Our Ref: 61651nno P/00/009 Regulation 3.2 AUSTRALIA Patents Act 1990 INNOVATION SPECIFICATION FOR AN INVENTION ENTITLED Invention title: Panel wall construction Name of Applicant: One Stop Building and Hardware Pty Ltd Address for Service A.P.T. Patent and Trade Mark Attorneys PO Box 222 Mitcham, S.A. 5062 The invention is described in the following statement: Panel Wall Construction This invention relates to construction of a building comprising a structural frame supporting concrete building panels, and in particular to a building and 5 a method a making a building with the use of staggered concrete building panels. INTRODUCTION 10 Aerated Autoclaved Concrete (AAC) has been used for several decades in the construction of buildings in Europe and these have over the last few decades also become more common in Australia and New Zealand. AAC as a material has several desirable properties over conventional building materials including insulation properties, fire rating properties, and particularly 15 where construction uses AAC panels there are advantages of speed of panel construction whilst having the perceived benefits of a masonry structure. The use of AAC panels also has the advantage that this is a lightweight material relative to conventional masonry materials. The use of AAC provides the capacity to handle panels manually rather than with mechanical assistance. 20 The AAC panels are typically formed such that they comprise an internal reinforcement mesh, however they are not relied on to comprise the primary structural component of the building. Where the building concerned is a domestic building such as a detached or semi-detached dwelling or 25 associated building such as a garage or shed the construction will include the erection of a structural frame typically of suitably approved timber or steel. The panels will be fixed to the structural frame but will typically be spaced apart from the structural frame by a cavity batten. 30 AAC panels are continually being developed and there is a trend to using lighter weight panels, which lighter weight is principally achieved by making them thinner. Currently AAC panels for residential buildings are provided in 50mm, 75mm and 100mm thicknesses. The 50mm panels are attractive by 2 reason of their cost advantage and because of their greater ease of transport and handling resulting from their lighter weight. Whilst panels do not comprise the principal structural feature of a building 5 they do impact and specifically their layout impacts on the structural integrity of a wall. Building regulations apply to construction of buildings comprising AAC panels and these provisions apply to the installation of expansion control joints 10 between panels around opening such as windows and doors and generally vertically. Also horizontal expansion joints are required at a prescribed height and within the floor joist zone. These expansion joints act to maintain the integrity of a wall formed by such panels and are intended particularly to obviate the formation of cracking between panel joints. 15 Such expansion control joints typically comprise a 10mm space between vertically adjacent panel edges. Expansion control joints are usually packed progressively with a solid packer, a backing rod and then outermost with a paintable external grade polyurethane sealant. The use of these joints 20 maintains the appearance of a wall formed by the panels by accommodating some movement along a line of weakness in the wall. Two disadvantages arise from use of control joints. A principal disadvantage is that particularly horizontal control joints are considered unsightly because it 25 is impossible to maintain a uniformity between the outer surface of adjacent panel and the outermost layer of sealant, in part because the sealant does shrink. Unlike vertical joints such horizontal joints are extended typically right the way around a building and are thus very visible. A second disadvantage is that some effort is required to construct an expansion joint, particularly a 30 horizontal one including to ensure that the spacing is made as uniform as practical, with considerable care being required to align top and bottom edges of vertically spaced panels. Some work and expense is also incurred by attendant filling and finishing off of expansion control joints. 3 Sometimes a feature moulding is fixed over the control joint to mask it, however, this involves further work and expense and is often considered to detract from the overall clean look of a flat wall. 5 Accordingly it is an object of the present invention to provide a method of constructing a building from building panels and a building so constructed that alleviates or minimises the problems set out above or at least provide the public with a useful choice. 10 SUMMARY OF THE INVENTION The present invention provides for a building and a method of constructing such building comprising a wall with vertically aligned concrete building panels supported by a structural frame, the panels being vertically staggered. This 15 form of construction provides for improved integrity of the wall. Another advantage of the construction according to this invention is that in some forms of buildings it provides a way of not requiring at least some horizontal expansion control joints that would otherwise be needed. 20 In one form of a first aspect the invention could be said to reside in a building, comprising a structural frame and a plurality of walls, at least one wall comprising at least two adjacent rows of a plurality of vertically aligned building panels supported by the structural frame, panels in said adjacent rows being vertically staggered. 25 The invention is applicable to a variety of building whether or not walls are considered at risk because panels that are staggered relative to panels in adjacent rows will provide for walls of greater integrity. 30 It will be understood, however, that the invention is particularly applicable to buildings where wall heights are such that the structural integrity of the wall is otherwise considered at greater risk. Lighter weight aerated autoclaved concrete (AAC) panels, for example, those having a thickness of 50mm are considered at risk if they have horizontally aligned joints with vertical 4 spacings. The present invention is therefore particularly applicable to buildings with various wall heights. Buildings with two or more stories have walls that comprise a floor joist zone 5 between the stories. The floor joist zone of the wall is also considered to be a zone at risk of compromised integrity, and accordingly regulations require that there be provision of an expansion joint where a horizontal join exists between adjacent rows of panels in the floor joist zone. 10 Accordingly in a second form of the first aspect the invention could be said to reside in a building comprising at least two stories and having a floor joist zone between said stories, said building further comprising a structural frame and a plurality of walls, at least one wall comprising two adjacent rows of a plurality of vertically aligned building panels supported by the structural frame, 15 panels in said rows being vertically staggered so as to present staggered horizontal joints at said floor joist zone. Panels comprise sides and ends, and as provided by commercial suppliers these panels typically have sides longer than ends, however, when cut the 20 panels may have shorter sides to fit in a particular space. Typically walls will comprise considerably more than two vertical rows of vertically aligned panels. The staggering may be uniform in the sense that each second row will be have panels of the same size and same position, with 25 the intervening rows having panels staggered relative to these and intervening rows also having like sizes and positions of panels. There is, however, no need for such regularity, and the panel sizes of various side lengths can be aligned in a row, and vertically staggered relative to 30 panels in an adjacent row. In this way off-cuts can be used thereby reducing waste. It is desired that the panels are vertically staggered to a degree that provides for a structural advantage. In a specific form such staggering may be at least 5 100 mm, 150mm, but preferably at least 200mm, for at least at one end of the panel and preferably both. Not all panels in the walls need be vertically aligned. It will understood in 5 construction of buildings particularly residential building such as detached or semi detached houses walls will comprise openings therethrough such as for windows and doors. There may be provided over the top of such openings a lintel comprising a horizontally laid panel, that will typically cut down in width to fit in with the general layout of the wall. Similarly adjacent panels will form 10 a horizontally aligned upper surface at the bottom of such openings to accommodate, for example, windows. Similarly it will be understood that the tops of the rows of panels will be aligned so as to typically be horizontal to form the top of the wall at the 15 approved height above the eaves line. Furthermore it may be desired to provide in the wall one or more horizontally aligned rows of a plurality of panels. It may be desired to provide for a horizontal lintel type structure across aligned tops of windows and doors, and 20 provided that these do not create a joint at heights, or within zones such as floor joist zones, that are at risk the present invention will be understood to encompass such structures. It will equally be understood, however, that the inclusion of such horizontally aligned rows of panels are not preferred. 25 It will be appreciated that this invention is applicable to a building constructed from aerated autoclaved cement panels. In a specific form of the invention the panels are about 50mm in thickness and less than 3.3m in length. Typically these are provided in lengths of approximately 2.2 metres. This is in most cases shorter than required to form the entire height of the wall. Hence 30 the requirement to have a plurality of vertically aligned panels for each row. In one preferred aspect of the invention vertically aligned panels are vertically staggered so as to not present a horizontal joint. 6 Panels of this type and also other thicknesses such as 75mm and 100mm preferably are not fastened directly onto the wall but are attached via a cavity batten. This provides for a cavity greater than the thickness of the structural frame and allows for a greater facility for installation of thermal and acoustic 5 insulation and other layers within the cavity. Several forms of cavity batten are used and are approved for use in this type of construction including galvanized steel battens, such as 0.42 BMT galvanized steel G300, timber battens such as H3 treated pine, or plastics battens such as Very High density (Class VH) EPS. These may be continuous lengths or may comprise discrete 10 blocks that are fastened to the structural frame. Various alternatives of the first aspect of the invention have been set out above, but it is to be appreciated that two or more alternatives may readily be combined. 15 A second aspect of the invention relates to the method of constructing a building of the first aspect of the invention. Accordingly in a first form of a second aspect the invention could be said to 20 reside in a method of constructing a building comprising the step of putting in place a structural frame, the step of erecting a plurality of walls to be supported by the structural frame, for at least one wall assembling two adjacent rows of building panels, comprising the step of vertically aligning a plurality of building panels in each row and fastening these to the structural 25 frame, wherein panels in said to adjacent rows are vertically staggered. In a second for of this second aspect the invention could be said to reside in a method of constructing a building comprising two stories comprising the step of putting in place a structural frame having a floor joist zone between said 30 stories, the step of erecting a plurality of walls to be supported by the structural frame, for at least one wall assembling two adjacent rows of building panels, comprising the step of vertically aligning a plurality of building panels in each row and fastening these to the structural frame, wherein panels in said 7 to adjacent rows are vertically staggered so as to present staggered horizontal joints at said floor joist zone. It will be understood that each individual aspect of the first form of the 5 invention or combinations thereof may be incorporated into the methods set out above. BRIEF DESCRIPTION OF THE DRAWINGS 10 For a better understanding the invention will now be described by reference to illustrated embodiments of the invention. In the drawings Figure 1 is a part cut-away perspective of a wall constructed using aerated autoclaved concrete (AAC) panels as practiced in the 15 prior art, Figure 2 is cross sectional view of a wall for a two story building made in accordance with the present invention, 20 Figure 3 is a side plan view of one embodiment of a layout of panels of a wall for a single story building in accordance with the present invention, and Figure 4 is a side plan view of a second embodiment of a layout of panels 25 of a wall for a two story building in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION 30 Figure 1 shows wall construction of a prior art building. Typically the building has a raft foundation (1) a structural frame (2) of either steel or treated timber comprising upright members (3) and horizontal members comprising top plate (5) and bottom plate (6), together with noggins (7) to maintain the upright 8 members in place. The structural frame is erected according to standard construction techniques. Cavity battens (8) are fastened to the upright members (3) of the structural 5 frame using approved fasteners. The cavity battens shown are elongate galvanised steel top hat members. They could equally be made of treated timber or plastics material such as very high density EPS (Polystyrene Foam). The battens need not be elongate, as shown, being substantially the same width as the wall. Battens could take the form of discrete blocks fastened to 10 the upright members, or perhaps if need be fastened to the noggins, particularly for back blocking. The purpose of the cavity battens is to provide an enlarged cavity between the inside face of the structural frame, facing inwardly of the building and the inside face of the panels (10), thereby providing allowance for movement, which minimises cracking and also 15 provides cavity for moisture and condensation to travel. The cavity battens are spaced in the illustrated prior art embodiment to support either end of the aerated autoclaved concrete (AAC) panels (10). The illustrated panels are 50mm thick, 600mm wide and are supplied in lengths of 20 2200mm. They are reinforced internally by a steel mesh (11). The panels are fixed to the batten via predetermined locations at least 150mm from side edges (12) and 150 mm from end edges (13) with screw threaded fasteners that engage with the battens. Approved thin bed adhesive is applied to edges of adjacent panels and form a joint (14) there between. 25 It can be seen that the panels are aligned vertically in two adjacent vertical rows (15, 16). It can also be seen that the lower two of the illustrated panels have been cut shorter and have an equal length, similarly, the upper of the two illustrated panels have the same length, these have not been cut to 30 length, rather they are the length as supplied. It will be appreciated that joint (14) is an elongate joint representing an extended line of horizontal weakness along the width of the wall. 9 The illustrated wall also shows the use of a combined flashing and damp proof course (20) between the raft and the structural frame. Building fabric (21) is fitted on the outside face of the structural frame as is standard building practice. The illustration does not show industry standard inside linings, for 5 example plaster board, that are fixed to the inside face of the structural frame, insulation that is fitted to the cavity formed between the inside lining and the panels (10). It is also standard practice for AAC panels to have a multilayered finish of approved coatings and paints applied to provide, stability, waterproofing and the desired finish to the outside of the wall, this is also not 10 shown. The present invention contemplates the use of standard industry practice, which is illustrated in figure 1, except for the layout of the panels (10) with consequent placement of the cavity battens where they are used. 15 Figure 2 shows a cross sectional view, in somewhat schematic form, of a wall of a two storey building according to the present invention. The raft foundation (1) supports the structural frame (2). The structural frame 20 is shown as encompassing a ground floor (30) and a first floor (31) comprising top plates (5) and bottom plates (6) for each storey with upright frame members (3) therebetween. The full height of the building is not shown the upright members are illustrated as broken at positions (35). 25 Floor joists (32) made of steel or timber and engineered in the approved manner are supported between the bottom plate (6) of the first floor and the top plate (5) of the ground floor. Internally extending flooring (33) is supported by the floor joists (32). In the illustrated embodiment a floor joist zone (34) of the wall comprises that region including the floor joists (32) and the bottom 30 plate (6) of the first floor and the top plate (5) of the ground floor. Horizontally aligned elongate cavity battens (8) are fastened to the outside face of the upright members (3) of the structural frame. Fasteners are not shown. A plurality of AAC panels (10) are fastened to the cavity battens using 10 standard fasteners in accordance with manufacturer's specifications. It can be seen that in this embodiment there is no expansion control joint between panels of a row in the floor joist zone (34) due to staggered panels elimination the requirement for an expansion control joint between the zone. 5 Figures 3 and 4 illustrate two different alternative arrangements of panels in single and two storey buildings respectively. Although it will be understood that many more such arrangements are contemplated by this invention. 10 The wall of the building illustrated in Figure 3 comprises 6 rows (40 - 45) of vertically aligned panels (10). The staggering of the panels of adjacent rows is repeated so that every second row (40, 42, 44) comprise a standard panel of 2200mm on the bottom and a panel cut back to 800 on the top, intervening rows (41, 43, 45) comprise a standard panel of 2200mm on the top with a 15 panel cut back to 800mm on the bottom. Panels of adjacent rows have a stagger of 14000mm. The height of the wall is thus 3 metres. The wall of the building illustrated in Figure 4 also comprise 6 rows (46 - 51). The cavity battens are shown in broken outline for example at (8). These are 20 shown as elongate battens. The wall of Figure 4 extends up to two storey, and shown in broken outline is the floor joist zone (34). The panels joints (14) within the floor joist zone are staggered in between floor joist zone. The staggering of the panels of adjacent rows is repeated so that every second row (46, 48, 50) comprise the following alignment from bottom to top a 25 standard panel of 2200mm, a panel cut to 1100mm, a 2200 standard panel and a top panel of 900mm. Intervening rows (47, 49, 51) comprise the inverse pattern. This arrangement results in staggered joints (14) in the floor joist zone (34). 30 It will appreciate that regularity of pattern facilitates the arrangement of panels particularly to that the number of elongate battens can be kept to a minimum. A wall could equally comprise rows all comprises differing panel combinations, but each panel is staggered relative to an adjacent panel at least at one end thereof. In a wall configured of uneven staggering of panels it 11 may be desired to introduce one or more cavity battens that are in the form of blocks, in addition to the elongate battens, to better secure individual panels that have been cut down to smaller size. In the alternative the block battens may be used exclusively. 5 It will be understood from the foregoing that the arrangement of panels can be varied considerably and a range of patterns can readily be conceived by the tradesman who installs these panels. 10 12