NZ759893A - Stud for wall construction - Google Patents

Abstract

A stud for use in panel formwork for solid filled walls, the stud comprising a pair of rails, each rail including, a rail body configured to be attached to an inner face of a respective wall sheet and a pair of spaced apart opposed flanges extending away from the rail body, each flange including a lip, and a plurality of spacer elements extending between the rails to hold the rails and respective wall sheets in a spaced apart arrangement, each spacer element including a spacer body and a connector provided at each end of the spacer body, each connector including shoulders that engage respective lips of the flanges to thereby fasten the connectors to the rails. ip, and a plurality of spacer elements extending between the rails to hold the rails and respective wall sheets in a spaced apart arrangement, each spacer element including a spacer body and a connector provided at each end of the spacer body, each connector including shoulders that engage respective lips of the flanges to thereby fasten the connectors to the rails.

Description

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 STUD FOR WALL CONSTRUCTION Background of the Invention The present invention relates to a stud for use in wall construction, a wall including the stud and a method of constructing a wall using the stud.

Description of the Prior Art The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

It is known to provide techniques for constructing walls using wall sheets as concrete formwork, which then form part of the completed wall structure.

WO2005/019552 describes a system comprising paired studs for attachment to inside surfaces of facing sheets to provide panel formwork for concrete walls. The studs comprise a head and outwardly extending spaced flanges with inwardly directed teeth and lips. Spacer elements are engaged with the recess between the flanges and may be formed from off-cuts of sheet material or as specifically formed elements. The latter are formed from hard plastic and in a preferred embodiment are formed as a rectangular box which can be orientated in alternate directions. The system may include end elements, internal top and bottom plates, internal corners, external corners and a shadow line junction between panels. The invention extends to panels formed with the above system and buildings formed from the panels.

WO2009/070830 describes a method of constructing a wall, the method including providing first and second spaced apart wall portions for receiving a filling material. Each wall portion includes at least one track on a support, at least two support members, each support member being aligned with the track and extending from the support, a wall panel supported by the at least one track and the at least two support members and at least one joining member C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 coupled to the wall panel and the support members. Spacers are also coupled to and extend between the wall portions.

Summary of the Present Invention In one broad form, an aspect of the present invention seeks to provide a stud for use in panel formwork for solid filled walls, the stud comprising: a pair of rails, each rail including: a rail body configured to be attached to an inner face of a respective wall sheet; a pair of spaced apart opposed flanges extending away from the rail body, each flange including a lip; a plurality of spacer elements extending between the rails to hold the rails and respective wall sheets in a spaced apart arrangement, each spacer element including: a spacer body; and, a connector provided at each end of the spacer body, each connector including shoulders that engage respective lips of the flanges to thereby fasten the connectors to the rails.

In one embodiment the rail body is a substantially planar elongate body.

In one embodiment the flanges extend from edges of the rail body.

In one embodiment the flanges extend substantially perpendicularly from the rail body.

In one embodiment the spacer body includes a pair of substantially parallel spaced webs extending between the connectors.

In one embodiment the connectors include plates extending between ends of the webs.

In one embodiment each web includes a structural ridge extending along a surface of the web.

In one embodiment each web includes a narrow waist.

In one embodiment the lips extend inwardly from the flanges and the shoulders extend outwardly from the connectors so that the connector is retained between the flanges.

In one embodiment the connectors are fastened to the rails using at least one of: snap fit engagement; and, cantilevered snap fit engagement.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 In one embodiment the lips are configured to engage the shoulders to thereby fasten the connector to the rail.

In one embodiment the flanges deform outwardly to allow the connector to pass between the lips.

In one embodiment the lips include a sloped outer lip surface that engages the shoulders to urge the flanges laterally to allow passage of the shoulders past the lips.

In one embodiment the sloped outer lip surface has a convex curved profile.

In one embodiment the shoulders include a sloped outer shoulder surface that engages the lips to urge the flanges laterally to allow passage of the shoulders past the lips.

In one embodiment the sloped outer shoulder surface has a convex curved profile.

In one embodiment the lips and shoulders include sloped outer surfaces having convex curved profiles to progressively increase the lateral mechanical force applied to the flanges as the shoulders move past the lips.

In one embodiment: at least one rail includes a plurality of holes spaced along an inner surface of the rail body; and, at least one of the connectors of each spacer includes a peg that projects from an outer surface of the connector, and wherein the peg is configured to engage one of the plurality of holes to thereby locate the spacer along the rail.

In one embodiment the hole extends at least part way through the rail body.

In one embodiment: each rail includes a plurality of holes spaced along in the inner surface of the rail body; and, each connector of each spacer includes a peg that projects from an outer surface of the connector to engage a respective hole.

In one embodiment the plurality of holes are spaced apart by a set distance to thereby maintain a set spacing between spacers.

In one embodiment the set distance is at least one of: greater than 200mm; greater than 250mm; greater than 280mm; less than 400mm; less than 350mm; less than 320mm; less than C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 eight times a height of the spacer; less than seven times a height of the spacer; more than four times a height of the spacer; more than five times a height of the spacer; approximately six times a height of the spacer; and, approximately 300mm.

In one embodiment the spacers have a height that is at least one of: greater than 25mm; greater than 40mm; less than 75mm; less than 60mm; and, approximately 50mm In one embodiment the spacer body has at least one of: a length of at least one of: greater than 90mm; greater than 100mm; less than 300mm; less than 255mm; approximately 123mm, approximately 138mm, approximately 153mm, approximately 188mm, approximately 253mm, and, approximately 103mm; and, a width of at least one of: greater than 40mm; greater than 42.5mm; less than 50mm; less than 47.5mm; and, approximately 45mm.

In one embodiment the rail has at least one of: a length of up to 3000mm; and, a width that is at least one of: greater than 40mm; less than 60mm; and approximately 50mm.

In one embodiment the rails are made of at least one of: a thermoplastic polymer; polyvinyl chloride; rigid polyvinyl chloride; and, recycled rigid polyvinyl chloride.

In one embodiment the spacers are made of at least one of: a thermoplastic polymer; polyethylene; high density polyethylene; and, recycled high density polyethylene.

In one embodiment the rail body is attached to a wall sheet using at least one of: adhesive bonding; mechanical bonding; polyvinyl acetate copolymer adhesive; polyvinyl acetate silane copolymer adhesive; solvent based polyvinyl chloride cements cyanoacrylates; 2-part epoxy adhesives; and, structural acrylic adhesives.

In one embodiment the wall sheet is at least one of: a fibre cement wall sheet; and, a polyvinyl chloride wall sheet.

In one broad form, an aspect of the present invention seeks to provide a wall structure including multiple wall sections, and each wall section including: a pair of wall sheets; a plurality of studs, each stud being attached to each of the pair of wall sheets to hold the wall sheets in a substantially parallel spaced apart configuration, each stud including: a pair of rails, each rail including: a rail body adapted to be coupled to an inner face of a respective wall sheet; a pair of C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 spaced apart opposed flanges extending away from the rail body, each flange including a lip; a plurality of spacer elements extending between the rails to hold the rails and respective wall sheets in a spaced apart arrangement, each spacer element including: a spacer body; and, a connector provided at each end of the spacer body, each connector including shoulders that engage respective lips of the flanges to thereby fasten the connectors to the rails.

In one embodiment the wall includes multiple wall sections arranged in end-to-end abutment and wherein at least one rail body spans a join between adjacent wall sheets of adjacent wall sections.

In one embodiment a space between the wall sheets is filled with a filling material.

In one embodiment the wall sheet is at least one of: a fibre cement wall sheet; and, a polyvinyl chloride wall sheet.

In one broad form, an aspect of the present invention seeks to provide a method of constructing a wall, the method including: providing at least one track on a support; attaching a number of wall sections to the track, each wall section including: pair of wall sheets to the at least one track; a plurality of studs, each stud being attached to each of the pair of wall sheets to hold the wall sheets in a substantially parallel spaced apart configuration, each rail including: a rail body adapted to be coupled to an inner face of a respective wall sheet; a pair of spaced apart opposed flanges extending away from the rail body, each flange including a lip; a plurality of spacer elements extending between the rails to hold the rails and respective wall sheets in a spaced apart arrangement, each spacer element including: a spacer body; and, a connector provided at each end of the spacer body, each connector including shoulders that engage respective lips of the flanges to thereby fasten the connectors to the rails; and, providing a filling material between wall sheets of the wall sections.

In one embodiment the method includes positioning reinforcing members between the wall sheets so that the reinforcing members are at least partially supported by the spacers, prior to providing the filling material.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 It will be appreciated that the broad forms of the invention and their respective features can be used in conjunction and/or independently, and reference to separate broad forms is not intended to be limiting.

Brief Description of the Drawings Various examples and embodiments of the present invention will now be described with reference to the accompanying drawings, in which: - Figure 1A is a schematic side view of an example of a wall; Figure 1B is a schematic plan view of the wall of Figure 1A; Figure 1C is a schematic end view of the wall of Figure 1A; Figure 2A is a schematic plan view of an example of a rail; Figure 2B is a schematic end view of the rail of Figure 2A; Figure 2C is a schematic perspective view of a part of the rail of Figure 2A; Figure 3A is a schematic plan view of a spacer; Figure 3B is a schematic side view of the spacer of Figure 3A; Figure 3C is a schematic end view of the spacer of Figure 3A; Figure 3D is a schematic perspective view of the spacer of Figure 3A; Figure 4 is a schematic end view of a stud including rails of Figure 2A and a spacer of Figure 3A; Figures 5A to 5C are schematic end views showing attachment of a spacer of Figure 3A to a rail of Figure 2A; Figure 6A is a schematic perspective view of wall section components; Figure 6B is a schematic perspective view of a partially constructed wall section; C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 Figure 7A is a schematic perspective view of a wall corner section; Figure 7B is a schematic perspective view of an example of a wall end cap; Figure 7C is a schematic perspective view of a portion of a wall; Figure 8A is a schematic perspective view showing a wall during construction; Figure 8B is a schematic close-up view of the tracks of Figure 8A; and, Figure 8C is a schematic diagram of an example of a partially constructed wall.

Detailed Description of the Preferred Embodiments An example of a wall construction will now be described with reference to Figures 1A to In this example, a wall is constructed on a support 101 such as a slab, footing, building foundation, or the like. The wall 100 includes a number of wall sections 110, which in this example are provided in an end-to-end arrangement to construct a straight wall 100. Each wall section 110 includes wall sheets 111, 112, such as fibre cement sheets, which are held in a parallel spaced apart arrangement by studs 113. The studs 113 typically extend substantially vertically for most of a height of the wall sheet, with multiple studs being spaced apart horizontally along the wall sheets 111, 112, so that each wall section includes multiple studs.

The studs 113 are attached to the wall sheets to hold the wall sheets in a spaced apart position, allowing a filling material, such as concrete, or the like, to be provided therebetween, as will be described in more detail below.

An example of a stud arrangement for such a wall construction technique will now be described in more detail with reference to Figures 2 to 4.

In particular, in the example, the stud is formed from a pair of rails 230, shown in Figures 2A to 2C, and a plurality of spacer elements 340, shown in Figures 3A to 3D, which extend between the rails 230 to hold the rails in a spaced apart arrangement, as shown in Figure 4.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 Each rail 230 includes a rail body 231 configured to be attached to an inner face of a respective wall sheet 111, 112. Each rail 230 also includes a pair of spaced apart opposed flanges 232, which extend away from the rail body 231 with each flange including a lip 233.

In this particular example, the rail body 231 is substantially planar and has a generally elongated rectangular shape, with the flanges 232 extending substantially perpendicularly away from opposing long edges of the rail body 231. However, it will be appreciated that this is not essential and other configurations could be provided. For example, the rail body could have an alternative shape, the flanges 232 could be spaced from the edges, or the flanges 232 could be provided at angles offset to perpendicular. Nevertheless, the above described arrangement is particularly advantageous as it can be easily created during an extrusion process, whilst using minimal amounts of material, thereby reducing environmental impacts and cost, but maintaining sufficient structural integrity.

In the current example, the stud 340 includes a spacer body that extends between connectors 342 provided at each end of the spacer body. Each connector includes shoulders 343 that engage the respective lips 233 of the flanges 232 to thereby fasten the connectors 342 to the rails 230. An example of this is shown in Figure 4, in which the connectors 342 are retained in position by the lips 233 of the rail flanges 232.

In one particular example, the spacer body includes a pair of substantially parallel spaced webs 341 extending between the connectors 342, which in this example are in the form of plates that extend between and beyond ends of the webs 341, to thereby form the shoulders 343. The webs 341 and connectors 342 can be separate components, although more typically these are integrally formed, for example as part of an extrusion process. Again it will be appreciated that the particular configuration of the spacer, and in particular the spacer body and connectors 342 could vary. For example, the spacer could include a single solid body, instead of the webs 341.

However, it will be noted that the webs provide could structural strength under compression or tension, whilst using minimal material, thereby reducing environmental impacts and cost.

Additionally, as will be described in more detail below, the use of webs provides an opening, which can received reinforcement members, such as rebar, and which also allows for flow of C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 filling material therethrough, which can assist in ensuring complete filling of the cavity between the wall sheets 111, 112.

Accordingly, the above described arrangement provides a pair of rails that can be attached to respective wall sheets, with a plurality of space elements being used to hold the rails and hence wall sheets in a substantially parallel spaced apart arrangement.

A number of features will now be described.

In the current example, the lips 233 extend inwardly from the flanges 232 with the shoulders 343 extending outwardly from the connector 342 so that the connector is retained between the flanges 232 as shown in Figure 4. In this regard, the term inwardly refers to the lip extending from one flange towards the opposing flange, so that the lips are provided between the flanges, whilst outwardly refers to the shoulders projecting beyond sides of the body. It will be appreciated, however, that this arrangement is not necessarily essential and alternative configurations could be employed. For example, the lips 233 could extend outwardly from the flanges 232 and be accommodated between inwardly projecting shoulders 343 on the connectors 342.

Nevertheless, the arrangement shown in Figure 4 is particularly advantageous as this provides for a significant degree of coupling strength whilst minimising the amount of material employed in construction of the rails and spacers, which in turn reduces material wastage and saves costs.

The connectors are typically fastened to the rails using snap-fit engagement and, in particular, a cantilevered snap-fit arrangement. In this configuration, the flanges 232 are resiliently deformable to allow passage of the connectors 342 and shoulders 343 between the lips 233. Once past the lips 231, the flanges 232 returning to their original position so that the lips 233 engage a rear of the shoulders 343, to thereby fasten the connector 342 and hence the spacer 340 to the rail 230. An example of this process is shown in more detail in Figures 5A to 5C.

In this example, as shown, the spacer 340 and rail 230 are urged towards each other to cause the flanges 232 to deform progressively outwardly so that the connector 342 passes between the lips 233.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 To facilitate this process, the lips 233 include a sloped outer lip surface 234 that engages the shoulders 343 to urge the flanges laterally outwardly to allow passage of the shoulders therebetween. Similarly, the shoulders 233 include a sloped outer surface 344 that engages the lips 233 to urge the flanges laterally outwardly to allow passage of the shoulders past the lips. In both cases, the sloped outer lip surface 234 and sloped outer shoulder surface 344 typically have a convex curved profile, which can facilitate the deformation of the flanges 232. In particular, the sloped surface allows movement of the spacer 340 and rail 230 towards each other to be translated into a lateral force which is applied to the flanges, thereby urging the flanges 231 apart. Furthermore, the use of the convex curved profile employs mechanical advantage to progressively increase the lateral force applied to the flanges 232 as the shoulders 343 move past the lips 233. An example of this is shown by the dotted lines in Figures 5A and 5B which show that as the flanges 232 deform outwardly, and the curved surfaces 234, 344 pass each other, the angle of contact changes to thereby increase the level of mechanical advantage and hence increase the magnitude of the lateral force applied to the flanges 232, thereby facilitating passage of the connector 342 between the lips 233.

The rail 230 and spacers 340 can be configured so that the spacers lock into defined positions on the rail 230, thereby maintaining a spacing between the spacers 340. In one example, this is achieved using a locking peg 345 provided on the spacer.

In this example, as shown in Figure 2A, the rail 230 includes a plurality of holes 235 spaced along an inner surface of the rail body 231, with the holes 235 being either recesses formed in a surface of the rail body 231, or could be apertures that pass through the rail body 231.

At least one of the connectors 342 of the spacer 340 includes a peg 345 that projects from an outer surface of the connector 342. In use, the peg 345 is configured to engage one of the plurality of holes 235 to thereby locate the spacer along the rail and, in particular, lock the spacer in a defined position relative to the rail 230. This prevents spacers inadvertently sliding relative to the rail 230 during wall construction, whilst maintaining a vertical spacing between the spacers 340.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 It will be appreciated that the holes 235 provided in only one of the rail bodies 230 and/or that pegs 345 may be provided in only one connector 342. In this instance, this can allow free movement of the spacers 340 relative to one of the rails 230 of each pair of rails, which can assist in the wall construction process, for example, to accommodate different levels of a support.

More typically, however, holes are provided in both rails, thereby locking a respective vertical positioning of the rails 230.

As previously mentioned, the holes are spaced by a set distance to thereby maintain a set spacing and in particular set vertical separation, between spacers 340. Part of the purpose of this is to ensure that there is sufficient open space within the stud to allow filling material to flow through the stud during the process of filling a wall section. This in turn helps ensure the wall cavity between the wall sheets 111, 112 is completely filled, avoiding the presence of voids, which can in turn affect the structural integrity of the wall. However, this must be balanced by ensuring a sufficient number of spacers 340 are provided, to adequately support spacing of the wall sheets 111, 112 during construction and filling of the wall.

To achieve this, the set distance is typically at least one of greater than 200mm, greater than 250mm, greater than 280mm, less than 400mm, less than 350mm, less than 320mm, less than eight times a height of the spacer, less than seven times a height of the spacer, more than four times a height of the spacer, or more than five times a height of the spacer. More typically, the set distance is approximately six times a height of the spacer or approximately 300mm.

The spacers typically have a height that is greater than 25mm, greater than 40mm, less than 75mm, less than 60mm, or more typically approximately 50mm, a length that is greater than 90mm, greater than 100mm; less than 300mm; less than 255mm; approximately 123mm, approximately 138mm, approximately 153mm, approximately 188mm, approximately 253mm, or more typically approximately 103mm, and a width that is greater than 40mm, greater than 42.5mm, less than 50mm, less than 47.5mm or more typically approximately 45mm.

The rail typically has a length dependent on the required wall height, but typically up to 3000mm and a width that is greater than 40mm, less than 60mm, or more typically approximately 50mm.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 Additionally, the webs 341 may include cut-outs 346, 347, defining a narrowing waist.

This reduces the amount of material required to manufacture the spacer which in turn reduces the spacer cost and environmental impact. Additionally, this can reduce the cross-sectional area of the spacer which can result in enhanced flow of filling material through the stud. Finally, this can also act as a mechanism to locate reinforcing members which can rest in a recess 347 so that these are centrally located within the wall section.

The spacer 340 may also include a structural rib 348 extending around an inner mid-point of the spacer, and in particular along the webs 341 and across the connectors 342, to provide additional structural strength.

Typically the rails are made of a thermoplastic polymer, such as polyvinylchloride (PVC) and, in particular, a rigid PVC. In one preferred example, the rails are manufactured from a recycled rigid PVC thereby significantly reducing the environmental impact of constructing the wall.

Similarly, the spacers are typically made of a thermoplastic polymer and, in particular, polyethyelene. In one example, this is high-density polyethylene (HDPE) and in a preferred example, recycled HDPE. The use of HDPE is particularly beneficial as this provides suitable strength and rigidity.

The rail bodies can be attached to the wall using a variety of techniques, such as adhesive or mechanical bonding. In one preferred example, a polyvinyl acetate copolymer adhesive, such as polyvinyl acetate-silane copolymer, is used to attach the rail body 231 to the wall sheets 111, 112, which are typically fibre cement sheets or similar. However, it will be appreciated that other wall sheet materials could be used. For example, one or more of the wall sheets could be made of a polyvinyl chloride (PVC) material, or similar, in which case alternative adhesives might be used, such as solvent based polyvinyl chloride cements, cyanoacrylates, 2-part epoxy adhesives, structural acrylic adhesives, or the like.

In this regard, permanent formwork for a below ground applications typically uses an extruded PVC unit, whilst fibre cement sheets are generally not preferred for below ground application due to the difficulty of preventing ground water movement into /through the C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 completed wall structure. However, in one example, one or both of the wall sheets could be made from PVC, allowing this to be used in a range of different applications. For example, for use in underground construction, such as basement walls or similar, the wall could include an outer PVC wall sheet which could be used to prevent ingress of moisture. Alternatively, for above ground applications, an inner PVC wall sheet could be used to provide a wall surface that is smoother than a traditional fibre cement wall sheet, which could facilitate painting or other finishing. It will also be appreciated that PVC wall sheets could be used both externally and internally, depending on the intended application.

As previously mentioned, the studs can be used to construct wall sections having a pair of wall sheets held in a spaced apart arrangement by a plurality of studs 113. To construct such a wall section, a number of rails 230 are initially laid on a pair of wall sheets 111, 112, and attached thereto using adhesive, as shown in Figure 6A. Spacers 340 are then attached to the rails on one of the wall sheets, before the other wall sheet is brought into engagement with the spacers, as shown in Figure 6B.

In the example shown in Figures 6A and 6B, one of the studs is provided projecting outwardly from an end of the wall to form a male wall section end, which in turn can be attached to a female end of an adjacent wall section, allowing the stud to span the wall sections 110, and hence physically attach the wall sections 110.

Typically, when constructing a wall, wall sections may be interconnected in direct abutment, but may also use additional components. For example, a wall corner section is shown in Figure 7A. The wall corner section 750 includes first and second wall sheets 751, 752, joined by a right-angled connector body 753 and an external reinforced webbing 754. A wall end section is shown in Figure 7B. In this example, the wall end section 760 includes a wall sheet 761 connected to two right-angled corner members 763, 762. As shown in Figure 7C, two wall sections can be interconnected at right angles using a corner section 750 with an end cap 760 being used to seal an end of a wall.

It will be appreciated that the studs 113 and other components can be used in a wall construction process, and example of which will now be described with reference to Figures 8A to 8C.

C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/10/2011 In this example, the wall is constructed by initially mounting a pair of tracks 871 on a support 881, such as a slab, foundation or similar. Wall sections 110 are then mounted to the tracks, for example, by fastening the wall sheets to the tracks using fasteners, such as screws, or the like, and supported in place by bracing 875.

Vertical reinforcing bars 872 are typically positioned between the webs 341 of the spacers 340, to thereby hold the reinforcing bar 872 in a vertical orientation, allowing the reinforcing bars 872 to be attached to starter rebars 873 extending out of the substrate. Horizontal reinforcing bars 874 are provided resting on the spacers 340, and attached to the vertical reinforcing bars 872. Additional reinforcement may also be provided in corner or other sections, as per the building structural design.

It will be appreciated that corner 750 and end caps 760 can be used as appropriate, to form a substantially enclosed internal wall cavity. Examples of this are shown in Figure 8C, which also shows how windows 880 can be provided utilising end caps 760 to define a window perimeter.

Once the completed wall sections are constructed, they can be filled with concrete or other similar building materials 876. This is typically achieved via filling holes provided in the wall sheets, which are spaced apart by 600mm, in order to ensure filling of the entire cavity, preventing the formation of voids, which can in turn affect structural integrity.

Throughout this specification and claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers. As used herein and unless otherwise stated, the term "approximately" means ±20%.

Persons skilled in the art will appreciate that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons skilled in the art, should be considered to fall within the spirit and scope that the invention broadly appearing before described.

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Claims (10)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1) A stud for use in panel formwork for solid filled walls, the stud comprising: a) a pair of rails, each rail including: i) a rail body configured to be attached to an inner face of a respective wall sheet; ii) a pair of spaced apart opposed flanges extending away from the rail body, each flange including a lip; b) a plurality of spacer elements extending between the rails to hold the rails and respective wall sheets in a spaced apart arrangement, each spacer element including: i) a spacer body; and, ii) a connector provided at each end of the spacer body, each connector including shoulders that engage respective lips of the flanges to thereby fasten the connectors to the rails.

2) A stud according to claim 1, wherein the rail body is a substantially planar elongate body.

3) A stud according to claim 1 or claim 2, wherein the flanges extend from edges of the rail body.

4) A stud according to any one of the claims 1 to 3, wherein the flanges extend substantially perpendicularly from the rail body.

5) A stud according to any one of the claims 1 to 4, wherein the spacer body includes a pair of substantially parallel spaced webs extending between the connectors.

6) A stud according to claim 5, wherein the connectors include plates extending between ends of the webs.

7) A stud according to any one of the claims 1 to 6, wherein each web includes a structural ridge extending along a surface of the web.

8) A stud according to any one of the claims 1 to 7, wherein each web includes a narrow waist.

9) A stud according to any one of the claims 1 to 8, wherein the lips extend inwardly from the flanges and the shoulders extend outwardly from the connectors so that the connector is retained between the flanges.

10) A stud according to any one of the claims 1 to 9, wherein the connectors are fastened to the rails using at least one of: a) snap fit engagement; and, b) cantilevered snap fit engagement. C:\Users\JZT\AppData\Local\Temp\7f54-c61e-9a93-0c7a.DOCX-24/