AU5779101A - Integrated wall system - Google Patents

Description

1 INTEGRATED WALL SYSTEM The present invention relates to improvements in wall and roof systems; that is to say systems of the kind which have claddings or veneer systems combined with structural support members. The present invention is primarily used in relation to wall and roof systems in domestic housing, but can be equally applicable to many different types of applications and to many different types of buildings.

The present invention is concerned with the integrated foam wall panel, in regard to its form, the nature of the encasement between the structural members and the foam wall block of the panel, the nature of the means of attaching other components and the method of manufacture of the integrated systems.

BACKGROUND TO THE INVENTION In known wall and roof structures of the kind that are lined with sheathing, sheet or cladding type coverings, such coverings are separate from the specifically designed structural members that form the framework and typically are installed or attached after the structural assembly is completed. In essence, there is a functional decomposition of building elements according to specific architectural or design requirements.

ooooo •.The integration of such external and/or internal linings with the specific structural elements is by cutting to size and fastening with a connection means. As such, the installation or attachment of linings to a structural assembly is a distinct and separate process in the o 20 construction of a building and so has certain material and installation time costs associated with it. The inclusion of materials that have insulating properties and others that provide a moisture sealing function also represent additional processes that have certain material and installation time costs associated with their use.

OBJECT OF THE INVENTION f 25 It is an object of the present invention to provide a wall and roof system including the types of components used and the method of their manufacture, integration and assembly, which substantially overcomes or ameliorates the disadvantages with known systems.

Specifically, this is achieved by the preferred embodiments using the integration of structural elements within external and/or internal linings, eliminating additional processes in building construction and reducing the number of components in erection, thus simplifying the overall building process and improving efficiency through reduced costs and construction times. At the very least the object of the present invention is to provide an alternative to known systems.

DISCLOSURE OF THE INVENTION The present invention provides an integrated building panel, comprised of at least one insulating foam block that has a support structure fixed to at least one of its surfaces, said block being adapted to attached directly to an existing structural element or having structural components incorporated therein to achieve required functions of strengthening, joining, installation and load bearing as required in the application of the panel within a wall or roofing system.

The veneer system of the present invention preferably comprises foam blocking such as expanded polystyrene with keyed edges to facilitate aligning and joining of adjacent panels.

The foam block is coated on at least one surface with a cementitious coating that can be finished by painting and the like, and can have integrated rails, clips, plugs, fastenings and the like to facilitate fixture to structural elements or other building surfaces.

oooThe integrated load bearing system of the present invention is preferably formed by cutting a series of shapes into a foam block, such as expanded polystyrene, which in the preferred ••form has the nominal overall dimensions ofa wall panel. The structural members, 20 preferably cold formed steel lipped or unlipped cee wall studs, are inserted into the foam panel from one or both ends and mating plate members which are preferably unlipped cee o sections are fixed to the top and bottom of the embedded wall studs. A hard cementitious surface is coated onto at least one surface of the panel and standard finishing treatments are applied as per typical painting practices. The structural wall panel assembly comprising structural members, foam blocking and the applied linings, finishings, coatings and the like can be formed or manufactured from many alternative materials that achieve the same functionality.

The typical embodiment of the wall system of the present invention is expanded polystyrene panels or sheets of depth to suit either the nominal veneer or overall building wall depth requirements, depending on non load bearing or load bearing applications 3 respectively. In load bearing applications the integrated structural are studs typically coldformed steel cee or lipped cee sections of 70mm x 35mm, 75mm x 35mm and 90mm x nominal dimensions with encasing plates or tracks of 70mm x 30mm, 75mm x and 90mm x 30mm nominal dimensions respectively, all in gauges ranging from 0.35 to 4.0mm and with galvanised or zinc/aluminium coatings. However, this by no means limits the wall system's ability to perform in a similar way in other sizes or in other base materials.

The preferred embodiments of the present invention provide an integrated building panel, comprised of at least one expanded polystyrene block that has metal or fibreglass mesh, sheeting or the like adhered or mechanically fixed to at least one of its surfaces and a cementitious finishing layer, typically render, applied over that. Structural components can be incorporated therein to achieve required functions of strengthening, joining, installation and load bearing as required in the application of the system. Alternatively, the panel can be attached directly to an existing structural element or surface by adhesives and/or fasteners.

In the preferred form of the present invention where the panel functions as a veneer or building lining, that is without specifically designed load bearing functions, only one face i of the panel has mesh and render finishing. In this form, cee section members can be used S"to cap over one or more of the perimeter sides of the panel and are attached by adhesive and/or mechanical fastening. Other sections such as top hats, square or rectangular tubes and the like can be attached across the unfinished side of the panel directly to the expanded polystyrene surface or on to clips, brackets and the like which themselves are attached to or anchored into the expanded polystyrene block, to facilitate attachment of the panel to structural elements. In this form, the sections are oriented substantially perpendicular to S 25 the structural elements the panel is being joined to.

The sections as described above can also be applied along cuts or trenches made in the expanded polystyrene so that the sections are contained within the surface of the expanded polystyrene or partially protrude from the surface. When a cee or zed section is incorporated into the panel in this manner whereby its web element is substantially perpendicular to the surface of the expanded polystyrene, one flange element is exposed to allow attachment of the panel to the structural elements and the other flange is encased in the expanded polystyrene block such that a fastening means can be installed through the mesh and block.

Also in the preferred form of the present invention where the panel functions as a veneer or building lining, it is desirable to have the ends of the expanded polystyrene block keyed to lock the joint between adjacent panels. These keying features can extend the entire side of the panel or be one or a plurality of individual keys. In wall panel applications, these joints are typically at the vertical ends of the panels. The keyed joint of this preferred form of the present invention is such that the panel which is being installed adjacent to an attached panel is aligned at an angle to the structural elements so that the edge of its tongue sits in the groove or channel and when the panel is rotated, pulls the joint tight and level on the outside surface. It is within the scope of the present invention to provide any known joint, key or locking profile.

The preferred form of the panel that functions as an integrated structural panel comprises at least one expanded polystyrene block portion and at least one structural stud member which can have a flange element that can in turn be stiffened with a lip element. In this instance the expanded polystyrene block portion can form either or both the external and/or internal linings of the wall system. It is within the scope of the present invention to provide any geometrical profile or form to the block portion or portions to suit any particular form of integrated structural member, and it is also within the scope to have any 20 geometrical or material form of structural member, for example rectangular section timber.

Typically, the load bearing structure of this preferred form of the present invention comprises a plurality of substantially parallel arranged structural stud members that are .joined at their extremities to plate members. The fastening means used to join the structural members together into framework can be screws, nails, rivets, bolts, welds and 25 the like or may be by integral clinches, hooks, clips, tags or adhesives. The expanded polystyrene can completely encase the stud members, in which case the mesh and render finish is preferably applied to both faces, or may encase one flange element and part or all of the web element of the stud members so that a flange element is exposed for the attachment of conventional linings such as plasterboard or for fixing off brick ties in brick veneer construction, then the mesh and render finish is only applied to one face.

'I r The attachment of the mesh to the expanded polystyrene can be such that the integrated system has a shear resistance that can be utilised as structural bracing.

It is also within the scope of the present invention to provide additional structural elements as required such as for heads and sills and jamb studs at openings in wall systems, as is typical in framed construction.

It is further within the scope of this preferred form of the present invention to provide horizontally aligned sections as disclosed above for the non load bearing form of the present invention. These can be attached to the expanded polystyrene for the form that encases the entire stud member in a manner as disclosed above, or directly to flanges of the stud member by mechanical fastening means.

In this preferred load bearing form of the panel of the present invention, keyed joints as disclosed above for the non load bearing form of the present invention can also be employed to join adjacent panels. They can also be installed into and joined using suitable capping members, preferably cee section tracks that are continuous through a join, when capped over the expanded polystyrene blocks or the studs, or the plate members depending on the orientation of the join.

S* It is within the scope of the present invention to have panels aligned and joined in any o• direction. For example, in walling applications the preferred form has joins running vertically at the ends of the panels, but it is equally applicable to have the joins running 20 horizontally with the panels stacked and keyed in on top of each other.

Services such as water, and electrical and communication cabling can be run through holes "formed through the panels, or cut into the surface, or in the gap between the panel and supporting structure, or in the top and/or bottom plates.

The joints between panels can be finished with sealant, rendered smooth, covered with trimmings and the like, or formed as expansion joints with appropriate material.

Qlo BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the present invention will now be described with reference to the drawings in which; 6 Fig. 1 is a perspective view of a non load bearing panel of a preferred form; Fig. 2 is a detail section view A of Fig. 1; Fig. 3 is a detail view B of Fig. 1; Fig. 4 is a plan view of the non load bearing panel of the preferred form of Fig. 1 showing the installation method associated with the keyed joint of the preferred form; Fig. 5 is a perspective view of another form of the non load bearing panel of the present invention showing its fixture to other structural elements; Fig. 6 is a detail section view C of Fig. Fig. 7 is an exploded detail perspective view of Fig. 5 showing the application of a fastening member of a preferred form to a clip of a preferred form; Fig. 8 is a detail perspective view of another preferred form of a non load bearing panel of the present invention; Fig. 9 is a detail view D of a fastening means of the preferred form; i Fig. 10 is a perspective view of a load bearing panel of a preferred form of the present 15 invention; Fig. 11 is a plan section view of the load bearing panel of Fig. Fig. 12 is a detail end view of the load bearing panel of Fig. •o i Fig. 13 is a perspective view of a panel of another preferred form of the present invention.

S Fig. 14 is a perspective view and an exploded perspective view of a panel of another preferred form of the present invention, Fig. 15 is a detail perspective view of panel interconnections, o.

Fig. 16 shows a corner connection of panels of Fig. 14, Fig. 17 is a detail perspective and end view of the connection of Fig. 16, Fig. 18 is view of a corner connection of panels of another embodiment, Fig. 19 is an exploded view of window and door detailing using panels of the present invention, Fig. 20 is a plan view of ground detailing, Fig. 21 is a perspective view of a panel of another embodiment of the present invention, and Fig. 22 is a perspective view of the panel of Fig. 21 shown being connected to a structural frame.

BEST MODE OF CARRYING OUT THE INVENTION The structure of the non-load bearing foam block panel 10 of the present invention shown in Fig. 1 preferably has an expanded polystyrene block 11 with a keyed type "fish tail" connection joint 12 which in turn has one edge 13 that is oriented substantially perpendicular to the plane 14 of the end of the panel 10 and the other edge 15 at a substantially acute angle to the plane 14 of the end of the panel 10. A metal, fibreglass or similar mesh 16 is attached to at least one surface of the panel 10 by means of pushing in or ooooo fastening a metal disc 17 with fastener 18 through the mesh 16 and into the foam block 11 and thus securing them. The other method is to apply a bonding agent onto the foam i: surface and attaching the mesh 16 to the foam block 11. A cementitious coating or finishing layer 2, typically render, is applied to the panel 10 over the mesh 16. The resulting smooth hard surface can then be painted or finished as per usual methods.

The installation arrangement 20 of adjacent wall panels 10 to structural elements 21, as shown in Fig. 2, is by aligning the edges or faces 13 of the keyed joint 12 and pivoting the new panel 10 at point 22 to bring keyed joint faces 13 together. This ensures the panels are flush and allows forjoints 12 to be made between adjacent structural elements 21. In the simplest form of the present invention as shown in Figure 4, the panels 10 are attached directly to flanges 23 of the structural elements 21 by adhesives, tapes, or fastened by screws, nails, rivets, bolts, and the like.

In another form of the present invention as seen in Fig. 5, the non load bearing panel 10 has intermediate sections 24 and 25 applied thereto to strengthen and facilitate fixing to conventional frameworks, shown as stud 26 and 27.

This veneer system, as shown in Fig. 5 has a foam block 11 that has spaced slots 27 cut into the surface which encase, preferably, a top hat intermediate section 24. As previously disclosed, the mesh 16 is fixed to the surface by the disks 17 and the fastener 18 with the cementitious coating of finishing layer 19 being applied over that. At the recess or spaced slots 27, a beam section is formed by the cementitious layer 19 which entraps the top hat section 24 and strengthens this panel 10. The top hat section 24 is fastened into the foam block 11 and through to the other side of the foam block 11 and into a clip 28 via a fastener 29. Such clips 28 and fasteners 29 are likewise spaced along the panel The other intermediate section 25, also preferably of top hat geometry, is fixed into the clips 28 by rotating the flange of the top hat 27 into the clip 28. The panel 10 of this form of the present invention is connected to the structural framework via these sections 25, thus providing a cavity between the veneer panel 10 and the framework. Fig. 7 shows a detail of the clip 28 and section 25 in the form of a rail and also a cold formed steel capping plate that protects the edge of the panel 9..

Another preferred form of the non load bearing panel 10 is shown in Fig. 8 where cees, zeds or other suitable sections 31 are inserted into appropriately cut or formed holes in the S" 20 foam block 11 such that they are partially encased. In this configuration, one flange 32 is o "available for the fastening of the disks 17 that fix the mesh 16 to the foam block 11, and the other flange 33 is attached to the structural framework in a manner similar to that disclosed •earlier.

S.Another preferred form of the present invention that is an integrated structural wall panel 40 as seen in Fig. 10 has structural stud members 41 which are encased along their length by the foam block 11 and at their extremities by top and bottom plate members 42, with mesh 16 and cementitious coating or finishing layer 19 applied to both surfaces of the block 11 in a similar manner to the previously described panels 10. In this form, as demonstrated in Fig. 12, the plate members 42 are flanged such that the ends of the stud members 41 nest up to the web element 43 in the top portion of the plate 42 where they can be connected in any conventional fashion, and the foam block 10 is encased by flanged 9 ends 44 of the flange elements of the plates 42. The preferred means of joining adjacent structural panels 40 of this form is via plates 45 that cap over the flanged plate profile through joints. In the case of the bottom plate 45, the plates or tracks 45 can be laid out and fixed down into a floor system by hold-down devices 46, with the structural panels fitted into the track 45 and connected with fasteners 47.

Another preferred form of the structural panel of the present invention as seen in Fig. 11 has a foam block 11 that encases one flange element 48 and a portion or all of the web element 49 of the stud members 41, thus leaving one flange element 50 exposed for the attachment of conventional wall linings 51 in a typical manner. This attached lining 51 can be on either the external or internal panel surface. The mesh 16 and the cementitious layer 19 are applied to the other surface as previously disclosed.

A further form of a non load bearing panel 60 of the present invention as seen in Fig. 13 is a veneer system having foam block 11 bonded together with a similar but offset block 61 with adhesive 62, on metal bonding strips 63. At the ends of the blocks 11 Ithe metal bonding strips 63 are bent to substantially the same angle as the corners of blocks 11 and 61 to protect edge 66. In this form, the fibreglass or metal type mesh 16 or alike is attached to the surface by means of plastic or metal disks 17 on the top block 11, with the adhesive or skim coat cementitious mix being applied as disclosed previously. Over this the top coat 19 can be applied. The method of attaching these non load bearing panels 20 is to overlap lips 67 and apply a screw or nail or alike through the top surface and into the foam 11 and steel sheet 65, then through the other block 61 and into a stud 68. In this form the block 61 can also be bonded with adhesives along the stud 68. The screw or nail will •leave a hole in the top block 11 but will finish with the head at the surface of the steel sheet *o or block 65 to maximise depth of penetration.

Another form of the present invention the "panel format" as depicted in Fig. 14a &14b, allows a rationalised method of assembly allowing for modular construction. The use of such panels 70 results in that large panels comprising entire walls are no longer required to be delivered to site using costly cranage devices and the like.

The single sided panel 70 has been modified, though not exclusively, to accommodate services on the inside face 71. The profiling of the inner face 71 allows for the addition of both wiring and plumbing due to a cavity now available for post fitting.

The panel construction is still predominantly based on the principle of encapsulated stud sections 41, preferably though not exclusively of non-lipped origin. To achieve a "panel format" a connection detail has been developed, as shown in Fig. 15. In this embodiment use of 35x35mm RHS ,37, has been used, but not exclusively, as this could also be achieved though custom rollforming. As shown in detail 73 in Fig. 15 sections in a similar configuration deliver a connection detail capable of interconnecting panels quickly and efficiently.

An interlocking system has been formed by the introduction of the two RHS sections 72, these do not have to be full length but are preferred in this embodiment. The RHS sections 72 can be further modified in a manner that facilitates for proper connection to be possible between panels as depicted 74 in Fig. As such in the present embodiment of the invention, the system of construction needs to be considered. Initially plates or tracks 75 are laid on the building surface, this could either be traditional concrete base or for that matter piers bearers and joists, the method of attachment will be similar in appearance but not exclusively. These tracks 75 are located around the perimeter of the construction as seen in Fig. 16. Once the tracks 75 are positioned the panels 70 can then be slotted together to form the outer walls of the 20 construction. The RHS sections 72 that are included now act as locating devices and also locking devices as the panels 70 can now be fixed together and hence also to the lower track In another arrangement of this embodiment of the present invention, internal and external 25 corners need to be treated as special locations, as does any door or window detailing. The corners in this case though not exclusively can be accommodated by the use of 75x75mm RHS and again the 35x35mm RHS configured such as in Fig. 17, as RHS 76 and 71 respectively. This ensures that both internal and external comers are possible, but not exclusively. To ensure that this is possible, these sections need to act as stand alone units with a ready fixed outer finish. This is achieved though the introduction of the non-load bearing veneer system 77 to the outer face of the section as depicted in Fig. 17.

11 In another arrangement, once panels 70 are fixed together it is then possible to fix a top hat section 78 as seen in Fig. 18. This allows for adequate load bearing capacity to be delivered to either support a further top storey or for that matter a roof construction. The connection detail to ground or between floors may require sheeting via traditional methods, as seen in Fig 20, but not exclusively as it is still possible to have the studs fully included into the system as previously described with special accommodation to for electrical and plumbing services, though not exclusively.

In another arrangement, window and door detailing can be done via the veneer method, as seen in Fig 19, where the necessary joining sections 79 to the standard panel design.

Similar requirements are needed when considering alignment to second storey additions or for that matter to ground detailing the following options present themselves as seen in Fig.

In another preferred arrangement, the veneer panel can be considered to be comprising a single homogenius panel. In this preferred embodiment of the present invention, though not exclusively a single piece panel 80 as seen in Fig. 21, facilitates a faster method of fabrication of the panel.

S 20 In the embodiment sandwiched strips 81 are located between two sheets of polystyrene, are "'positioned by cutting slots 82 into the single panel 80 in a manner that allows for screw heads to be adequately recessed to allow for more effective fixing it also allows for panels to be tongue and grooved into each other without the requirement for an offset.

S 25 As can be seen in Fig. 22, the panel 80 is arranged in such a manner as to allow for both adequate recessing of the screw head and also mechanical fastening through applied 0 00 pressure to the polystyrene panel.

Further to this embodiment, the panel 80 is designed to be used in areas where it is being 30 fixed to only traditionally framed domestic housing systems. In areas where it may be expected that greater strength is required in the panel construction due to impact forces a further rigid material can be fitted between the studs and the polystyrene panel, this can be but not exclusively based on the use of a rigid substrate 82 comprising plywood or the like.

To accommodate this embodiment of the design it becomes necessary to profile the rear face of the panel 80 such that moisture ingress is not contained between both the rigid substrate 82 and the outer panel faces, hence sarking 83 at this stage can also be included to further protect the internals if deemed necessary.

Those skilled in the art will appreciate that the invention described here in, is susceptible to variations and modifications other than those specifically described.

For example, the outer layers may both be rendered rather than one side rendered and the other sheeted or for that matter that panel could be delivered to site without having any prefinished coating being applied.

Or for example the connection detail may be depicted by a similar but not exactly the same connection delivering the same benefit.

All such variations and modifications are to be considered within the ambit of the present invention, the nature of which is to be determined from the fore going descriptions.

In the claims that follow, and the preceding summary of the invention, except where the context requires otherwise due to express language, necessary implication, the word 20 comprising is viewed in the sense "including" that is, the feature specified may be •associated with further features in various embodiments of the invention.

S o oo• coS* •oo S

Claims (21)

1. An integrated building panel, comprised of at least one insulating foam block that has a support structure fixed to at least one of its surfaces, said block being adapted to attach directly to an existing structural element or having structural components incorporated therein to achieve required functions of strengthening, joining, installation and load bearing as required in the application of the panel within a wall or roofing system.

2. The building panel according to claim 1 wherein the insulating foam block is expanded polystyrene with keyed edges to facilitate aligning and joining of adjacent panels.

3. The building panel according to any one of the preceding claims wherein the foam block is coated on at least one surface with a cementitious coating that can be finished by painting and the like.

4. The building panel according to any one of the preceding claims wherein the panel has integrated rails, clips, plugs, fastenings and the like to facilitate fixture to structural elements or other building surfaces.

The building panel according to any one of the preceding claims wherein the structural members are cold formed steel lipped or unlipped cee wall studs, and are inserted Ioo• into the foam block from one or both ends and mating plate members which are unlipped cee sections are fixed to the top and bottom of the embedded wall studs. too" 20

6. The building panel according to any one of the preceding claims wherein in load bearing applications the integrated structural are studs typically cold-formed steel cee or lipped cee sections of 70mm x 35mm, 75mm x 35mm and 90mm x 35mm nominal dimensions with encasing plates or tracks of 70mm x 30mm, 75mm x 30mm and 90mm x 0* 30mm nominal dimensions respectively, all in gauges ranging from 0.35 to 4.0mm and with galvanised or zinc/aluminium coatings.

7. The building panel according to any one of the preceding claims wherein structural components are incorporated therein to achieve required functions of strengthening, joining, installation and load bearing as required in the application of the system or the panel is attached directly to an existing structural element or surface by adhesives and/or fasteners.

8. The building panel according to any one of the preceding claims wherein where the panel functions as a veneer or building lining, that is without specifically designed load bearing functions, only one face of the panel has mesh and render finishing, whereby cee section members are used to cap over one or more of the perimeter sides of the panel and are attached by adhesive and/or mechanical fastening, or other sections such as top hats, square or rectangular tubes and the like are attached across the unfinished side of the panel directly to the expanded polystyrene surface or on to clips, brackets and the like which themselves are attached to or anchored into the expanded polystyrene block, to facilitate attachment of the panel to structural elements.

9. The building panel according to claim 8 wherein the sections are oriented substantially perpendicular to the structural elements the panel is being joined to.

10. The building panel according to claim 9 when a cee or zed section is incorporated 15 into the panel its web element is substantially perpendicular to the surface of the expanded °o polystyrene, one flange element is exposed to allow attachment of the panel to the structural elements and the other flange is encased in the expanded polystyrene block such that a fastening means can be installed through the mesh and block.

11. The building panel according to claim 10 where the panel functions as a veneer or building lining, the ends of the expanded polystyrene block keyed to lock the joint between adjacent panels, these keying features extending the entire side of the panel or be one or a oo'plurality of individual keys.

12. The building panel according to claim wherein 11 Ithe joints are typically at the vertical ends of the panel and the keyed joint is such that the panel which is being installed adjacent to an attached panel is aligned at an angle to the structural elements so that the edge of its tongue sits in the groove or channel and when the panel is rotated, pulls the joint tight and level on the outside surface.

13. The building panel according to claim 1 wherein at least one expanded polystyrene block portion and at least one structural stud member which have a flange element that in turn is stiffened with a lip element.

14. The building panel according to claim 1 wherein the block portion forms either or both the external and/or internal linings of the wall system.

The building panel according to claim 1 wherein any, the load bearing structure comprises a plurality of substantially parallel arranged structural stud members that are joined at their extremities to plate members, the fastening means used to join the structural members together into framework being screws, nails, rivets, bolts, welds and the like or are integral clinches, hooks, clips, tags or adhesives.

16. The building panel according to claim 15 wherein the expanded polystyrene completely encases the stud members, in which case the mesh and render finish is applied to both faces, or encases one flange element and part or all of the web element of the stud members so that a flange element is exposed for the attachment of conventional linings 15 such as plasterboard or for fixing off brick ties in brick veneer construction, then the mesh V and render finish is only applied to one face.

17. The building panel according to claim 16 wherein the attachment of the mesh to the expanded polystyrene such that the integrated system has a shear resistance that is utilised as structural bracing.

18. The building panel according to claim 17 wherein, keyed joints for the non load 0: bearing form are used to join adjacent panels, the joints being installed into and joined using suitable capping members, that are continuous through a join, when capped over the Mexpanded polystyrene blocks or the studs, or the plate members depending on the 0" orientation of the join.

19. The building panel according to claim 18 wherein in walling applications the joins run vertically at the ends of the panels or the joins run horizontally with the panels stacked and keyed in on top of each other.

The building panel according to claim 19 wherein services such as water, and electrical and communication cabling are run through holes formed through the panels, or cut into the surface, or in the gap between the panel and supporting structure, or in the top and/or bottom plates.

21. The building panel according to claim 20 wherein the joints between panels are finished with sealant, rendered smooth, covered with trimmings and the like, or formed as expansion joints with appropriate material. DATED this THIRD day of AUGUST 2001 AUSTRALASIAN METAL FORMING INDUSTRIES PTY LTD Patent Attorneys for the Applicant WILSON YOUNG a o o