearwardly from the adjacent front surface of the main body. In such case, the panel preferably curves or is inclined forwardly from the inner land to the main body, to define an abutment surface which faces towards the outer edge of the upper margin.

In a second form, the upper margin has a land at only one side of its ,g::;roove, preferably the side of the groove nearer to the outer edge of the upper SRNC IRN41 857b *c.01110/V margin. Again, the panel preferably is curved or inclined to the main body of the panel, adjacent the inner edge of the upper margin, to define an abutment surface which faces towards the outer edge of that margin. Where the one land is at the side of the groove nearer to the outer edge, the abutment surface can define a side wall of the groove at its side nearer to the inner edge.

A main part of the width of the lower margin may be set rearwardly from the front surface of the adjacent main body. From such main part, the panel may curve or be inclined forwardly to the main body, over a part of the width of the lower margin by which interlocking with an upper margin is provided. In one form, the curvature is such that the lower margin has a re-entrant groove which faces across the main part of its width towards the outer edge of the lower margin. Such re-entrant groove is defined with respect to the front surface of the panel, such that A rib facing across the back of the main body is defined with respect to the rear surface. Such rib is provided where the upper margin defines an interlock groove, as detailed above, with the rib and groove providing means by which a lower margin of one panel can interlock with the upper margin of an adjacent panel.

With an upper margin of the first form, the lower margin may have the form of a channel which opens towards the front surface of the panel. In such case, the S. base of the channel defines the rearwardly set main part of the its width, while the 20 outer side of the channel may define an abutment surface which is co-operable with an upper margin abutment surface when the lower margin overlaps and interlocks with the upper margin of an adjacent panel. The arrangement may be such that, with the panel applied to a building structure, the base of the channel is 2 able to directly engage the structure, and this usually is the case for the channel 25 of the lower margins of panels of a first row of an array. In that case, the channel is secured by fasteners applied therethrough into the structure and, if required, the 'fasteners can be concealed by any suitable means. However, the lower margin S for panels a subsequent row overlap and interlock with upper margins of the preceding row such that the channel indirectly engages the structure and, in this latter case, the lower margin of the panel can be secured to the structure in either of two alternative arrangements. In the first arrangement, in which fasteners are to be concealed, the lower margin is overlapped and interlocked with a fastener secured, upper margin of an adjacent panel, such that the base of the channel extends over and conceals the fasteners. In the second arrangement, in which IRN416857b doc 0110199 6 fasteners are to be revealed, the lower margin is overlapped and interlocked with the upper margin of an adjacent panel, and fasteners are applied at intervals along the base of the channel, through each of the margins.

With an upper margin of the second form, the lower margin may be as described for a lower margin for use with the first form of the upper margin.

However, an alternative form of lower margin can be provided where the upper margin is of the second form. In the alternative form, the lower margin does not define a channel which opens towards the front surface of the panel. Rather, the lower margin comprises a land which is set rearwardly with respect to the main body of the panel, with the panel curving or being inclined at the inner edge of the lower margin, between the land and the main body. At its outer edge, the lower margin has a turned portion which extends rearwardly with respect to the land, and delines an abutment surface which faces away from the main body. The turned portion may simply comprise a flat edge strip. Alternatively, the turned portion may be of V-section, such that it has a first leg extending rearwardly from the land and defining the abutment surface and a second leg which extends forwardly, towards the rear face of the land.

In the preceding description, there is reference to interlocking of 9 2 overlapping margins by a rib of the lower margin engaging in an interlock groove 20 of the upper margin. However, a complementary arrangement is possible, using a S°rib on the upper margin and an interlock groove on the lower margin. Also, there can of course be a respective, relevant one of a co-operable rib or interlock groove i9 at each side of each margin. Moreover, the form of the rib and of the interlock o*99 groove with which the rib is co-operable can differ from the forms described and illustrated herein.

In at least some forms of the panel of the invention, the margins can be such as to support the panel until fasteners are applied, where the panels are being disposed in an array in which their margins extend horizontally. Thus, with the lower margin of a panel overlapping and interlocked with the upper margin of a panel of a preceding row, the interlocking can suffice to hold the former panel in a vertical disposition (assuming that wind conditions do not preclude this). Where the panels are of this self-supporting form until secured by fasteners, one operator can form an array of the panels. That is, the operator can lift successive panels 4 into interlocking position, usually necessitating use of both hands, and then leave :RNC IRN416857b Ooc011"q a positioned panel to take up fasteners and a tool by which the fasteners are to be applied.

The panel preferably is of sheet metal, such as of aluminium alloy, or steel, or of suitable plastics material. The thickness, length and width of the panel can vary as required, as can the width of the side margins relative to that of the main body. In the case of a metal panel, it can be embossed or patterned and/or provided with a suitable protective or colour coating, such as a Colorbond or Zincalume coating in the case of a panel of steel.

The panel can be produced by any suitable process for the chosen material of construction. These processes include extrusion where the material is a plastics material or aluminium alloy, and roll forming, folding or pressing in the case of steel.

xeference now is directed to the accompanying drawings, in which: Figure 1 shows a perspective view of an end-section of a panel according to the invention; Figure 2 is a sectional view taken on line II-II of Figure 1; Figures 3 and 4 show respective arrangements for securement of margins of two adjacent panels as in Figure 1; and °ooo Figures 5 to 8 correspond to Figures 1 to 4, but illustrate a further panel 20 according to the invention.

In Figures 1 and 2, there is shown a panel 10 which has a front surface 0la and a rear surface 10b. The panel 10 has a substantially constant cross-section from the one end 10c shown in Figure 1 to the remote end (not shown). In that 5 cross-section, the panel 10 has a main body 12, a first or lower side margin 14 along one side of body 12 and a second or upper side margin 16 along the other side of body 12.

The body 12 has a longitudinal, substantially central channel 18 formed 5 "therein which opens at front surface lOa. The channel 18 separates respective sections 20 of body 12, with each section 20 shaped to an external profile similar in form to that of a weather-board. Thus, the intention is to apply panel 10 to a building frame structure, as part of an array of similar panels to provide external cladding for the building, with margins 14, 16 disposed horizontally, margin 16 uppermost and front surface 10a facing outwardly from the structure.

A'iC IRN416857bdoc IQIOI 8 Each of the margins 14, 16 has a form defining a respective longitudinal channel 15, 17 which is open at the front surface. However, while the margins 14, 16 are partly complementary in form, they are not the same.

The upper margin 16 has the form of a channel 17 which has stepped base which defines a longitudinal groove 22 and, at each side of the groove 22, a respective land 24. As with the channel 17, the groove 22 opens at the front surface 10a. Also, the base 22a of the groove 22 is substantially parallel with lands 24 and substantially co-planar with the base 18a of the channel 18 of body 12. From the inner one of the lands 24 to body 12, panel 10 extends forwardly to define a longitudinal abutment surface 26 which faces outwardly across groove 22.

At the outer extent of the margin 16, panel 10 is curved so as to extend back over the outer land 24, in a reverse S-form in the orientation shown, to define a longiti dinal re-entrant goove 28 in front surface 10a and an out-turned flange Groove 28 opens in a direction across groove 22, towards the abutment surface 26.

The lower margin 14 has the form of a channel 15 which has a base which is substantially co-planar with the bases 18a and 22a of respective grooves

S

S.

S

RNC IRN416857b doc 01/1&99 18 and 22. From base 15a to body 12, panel 10 curves forwardly in a reverse S-form in the orientation shown, to define a longitudinal re-entrant groove 32 in front surface 10a. The groove 32 result in a rib 34, at the rear surface 10b of panel 10, which faces across body 12 towards margin 16. The groove 32 is similar to groove 28 of margin 16, such that rib 34 is substantially complementary to groove 28.

The outer extent of channel 15 is defined by a forwardly extending flange 36 of margin 14. The spacing of flange 36 from groove 32 corresponds substantially to the spacing between abutment surface 26 and groove 28, while surface 26 and flange 36 are substantially parallel.

In forming cladding for a building with a plurality of panels 10, a first, lower row of the panels are applied to a frame striictiire of the hibuildrling, using fasteners such as screws, with the panels of that row in overlapping end-to-end relationship.

Successive further rows then are similarly applied, with the margins 14 of each 15 successive row overlapping and interlocked with the margins 16 of the preceding "row. The nature of the interlocking is shown in Figures 3 and 4, while a respective one of two alternatives for applying fasteners is shown in each of Figures 3 and 4.

Figures 3 and 4 show a margin 14 of a panel 10 being applied in relation to an adjacent panel 110 while components of panel 110 having the same reference numerals used in Figures 1 and 2, plus 100.

As shown in each of Figures 3 and 4, the interlocking of the overlapping margin 14 of a panel 10 with a margin 116 of the adjacent panel 110 is by location of rib 34 of the margin 14 in groove 128 of the margin 116. The arrangement is such that the base 15a of margin 14 is supported on lands 124 of margin 116 and extends across the opening of groove 122 of margin 116. Also, the rear surface of panel 10, at its flange 36, abuts against abutment surface 126 of margin 116.

In Figures 3 and 4, slight clearances are shown between margins 14 and 116 of panels 10 and 110. This primarily is for ease of illustration. However, with interlocking, there preferably is good surface to surface contact between the margins 14, 116, resulting from the following procedure.

RNC:IR434098.DOC:3/7g96 In Figures 3 and 4, panels 10 and 110 are disposed vertically, with the margins extending horizontally and interlocked as applied to a building frame (represented by the designation The building frames typically will be a vertical wall frame, such that panels 10, 110 are disposed vertically, with panel 110 being one panel of a lower row secured to the wall frame and panel 10 being one panel of a next adjacent row being applied above the row including panel 110. In Figures 3 and 4, panel 110 is secured to the wall frame by respective fasteners and 42 applied at intervals through its first margin 114 (not shown) if its row is a bottom row, or by interlocking of its margin 114 with a first margin of a panel of an next adjacent lower row of panels. Also, in Figure 3, panel 110 is further secured to the wall frame by fasteners 40 applied at intervals along its margin 116, prior to positioning panel 10, whereas in Figure 4, panel 110 is further sicIIrd hby fasteners 42 applied through its margin 116 after positioning panel .ogo With panel 110 secured to the wall frame, panel 10 then is positioned to 0:,0 15 overlap and interlock its margin 14 with the margin 116 of panel 110. The **interlocking is by a snap-fit, to locate rib 34 into groove 128. Panel 10 then is pulled vertically (in the direction of arrow to complete the interlocking by causing base 15a of margin 14 to contact lands 124 and to bring flange 36 into firm contact with abutment surface 126. The contact between flange 36 and surface 126 retains the interlocking to enable the next step in the application of 9°99** panel 10 to the wall frame. In the case of Figure 3, the next step in the application of panel 10 is application of further fasteners 40 at spaced intervals along its second margin 16 (not shown). In the case of Figure 4, the next step is the application of fasteners 42 through the first flange 14 of panel 10, at spaced intervals therealong, with the fasteners 42 also being applied through margin 116 of panel 110, to complete application of panel 110 to the wall frame.

In each of Figures 3 and 4, it will be appreciated that respective fasteners 42 are applied so as to engage in the material of the wall frame. In the case of Figure 3, the fasteners 40 are applied through margin 116, substantially centrally in base 122a of its groove 122, to cause surface 110b of panel 110 to firmly contact the wall frame. The head 40a of each fastener thus is received into RNC:IR434098.DOC:3/17/96 11 groove 122 and, on subsequent application of panel 10, the heads 40a are concealed by base 15a of margin 14 of panel In the case of Figure 4, the fasteners 42 are applied through overlapping and interlocked margins 14 and 116 of respective panels 10 and 110. The fasteners preferably are applied substantially centrally through the base of the groove 122 of margin 116 and, to facilitate this, a score line or other suitable marker can be provided in surface 10a of panel 10, at a substantially central location along its base 15a. Thus, each fastener 42 is revealed in that its head 42a is visible exteriorly of the building to which cladding of the panels is applied.

While generally not necessary for securement of the panels, further fasteners can be applied through the base of 18a of channel 18, at intervals spaced therealong. This, of course, would be aesthetically undesirhable in the arrangement of Figure 3. However, in the case of Figure 4, where this is adopted for providing a visual perception of the adequacy of securement for the cladding, S 15 fasteners through base 18a can enhance that perception.

The panel 50 of Figures 5 to 8 generally will be understood from the preceding description of panel 10. Parts of panel 50 which correspond to those of panel 10 are identified by the same reference numerals, while description of panel 50 is limited to principal features by which it differs from panel One difference in panel 50 is in the form of profiling along the central region of its body 12. This does not comprise a groove 18 as in panel 10, but rather an asymmetrical groove 52 which has an upper part 52a and a lower part 52b. The upper part 52b merges with upper section 20 of body 12 and is of arcuate section.

0° The lower part 52b is of V-section and increases the depth of groove 52 before merging with lower section 20. This overall profile of groove 52 is such that, in an assembly of interlocked panels, such as panels 50 and 150 as shown in part in Figures 7 and 8, groove 52 somewhat simulates the appearance of overlapping margins when the panels are viewed under normal horizontal lighting conditions.

The sections 20 of body 12 also are of a different form. Each section has a lower main part 20a which is substantially planar, and a shallow, somewhat arcuate upper part 20b comprising a series of adjacent facets 20c. This RNC:IR434098,DOC:3n17/96 r 12 arrangement heightens an appearance of narrower panels, each of half the overall width, when an array of the panels is viewed under normal lighting conditions.

Panel 50 also differs in the form of margins 14 and 16. In the case of margin 16, the depth of groove 22 is increased slightly along a narrow central region of its base 22a, to define a slot 56. As will be appreciated, slot 56 facilitates the centring of fasteners, at least where the fasteners are to be concealed as in Figure 7. Outwardly from slot 56, margin 16 of panel 50 is of similar form to margin 16 of panel 10. However, inwardly of slot 56, margin 16 differs in that a land 24 has been omitted. Thus, abutment surface 26 is defined by the inner side wall of groove 22. Also, it is less relevant in this case to distinguish between a channel 17 and a groove 22 as in margin 16 of panel In the case of margin 14 of panel 50, it does not define a channel !5 as for panel 10. Rather, the margin 14 of panel 50 has a land 58 which is wide relative 00 :to the land 24 of its margin 16. However, the form of margin 14 of panel 50, to the 15 outer edge of land 58, is similar to the form of margin 14 of panel 10 outwardly to the outer edge of base 15a of the latter margin. At the outer edge of land 58, the margin 14 of panel 50 has a rearwardly turned portion 60 of V-section, with portion 60 having an outermost leg 60a by which it is integral with land 58 and an inner S: leg 60b which extends towards the rear face of land 58. The leg 60b is desirable, but can be omitted if required such that portion 60 simply comprises a rearwardly t .too turned flange.

In panel 50, the spacing of leg 60a from groove 32 corresponds substantially to the spacing between abutment surface 26 and groove 28. Leg and surface 26 are oppositely inclined rather than substantially parallel.

Despite this, the junction between legs 60a and 60b of a margin 14 of a panel is able to engage the surface 26 of a margin 16 of a similar panel, as shown in Figures 7 and 8; while similar engagement is obtained if leg 60b is omitted. Also, if required, leg 60a can be substantially parallel to surface 26, whether or not leg is provided, to achieve surface to surface contact between leg 60a and surface 26.

Principal requirements for the panel of the invention are that the lower margin of one panel is able to overlap and interlock with the upper margin of a RNC:IR434098.DOC:3/7196

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13 similar panel and that, in that relationship, at least one cavity is defined between the overlapped margins. Thus, while forms of the margins have been described and illustrated, other forms which satisfy these requirements are possible. Thus, for example, in relation to the panel 10 of Figures 1 to 4, groove 22 can be omitted from margin 16 such that channel 17 has a base which extends across a major part of the width of margin 16. In that case, base 15a of margin 14 may have a central raised rib so as to define a groove along the rear face of base 15a such that, when margins 14 and 16 of respective panels are overlapped and interlocked, that groove along the rear face of base 15a and the base of channel 17 define the cavity in which the heads of fasteners can be concealed. That modified form for margin 14 also could be used with a margin 16 as shown in Figures 1 to 4, with the groove at the rear face of base 15;a and groove 22 together defining the cavity. Also, as with groove 22, the rib giving rise to a **groove at the rear side of base 15 could be of arcuate or rounded cross-section, rather than the more rectangular section shown for groove 22.

Reference above is made to at least one cavity, whereas the description essentially is in relation to a single longitudinal cavity between overlapped and interlocking margins. However, instead of such single cavity, a longitudinal series gof cavities can be defined between the margins, whether each of these cavities 20 are of elongate form or even such that each is able to accommodate the head of a e single fastener. The provision of such series of cavities most preferably is such that successive cavities are relatively closely spaced. Also, a series of cavities also necessitates a change in the manner in which at least one of the margins is formed. Thus, in the case of the panel 10 of Figures 1 to 4, its groove 22 would need to be replaced by either a series of longitudinal grooves or a series of depressions. Similarly, where a groove is indicated as provided at the rear of base 15a in margin 14, there instead would be provided a series of grooves or depressions.

In panel 50 of Figures 5 to 8, a groove 56 is shown in margin 16. In panel 10 of Figures 1 to 4, the same feature could be provided in the base of groove 22 (or in the base of channel 17 if groove 22 is omitted). However, in each case, RNC:IR434098.DOC:3n7/96 I 1 14 longitudinally continuous groove 56 could be replaced by a longitudinal series of slots or holes enabling the passage of fastener shanks therethrough.

The panel 10 of Figures 1 to 4, and also panel 50 of Figures 5 to 8, preferably is formed of roll formed steel sheet. The panel can be of any length and width suitable for cladding, such as about 260mm wide and of a length of up to 6 to 10 metres or longer. The thickness can vary, with typical base metal thicknesses being about 0.4 and 0.55mm. The fasteners may be self-tapping screws, for application to steel or timber wall framing, preferably wafer head screws or hex head screws. However, the fasteners may be pop rivets for use with steel framing, or clouts for timber framing.

Finally, it is to be understood that various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention.

RNC:IR434098.DOC:3/7/96

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Claims (29)

1. A cladding panel for a building, wherein the panel has opposite, first and second side margins which are separated by a main body-portion of the panel and which extend between respective ends thereof; wherein the margins are formed such that each has a configuration which is at least partly complementary to the other, to provide for interlocking between the first margin of the panel and the second margin of an adjacent like panel; and wherein the configuration of said margins enables securement of like panels in an array with the first margin of one panel overlapping, and interlocking with, the second margin of a laterally adjacent panel, the second margin having an inner edge adjacent to the body portion and an outer edge and, intermediate of its inner and outer edges, a longitudinal groove or trough, such that with the panel applied to a building structure, a base surface VI Me yuove or trough engages the structure and the panel can be secured to the structure by a respective fastener through the base at intervals therealong, and the body portion having at least one groove or channel which is substantially parallel to the margins and has a base surface which is aligned with the base surface of the second margin; whereby the panels of the array can be secured to the building structure by a concealed fix arrangement where fasteners are applied through the second margin of each panel or by a revealed fix arrangement where fasteners 20 are applied through the first margin of each panel and the second margin of a laterally adjacent panel and through the base surface of the body portion.

2. A panel according to claim 1, wherein the first margin is of a configuration such that when it is overlapping, and interlocking with, the second margin of a bao. S* laterally adjacent like panel, the first margin extends across the groove or trough of 0*00 25 the second margin in spaced relationship to the base of the groove or trough, to Sdefine a cavity having a depth sufficient to accommodate the head of fasteners 3 applied through the base of the groove or trough where concealed fastening is required.

3. A panel according to any one of claims 1 or 2, wherein the configuration of the margins is such that the first margin is able to overlap, and interlock with, the second margin of an adjacent like panel in an arrangement in which the first margin abuts against, or is closely adjacent to, a respective land of the second margin at each side of the groove or trough. :1:RNC IRN4l6857bdoc Oi/0/9 I

4. A panel according to claim 3, wherein the margins are configured such that they enable interlocking laterally between like, adjacent panels along and adjacent an outermost one of the lands with respect to the body portion.

A panel according to claim 4, wherein the margins are configured such that said interlocking is enabled by an outer portion of the second margin which extends forwardly with respect to the main body, at least partly over the outermost land, to define an interlock groove between the outer portion and the outer land.

6. A panel according to any one of claims 3 to 5, wherein the innermost one of the lands is recessed rearwardly from an adjacent portion of a front surface of the main body.

7. A panel according to claim 6, wherein the panel is curved or is inclined forwardly from the inner land to the main body to define an abutment surface ,diues towardte outer edge of the second margin.

8. A panel according to any preceding claim, wherein the configuration of the margins is such that the first margin has a land along only one side of said groove or trough and the first margin is able to overlap, and interlock with, the second margin of an adjacent panel in an arrangement in which the first margin abuts against or is closely adjacent to said land.

9. A panel according to claim 8, wherein said land is at the side of the groove 20 or trough nearer to the outer edge of the second margin. S:

10. A panel according to claim 9, wherein the panel is curved or inclined to the main body, adjacent to the inner edge of the second margin, to define an abutment i surface which faces towards the outer edge of the second margin.

11. A panel according to claim 10, wherein the abutment surface defines a side wall of the groove or trough. S0

12. A panel according to any preceding claim, wherein a main part the width of the first margin is set rearwardly from a front surface of an adjacent portion of the a main body.

13. A panel according to claim 12, wherein the panel curves or is inclined, from the main part of the first margin to the main body, over a part of the width of the first margin providing for interlocking with a second margin.

14. A panel according to claim 13, wherein the part of the width of the first margin curves or is inclined such that the first margin has a re-entrant groove which faces across the main part towards the outer edge of the first margin, and a (2 R! CIRN418857b doc I. I_ resultant rib which faces across the back of the main body and by which the first margin is able to interlock with a second margin.

A panel according to any preceding claim, wherein the first margin is configured to the form of a channel which opens towards a front surface of the panel and has a base of which an outer side defines an abutment surface co-operable with a second margin.

16. A panel according to claims 8 to 14, wherein the first margin defines a land which is set rearwardly with respect to the main body, with the panel being curved or inclined at the inner edge of the first margin, between the land and the main body.

17. A panel according to claim 16, wherein the first margin has a turned portion at its outer edge which extends rearwardly with respect to the land and defines an ,en su Id U; wnhicn faces away from the main body.

18. A panel according to claim 17, wherein the turned portion is of V-section such that it has a first leg extending rearwardly from the flange and defining the abutment, and a second leg which extends forwardly from the second leg towards the rear of the land.

19. A panel according to any preceding claim, wherein the margins are configured such that the first margin is adapted to interlock with the second margin 20 of an adjacent like panel by a rib adjacent to one side of the first margin engaging *in an interlock groove adjacent to the other side of the second margin.

A panel according to any one of claims 1 to 18, wherein the margins are configured such that the first margin is adapted to interlock with the second margin of a an adjacent like panel by a respective rib adjacent to each side of the first margin engaging in a respective interlock groove adjacent to a respective side of the second margin.

21. A panel according to any one of claims 1 to 19, wherein the margins are configured such that the first margin is adapted to interlock with the second margin of an adjacent like panel by an interlock groove at one side of the first margin engaging with a rib adjacent to the other side of the second margin.

22. A panel according to any one of claims 1 to 4, or to any one of claims 6 to 18 when not appended directly or indirectly to claim 5, wherein the margins are configured such that the first margin is adapted to interlock with the second margin an adjacent like panel by a respective interlock groove adjacent to each edge of 4C CIRN4168C 01 Oc DIIM. 18 the first margin engaging with a respective rib adjacent to a respective side of the second margin.

23. A panel according to any preceding claim, wherein the margins are configured such that, with a first panel secured to a vertical wall structure with its margins horizontal and its second margin uppermost, a second like panel can be placed against the first panel with its first margin overlapping and interlocked with the second margin of the first panel, and the interlocked margins are able to support the second panel until fasteners are applied to secure the second panel to the structure.

24. A panel according to any preceding claim, wherein the at least one groove or channel of the main body opens to the front surface thereof.

A panel according to claim 23 or claim 24, wherein the at least one groove o r r h n n H or channel divides the main boduuuy into at least two portions with each portion of the main body being configured so as to simulate the form of a timber weather-board.

26. A panel according to any preceding claim, wherein said panel is formed of sheet material. 0

27. A panel according to claim 26, wherein said panel is formed of metal sheet 0" material by roll forming, folding and/or pressing.

28. A panel according to claim 1, substantially as herein described with 20 reference to any one of the embodiments thereof illustrated in the accompanying drawings.

29. A building structure having applied thereto a wall cladding formed from an 00** too"" array of panels each according to any one of claims 1 to 28, wherein the panels 9. are disposed in successive, laterally adjacent rows in which the first margin of the 925 or each panel of one row overlaps and is interlocked with the second margin of the or at least one panel of a next adjacent row. A structure according to claim 34 comprising a wall, with said rows extending horizontally and each panel having its second margin uppermost. DATED: 7 October 1999 PHILLIPS ORMONDE FITZPATRICK Attorneys for: STRAMIT CORPORATION LIMITED SRNC RN416857bdo OC01Jg9