"Permanent Formwork Stud"

[0001] Throughout this specification, unless the context requires otherwise, the word "comprise" and variations such as "comprises", "comprising" and

"comprised" are to be understood to imply the presence of a stated integer or group of integers but not the exclusion of any other integer or group of integers

[0002] Throughout the specification unless the context requires otherwise, the word "include" or variations such as "includes" or "including", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Technical Field

[0003] The present invention relates to a stud and to a method of making a wall using such studs. In particular, the stud is for use in permanent formwork walling. The stud may be embodied, for example, as a wall stud, a header stud or a footer stud.

Background

[0004] Any discussion of background art, any reference to a document and any reference to information that is known, which is contained in this specification, is provided only for the purpose of facilitating an understanding of the background art to the present invention, and is not an acknowledgement or admission that any of that material forms part of the common general knowledge in Australia or any other country as at the priority date of the application in relation to which this specification has been filed.

[0005] Various types of studs have been used in permanent formwork wall construction. Such studs generally have a web with a part flange-like portion. These studs often have an end profile that is substantially C-shaped, H-shaped or I-shaped. Openings are provided in the web to enable concrete to pass therethrough and embed the stud as part of the wall structure once the concrete sets. However, there are many variations in such studs, both in respect of their design elements and material from which they are manufactured. For example, some studs may be made from metal, e.g. steel or aluminium, which can provide high strength in wall construction. However, metal studs have the disadvantage of having to be screwed or welded together and needing sheet materials to be screwed to them instead of the less costly and quicker nailing methodology. This makes handling more awkward and use of metal may also add to the cost of the studs. In addition, metal studs have undesirable thermal bridging characteristics, in that they readily conduct heat thereby leading to undesirable heat losses or gains in buildings. Steel stud flanges near the surface of a wall have been known to corrode and rust. Aluminium, on the other hand, reacts strongly with concrete. These oxidisation reactions typically lead to concrete cancer.

[0006] Plastic studs of varying types have been used. While these address thermal bridging and corrosion issues they lead to a fire path through a wall in a fire event as the plastic studs combust.

[0007] Thus, reduction in thermal bridging and reduction in undesirable oxidisation reactions whilst maintaining fire performance of such studs is desirable. Further to this, steel, aluminium or solid polymer studs are not very suitable to being pneumatically nailed together or to pneumatically nail sheet linings there onto. Timber is very suited to nailing but timber also leads to fire paths in the wall and timber cannot be embedded in concrete as it rots in concrete.

[0008] It is in light of such background art, for example, that the present invention has arisen.

Summary of Invention

[0009] In accordance with one aspect of the present invention, there is provided a permanent formwork stud comprising

[0010] a metal web member having a pair of faces and a pair of longitudinally extending edges, the longitudinally extending edges being transversely opposed,

[0011] a first polymer flange member and a second polymer flange member provided at a respective longitudinally extending edge of the metal web member, [0012] wherein each polymer flange member comprises a pair of elongate members that are fixed to the metal web member at respective faces of the metal web member,

[0013] each pair of elongate members extend beyond a respective edge of the metal web member such that an elongate gap is formed between each pair of elongate members, and

[0014] filler material is provided in the respective elongate gaps to cover and embed the longitudinally extending edges of the metal web member such that the longitudinally extending edges of the metal web member are not exposed.

[0015] Preferably, openings are provided in the metal web member such that, in use, concrete or any other cementitious filler material may pass through the openings.

[0016] Preferably, the openings have self-centring means such that, in use, reinforcing bars are positionable substantially equidistantly spaced from the first and second polymer flange members.

[0017] Preferably, the self-centring means comprises a shaped edge of the openings such that the reinforcing bars centre at the shaped edges under the influence of gravity.

[0018] Preferably, stiffening members are provided in the metal web member.

[0019] Preferably, the stiffening members are provided alternately on respective faces of the metal web member.

[0020] Preferably, the stiffening members are formed by pressing of the metal web member.

[0021] Preferably, apertures are provided in the metal web member such that, in use, one or more reinforcing bars may extend through one or more of the apertures.

[0022] Preferably, the apertures are provided in the stiffening members.

[0023] Preferably, the apertures are slot-like.

[0024] Preferably, the filler material comprises an adhesive and/or a sealant. [0025] Preferably, the elongate members are fixed to the metal web member by mechanical and adhesive fixing/bonding.

[0026] Preferably, the metal web member is provided with keying/gripping means to grip and retain the elongate members and mechanically fix the elongate members to the metal web member.

[0027] Preferably, the keying/gripping means is provided proximate to the edges of the metal web member on each face of the metal web member.

[0028] In accordance with another aspect of the present invention, there is provided a method of making a wall comprising

[0029] arranging permanent formwork studs, of the type herein before described, in a substantially parallel and spaced apart arrangement,

[0030] joining the permanent formwork studs, at their respective ends, to a header stud and a footer stud,

[0031] attaching sheet material to the first polymer flange members of the permanent formwork studs and attaching sheet material to the second polymer flange members of the permanent formwork studs such that a void is provided between the sheet material that is attached to the first polymer flange members and the sheet material that is attached to the second polymer flange members, and

[0032] pouring filler material into the void and allowing the filler material to set.

[0033] The filler material, for example, may be cementitious material, such as concrete.

[0034] Preferably, the method of making a wall further comprises inserting reinforcing bars into the openings of the studs prior to pouring the filler material.

Brief Description of Drawings

[0035] The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which : [0036] Figure 1A is a perspective view of a first embodiment of a stud in accordance with an aspect of the present invention;

[0037] Figure IB is a perspective view of a portion of the stud shown in Figure 1A, with one of the flange members removed to show the keying/gripping elements;

[0038] Figure 1C is an end view of the stud shown in Figure 1A;

[0039] Figure ID is a detail of the end view shown in Figure 2A;

[0040] Figure IE is a detail view of an embossing pattern applied to the metal web member of the stud of the present invention;

[0041] Figure 2 is a perspective view of another embodiment of a stud in accordance with an aspect of the present invention, with one of flange members removed to show the keying/gripping elements;

[0042] Figure 3A is a perspective view of another embodiment of a stud in accordance with an aspect of the present invention;

[0043] Figure 3B is a perspective view of a portion of the stud shown in Figure 3A, with one of the flange members removed to show the keying/gripping elements;

[0044] Figure 4 is a perspective view of another embodiment of a stud in accordance with an aspect of the present invention, with one of flange members removed to show the keying/gripping elements;

[0045] Figure 5 is a perspective view of another embodiment of a stud in accordance with an aspect of the present invention, having a second embodiment of the openings in the metal web member and with one of flange members removed to show a third embodiment of the keying/gripping elements;

[0046] Figures 6A and 6B are side views of another embodiment of a stud in accordance with an aspect of the present invention, showing two respective different sizes for the openings in the metal web member;

[0047] Figure 6C is a side view of another embodiment of a stud in accordance with an aspect of the present invention; [0048] Figure 6D is a side view of the stud shown in Figures 6A and 6B, showing reinforcing bars in position;

[0049] Figure 6E is a side view of the stud shown in Figure 6C, showing reinforcing bars in position;

[0050] Figure 7A is a perspective view showing the stud shown in Figure 1A, in use as a wall stud, connected to a sixth embodiment of a stud, embodied as a header stud and a footer stud, in accordance with an aspect of the present invention;

[0051] Figure 7B is a perspective view showing the stud shown in Figure 3A, in use as a wall stud, connected to a sixth embodiment of a stud, embodied as a header stud and a footer stud, in accordance with an aspect of the present invention;

[0052] Figure 8A is a plan view of the connection between a wall stud and a header or footer stud in accordance with the present invention;

[0053] Figure 8B is a perspective view of a several studs connected to a header stud and footer stud in accordance with the present invention;

[0054] Figure 8C is an exploded view of a stud and joining blocks in accordance with the present invention;

[0055] Figure 8D is an exploded view of a header or footer stud and joining blocks in accordance with the present invention;

[0056] Figure 9 is a perspective view of a plurality of wall studs connected to a header stud and a footer stud to form a formwork for a wall;

[0057] Figure 10 is a perspective view showing sheets or panels affixed to the formwork shown in Figure 9 to form a wall; and

[0058] Figure 11 is perspective view showing doorway and window openings cut out from the wall shown in Figure 10.

Description of Embodiments

[0059] In Figures 1A to ID, there is shown a stud 1 comprising a metal web member 10 and first and second polymer flange members 12 and 14, respectively. The metal web member 10 and the pair of polymer flange members 12 and 14 extend longitudinally. The metal web member 10 has a pair of faces 16 and 18 and a pair of edges 20 and 22. The edges 20 and 22 are transversely opposed and longitudinally extending . The polymer flange members 12 and 14 are provided at respective edges 20 and 22 of the metal web member 10.

[0060] Each of the polymer flange members 12 and 14 comprises a pair of elongate members 24, which are made of polymer. The elongate members 24 extend longitudinally, i.e. in the longitudinal direction of the metal web member 10.

[0061] The elongate members 24 are provided at respective faces 16 and 18 of the metal web member 10 and proximate to the edges 20 and 22 of the metal web member 10.

[0062] The elongate members 24 are fixed to the metal web member 10 at respective faces 16 and 18 of the metal web member 10, as will be now further described.

[0063] The metal web member 10 is provided with keying, or gripping, elements 26 proximate to the respective edges 20 and 22 of the metal web member 10, best seen in Figure IB, and are provided in a longitudinal arrangement along the metal web member 10. The keying/gripping elements 26 provide means for mechanically joining, or connecting, the elongate members 24 to the metal web member 10.

[0064] The keying/gripping elements 26 may be formed by punching a line of holes 30 in the metal web member 10, proximate to its respective edges 20 and 22, such that jagged edges are formed extending outwardly from the faces 16 and 18 of the metal web member 10. The holes 30 may be punched alternately from the faces 16 and 18 of the metal web member 10. This can be seen, for example, in Figure IB in which keying/gripping element 26a has been punched from the face 16 of the metal web member 10 such that the material of the metal web member 10, that is punched out upon creation of the hole 30a, creates jagged edges extending from the face 18 of the metal web member 10. Adjacent to keying/gripping element 26a, there is a keying/gripping element 26b. This keying/gripping element 26b has been punched from the face 18 of the metal web member 10 such that the material of the metal web member 10, that is punched out upon creation of the hole 30b, creates jagged edges extending from the face 16 of the metal web member 10. This pattern repeats along the length of the metal web member 10 such that the jagged edges extend alternately from the faces 16 and 18 of the metal web member 10.

[0065] The jagged edges may be of any suitable form. For example, in the first embodiment of the stud 1 (as shown in Figures IB, 1C and ID) and in the embodiment of the stud 3 (as shown in Figure 3B), the keying/gripping elements 26 form jagged edges that are crown-like formations. In the embodiment of the stud 2 (shown in Figure 2), the embodiment of the stud 4 (shown in Figure 4) and in the embodiment of the stud 5 (shown in Figure 5), the keying/gripping elements 26 form jagged edges that are tab-like formations.

[0066] Adhesive is applied to a first face of each of the elongate members 24, which is then pressed against the metal web member 10 such that the

keying/gripping elements 26 grip the elongate members 24 and are embedded into the elongate members 24. This is done for each of the elongate members 24 such that the respective first face of two elongate members 24 abuts with the face 16 of the metal web member 10 and the respective first face of the other two elongate members 24 abuts with the face 18 of the metal web member 10, adjacent the respective edges 20 and 22 of the metal web member 10. The keying/gripping elements 26 keep the elongate members 24 in place once they are pressed on the metal web member 10, significantly reducing the time required to forcefully press the elongate members 24 against the metal web member 10 while the adhesive is drying.

[0067] The polymer flange member 12 is thereby formed by the two elongate members 24 that are fixed to the metal web member 10 on respective faces 16 and 18 adjacent the edge 20. Similarly, the polymer flange member 14 is thereby formed by the two elongate members 24 that are fixed to the metal web member 10 on respective faces 16 and 18 adjacent the edge 22. The connection of the elongate members 24 to the metal web member 10 to form the flange members 12 and 14 is best seen in Figures 1C and ID.

[0068] By providing the holes 30 in the metal web member 10, each pair of elongate members 24 adjacent respective edges 20 and 22 of the metal web member 10 can be bonded together, through the holes 30, by the adhesive applied to the first surfaces of the elongate members 24. This is because the adhesive is able to pass through the holes 30. This ensures continuity between the two neighbouring elongate members 24 that form the respective polymer flange members 12 and 14. In effect, this is very similar to spot welding each of the two neighbouring elongate members 24 at short repeated locations (of the holes 30). This significantly increases the strength of the connection between the two elongate members 24 that form the respective polymer flange members 12 and 14, since it, in effect, makes a reasonably significant proportion of their interface monolithic.

[0069] By providing the jagged edges, which are formed when the holes 30 are punched in the metal web member 10, there is no need to nail the elongate members 24 onto the metal web member 10 to assist in holding them in position until the adhesive dries because the jagged edges have comparable, or greater, holding power than a nail, and so they perform this function themselves. This negates the need to keep the materials pressed together, after initial pressing, until the adhesive cures, which may speed up the manufacturing process.

[0070] The combination of a mechanical and an adhesive fixing of the elongate members 24 to the metal web member 10, to form the polymer flange members 12 and 14, works as a composite fixing and makes the joint very strong.

[0071] Furthermore, the keying/gripping elements 26 contribute significant bending stiffness to the metal web member 10, and the stud 1, along its longitudinal axis. This assists in the handling and framing procedure because the stiffness and manufacturability of the stud 1 are significantly improved relative to steel, aluminium or polymer studs.

[0072] The elongate members 24 are fixed to the metal web member 10 such that they extend beyond the edges 20 and 22 of the metal web member 10. The elongate members 24 extend beyond the edges 20 and 22 of the metal web member 10 by a relatively small amount, e.g. a few millimetres. In this way a gap, or spacing, is formed between the edges of respective pairs of elongate members 24 that form the polymer flange members 12 and 14. Each such gap, or spacing, is elongated and extends in the longitudinal direction of the stud 1 and is bounded by an edge 20/22 of the metal web member 10 and the respective pairs of elongate members 24.

[0073] As best seen in Figure ID, filler material 28 (shown by hatched lines in Figure ID) is provided in the respective gaps, or spacings, to cover the edges 20 and 22 of the metal web member 10 such that the edges 20 and 22 of the metal web member 10 are not exposed, i.e. the edges 20 and 22 are sealed by the filler material 28. This prevents the edges 20 and 22 coming into contact with agents, e.g. water, which may otherwise cause corrosion to commence at the edges 20 and 22 the metal web member 10. Any excess filler material 28 is removed during manufacture of the stud 1 such that the outwardly facing surfaces 32 of the polymer flanges members 12 and 14 are machined true and flat. When the filler material 28 has set, or cured, it effectively forms part of the polymer flanges members 12 and 14, and the edges 20 and 22, of the metal web member 10, are embedded in the filler material 28. The filler material 28, for example, may be adhesive, sealant, or other suitable filler material.

[0074] Openings 34 are provided in the metal web member 10. The openings 34 may be provided at regular spaced distances along the length of the metal web member 10. The openings 34 are provided such that, when the stud 1 is used to construct a wall (as is further described herein), concrete may pass through the openings 34. In this way, the openings 34 form concrete pour openings.

[0075] The openings 34 of the stud 1 have a self-centring feature such that, in use, reinforcing bars 102 may be positioned substantially equidistantly spaced from the polymer flange members 12 and 14, without manual manipulation to so position the reinforcing bars 102.

[0076] The self-centring feature comprises a shaped edge of the openings 34 such that a reinforcing bar 102 that is inserted through an opening 34 is centred in the opening 34 under the influence of gravity.

[0077] Each of the openings 34 of the stud 1 has an end edge 38, in the longitudinal direction of the stud 3, that angled in a V-shape to provide the self- centring feature.

[0078] Figures 6A, 6B and 6D show an embodiment of a stud 6 and Figures 6C and 6E show an embodiment of a stud 7, in which one of end edges 38 of the openings 34, in the longitudinal direction of the studs 6 and 7, are also angled in a V-shape to provide the self-centring feature. Figure 6E shows reinforcing bars 102 in position in the openings 34 to show how the V-shaped edges 38 centre the reinforcing bars 102.

[0079] The broken lines through the openings 34 in Figures 6A and 6B signify that the length of the openings 34 (in the longitudinal direction of the stud 1) may be varied, as required, at the time of manufacture. [0080] Figure 5 shows an embodiment of a stud 5 having an alternative embodiment of shaped edge of the openings 34 to provide the self-centring feature. In the stud 5, the opposed end edges 36 of the openings 34, in the longitudinal direction of the stud 3, are rounded.

[0081] However, as a further alternative, the self-centring feature may be omitted. The embodiments of the studs 3 and 4, shown in Figures 3A and 3B and Figure 4, respectively, have a straight edge in place of rounded edges 36 and V- shaped edges 38. When using the studs 3 and 4, the reinforcing bars 102 would be manually manipulated to centre them, or centred by some other suitable means.

[0082] Whilst the openings 34 shown in the drawings are of substantially square or rectangular shape, any suitable shape may be used, including, for example, circular and elliptical. The openings 34 may be spaced apart as required, for example, depending on the spacing required for the reinforcing bars 102. During construction of a wall using studs 1, these openings 34 allow concrete to flow through the openings and around the studs in the wall panel to enable a monolithic wall structure to be constructed.

[0083] The metal web member 10 of the stud 1 is provided with stiffeners 40. The stiffeners 40 may be substantially square or rectangular in shape. The stiffeners 40 are formed by pressing the metal web member 10. The stiffeners 40 are spaced apart on the faces 16 and 18 of the metal we member 10 as required, for example, depending on the spacing required for the reinforcing bars 102.

[0084] The stiffeners 40 may be punched alternately from the faces 16 and 18 of the metal web member 10. This can be seen, for example, in Figures 1C and ID in which stiffeners 40 can be seen extending from both faces 16 and 18 of the metal web member 10.

[0085] These stiffeners 40 substantially assist lateral overturning resistance of the stud of the present invention, which is the ability of the stud to stay upright when placed on a table or framing apparatus for framing. This is particularly pertinent with studs of 200mm, or greater, thickness for thick walls and columns as the slenderness ratio of the stud is greatly increased.

[0086] The stiffeners 40 may be provided with apertures 42 for reinforcing bars 102. Such apertures 42 are shown in the studs in Figures 1A, IB, 3A, 3B, 4, 5, 6A, 6B and 6D. Figure 6D shows reinforcing bars 102 positioned in the apertures 42. The apertures 42 are slot-like in shape such that two reinforcing bars 102 can extend through an aperture. This enables overlapping of reinforcing bars 102 in the apertures 42 when wall sections, constructed using the studs in accordance with the present invention, are assembled adjacent to one another for joining.

[0087] The openings 34 may have a flange lip swaged into them in the opposite direction to that of the stiffeners 40. This also assists to stiffen the stud substantially with a smaller thickness of metal compared to not having the stiffeners 40 present. The openings 34 of the stud 5, shown in Figure 5, are provided with such a flange lip 34a.

[0088] The metal web member 10 of the stud in accordance with the present invention may be embossed with a pattern 46, as shown in Figure IE, which has the effect of doubling its BMT (Base Metal Thickness).

[0089] The stud in accordance with the present invention is substantially I- shaped in profile.

[0090] The stud in accordance with the present invention may be of any suitable length and width. The stud has length that is appropriate for the height of the wall to be constructed. Typically, the stud has a width of 150mm, however, other width dimensions for the stud may be used. For example, width dimensions in the range 75mm to 600mm cover most commonly encountered applications. The metal web member of the stud may be made from steel sheet having a thickness of 0.35mm, however, steel sheet of other thickness dimensions may be used. Similarly, suitable metal sheet other than steel sheet may be used from which to make the metal web member 10.

[0091] The polymer flanges 12 and 14 reduce thermal bridging compared to metal flanges, avoid the risk of metal corrosion close to the surface of the wall and exposed to the elements (e.g. steel is prone to this), avoid the risk of metal reacting with concrete (e.g. aluminium is prone to this), and can be reliably nailed using pneumatic nail guns. The polymer flanges 12 and 14, for example, may be made from solid polymer or foamed polymer. Foamed polymer enhances the nailability of the polymer flanges 12 and 14 using pneumatic nail guns.

[0092] Given that the stud in accordance with the present invention is a composite polymer and steel stud, the steel web section is stronger in tension than a polymer web, and unlike a polymer web, will not melt and burn in a fire event allowing fire to pass through the wall.

[0093] The stud in accordance with the present invention may be manufactured by pressing (to form the stiffeners 40) and punching (to form the openings 34, apertures 42 and keying/gripping elements 26) sheet metal, and then cutting the sheet metal to the required size for the metal web member 10. The elongate members 24 are then fixed to the metal web member 10 to form the polymer flange members 12 and 14. Filler material 28 is then applied to the gap, or spacing, between the respective pairs of elongate members 24 to cover and embed the edges 20 and 22 of the metal web member 10 such that the edges 20 and 22 of the metal web member 10 are not exposed.

[0094] The stud according to the present invention may be described as a composite stud in that the stud is made of both metal (the metal web member) and polymer (the polymer flange members).

[0095] Figures 7 A to 11 show how studs in accordance with the present invention may be used to construct a wall, in particular, for framework for permanent formwork walling . Any of the studs of the embodiments herein before described may be used to construct a wall.

[0096] A wall made using the studs, in accordance with the present invention, may be made partly off-site and then transported to the building site where construction of the wall is completed. For most building applications, the studs are used to partly make sections of a wall (also referred to herein as wall sections) off-site (for example, at a factory) which are later transported to the building site where the wall sections are completed and connected and the entire wall erected. The wall sections are made off-site up to a stage where they provide the concrete formwork that becomes a permanent part of the completed entire wall, as will be later herein described. The required number of such wall sections can then be installed and connected, or coupled, onsite to form the entire wall required, as will be herein described.

[0097] To construct a wall section 100, as shown in Figure 9, using studs, in accordance with the present invention, the required number of studs are connected to a header stud 6a and a footer stud 6b in a parallel arrangement. This is shown in Figure 8B. The spacing interval between consecutive studs will depend upon various factors such as, for example, the size of the wall section 100, the type of concrete that will be used, the location of openings, such as doors and windows, and the location of T intersections with other walls. By way of example, a typical spacing interval between consecutive studs may be 240mm. The studs are arranged such that the outwardly facing surfaces 32 of all the polymer flange members 12 are in substantially the same (first) plane and the outwardly facing surfaces 32 of all the polymer flange members 14 are in substantially the same (second) plane. These first and second planes are substantially parallel. The openings 34 of the studs, that are at the same height, are aligned. The apertures 42 of the studs, that are at the same height and adjacent the same edge 20 or 22, are aligned. Furthermore, the metal web members 10 of the studs are substantially parallel to one another.

[0098] The header stud 6a and the footer stud 6b are substantially similar to the studs of the other embodiments of the present invention previously hereinbefore described, except that they do not have stiffeners 40 and the openings 34 do not have a self-centring feature. The location and the spacing of the openings 34 in the header stud 6a and footer stud 6b is predetermined so as the metal web member 10 of these header and footer studs 6a and 6b align with the main studs.

[0099] The studs are joined to header stud 6a and footer stud 6b by joining blocks 104. The joining blocks 104 are also shown in Figure 1A and Figure 3A, as they are partly obscured in Figures 7A and 7B. The joining blocks 104 are also shown in Figures 8A, 8B, 8C and 8D. The joining blocks 104 are fixed to metal web members 10 adjacent to the ends of the metal web members 10, such as by using nails 106. Joining blocks 104 may also be fixed to both faces of the metal web members 10 of the header and footer studs 6a and 6b, as shown in Figures 8B, 8C and 8D. Nails 108 are then driven through the metal web member 10 of the header and footer studs 6a and 6b into the joining blocks 104. This is best seen in Figures 7A, 7B and 8A. Figure 9 shows the framework of connected studs and the header and footer studs 6a and 6b for a wall section 100. This feature allows the studs 1 to be framed in the same manner as timber studs in timber framing.

[00100] Sheet material 108 is then attached at the outwardly facing surfaces 32 of the first polymer flange members 12 of the studs 1. Multiple pieces of sheet material 108 may be attached to the outwardly facing surfaces 32 of the first polymer flange members 12 to thereby cover all of the first polymer flange members 12 of the studs and the spaces between the studs. The pieces of sheet material 108 are attached to the outwardly facing surfaces 32 of the first polymer flange members 12 such that the edges of adjacent pieces of sheet material 108 are in abutment so that there are no gaps there between.

[00101] Once the sheet material 108 has been attached at the outwardly facing surfaces 32 of the required number of first polymer flange members 12, this sheet material 52 forms a first side, or face, of the wall section 100. Holes and penetrations may then be cut or routered out of the sheet material 108 at required locations to form windows, doors, outlets for services, such as electrical wiring, telecommunications cables and plumbing, to accommodate electrical backer boxes, plumbing fixtures and pipes. Services cabling and pipework may be run along the inside of the wall section 100. Services cabling and pipework in the wall section 100 is then ready for later connection to electrical and plumbing networks on site once the wall section 100 has been completed and transported to site where the building is being constructed.

[00102] Sheet material is then attached to the second polymer flange members 14 of the studs. The sheet material 108 is attached to outwardly facing surfaces 32 of several second polymer flange members 14 of consecutive studs in a manner similar to that as herein before described with reference to the

attachment of the sheet material 108 to the outwardly facing surfaces 32 of the first polymer flange members 12 of the studs. Once the sheet material 108 has been attached to the outwardly facing surfaces 32 of the second polymer flange members 14, this sheet material 108 forms the second side, or face, of the wall section 100.

[00103] A void 110 is formed between the sheet material 108 that is attached to the outwardly facing surfaces 32 of the first polymer flange members 12 and the sheet material 108 that is attached to the outwardly facing surfaces 32 of the second polymer flange members 14, with the studs located in the void 110. This is best seen in Figures 9, 10 and 11.

[00104] The pieces of sheet material 108 may be affixed to the first and second polymer flange members 12 and 14 by suitable adhesive. However, alternative or additional attachment means may be used, e.g. fasteners, such as screws or nails. The composite steel-polymer is very well suited to receive and hold pneumatically driven nails. [00105] The abutting edges of adjacent pieces of sheet material 108 may be taped and jointed or flushed. This avoids the need to perform this step after the wall section 100 has been completed and transported to the building site.

[00106] The width of a wall section 100 may be the same as the width of the sheet material 108 being used. Alternatively, the width of a wall section 100 may be less than the width of the sheet material 108 being used, in which case the sheet material 108 is cut to the width required for the wall section 100. However, a wall section 100 may have a width of up to substantially 12 meters in a situation where several pieces of sheet material 108 are arranged adjacent to one another to create a larger wall section 100.

[00107] The pieces of sheet material 108 may be of a suitable size to permit ready handling. For example, the sheet material 108 may be 2400mm x 1200mm x 10mm.

[00108] The sheet material 108 may be made of any suitable material. For example, the sheet material 108 may be fibre cement sheet material.

[00109] Reinforcing bars 102 may be inserted through the aligned openings 34 and/or apertures 42 of the studs, as required. The reinforcing bars 102 are thereby provided along the height of the wall section 100 and along the whole width of the wall section 100.

[00110] If required, door openings 112 and/or window openings 114, as shown in Figures 9 and 11, can be formed in the wall section 100. These can be formed by combining together sub-assemblies 120 of framework (shown in Figure 9). In Figure 9, the sub-assemblies 120 are the sections of the framework above the door openings 112 and the sections of the framework above and below the window openings 114. The openings 112/114 can either be sheeted through or sheet optimization can allow the correct sized sheet to be fixed to the frame. Door reveals 116 and window reveals 118 are then fixed in place at the edges of the door openings 112 and window openings 114, respectively, to cap off the open edges of the door openings 112 and window openings 114. Plastering angle beads, which have been cut to the required lengths, are then fitted to the door and window reveals 116 and 118. This avoids the need to perform this step after the wall section 100 has been completed and transported to the building site. [00111] Windows and doors (not shown in the drawings) may then be fitted in the door and window reveals 116 and 118, respectively. This avoids the need to install doors and windows after the wall section 100 has been completed and transported to the building site. For example, fully pre-fabricated windows consisting of the window frames and plate glass may be fitted in the window reveals 118 as single units.

[00112] Other openings that may be required in a wall section 100, e.g. to accommodate vents, mail boxes, light switches and power outlets, may also be cut out in a manner similar to that for the door openings 112 and window openings 114 as herein before described.

[00113] For the construction of the walls of a building, some wall sections 100 will be made with various types of openings, as herein before described, whilst other wall sections 100 will have no openings. Some will have openings to connect to another wall in a T intersection.

[00114] As an alternative to inserting the reinforcing bars 102 at the time as herein before described, the reinforcing bars 102 may be inserted once the wall section 100 has been positioned on-site.

[00115] The wall section 100, as so far described herein, has been made off-site (such in a factory) to a stage such that it provides the formwork that becomes a permanent part of a completed entire wall, as will be now described, and can be transported to the building site where it is required.

[00116] Once transported to the required building site, the required wall sections 100 are positioned as required and connected together.

[00117] The required wall sections 100 are positioned and secured in place by suitable means. For example, the bases of the wall sections 100 may be secured to a floor or to retention tracks (not shown) fixed to the floor of the building being constructed.

[00118] Lapping reinforcing bars (not shown) and other connection members, as required, may be used to connect together wall sections 100 that are next to each other.

[00119] Once the lapping reinforcing bars and other connection members have been positioned as required, a suitable filler material may be poured into the voids 110 between the sheet material 108 that is attached to the first and second flange members 12 and 14. A suitable filler material may be cementitious material (such as concrete) or a suitable filler/bonding material. The description that follows is with reference to the filler material being concrete. The concrete flows around the reinforcing bars 102 in the void 110 as well as through the openings 34 in the studs. The concrete may be vibrated by use of an immersion vibrator. The reinforcing bars 102 and the studs become embedded in the concrete as it sets. Adjoining wall sections 100 are thereby connected and the structural strength of the walls sections 100 and the wall/s formed by them is achieved.

[00120] Once the concrete has set, the joints between the sheet material 108 may be set and the surfaces of the sheet material 108 may be coated if required. For example, in the case of wall sections 100 that are used to form an internal wall, the sheet material 108 on both sides of the internal wall may be coated with a suitable plaster. The coating of plaster may be applied by a machine to a suitable thickness. For example, the thickness of the coating of plaster may be substantially 3mm. The coating of plaster may be painted, as required. In the case of an external wall (best seen in FIG 11), the side of the external wall that is to face externally may be lined with a suitable foam insulating material as required. Such insulating material is commercially available in panels of various sizes. For example, the insulating material may be provided with a thickness in the range of 20mm to 1000mm. If required, a render coating or another fibre cement sheet material may be applied to the surface of the insulating material. The render coating, for example, may be a polymer altered reinforced render with a fibreglass mesh.

[00121] When the stud is loaded with force from the hydrostatic pressure (arrows H in Figure 1C) of the plastic concrete pushing against the sheet material 108, a significant shear force is created in the plane between the edge of the polymer flange members 12 and 14 and the metal web member 10. The keying/gripping elements 26 offer very significant shear resistance in this plane because of the cross-sectional area of steel resisting this shear force in this plane. Further to this, because the keying/gripping elements 26 are relatively large in diameter compared to a nail or a staple doing the same task, the polymer material of the polymer flange members 12 and 14 is much less likely to tear out past the keying/gripping elements 26 if, for example, the adhesive failed. [00122] When the stud is loaded with hydrostatic pressure from plastic concrete, a bending moment will cause the flange to pivot around point A (Figure 1C) in the direction shown by the arrow BM 1. The inner faces 44 (Figure 1C) of the polymer flange members 12 and 14 will go into tension and bond line B (Figure 1C), between the elongate members 24 and the metal web member 10, will begin to peel at the inside face of the flange nearest inner face 44. Adhesive is generally weakest when subject to peeling forces and an adhesive joint is generally strongest in tensile lap shear. With the provision of the keying/gripping elements 26, a relatively large surface area of metal is bonded with adhesive to the polymer material of the flange members 12 and 14 both inside and outside the keying/gripping elements 26. This adhesive joint between the keying/gripping elements 26 and outside the "barrel" is subject to tensile lap shear forces at face F, shown in Figure ID, which greatly enhances its ability to resist the forces being put on it compared to a straight butt joint of the same materials and adhesive between the elongate members 24 and the faces 16 and 18 of the metal web member 10. This strengthens the connection between the elongate members 24 and the metal web member 10 considerably.

[00123] When the stud is subjected to the force of pneumatically fired, powder actuated, gas actuated nail, staple or other missile fastener entering the polymer flange members 12/14 at very high velocity (such as when the sheet material 108 is being fastened to the polymer flange members 12/14, the polymer flange members 12/14 will try to pivot around point D (Figure 1C). This will exert peeling stress on the adhesive joint of the polymer flange member 12/14 and the metal web member 10 at point A. Adhesive is generally weakest when subject to peeling forces. An adhesive joint is generally strongest in lap shear. With the provision of the keying/gripping elements 26, a relatively large surface area of metal is bonded with adhesive to the polymer material of the polymer flange members 12 and 14. This adhesive joint is subject to tensile lap shear forces along face E, shown in Figure ID, which greatly enhances its ability to resist the forces being put on it compared to a straight butt joint of the same materials and adhesive.

[00124] With the large turning moment created around point D, when a high velocity nail 122 is being driven through a polymer flange member 12/14 from the outwardly facing surface 32 (as shown in Figure 1C, ordinarily the polymer flange member 12/14 will deflect downwards, if for example the polymer flange member 12/14 was made from a light gauge metal such as steel or aluminum, because of a lack of stiffness in the polymer flange member 12/14. This may cause major problems for the sheet material 108 (which may be cementitious board). This deflection allows the nail 122 exiting the sheet material 108 to mushroom out similar to a bullet exit hole. This results in the sheet material 108 not being flush with the polymer flange member 12/14 and results in a poor to no adhesive bond as there is a gap between the surfaces. In contrast, the stiffness of the stud in accordance with the present invention, from the pressing, embossing and lip deformations and connection between the metal web member 10 and the polymer flange members 12/14 and the polymer flange members' 12/14 own substantial thickness, for example 12mm, and stiffness, resists this turning moment significantly resulting in a tight adhesive joint between the two planar surfaces when a nail 122 passes through the sheet material 108 and the polymer flange member 12/14 at high velocity as the polymer flange member 12/14 does not allow the sheet material 108 to mushroom out. Further, once the nail 122 comes to a rest, the thickness and properties of the polymer material of the polymer flange member 12/14 is substantially similar to timber such that the polymer flange member material has a very strong friction grab on the nail 122 which stops it from slipping out when subjected to various forces.

[00125] When the stud is subjected to the force of pneumatically fired, powder actuated, gas actuated nail 124, staple or other missile fastener entering the flange member 12/14 from the outwardly facing surface 32, close to the metal web member 10, at very high velocity, the polymer flange member 12/14 will try to both shear along the adhesive joint J (Figures 1C and ID) and it will also expand out towards the edge of the flange member 12/14 at G. This will exert significant lap shear stress and will also create significant tension between the flange member 12/14 and the metal web member at J as it is very similar to driving a wedge down between the two materials. With the provision of the keying/gripping elements 26, a relatively large surface area of metal web member 10 is bonded with adhesive to the polymer material of the flange members 12/14. This adhesive joint is subject to tensile lap shear forces over a relatively large area which greatly enhances its ability to resist the forces being put on it compared to a straight but joint of the same materials and adhesive or nails or staples or both.

[00126] By providing holes 30, via the keying/gripping elements 26, each elongate member 24 has some surface area to bond itself to its neighboring elongate member 24, as previously herein before described. [00127] Another feature of the invention lies in how it is applied on site in the field. In the prior systems, sheets of cementitious material are normally applied to the stud framework typically extruded PVC, steel C section or aluminum flanges. Cementitious sheets are suitable to be used as permanent formwork. One additional application of the present invention is where sheets of foam insulation are fixed to the frame using adhesives and or staples or nails. Typically, Polyisocyanurate Foam (PIR), Polyurethane Foam, Phenolic Foam, Expanded Polystyrene Foam (EPS) or Extruded Polystyrene Foam (XPS) is used. Water vapour trying to escape the concrete as it dries out builds pressure behind the foam material as it tries to escape into the surrounding air. This pressure will try to delaminate the foamed insulation from the stud framework and from the concrete. This is a known phenomenon in applied finishes such as epoxies, timber flooring, floor paints etc. to concrete flooring slabs. Since the high-pressure water vapor tries to follow the path of least resistance it will migrate towards the joints in the insulation board to its neighbor. Because the joints have been treated with joint filling compound the water vapor pressure will cause the joints to bulge out. This is undesirable as it affects the architectural aesthetic of the finished wall. The solution is that the foam insulation is perforated through itself with a needle sized object. This is allows water vapour from the drying concrete to pass through the perforated foam. Once it passes through the perforated foam it can escape out through the vapor permeable applied render. Otherwise the vapour pressure will cause joint fatigue and can result in cracks developing in the joints. The foam is also reinforced with a layer of glass roving on both faces. This glass roving is applied to the foam during manufacturing of the foam. The glass roving helps to transfer forces from the stud through the adhesive which is infused into the glass roving. This greatly increases the strength of the bond between the stud frame and the insulation. Also when the render system is applied to the glass roving on the outside it greatly increases the bond between the render and the board. Although perforated boards are commercially available, their purpose is to allow water vapor during the occupancy of the building from areas such as kitchens, laundries and bathrooms with high water vapour generation to escape. Although perforated insulation boards with glass roving are commercially available to render onto, they do not have the glass roving on the opposite side to the render side that is being used to reinforce a structural adhesive bond to a stud framework for application in a permanent formwork scenario. As part of the manufacturing process, a base coat render with glass reinforcing mesh is applied to the outside face of the insulation in the factory. This has multiple effects. Firstly, it negates the need to flush board joints out onsite. Secondly it strengthens significantly this face of the insulation board material when it goes into tension when the concrete hydrostatic pressure is applied to the board material. Further to this, factory applied coat is done by automation. Normally this coat would be done onsite using traditional rendering methods. This coat of base reinforced render makes the insulation strong enough to be used as a permanent formwork for plastic concrete.

[00128] Whilst one or more preferred embodiments of the present invention have been herein before described, the scope of the present invention is not limited to those specific embodiments, and may be embodied in other ways, as will be apparent to a skilled addressee.

[00129] Modifications and variations such as would be apparent to a person skilled in the art are deemed to be within the scope of the present invention.