Patent Publication Number: US-2016244974-A1

Title: Building array

Description:
FIELD OF THE INVENTION 
     The present invention relates to a building array comprising a building element and a boundary element which are suitable for use as decking, flooring or cladding materials, in particular the building array is suitable for use as a non-combustible exterior decking, interior flooring or an interior and exterior cladding array. 
     The invention has been developed primarily for use as a non-combustible decking array for exterior use in a residential dwelling or as an exterior and/or interior cladding system in a residential dwelling or commercial building. The use of the present invention will be described hereinafter with reference to the aforementioned applications. It is to be understood that reference to the use of the present invention in relation to a non-combustible decking array or as an exterior or interior cladding system should not be seen as limiting. It is also to be understood that the terms decking array, exterior cladding system and interior cladding system are used interchangeably throughout the specification to describe the present invention. 
     BACKGROUND OF THE INVENTION 
     Any discussion of the prior art throughout the specification should not be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field. 
     Aesthetically pleasing exterior decking partially or completely surrounding at least one level of a residential dwelling construction is known. Decking is traditionally made of wood for its ease of use and installation. In recent years, decking has also been made from wood-plastic composites (WPCs) which mimic the appearance and feel of timber. Neither timber nor WPC decking is fire resistant. Consequently the hazard of using such material to build decking particularly in fire prone areas is prohibitive. Separately, construction of decking, could also be prohibited by local or national building codes or regulations. 
     Attempts have been made in the past to modify the physical properties of timber to improve its fire resistant properties. Such attempts include, for example, impregnation of timber materials with fire retardant chemicals. The cost of treated timber is higher than that of untreated timber, which in turn impacts the end-user. There are also environmental concerns when using treated timbers due to the increased possibility of environmental pollution should the chemicals be released from the timber. 
     Furthermore the original method of fastening building materials, such as decking or cladding, to underlying support structures has been nailing through the face of the building material and into the underlying support structure. Face nailing is quick and requires a minimal initial skill level but subsequently requires a higher skill trades person to disguise or obscure fixing points to enable an acceptable finish level to be created in the completed construction. 
     Different cladding applications require different nail installation techniques, either ending in nail heads sitting just above the cladding surface, flush with the cladding surface, or punched below the cladding surface. When installing over large cladding expanses, nailing to a consistent nail head position is difficult. In addition, nailing or screw fastening onsite is not desirable when the cladding material is prefinished with a decorative surface coating. Precoating fasteners to colour match provides some level of disguise but the actual fastener heads are still visible, detracting from the aesthetics of a completed wall section installation. 
     OBJECT OF THE INVENTION 
     It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. 
     It is therefore an object of the present invention to provide an aesthetically pleasing building array suitable for use as a non-combustible decking array for exterior use in a residential dwelling or as an exterior and/or interior cladding system in a residential dwelling 
     It is acknowledged that the term ‘comprise’ may, under varying jurisdictions be provided with either an exclusive or inclusive meaning. For the purpose of this specification, the term comprise shall have an inclusive meaning that it should be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components. Accordingly, the term ‘comprise’ is to be attributed with as broad an interpretation as possible within any given jurisdiction and this rationale should also be used when the terms ‘comprised’ and/or ‘comprising’ are used. 
     Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only. 
     SUMMARY OF THE INVENTION 
     According to the invention, there is provided a building array comprising,
         at least one building element comprising a first face, a second face and a peripheral edge member, the first face and second face being spaced apart to define an intermediate portion, the peripheral edge member extending around the intermediate portion whereby at least a portion of the peripheral edge member comprises an edge profile; and   at least one boundary element comprising a planar base member removably attachable to a structural support element, at least one flange extending substantially orthogonally from the planar base member and an edge restraining formation extending laterally from the flange remote from the planar base member wherein the edge restraining formation is configured for releasably engaging with the edge profile of the building element,   whereby, the at least one building element and the at least one boundary element are arrangeable together in series on a structural support element to form the building array.       

     The advantage of the building array of the present invention is that it provides an aesthetically acceptable level of surface finish in a completed construction that is also quick and simple to install. Conveniently the building elements of the invention can be formed from any material suitable for use in an exterior or interior building application, as required. Such materials may include timber, engineered cement composites including fibre cement, engineered wood composites, polymers, polymer composites and the like. When a non-combustible building array is required by an end user it is preferable for the building elements to be formed for a suitable non-combustible material such as fibre cement. 
     In one embodiment of the invention each of the first and second face, the intermediate portion and the peripheral edge member are integrally formed together as a single unit. 
     In a further embodiment of the invention the thickness of the intermediate portion is variable and is selected by the manufacturer. In the preferred embodiments of the invention the thickness of the building elements are tailored to provide consumers with a choice of predetermined thickness options for a given product or product range. In one embodiment of the invention the intermediate portion of the building element is at least approximately 12 mm thick. The advantage of this particular thickness is that the building element is able to sustain significant wind loading when placed in a building array which is in the form of an exterior cladding system. 
     In a further embodiment of the invention, the integrally formed peripheral edge member comprises two pairs of spaced apart opposing side edges. In a preferred embodiment of the invention each pair of spaced apart opposing side edges is positioned in a contiguous orthogonal arrangement relative to the other pair of spaced apart opposing side edges such that each side edge in a pair is in abutment with both side edges in the other pair, the side edges thereby extending around each side of a substantially rectangular building element enclosing the intermediate portion. It is to be understood that the substantially rectangular building element of the invention can be of any shape or size as determined by the person skilled in the art. It is preferable when the building element is being used as part of a building array in the form of a decking system that the substantially rectangular building element is in the form of an elongate substantially rectangular building element. 
     In a further embodiment of the invention the edge profile can be formed on one or more of the side edges of the building element. 
     In a further embodiment the edge profile is in the form of a recess or channel or groove. 
     In a further embodiment of the invention, the edge profile divides the peripheral edge member or side edges of the building element into a first portion and a second portion, the first portion corresponding to the section of the building element including and adjacent to the first face and the second portion of the building element including and adjacent to the second face. The relative position of the edge profile is selected to provide alternate aesthetic effects within the building array or completed construction. It is preferable to ensure that a sufficient thickness of material is retained within the first and second portions such that the first portion has sufficient depth to assist in prevention of damage to the building element during handling and installation. 
     In one embodiment of the invention, the edge profile has a predominantly central position on the peripheral edge member or side edge. 
     In a further embodiment of the invention, the building array comprises a building element in which the second portion of the peripheral edge member or side edge is of a different size to that of the first portion of the peripheral edge member or side edge. In one embodiment of the invention the distance between opposing points on the peripheral edge member of the first portion is greater than the distance between opposing points of the peripheral edge member of the second portion such that the second portion is shortened relative to first portion of the peripheral edge member or side edge. 
     In a further embodiment of the invention the first face is defined as the visual face or surface of the building element. In one embodiment of the invention the first face is adapted to receive a range of surface treatments such as a decorative paint finish, tiles, and the like. In another embodiment of the invention the second face is adapted to receive a range of surface treatments. In one embodiment of the invention, the surface treatments are mechanically or chemically fixed to the second face to modify the aesthetic or physical properties of the building array. An example of a surface treatment includes adhesion of a thermal insulation material to the second face. In a further embodiment of the invention both the first and second faces are adapted to receive one or more of a range of surface treatments, examples of which are outlined above. 
     In one embodiment of the invention the boundary element comprises a boundary edging element suitable for use as the first edge or terminating edge of a building array. The boundary edging element of the invention comprises a planar base member, at least one flange extending substantially orthogonally from the planar base member and an edge restraining formation extending laterally from the flange remote from the planar base member, whereby the base member, flange and edge restraining formation are arranged to form a substantially ‘C’-shaped channel. 
     In a further embodiment of the invention the flange of the boundary edging element extends substantially orthogonally from a central or median position on the planar base member such that the planar base member extends outwards in opposing directions on either side of the flange. It is to be understood that the portions of the planar base member extending on either side of the flange do not need to be equidistant. 
     In a further embodiment of the invention, the boundary edging element of the invention is adapted to receive the first face of the building element thereby providing a capping member that encloses at least a portion of the peripheral edge member of the building element. 
     In a further embodiment of the invention the boundary element comprises a boundary joining element, comprising at least two spaced apart flanges extending substantially orthogonally from the planar base member, whereby the two spaced apart flanges and base member are configured to form at least one substantially “U” shaped channel. In this embodiment of the invention, each flange terminates in a leg or edge restraining formation extending substantially parallel to the planar base member. 
     In a further embodiment of the invention the boundary joining element comprises a planar base member which is configured together with flanges to provide three conjoined channels wherein the central channel is a substantially “U”-shaped channel, the base member and flanges of the boundary joining element forming the base member and side members of the central channel and the channels on either side of the central channel are substantially ‘C’-shaped channels facing in opposing directions, the flanges, base member and edge restraining formation forming the base members and respective side members of the channels positioned on either side of the central channel. 
     In a further embodiment of the invention, the boundary joining element is sized and shaped to facilitate a junction between two panels of unequal thickness or alternatively a junction between a building element of the invention and an alternate building material or structure. 
     In a further embodiment of the invention the base members of the boundary elements further comprise at least one fixing location indicators. One or more fixing location indicators being selected from the group comprising an aperture, recesses such as indentations or surface markings engraved into the surface or applied to the surface. 
     In one embodiment of the invention the fixing indicators are positioned on the base member such that a building element will cover the fixing location indicators when positioned within a building array. 
     The advantage of the fixing indicators is that they show a user the preferred point at which the boundary elements should be fixed to a structural support member. Ideally, the boundary elements are secured to a structural support element, by means of mechanical fixing means such as nails, screws, staples and/or scrails. 
     The boundary elements engage with the building elements such that boundary elements attach the building elements to a structural support member without the need for face fixing of the building elements. Significantly, the boundary elements when secured to a structural support member prevent substantial lateral or orthogonal movement of the building element relative to the structural support member. The advantage of this is that the building elements have freedom to cycle through thermal expansion and contraction effects due to environmental conditions without stress being placed at specific sites of a building element where mechanical fixing means would normally be positioned. 
     In a further embodiment of the invention, the building array further comprises a cover element comprising a top member including a first cover element face and a second cover element face and a pair of legs, each leg extending substantially orthogonally from the second cover element face. The cover element is used to conceal at least a portion of boundary joining element. 
     In a further embodiment of the invention each leg further comprises a restraining formation shaped to form a frictional fit of the cover element into the “U” shaped channel of the boundary joining element. 
     In a further embodiment of the invention, the flanges of the boundary joining element are provided with a detent at an appropriate location to seat and hold the restraining formation of the cover element such that the restraining formation can only be released from the detent by application of an external force. Advantageously, the restraining formation and detent are of complimentary shape to enable the detent to position and hold the restraining formation. 
     In a further embodiment of the invention, the cover element comprises a protrusion extending from at least a portion of the first cover element face. The protrusion is provided to alter the direction of flow of water away from the visual face of the building elements when in a building array. By altering the direction of flow of water away from the building array, the opportunity for water to percolate between the cover element and the boundary element of the building array is minimised. Conveniently the protrusion can be of any suitable shape or form to achieve the desired effect. In one embodiment of the invention, the protrusion is in the form of an ‘I’ or an I′ shaped protrusion. It is to be understood that these shapes should not be seen as limiting, any shape known to a person skilled in the art which will achieve the desired effect can also be used. 
     In a further embodiment of the invention, the first cover element face has an applied surface treatment. Ideally, the surface treatment is selected to suit the material from which cover element is made and is used to provide a low cost aesthetically pleasing finish on the first cover element face. For example, when the cover element is a metal cover element, surface treatments include abrading, machining, painting, etching, and/or anodising. Alternatively, in a further embodiment of the invention the surface treatment may consist of applying a polymer trim by chemically fixing the trim to the first cover element face. Usually, such a polymer trim would be chemically fixed by gluing. 
     In a further embodiment of the invention, the boundary elements and cover element are formed from any one of the materials selected from the group comprising metals, ceramics, polymers or polymer composites. In a further embodiment of the invention, the boundary elements, cover element and channels formed therein are preferably formed by techniques known to the person skilled in the art. For example, where the boundary elements or cover element are formed from a polymer or polymer composite material, the or each element may be formed by any suitable method known in the art, such as extrusion, pultrusion, injection moulding, compression moulding, vacuum forming and line bending. Alternatively, the boundary elements or cover element may be formed from a metal, by commonly known methods such as extrusion. 
     In a further embodiment of the invention the boundary elements or cover element may also be formed as discrete units or may be formed in predefined lengths, for example, in the form of elongate boundary or cover elements, depending on the forming method selected. 
     According to the invention, there is also provided a method of constructing a building array on a structural support element, the method comprising the steps of
         (a) installing a boundary element on at least a portion of the structural support element using at least one conventional fixing means, the elongate boundary element comprising a planar base member removably attachable to a structural support element, at least one flange extending substantially orthogonally from the planar base member and an edge restraining formation extending laterally from the flange remote from the planar base member;   (b) seating a first building element into the boundary element, the building element comprising a first face, a second face and a peripheral edge member, the first face and second face being spaced apart to define an intermediate portion, the peripheral edge member extending around the intermediate portion whereby at least a portion of the peripheral edge member comprises an edge profile configured for releasably engaging the edge restraining formation, the building element being seated such that the edge restraining formation of the boundary element engages with the edge profile of the building element;   (c) installing a further boundary element on a further portion of the structural support element using at least one conventional fixing means such that the edge restraining formation of the further boundary element engages with a further portion of the edge profile formation of the building element to secure the building element in position on the structural support element.       

     In a further embodiment of the invention the method further comprises the following steps after step (b) and before step (c);
         (b1) installing a boundary element on a further portion of the structural support element using at least one conventional fixing means, the boundary element comprising at least two spaced apart flanges extending substantially orthogonally from the planar base member, whereby the two spaced apart flanges terminate in first and second edge restraining formations respectively, the two spaced apart flanges and base member are configured to form at least one substantially “U” shaped channel,
           such that the first edge restraining formation of the boundary element engages with an portion of the edge profile formation of the building element of step (b) to secure the building element of step (b) in position on the structural support element; and   
           (b2) seating a further building element such that the second edge restraining formation of the boundary element engages with a portion of the edge profile formation of the further building element;   (b3) installing a further boundary element from step (b1) on a further portion of the structural support element using at least one conventional fixing means, such that the first edge restraining formation of the boundary element engages with an portion of the edge profile of the building element of step (b2) to secure the building element of step (b2) in position on the structural support element; and   (b4) repeating the steps of (b2) and (b3) as required.       

     In a further embodiment of the invention, the method further comprises the step of;
         (d) installing a cover element into the substantially “U” shaped channel of the boundary element of step (b1), the cover element comprising a top member including a first cover element face and a second cover element face and a pair of legs, each leg extending substantially orthogonally from the second cover element face.       

     When the building array of the present invention is used in a decking application, particularly in a bushfire prone area, one advantage of using continuous length elongate boundary joining elements is that there is no gap between cladding elements to allow hot embers and the like to pass through the deck to any underlying material. Thus elongate boundary joining elements eliminate the gaps traditionally found between decking elements. Removal of these gaps prevents hot embers being able to migrate between decking elements and ignite any flammable materials deliberately or unintentionally present in the ground clearance space beneath the decking. 
     When the building array of the present invention is used in a cladding application, the building elements and boundary elements are arranged to form a rain screen over the structural substrate. In a further embodiment of the invention there is provided a water impermeable and/or breathable membrane in the form of a building wrap intermediate the building array and the structural substrate to form a water impermeable barrier over the structural substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described more particularly with reference to the accompanying drawings, which show by way of example only four embodiments of the building array of the invention. 
       In the drawings, 
         FIG. 1  is a partial perspective view of a building element according to the invention; 
         FIG. 2  is a partial perspective view of a boundary joining element according to the invention; 
         FIG. 3  is a partial perspective view of a cover element according to the invention; 
         FIG. 4  is a partial perspective view of a boundary edging element according to the invention; 
         FIG. 5  is a partial perspective view of an alternately configured boundary edging element according to the invention; 
         FIG. 6  is a partial perspective view of an alternate configuration of the building element of  FIG. 1 ; 
         FIG. 7  is a partial perspective view of an alternate configuration of the boundary joining element of  FIG. 2 ; 
         FIG. 8  is a cross-sectional partial side view of a first embodiment of the building array according to the invention 
         FIG. 9  is a cross-sectional partial side view of a second embodiment of the building array according to the invention; 
         FIG. 10  is a cross-sectional partial side view of a third embodiment of the building array according to the invention; 
         FIG. 11  is a front partial-sectional view of a fourth embodiment of the building array according to the invention; and 
         FIG. 12  is a front partial-sectional view of a fifth embodiment of the building array according to the invention. 
     
    
    
     Referring initially to  FIGS. 1 and 6 , there are shown two embodiments of a building element  100 ,  200  of the present invention. Building elements  100  and  200  each comprise a first face  102 ,  202  and a second face  104 ,  204 , the second face being spaced apart from the first face  102 ,  204  to define an intermediate portion  106 ,  206  of predetermined thickness. The first face  102 ,  202  is also defined as the visual surface of building element  100 ,  200 . The thickness of the intermediate portion is variable and is selected by the manufacturer. The thickness of the building elements  100 ,  200  are tailored to provide consumers with a choice of predetermined thickness options for a given product or product range. In a further embodiment of the building elements of the invention  100 ,  200  the first face  102 ,  202  is adapted to receive a range of surface treatments such as a decorative paint finish, tiles, and the like. In another embodiment of the building elements of the invention  100 ,  200  the second face  104 ,  204  is also adapted to receive a surface treatment such as a thermal insulation material mechanically or chemically fixed to the face  104 ,  204  to modify the physical properties of the building array. Optionally, in a further embodiment of the invention both the first  102 ,  202  and second faces  104 ,  204  are adapted to receive surface treatments as outlined above. 
     Building elements  100 ,  200  of the invention can be formed from any material suitable for use in an exterior or interior building application, as required. Such materials may include timber, engineered cement composites including fibre cement, engineered wood composites, polymers, polymer composites and the like. 
     The building elements  100 ,  200  further comprise an integrally formed peripheral edge member  108 ,  208  extending around the intermediate portion  106 ,  206 . In the embodiments shown, building elements  100 ,  200  comprise a hexahedron shape whereby four faces of the hexahedron shape are formed by the integrally formed peripheral edge member  108 ,  208 . In the embodiments shown, the integrally formed peripheral edge member  108 ,  208  comprises two pairs of spaced apart opposing side edges. Each pair of spaced apart opposing side edges are positioned in a contiguous orthogonal arrangement relative to the other pair of spaced apart opposing side edges such that each side edge in a pair is in abutment with both side edges in the other pair, the side edges thereby extending around each side of the substantially rectangular building elements  100 ,  200  enclosing the intermediate portion  106 ,  206 . Only one pair of spaced apart opposing side edges are shown  110 ,  210  in  FIGS. 1 and 6 . In the preferred embodiment of the invention each of the first  102 ,  202  and second face  104 ,  204 , the intermediate portion  106 ,  206  and the peripheral edge member  108 ,  208  are integrally formed together as a single unit. 
     Each of side edges  110 ,  210  comprise an edge profile  112 ,  212 . It is to be understood, edge profile  112 ,  212  can be formed on one or more of the side edges of the building element  100 ,  200 . In the embodiments shown, the edge profile  112 ,  212  is in the form of a recess or channel or groove. The edge profile  112 ,  212  is adapted to releasably engage an edge restraining formation  310 ,  410 ,  510 ,  610  as shown in  FIGS. 2, 4, 5 and 7 . The edge profiles  112 ,  212  of building elements  100 ,  200  formed on the elongate side edges  110 ,  210 , divide side edge  110 ,  210  into a first portion  114 ,  214  and a second portion  116 ,  216 . In the embodiments shown, edge profile  112 ,  212  has a predominantly central position on the side edge  110 ,  210 . It is to be understood that the edge profile  112 ,  212  does not need to be centrally located on the side edge  110 ,  210  any suitable location known to a person skilled in the art can be used. The relative position of edge profile  112 ,  212  is selected to provide alternate aesthetic effects within the building array or completed construction. It is preferable when determining the position of the edge profile  112 ,  212  to leave sufficient material on the visual surface, i.e. the first face  102 ,  202  to prevent damage during handling and installation. 
     The difference between the building element  100  of  FIG. 1  and building element  200  of  FIG. 6  is that the second portion  216  of side edge  210  adjacent edge profile  212  has been shortened relative to first portion  214  of side edge  210 . 
     Referring now to  FIGS. 2   4 ,  5  and  7 , there are shown a partial perspective views of four embodiments of a boundary element. The embodiments shown in  FIGS. 2 and 7  are boundary joining elements  300 ,  400 , whilst the embodiments shown in  FIGS. 4 and 5  are boundary edging elements  500 ,  600 . 
     Boundary joining elements  300 ,  400  are configured to form at least one substantially “U” shaped channel  302 ,  402 , having a base member or web  304 ,  404  from which two spaced apart flanges  306 ,  308 ,  406  and  408  extend substantially orthogonally. Each flange  306 ,  308 ,  406 ,  408  terminates in a leg or edge restraining formation  310 ,  410  extending substantially parallel to base member  304 ,  404 . Boundary joining element  300  differs from boundary joining element  400 , in that the base member  304  of boundary joining element  300  extends outwardly in the same plane in opposing directions such that the base member  304  is configured together with flanges  306 ,  308  and legs  310  to provide three conjoined channels  302 ,  302   a  and  302   b . Channel  302  is a substantially “U”-shaped channel wherein the base member  304  of the boundary joining element  300  forms the base member and flanges  306 ,  308  form the side members of channel  302 . Channels  302   a  and  302   b  are substantially ‘C’-shaped channels facing in opposing directions, flanges  306 ,  308  form the respective base members of channels  302   a  and  302   b  and base member  304  and edge restraining formation  310  of the boundary joining element  300  form the respective side members of channels  302   a  and  302   b.    
     Each of base members  304 ,  404  are configured to provide fixing indicators  312 ,  412 . As shown in  FIGS. 2 and 7 , fixing indicators  312 ,  412  are in the form of at least one aperture. In alternate embodiments of the invention fixing indicators  312 ,  412  may also be in the form of recesses such as indentations, surface markings as engraved or applied to the surface, and the like. The fixing indicators  312 ,  412  are provided to show a user the preferred point at which the boundary joining element  300 ,  400  should be fixed to a structural support member, for example, a timber frame. As detailed below, in use the boundary joining elements  300 ,  400  are secured to a structural support element, by means of mechanical fixing means such as nails, screws, staples and/or scrails. 
     Referring now to  FIG. 4 , there is shown a first boundary edging element  500  for use at an edge of an array of building elements  100 ,  200 . First boundary edging element  500  is suitable for use as the first edge of a building installation. First boundary edging element  500  comprises a first arm or flange  506  extending substantially orthogonally from base member  504 . Flange  506  terminates in edge restraining formation or leg  510  extending substantially parallel to base member  504 , forming a substantially ‘C’-shaped channel  502   a . Base member  504  includes a number of fixing location indicators  512 . In the embodiment shown, fixing indicator  512  is in the form of an aperture. Alternative fixing indicators  512  could be recesses such as indentations or could be surface markings engraved into the surface or applied to the surface. The position of fixing indicators  512  in the embodiment shown requires that first boundary edging element  500  is fixed in position before the first building element  100 ,  200  is positioned in the building array. Once in place, building elements  100 ,  200  will obscure the fixing location indicators  512  on first boundary edging element  500 . 
     Referring now to  FIG. 5 , there is shown an alternate configuration for a boundary edging element  600 . Second boundary edging element  600 , is also suitable for use at an end of an array of building elements  100 ,  200 . Second boundary edging element  600  has a first flange or arm  606  extending substantially orthogonally from base member  604 . Flange  606  supports edge restraining member or leg  610  extending substantially parallel to base member  604  forming a substantially ‘C’-shaped channel  602   a . Fixing indicators  612  in base member  604  provide guidance for users as to preferred or recommended fixing spacings for attaching the boundary edging element  600  to a structural support by means of mechanical fixing. In this example, the location of the fixing indicators  616  is not obscured by positioning of building elements  100 ,  200 . Accordingly second boundary edging element  600  and can be used as either the first installed or the last installed boundary edging element, for providing a restraining edge formation in a building array. 
     Referring now to  FIG. 3 , there is shown a cover element  700  of the invention. Cover element  700  is used to conceal at least a portion of boundary joining element  300 ,  400  of  FIGS. 2 and 7 . Cover element  700  comprises a substantially ‘Omega/Ω’-shaped profile  702  comprising a top or planar member  704  including a first cover element face  706  and a second cover element face  708  and a pair of legs  710 ,  712 , each leg  710 ,  712  extending substantially orthogonally from the second cover element face  708 . Each leg  710  and  712  is provided with a restraining formation  710   a ,  712   b  to form a frictional fit of the cover element  700  into the “U” shaped channel  302 ,  402  of boundary joining element  300 ,  400 . Although not shown in  FIG. 3 , the first cover element face  706  has an applied surface treatment (Feature  706   a  of  FIG. 10 ). The surface treatment is selected to suit the material from which cover element  700  is made and is used to provide a low cost aesthetically pleasing finish on the first cover element face  706 . For example, when the cover element  700  is a metal cover element, surface treatments include abrading, machining, painting, etching, and/or anodising. Alternatively, in a further embodiment of the invention the surface treatment may consist of applying a polymer trim by chemically fixing the trim to the first cover element face  706 . Usually, such a polymer trim would be chemically fixed by gluing. 
     The boundary elements  300 ,  400 ,  500 ,  600 , cover element  700  and channels formed therein are preferably formed by extrusion techniques as known to the person skilled in the art. For, example, where the boundary elements  300 ,  400 ,  500 ,  600  or cover element  700  are formed from a polymer or polymer composite material, the or each element may be formed by any suitable method known in the art, such as extrusion, pultrusion, injection moulding, compression moulding, vacuum forming and line bending. Alternatively, the boundary elements  300 ,  400 ,  500 ,  600  or cover element  700  may be formed from a metal, by commonly known methods such as extrusion. The boundary elements  300 ,  400 ,  500 ,  600  or cover element  700  may also be formed as discrete units or may be formed in predefined lengths, depending on the forming method selected. 
     Referring now to  FIGS. 8 and 10 , there is shown a cross-sectional partial side view of a first embodiment of an assembled building array in the form of a decking array  800 . The portion of decking array  800  shown in  FIG. 8  comprises the components of  FIGS. 1, 2 and 3  seated together on a structural substrate  802 , referred to as a structural decking substrate for the purposes of this embodiment. The portion of decking array shown in  FIG. 10  is an enlarged view of a boundary joining element  400  intermediate two adjacent building elements  100 . For the sake of clarity, not all of the reference numerals shown in  FIGS. 1, 2 and 3  have been replicated on  FIGS. 8 and 10 . It is to be understood that the reference numerals referred to below in respect of  FIGS. 8 and 10  correspond to those elements in common with and as shown in  FIGS. 1, 2 and 3 . 
     Although the edge of the area to be covered is not shown, the non-combustible decking array  800  as shown in  FIG. 8  is provided by first installing an elongate boundary edging element  500 ,  600  at one edge of the area to be covered. The elongate boundary edging element  500 ,  600  is positioned in a user defined location on structural decking substrate  802  and fixed to it in at least one location using at least one conventional fixing means  804  such as nailing, screwing, bolting and the like. A first building element  100  is positioned so that the second portion  116  of side edge  110  is seated within the substantially ‘C’-shaped channel  502   a ,  602   a . In this way, edge member  108  is restrained in position. First portion  114  of side edge profile  110  covers edge restraining formation  510 ,  610  providing protection for the edge restraining formation  510 ,  610  and provides an improved aesthetic in the installed array  800 . 
     In the embodiment shown in  FIG. 8 , a boundary joining element  300  is then positioned such that the second portion  116  of the opposing side edge  110  of the first placed building element  100  is seated within the substantially ‘C’-shaped channel  302   a  of boundary joining element  300 . The position of this and subsequent boundary joining elements  300  is determined by the size of the building elements  100  being used. Base member  304  of boundary joining element  300  ensures that the second face  104  of building element  100  is slightly raised from structural decking substrate  802  to provide a capillary break. Provision of a capillary break, improves moisture drainage between building elements  100  and structural decking substrate  802  on which building elements  100  are installed. 
     The procedure of placement of building elements  100 ,  200  and boundary elements  300 ,  400 ,  500 ,  600  is repeated until the desired area is covered by an array of building elements  100 ,  200 , elongate boundary joining elements  300 ,  400  and boundary edging elements  500 ,  600  to form a non-combustible decking array  800 . Boundary joining elements  300 ,  400  and boundary edging elements  500 ,  600  are placed to prevent movement of the building elements  100 ,  200  away from the structural decking substrate  802  in lateral and orthogonal directions. 
     The decking array embodiment shown in  FIG. 10  is constructed in a similar way to that of  FIG. 8  however the second portion  116  of the opposing side edge  110  of the first building element  100  is seated within the gap formed between the edge restraining formation  410  and the structural decking substrate  802 . An optional breathable membrane or building wrap  808  is positioned between the second portion  116  of building element  100  and the structural decking substrate  802 . In each case base member  304 ,  404  is maintained in contact with structural decking substrate  802  and is fixed in place at one or more fixing locations using conventional mechanical fixing means  804 . 
     Cover element  700  is placed in position to cover and conceal the boundary joining element  300 ,  400  intermediate two adjacent building elements  100 . Legs  710  and  712  provide a frictional fit of the cover element  700  into the “U” shaped channel  302 ,  402  of boundary joining elements  300 ,  400 . Each cover element  700  is positioned by applying pressure to the first cover element face  706  sufficient to overcome the frictional resistance of restraining formations  710   a ,  712   b  and to urge legs  710  and  712  into the recess of the substantially ‘U’-shaped channel  302 ,  402  of boundary joining elements  300 ,  400 . The travel distance of the cover element  700  is limited by the second cover element face  708  contacting the ends of flanges  306 ,  308 ,  406 ,  408  of boundary joining elements  300 ,  400  remote from the base element  304 ,  404 . Cover element  700  is maintained in position by tension forces between restraining formation  710   a  and  712   b  and flanges  306 ,  308 ,  406 ,  408  of joining elements  300 ,  400 . 
     Referring now to  FIG. 9 , there is shown a similar building array to that shown in  FIG. 8 , wherein the building elements  200  ( FIG. 6 ) are joined using the boundary joining element  400  ( FIG. 7 ) to form the non-combustible decking array. In this embodiment of the invention the building element  200  as shown in  FIG. 6  and boundary joining element  400  as shown in  FIG. 7  are configured so that building element  200  has second portion  216  of side edge  210  recessed compared to first portion  214  of side edge  210 . In this way, when edge profile  210  is releasably engaged with edge restraining formation  410  of boundary joining element  400 , each edge restraining formation  410  are concealed from direct view by first portion  214  of side edge  210  of building element  200 . Mechanical fixings  804  and/or fixing indicators (not shown) are visible in this configuration. The decking array of  FIG. 9  is constructed in the same manner as described for  FIGS. 8 and 10 . 
     In a decking application, particularly for a bushfire prone area, one advantage of using continuous length elongate boundary joining elements is that there is no gap between cladding elements to allow hot embers and the like to pass through the deck to any underlying material. Thus elongate boundary joining elements eliminate the gaps traditionally found between decking elements. Removal of these gaps prevents hot embers being able to migrate between decking elements and ignite any flammable materials deliberately or unintentionally present in the ground clearance space beneath the decking. Building elements  100 ,  200 , boundary joining elements  300 ,  400 ,  500  and  600  and cover element  700  are each formed from non-combustible materials and so will also prevent combustion of the decking structure caused by contact with hot embers. 
     Referring now to  FIGS. 11 and 12 , there is shown a front partial-sectional view of a façade cladding system  900 ,  902 . The façade cladding system  900  comprises a boundary edging element  600  and a boundary joining element  300  which is fixed to structural substrate element  802  in a predetermined position using mechanical fixings  804  such as nails, screws, scrails, staples and the like, and a plurality of building elements or façade panels  100 . 
     Façade panels  100  are positioned so that an edge profile  112  releasably engages an edge restraining formation  610 ,  310  of boundary edging element  600  and boundary joining element  300  respectively. Optionally, adhesive  806  may be used on some structural support elements  802  to provide either a temporary or a permanent benefit in the façade construction, either acting simply as an aid to installation or to provide additional mechanical strength to the constructed façade. Where this option is used, adhesive  806  makes contact with second face  104  of building elements or façade panels  100  when in position. It is to be understood that in the example shown building elements  100  are used, any other suitable type of building element, for example, building element  200  could also be used in the façade cladding system of the invention. 
     Once a building element or façade panel  100  is fixed in a desired position, additional boundary joining elements  300  are positioned such that one of a pair of edge restraining formations  310  releasably engages an edge profile  112  on building element  100 . Boundary joining elements  300  may be discrete elements or may be lengths sufficient to restrain a side edge of one cladding element or sufficient to restrain several cladding elements. The base member  304  of each boundary joining element  300  is fixed to structural support element  802  in user selectable positions. Fixing indicator positions  312  may be indicated by markings or recesses in, or apertures through, base member  304 . Fixing indicator positions  312  enable consistent and reproducible fixing spacing guides for installers. In practice, a first building element  100  is positioned, and two adjacent edges are restrained by installing at least one boundary joining element  300 . In  FIG. 11 , the lower two building elements or façade panels  100  are shown in cutaway view to more clearly show the arrangement of underlying structural support element  802  and boundary joining elements  300 . The dotted line  100   a  outlines show the depth of the side edge profiles  112  and the edge restraining formations  310  provided by each boundary joining element  300 . 
     In this example building element  100 , is a façade panel with a factory applied coating. In alternate embodiments, the coating may be applied onsite during installation. Factory applied coatings may include several layers, but has at least one layer performing as a top coat which may perform a decorative and/or protective function. The façade panel may be coated on some or all sides, however at least the building element first face or visual surface  102  is intended to have an applied top coat. 
     It is understood that façade cladding systems do not need to use building elements or façade panels all of the same dimensions. Interesting and aesthetically pleasing façades can be constructed by combining cladding elements of various sizes. Referring now to  FIG. 12 , there is shown a façade cladding system  902 , comprising building elements  120 ,  140 ,  160  and  180  of varied sizes restrained in position by boundary joining elements  300  fixed to a structural support element, such as a timber frame (not shown). Fixing elements  804  are visible in the façade system unless cover elements  700  are used to conceal them. In  FIG. 12 , a partial cutaway view of a constructed façade system shows cover elements  700  installed to provide an aesthetic highlight. First face  122 ,  142 ,  162  and  182  of building elements  120 ,  140 ,  160  and  180  in this example has a factory applied paint finish, including a top coat. 
     It will be appreciated that the cladding system as illustrated In  FIGS. 11 and 12  provides a cladding system that is quick and simple to install and that enables an aesthetically acceptable level of surface finish to be achieved in a completed construction without the need for face fixing of the building elements of the building array to a structural substrate. 
     It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the appended claims.