A STRUCTURE

FIELD OF THE INVENTION

This invention relates to a method of forming a structural element and a structure including the structural element. The invention also extends to a method of building a structure and a structure formed by the method. Further the invention also extends to a building including the structural element and the structure.

This invention relates particularly but not exclusively to method of forming a linear structural element such as a rod, post, column or a beam for a structure that is a building and a structural element formed in accordance with this method. The structural element may form part of an underlying frame of the building, e.g. a light frame used for building homes, and the invention relates particularly to a method building such a building and the building produced by this method. In fact the invention finds particular application in the construction of domestic dwellings that are detached houses on their own block of land. It will therefore be convenient to hereinafter describe the invention with reference to this example application. However at the same time it must be recognized that the invention is capable of broader application. For example the invention could be used for structures other than buildings such as walls and barriers.

DEFINITIONS

In the specification the term "comprising " shall be understood to have a broad meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the term "comprising" such as "comprise" and "comprises".

In this specification the term 'structural element" shall be used to define a simple or most basic unit of a complex that cannot be broken down any further. One form of a structural element is a linear structural element and this includes a rod which carries an axial load. Another basic structural element is a compression member such as a post or a column which carries a compressive load. Another form is a beam which carries an axial and a bending load. It also includes the two basic types of structural elements in building frames, namely a stud which is a compression member and a plate for a house frame which carries an axial and a bending load. In this specification the term "frame" or "structural frame" shall be interpreted broadly and can include two or more frame members. While it includes a light frame for a building it is not to be limited to this particular form of a frame.

In this specification the term "cementitious material" shall be interpreted broadly and shall refer to any material that can be dispensed into a formwork spaced and occupies the space and takes on the character of that space.

BACKGROUND TO THE INVENTION

One conventional method of construction of a building involves erecting a light frame of structural elements. The light frame forms an underlying skeleton or support structure for the building. Some of the structural elements are vertically extending and are called studs. Other structural members are horizontally extending and are called plates. The studs and plates are often formed of timber members and are cut to size and then assembled into the light frame by a carpenter who is qualified in building house frames.

Light frame construction using standardised dimensional timber has become the dominant construction method in North America and Australia because of its economy and low cost. The use of minimal structural materials to form the light frame enables builders to enclose a large area at minimal cost.

Once the light frame has been assembled, a wall for the structure is formed comprising inner and outer wall coverings. The outer wall covering may comprise a brick veneer or an arrangement of timber boards. The inner wall covering may comprise sheets of plasterboard, often called GYPROCK, which are fastened to the studs and plates of the frame.

The use of this building technique has a number of well documented shortcomings. The dimensional tolerance of timber frame structures is not very precise. This can lead to difficulties during later stages of the building operation. Further timber is prone to warping and changing shape when it gets wet. If a timber frame is exposed to moisture during the building phase it can deform out of shape. Yet further timber, particularly soft timber, has a limited life time and is not as long lasting as say concrete material.

Further more the tolerance or accuracy with which the frame is constructed varies considerably depending on the individual skill of the particular carpenter doing the job.

Further the timber frame is built by carpenters who essentially build the frame up from timber planks. The carpenter cuts the planks to size and progressively builds up the framed structure. The process is quite time consuming and therefore the labour cost of erecting the light frame is considerable. It is also imprecise and the dimensional tolerance or accuracy with which the frame is constructed varies considerably depending on the individual skill and expertise of the particular carpenter doing the job. Further if a brick veneer is required to form the outer layer of the building, then another trade namely a bricklayer is required to lay the bricks of the outer layer. The need to use different trades generally leads to longer construction times for building houses.

Yet further another shortcoming of a timber frame is that it is light and accordingly has limited strength. This strength may be tested in extreme weather events such as a cyclone. It would therefore be advantageous if a stronger frame than a timber frame could be devised, particularly so in areas exposed to hurricanes and cyclones.

Clearly it would be advantageous if a new structure for use in buildings and a new method of building could be devised that at least ameliorated the shortcomings of the prior art structures and building method described above. SUMMARY OF THE INVENTION

According to one aspect of this invention there is provided a method of forming a structural element for a structure, including:

arranging at least one wall component that forms a permanent part of a wall of the structure so that it also forms at least part of a formwork defining an elongate formwork zone;

pouring a flowable material into the formwork zone that is capable of setting in the formwork zone, and allowing sufficient time for the material to set in the formwork zone, whereby to form a structural element within the structure that is capable of carrying structural load.

Said pouring of a flowable material into the formwork zone may include pouring a cementitious material into the formwork zone that sets when it is allowed to stand. The cementitious material may be concrete.

The at least one wall component may comprise a plurality of wall panels, and arranging the at least one wall component may include arranging the plurality of wall panels such they are configured to form the formwork defining the formwork zone. The panels may be formed of aerated concrete material.

Arranging the plurality of wall panels may include arranging at least one wall panel forming part of an inner layer of the wall and at least one other wall panel forming part of an outer layer of the wall so that they form part of the formwork defining the formwork zone. The at least one wall component may further include at least one cross member extending between the at least one panel forming part of an inner layer of the wall and the at least one other wall panel forming part of an outer layer of the wall. Arranging the at least one wall component may include configuring the cross member/s so that it forms part of the formwork defining the formwork zone.

Arranging the wall panels and the cross members may include arranging the wall panels and the cross members into a formwork defining a vertically extending elongate formwork zone for forming a structural element that is a post or column that is capable of carrying vertical compressive load within the structure.

Arranging the wall panels and the cross members may include arranging the wall panels and the cross members into a formwork defining a horizontally extending elongate formwork zone for forming a structural element that is a beam or a plate carrying axial and bending loads within the structure.

Forming a structural element for a structure may comprise forming a frame member forming part of a light weight frame of a structure that is a building.

The method may further include positioning at least one elongate member in the formwork zone extending in a direction of elongation of the formwork zone through the formwork zone, prior to pouring the settable material into the formwork zone, and wherein the settable material surrounds the elongate member when it is subsequently poured into the elongate formwork space to reinforce the structural element. The elongate member may be a rod of a material having some tensile strength. In particular the rod may be a reinforcing rod made of steel. The method may also include using a rod locating formation in its central position within the formwork when the material is poured into the formwork.

The invention also extends to a structural element made in accordance with the method defined in the preceding aspect of the invention. The structural element may have any one or more of the optional features defined in the preceding aspect of the invention.

In one form of the invention the structural element may have a length of 100mm to 300mm and a width of 100m to 300mm. In one form the structural element may have a length and width in cross section that are the same. Further a vertical extending structural element may have a height in the range of 2.3m to 3.0 m. A horizontal extending structural element may have a length that is much longer than this, for example a length in the range of 5.0 m to 12.0 m. The invention also extends to a structure including the structural element defined above. The structure may be a detached building such as a house and the house may be built on a building support that is a concrete slab that is positioned on the ground.

According to yet another aspect of this invention there is provided a method of forming a structural element for a structure, including:

arranging at least building component so that it forms at least part of a formwork defining a formwork zone; and

pouring a flowable material into the formwork zone that is capable of setting in the formwork zone, and allowing sufficient time for the material to set in the formwork zone, whereby to form the structural element.

The method may include any one or more of the features or optional method steps of the method defined in the preceding aspect of the invention.

According to another aspect of this invention there is provided a structure including:

at least one wall component that forms part of a wall of the structure, the at least one wall component forming a formwork defining a formwork zone; and

a body of material that has been formed within the formwork zone by casting a flowable material into the formwork zone and then allowing it to set and harden, whereby to form a structural element that is capable of carrying a load within the formwork zone.

The body of flowable material may be a cementitious material that sets when it stands for a certain length of time. Said at least one wall component may be formed of an aerated cementitious material, e.g. an aerated concrete material such as that sold under the trade mark HEBEL.

The structure may have a plurality of wall components that form the formwork and the wall components may include wall panels. In particular the plurality of wall panels may include at least one wall panel forming an inner layer of the wall and at least one wall panel forming an outer layer of the wall.

The plurality of wall components may further include at least one cross member extending between the inner layer of the wall and the outer layer of the wall. Further each cross member may extend substantially the full height of the formwork zone.

In particular the plurality of wall components may include two said cross members spaced from each other extending between the inner and outer layer of the wall. The two cross members and the panels forming the inner and outer layers may together form a formwork defining an elongate formwork zone having four sides. Each of the inner and the outer layers of the wall may comprise a plurality of wall panels that are arranged end to end to form a course of wall panels extending generally in the direction of length of the wall.

Each of the inner and outer layers may further include a plurality of courses of wall panels that are arranged on top of each other, and the different courses may be arranged so that the panels in the different courses have their ends being in vertical alignment with each other.

According to yet another aspect of this invention there is provided a method of building a building structure, including:

providing a cladding support arrangement for installation of the cladding;

mounting wall cladding on the cladding support arrangement to form a wall, wherein the wall cladding is also arranged so that it forms a formwork that defines a plurality of formwork zones each of which is suitable for forming a frame element; and pouring a flowable material into the formwork zone/s and allowing the material to set and harden forming a frame element for the structure.

Said pouring a flowable material into the formwork zone/s may include pouring a cementitious material into each formwork zone, and allowing the material to set and harden may includes allowing the material to stand for a sufficient time to allow it to cure and harden.

The cladding mounting arrangement may include a plurality of support brackets having a support leg and a mounting leg for mounting to a wall panel on the inner layer for supporting the wall panel in the correct orientation and in the correct position. Said providing of the cladding arrangement may include mounting the support legs on a building slab. Further ach bracket may include a turnbuckle and the method may include adjusting the orientation of the bracket by adjustment of the turnbuckle.

Said mounting of wall cladding on the cladding support arrangement may include mounting an inner layer of wall panels on the cladding support arrangement. The cladding support arrangement may be capable of adjustment and the method may include adjusting the cladding support arrangement, e.g. adjusting its upright orientation.

Mounting an inner layer of wall panels on the cladding support arrangement may include passing fixing elements through each of the wall panels and openings on the mounting leg of each bracket. Said mounting of wall cladding on the cladding support arrangement may further include mounting at least one cross member on the inner layer of wall panels. Said mounting may thereafter further include mounting an outer layer of wall panels on the cross member/s.

Said mounting of each cross member on the inner layer may include passing fixing elements through each of the cross member and the adjacent panels of the inner layers. Further said mounting of the outer layer of wall panels on the cross member/s may include passing fixing elements through the adjacent panels on the outer layer and the cross member/s.

The method may further include positioning an elongate member which is a reinforcing rod within one or more elongate formwork zones, before said pouring of the flowable material into the formwork zone/s.

The method may includes removing the cladding support arrangement once the material poured into the formwork zones has set and hardened and the frame elements formed thereby have acquired their design strength enabling them to carry the load imposed on them by the building structure.

Said removing of the cladding support arrangement may include detaching the brackets from the panels of the inner layer to which they are fixed and then detaching each bracket from the building support to which it is fixed.

Said mounting of wall cladding on the cladding support arrangement may include arranging the cladding members so as to form a plurality of vertically extending elongate formwork zones, and pouring of the flowable material that can set into each vertical extending formwork zone may result in the formation of vertically extending frame elements that form posts, or columns or studs.

Said mounting of wall cladding on the cladding support arrangement may include arranging the cladding members so as to form a plurality of horizontal extending formwork zones, and pouring of the flowable material that can set into each vertical extending formwork zone may result in the formation of horizontal extending frame elements that form beams or plates of a frame.

According to yet another aspect of this invention there is provided a method of building a building structure, including:

arranging at least one building component so that it forms a formwork that defines a formwork zone for forming a structural element for the building structure; and

pouring a flowable material into the formwork zone/s where it assumes the shape of the formwork and allowing the material to set and harden in the formwork whereby to form a structural element for the building structure. The method may further include mounting at least one building component on a building support on which a building is to be built and then arranging the building component so that it forms the formwork.

The method may include any one or more of the features or optional method steps of the method defined in the preceding aspect of the invention.

According to yet another aspect of this invention there is provided a building structure, including:

a structural frame providing underlying structural strength to the structure, the frame comprising a plurality of vertical extending and horizontal extending frame elements that are interconnected; and

a wall cladding mounted on the structural frame, wherein the wall cladding is arranged to form a formwork defining at least one formwork zone within which a said horizontal or vertical frame element of the structural frame is cast and formed;

wherein the horizontal or vertical frame element has been formed in each formwork zone during construction by pouring a flowable material into the formwork zone and then allowing the material to set whereby to form said horizontal or vertical frame element.

The wall cladding may include an inner layer of wall panels and an outer layer of wall panels. The inner and outer layer of panels may form part of said formwork defining said formwork zone/s within which the frame element/s is formed.

The wall cladding may further include at least one cross member extending between the inner layer and the outer layer of the wall, and the cross member/s may also form part of the formwork defining said at least one formwork zone/s within which the frame element/s are formed.

The formwork defining at least one formwork zone may comprise the inner and outer layers of the wall and two cross members that are spaced apart from each other extending between the inner and outer layers.

One or more of the horizontal or vertical frame elements that have been formed in a formwork zone may have a reinforcing rod passing therethrough for reinforcing the frame element. The reinforcing rod is cast into the frame element within the formwork when the material is poured into the formwork.

The frame may include a plurality of vertical frame elements that have been formed in a formwork zone from the flowable material, positioned at spaced intervals apart from each other in the direction in which the wall cladding extends. The building structure may include a plurality of corners and the frame may have a vertical extending frame element made of cementitious material located in each corner thereof. Further the building structure may have at least one window or door opening defined in the wall cladding thereof for receiving a window, and the frame may include a vertical extending frame element adjacent each side of the window or door opening for providing structural support.

The frame may further include at least one horizontal element that is formed from said flowable material that sets and hardens in the formwork, and said at least one horizontal element may connect with an upper end of at least two vertical extending frame elements and may replicate an upper plate of a frame. Yet further said at least one horizontal member may extend along an upper edge of the wall cladding.

The frame may further include a horizontal extending frame element extending across the window or door opening above the window or door opening and interconnecting with said vertical extending frame elements on each side of the window opening.

The wall cladding may extend the length of said a plurality of vertical frame elements and covers and fill in the space defined by all said plurality of vertical elements.

The flowable material that can set may be a cementitious material that cures and hardens over time after it is allowed to stand. Further the wall cladding may be formed of an aerated cementitious material, such as a material sold under the trade mark HEBEL in Australia.

DETAILED DESCRIPTION OF THE INVENTION

A method of making a structural member and building a structure in accordance with this invention may manifest itself in a variety of forms. It will be convenient to hereinafter describe several embodiments of the invention in detail with reference to the accompanying drawings. The purpose of providing this detailed description is to instruct persons having an interest in the subject matter of the invention how to carry the invention into practical effect. However it is to be clearly understood that the specific nature of this detailed description does not supersede the generality of the preceding broad description. In the drawings:

Fig 1 is a schematic plan view of part of a structure defining an elongate formwork space for forming a frame element therein in accordance with one embodiment of the invention;

Fig 2 is a perspective view of the part of the structure shown in Fig 1 ; Fig 3 is a perspective view of the structure of Figure 1 showing in one position a formed frame element and in another position showing a cementitious material being poured into the elongate formwork space;

Fig 4 is a perspective view of a part of a structure that is similar to that in Fig 1 including a wall that has three elongate formwork spaces at spaced intervals along the length of the wall, prior to pouring of the cementitious material therein;

Fig 5 is a perspective view of the structure in Fig 5 showing cementitious material being poured into the elongate formwork zones to cast the structural element;

Fig 6 is a schematic perspective view of the structure in Fig 5 once it has been built highlighting the frame members that have been formed of cementitious material within the elongate formwork zones to form an underlying frame for the structure;

Fig 7 is a perspective view of a complete structure made in accordance with one embodiment of the invention;

Fig 8 is a perspective view of a building support in the form of a slab, and a temporary wall cladding support arrangement mounted on a building support in preparation for building of a structure;

Fig 9 is a perspective view showing how an inner layer of panels are progressively mounted on the building support to form an inner layer of a wall; and

Fig 10 is a schematic drawing showing how cross members are mounted on the inner layer of the wall; and

Fig 1 1 is a schematic drawing showing how an outer layer of building panels are progressively mounted on the cross members to form an outer layer of the wall and also define elongate formwork zones for forming the frame elements.

In Figures 1 to 3 reference numeral 10 refers generally to a structure in accordance with one embodiment of the invention.

The structure 10 comprises basically a wall 12 including a formwork 18 defining an elongate formwork zone 19 into which a flowable material, that is a cementitious material, is poured that is capable of setting and hardening into a cementitous body that after a period of time. The cementitious body is shaped by the formwork 18 and forms a structural element that is capable of carrying a load.

The wall includes an inner layer 14 and an outer layer 16. As shown in the drawings each of the inner and outer layers 14, 16 of the wall 12 is formed from an arrangement of building panels 20. The building panels 20 are arranged end to end to form a course or row of panels 20. Further a plurality of courses or rows of panels 20 can be arranged on top of each other to build up the wall 12. Conveniently as shown in the drawings the panels 20 in the different rows can be arranged with their ends 22, 24 being in vertical alignment with each other. This is in contradistinction to an arrangement where the panels 20 are staggered relative to each other.

The wall 12 also includes cross members 26 that extend between the inner and the outer layers 14 and 16 thereof that fix the inner and outer layers 14 and 16 of to each other. In fact each pair of aligned inner and outer panels 20 can have one cross member 26 fixing them to each other towards one end and another cross member 26 fixing them to each other towards their other end. Each of the cross members 26 can extend substantially the full height of each panel 20.

In the illustrated embodiment the formwork 18 is formed by an inner surface of adjacent panels that form the inner layer 14 of the wall 12 and also an inner surface of the adjacent panels forming the outer layer 16 of the wall 12 each form part of the formwork arrangement 18.

It is also formed by the cross members 26, 27 that extend between the inner surface of the inner layer 14 and the inner surface of the outer layer 16 towards each end of each panel 20. In this arrangement the cross member 26 on one panel and the cross member 27 on the adjacent panel interact with and combine with the inner surfaces of the inner and outer layers 14 and 16 as described above to perform the crucial function of forming the formwork arrangement 18 within which each structural element 10 can be formed.

Each cross member 26 can conveniently be coupled to its adjacent building panels 20 forming the inner and outer layers 14 and 16 of the wall 12 by means of fixing elements 28 that are passed through the inner and/or outer layers 14 and 16 and also through the cross member 26. Conveniently the fixing elements 28 are in the form of fixing bolts having an enlarged head on one end and a bolt retainer mounted in a retained fashion on the free end of the bolt.

Thus the panels 20, in addition to their function of defining the formwork arrangement 18 are also used to form a permanent wall of the structure 10.

The structure 10 in turn is mounted on a building support that is a concrete slab (not shown) that is mounted on the ground by means of footings. As the formation of the concrete slab and its mounting on the ground would be well known to persons skilled in the art and it does not form part of this invention it will not be described further in this specification. The building panels are mounted on the concrete slab to build up the inner and outer layers of the walls. As shown in Figures 2 and 3 an elongate element that is a rod or bar of reinforcing steel 32 can be received within the formwork arrangement 18 prior to the cementitious material being cast therein. The rod 32 is sized so that it projects out above an upper end of the formwork arrangement 18. In practice a rod positioning formation is used to hold the reinforcing rod in its position centrally located in the formwork zone when the cementitious material is poured into the formwork 18. If the rod positioning formation was not present then the rod would be displaced to one side and would not remain centrally located with an even thickness of cementitious material around it. It is important for the reinforcing rod to remain centrally located during the pouring of material into the formwork for it to properly perform its reinforcement function in the finished structural element.

In use the basic structure described above and illustrated in Figure 1 is formed. At this point the structure 10 is provided by an assembly comprising the panels 20 forming the inner and outer layers 14 and 16 of the wall 12, and the cross members 26. In addition a temporary support arrangement called a wall cladding support arrangement, which is separate from the components above that form a permanent part of the structure can conveniently be used to hold the inner layer of panels securely in position fixed to the slab.

Thereafter as is illustrated schematically in Figure 3, a cementitious material, such as construction concrete, is poured into the formwork arrangement 18 to cast the body of cementitious material. This material together with the reinforcing bar forms a structural element 36. Typically a hose with a nozzle, such as that shown by numeral 38 in Figure 3, is used to direct the cementitious material into the formwork 18. Once a certain period of time has elapsed after the material is cast into the formwork zone 19, the material cures or 'goes off, and hardens forming the structural element 36 having significant structural strength. The strength of concrete and its utility in forming load bearing members within building structures would be well known to persons skilled in the art and will not be described in greater detail in this specification.

Figure 3 also shows another part of the structure where a structural element 36 of cured cementitious material and having a reinforcing rod 32 passing there through has already been formed.

Figures 4 to 6 illustrate a structure in accordance with another embodiment of the invention. This structure is more extensive than the part of a structure shown in Figures 1 to 3. As this structure is very similar to the structure illustrated in Figures 1 to 3 the same reference numerals will be used to refer to the same components unless otherwise illustrated.

The structure which is indicated generally by reference numeral 50 comprises broadly a wall 52 comprising an inner layer 54 and an outer layer 56. The wall 52 has a window opening shown generally by the numeral 57 within which a window for the structure 50 is received when the structure 50 is completely built.

The structure 50 also includes a formwork arrangement defining three separate vertically extending formworks indicated respectively by reference numerals 58, 60 and 62 for receiving a cementitious material to form a structural element.

The formwork 58 is located on the corner of the wall 52 of the structure 50. The formwork 60 is located on one side of the window opening 64 and the formwork 62 is located on the other side of the window.

Each of the formworks 58, 60 and 62 is formed in an analagous way to the formwork 18 described above with reference to Figures 1 to 3. That is it is formed from a combination of the inner and outer layers 14 and 16 of the wall 12 and the cross members 36 extending between the inner and outer layers 14 and 16 on each side of the elongate formwork zone 19. Each of these formworks 58, 60 and 62 typically further includes a reinforcing rod 32 therein which is cast into the cementitious material when it is poured as shown in Fig 5.

The structure 50 also includes a horizontally extending formwork 66 extending along the upper edge of the wall 52 for forming a horizontal structural element that is associated with the wall 52.

The formwork arrangement 66 is formed by a combination of the inner and outer wall layers 54 and 65 and cross members that form a bottom or floor of the formwork arrangement 66. The arrangement 66 illustrated in the drawings is shown with an open top. However it can also be closed off at the top by a top or cover member that extends between the inner and outer layers at the top of the inner and outer layers 64 and 66. In the illustrated embodiment the formwork arrangement 66 extends along the full length of the wall 52 and undergoes a ninety degree turn intermediate its ends at a corner 68 of the wall 12. The formwork arrangement 66 also includes a reinforcing rod or bar therein that functions in the same way as the reinforcing rods 32 in the vertical formwork arrangements. This reinforcing rod has not been drawn in on the exploded view shown in Figure 4. In practice this horizontal reinforcing rod is fixed to each of the rods 32 within the vertical formwork arrangements shown in the drawing to tie the whole structure together. The horizontal rod is fixed or tied to the vertical rods in a way that is known in the art.

In use a cementitious material is poured into the formwork arrangements 58, 60 and 62 to form three vertically extending linear structural elements that are posts in the structure 50 where they are subjected to compressive load. In an analogy with a light frame in a framed construction these linear elements 70 would form the studs of the frame. Once the posts 70 have been formed, the cementitious material is poured into the horizontally extending formwork arrangement 66. After some time the cementitious material cures and hardens to form a horizontally extending linear structural element which is indicated by the reference numeral 72 in Figure 5. This element 72 acts like a beam as it is subjected to both axial and bending loads. In framed construction building this structural element is described as a top plate. The element 72 also functions like a lintel above the window opening where it supports the structure above the window opening. The horizontal upper plate or beam 72 often has a reinforcing rod 32 therein as shown in Fig 5 which enhances the tensile strength thereof and consequently its ability to carry bending loads. However it must be understood that the upper plate or beam 72 can also be formed without a reinforcing rod 32 therein.

Figure 6 schematically illustrates the overall structure 50 once the three posts 70 and the upper plate 72 have been formed. The structure 50 contains two basic parts at a conceptual structural level, namely the wall 52 described above and an underlying light frame or structural frame shown generally by numeral 74. The frame 74 comprises the posts 70 and top plate 72 providing structural support for the structure. Figure 6 has been drawn within the hidden detail of the frame 74 shown in bold solid lines and the wall or cladding 52 which is supported by the frame shown in dotted lines. This is different to normal draughtsman's practice but has been done to better illustrate the invention that is the subject of this application. This drawing highlights the posts 70 and the upper plate 72 that have been formed in the various formwork arrangements and which form the underlying frame 74 which affords strength and support to the overall structure 50.

In particular the corner post 70 provides compressive load support at a corner of the structure 50. The other two posts 70 are located on each side of a window opening 76 and provide support in this part of the structure 50. The posts 70 carry compressive load and support the top plate 72 and also the weight of a roof that is mounted on the structure. In the embodiment illustrated in Figures 4 to 6, each of the posts 70 is shown either located on a corner or adjacent to a window opening. In structures where there is a long span of uninterrupted wall then posts 70 may also be located at spaced intervals along the length of the wall. In such instances posts 70 would be located at regular spaced intervals along the length of the wall 70. In some instances the posts 70 are spaced 2 to 4 meters apart from each other along the wall. However other spacings may be chosen depending on the spacings specified by engineers. For example in cyclone affected areas a closer spacing of adjacent posts 70 may be specified to increase the strength of the structure.

Figure 7 illustrates an overall building structure in accordance with one embodiment of the invention. In the drawing some parts have been omitted such as the roof to assist in illustrating and describing the features of the invention.

The structure is a detached building which could be used as a dwelling that is indicated generally by the reference numeral 80. The structure 80 has an underlying light frame that is shown generally by the reference numeral 82. The light frame 82 is shown in dotted lines in accordance with normal drawing conventions because it represents hidden detail and use of dotted lines is the usual convention to show hidden detail. The structure 80 also includes a wall 85 which is shown in solid lines.

As shown in the drawings, the frame 82 comprises a plurality of posts 84 that are located at intervals along the length of the perimeter wall 85. Each post 84 is formed in accordance with the methods described above with reference to the embodiment in Figs 1 to 3 and the embodiment in Figs 4 to 6. In particular the building 80 has four posts 84 that are located in the each of the corners thereof.

The building 80 also has posts 84 located on either side of each window opening 86, and also has posts on either side of each door opening 87. The drawing also shows posts 84 that are positioned along a span of uninterrupted wall providing intermediate support to the wall.

The frame 82 also includes a top plate 86 that extends around the top of the wall and is connected to upper ends of each of the posts 82. The posts 84 and the top plate 86 are rigidly fixed to each other or integrally formed with each other so that once constructed they form an underlying frame having strength.

The building 80 also includes a wall 88 comprising an inner layer on an inside of the frame 82 and an outer layer on the outside of the frame 82. Further the inner and outer layers of the wall mounted on the frame 82 and are supported in position by the frame 82. Figures 8 to 1 1 illustrate a method in accordance with one embodiment of the invention of erecting a structure such as that shown in Figure 7 in accordance with one embodiment of the invention.

The method is commenced by laying a building support such as a concrete slab 90. The slab 90 conveniently has a rebate 92 extending around its periphery corresponding to the position of a perimeter wall.

Thereafter a wall cladding support arrangement 100 is mounted on the slab 90 as shown in Figure 8. The wall cladding support arrangement 100 comprises a plurality of brackets 102 that are mounted on the slab 90 at spaced intervals around the periphery of the slab 90. The cladding support arrangement 100 is a temporary structure that enables cladding panels forming the walls to be erected without an internal 'structural frame' on which the cladding can be mounted. Later on the internal frame is cast from cementitious material that is poured into formwork defined by the cladding panels and when this material has set the cladding support arrangement 100 can be removed.

Each bracket 102 is mounted on the slab 90 just inward of a position where a wall, e.g. a perimeter wall, is to be located. The bracket 102 comprises a support leg or base member 104 extending across the slab 90 and a mounting leg or upright member 106 to which the cladding panels for the wall can be temporarily mounted. The mounting leg 106 also helps to correctly locate and position the panels. Each bracket 102 also includes a turnbuckle 108 extending between the support leg 104 and the mounting leg 106 for enabling the vertically extending orientation of the mounting leg 106 to be capable of fine adjustment. This permits a workman with a spirit level to adjust the mounting leg 106 so that it is plumb. Each mounting leg 106 includes a plurality of openings 109 which are used to temporarily attach cladding panels thereto as will be described in more detail below. Each bracket 102 has to be very carefully and accurately put in position as this directly influences the position and orientation of the cladding panels that are subsequently mounted thereto to form the walls.

The next step in building the structure is to mount cladding panels indicated generally by numeral 1 10 one by one to the brackets 102 of the support arrangement 100 as shown in Figure 9.

The first stage of mounting the panels 1 10 involves mounting a lowermost panel 1 10, to two brackets 102, which are positioned towards the ends of the panel 1 10. Thereafter a number of further panels 1 10 can be mounted in turn on the same two brackets to progressively build up a wall body or wall section having some height. This is achieved by passing a fixing member such as a bolt through the panel 1 10 and then also through an accurately positioned opening 109 for a fixing element on the bracket 102. The openings on the brackets 102 are positioned so that each of the panels 102 is mounted snugly and tightly on top of the panel 1 10 beneath it with no gaps.

Thereafter a similar process is followed on succeeding pairs of brackets 102. As shown in the drawings adjacent ends of the panels 1 10 abut up against each other. This process described above and shown in Figure 8 uses the panels 1 10 to build up an inner layer of the ultimate wall of the structure.

Thereafter cross members 120 are mounted to the panels 1 10 as shown in Fig 10 to provide the support on which an outer layer of panels can be mounted to form an outer layer of the wall.

As shown in the drawing a vertically extending cross member 120 is fixed to the surface of the inner layer of panels 1 10 at a point spaced a short distance in from the end of the panel 1 10. Conveniently the cross member 120 is aligned with the mounting leg 106 of the bracket 102. The cross member 120 is conveniently fixed to the adjacent panels by fixing members that are passed through the associated panel of the inner layer 1 10 and the cross member 120. On completion each cross member 120 extends substantially the full height of the associated inner wall panel 1 10 to which it is mounted.

Thereafter an outer layer of panels 122 can be mounted on the cross members 120. This is built up in a similar way to the inner layer of panels 1 10. That is individual panels are laid in turn on top of each other to progressively build up the height of the outer layer 122.

The panels forming the outer layer 122 can be attached to the cross members 120 and optionally also the panels 1 10 on the inner layer by means of fixing elements that are passed therethrough. The cross members 120 space the outer layer of panels 122 away from the inner layer of panels 1 10 and also provide sturdy support for the mounting of the outer layer on the inner layer.

The structure has two cross members spaced a short distance away from each other extending between opposing panels forming the inner and the outer layers of the wall. The two cross members and the associated panels of the inner and outer layers collectively form a formwork defining a formwork zone for casting a vertically extending structural element such as a post therein.

As shown in the embodiment illustrated in the drawings, and described above, cross members are spaced a short distance away from each end of each panel in the inner layer. Thus when two panels are arranged side by side there are two closely spaced cross members positioned on either side of the edges of the panels which are abutting against each other. Further the arrangement of panels on the outer layer is both longitudinally and laterally aligned with the panels on the inner layer. This way the two adjacent panels of the inner layer and the two adjacent panels of the outer layer and the two cross members bridging between the inner and outer layers can define a formwork having a rectangular section suitable for casting a post therein.

This particular arrangement of the cross members towards each side of the panels provides efficacious mounting of the inner layer panels onto the brackets and also efficacious mounting of the outer layer panels onto the outer layer. It also is convenient and suitable for use in forming the formwork that is formed to cast the structural elements.

Once this stage is reached the structure is ready for cementitious material to be poured into the formwork to cast the structural elements. This carried out in the manner described above with reference to Figures 1 to 3. Once the cementitious material has set and cured then the linear structural elements formed of this material confers significant frame support and structural strength on the structure as a whole. At this stage the cladding support arrangement 100 can be removed. This is done by removing the fixing members that fixed the brackets to the panels of the inner layer. In addition the brackets 102 are released from their releasable fixing to the slab 90.

This provides a structure like that shown in Figure 7 with walls and window and door openings. Further there are linear structural elements extending above each door and window opening providing the appropriate lintel and beam support. Thereafter the house can be finished with known fittings and using known techniques. Thus the cross members perform an important function other than providing support for the outer layer and correctly spacing the inner layer away from the outer layer. That is together with the panels they define the formwork arrangement in which the structural elements that form the 'frame' for the building are formed.

The wall panels can conveniently be formed of lightweight aerated concrete panels that are sold under the trade mark HEBEL (which is trade mark owned by CSR Ltd) and which can be obtained from CSR Panel Systems in Australia. The panels may be 75 mm thick lightweight panels that are reinforced with steel mesh and are sold as POWER panels under the HEBEL trade mark.

The method of building a building structure described above with reference to the drawings can be used to build a multistorey building structure. The frame shown in the drawings is basically repeated in each storey. Further the posts in each storey can be tied into the plate from the storey below thereby to develop a repeating frame over the multi storey structure.

It should be borne in mind that the space defined between the inner and the outer layers of the wall that is filled with air can also be filed with an insulating material that has stronger insulation properties than air. For example it may be filed with an insulating material that is selected from polyurethane or polystyrene. This is particularly useful when the invention is used to build structures in extreme climates, e.g. in the countries of Northern Europe.

An advantage of the method of building a structure such as a house as described above with reference to the drawings is that the frame elements of the structure are formed of a set cementitious material containing a reinforcing element such as a reinforcing steel rod or bar. Consequently the structure overall is much stronger than a structure where the frame elements are made of a timber, e.g. a soft timber. The frame and the overall structure is not only incrementally stronger than a structure with a light timber frame. Rather it is several orders of magnitude stronger than the typical timber frame. This property will have utility in cyclone prone areas such as North Queensland where the structure has to be built to withstand extreme weather events. It will also be readily apparent that a frame that is made of cementitious material will not be susceptible to termite damage and termite infestation.

The cladding members can be cladding panels formed of aerated concrete which have excellent properties such as thermal insulation and acoustic insulation. This assists in conferring very favourable properties on the structure as a whole. Further if inner and outer layers of cladding panels are utilised as shown in the drawings with the frame elements in between the inner and outer layers the thermal and acoustic insulation properties can be considerably further enhanced. Applicant has established that the inner and outer layers of aerated concrete panels with an air spaced in between the inner and outer layers gives outstanding results.

A further advantage of the structure and method described above is that it is built from standard components which are largely panels of aerated concrete. A supply of standard off the shelf panels can be delivered to a building site and then cut to size using basic hand held cutting tools. Further the panel supporting arrangement that is used to fix and support the panels during the construction process before the frame is formed, comprises a plurality of uniform components that can easily be transported on a small truck to the building site. A further advantage of the structure and method described above is that it can be leads to significant cost savings in the construction process. Firstly the structure is largely built from a single component namely a standard sized aerated concrete panel. Secondly the building method does not require much specialised equipment and it does not require any heavy equipment. The construction process can be assisted by having a small crane which lifts each of the panels off a stack of panels and places it in position on the building support.

Further the structure can be constructed by a worker having very basic skills. Building the structure essentially requires the panels to be placed in position and then fixed to the panel support brackets and then to each other. Thereafter a reinforcing rod has to be inserted into the elongate formwork space. After that concrete is poured into the elongate formwork space using a hose. These building activities are basic skills that do not require special qualifications. Pertinently there is no timber frame in this structure so a carpenter is not required to build the basic timber frame. Secondly there is no brick veneer and thus a bricklayer is not required to build a brick veneer on the outside of the frame. Related to these advantages is the fact that the structure can be constructed very quickly. Further there are no delays caused by waiting for the availability of different trades and the structure can be constructed very quickly.

It will readily be appreciated by persons skilled in the art that this structure and method of construction is well suited to building structures in remote locations. Once the basic materials have been delivered the basic structure less the frame can be erected and thereafter a batch of concrete delivered and all the frame elements can be cast with that batch of concrete. Thereafter once the concrete has hardened and cured the panel support arrangement can be removed and final structure is in place on the building support.

It will be appreciated that the method articulated above with reference to the drawings is simple in concept and inexpensive. The wall panels can be used to form suitable formwork or conduits for pouring cementitious material that is concrete therein. This yields strong structural elements that can serve as posts in the overall structure. Further it will be appreciated that concrete is an inexpensive material.

It will further be appreciated that the method described above with reference to the drawings builds a building in a reverse order to known methods and in a counter intuitive manner to known methods. In the known methods a structural frame is erected first from solid members such as a length of timber of steel. This forms the underlying structural strength of the building and the wall cladding and the roof are then mounted on the frame. By contrast in the current invention a support arrangement is provided that enables the wall cladding to be permanently mounted in position in its final position. The wall cladding is arranged to be properly and securely mounted in position and it is also arranged to form formwork within which a concrete material can be poured to form frame members to form the underlying structural frame of the building. The concrete is then poured and its sets and hardens to provide an exceptionally strong underlying frame. Thus in this method the wall cladding is erected first and then the frame structure with frame elements is subsequently formed in formwork defined by the wall cladding. This completely different and counter intuitive approach leads to numerous advantages both in the construction process and in the final structure that is built which have been discussed at length above.

It will of course be realized that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of the invention as is herein set forth.