GB2563325A

GB2563325A - Profiles

Info

Publication number: GB2563325A
Application number: GB1805868.5A
Authority: GB
Inventors: Castellucci Michael
Original assignee: Hadley Industries Overseas Holdings Ltd
Current assignee: Hadley Industries Overseas Holdings Ltd
Priority date: 2017-04-07
Filing date: 2018-04-09
Publication date: 2018-12-12
Anticipated expiration: 2038-04-09
Also published as: GB201805868D0; GB201903381D0; GB2563325B; GB2570228B; GB201705610D0; GB2570228A

Abstract

A stud profile (1) for a dry wall, the stud profile (1) comprises a longitudinal central web (2) from opposed edges of which longitudinal flanges (3, 4) extend, the central web (2) having a width of from 68mm to 72mm, one flange (3) having a width of from 37mm to 42mm and the other flange (4) having a width of from 34mm to 39mm, and wherein the ratio of width of central web (2) to average width of the flanges (3, 4) is between 1.67 and 2.03. The flanges may be asymmetric, that is one may be wider than the other by between 2 and 5 mm. rib formations may be provided where the flanges join the web.

Description

PROFILES

This invention relates generally to profiles. More specifically, although not exclusively, this invention relates to C-section profiles.

It is known in the building industry to make ‘dry walls’ from plasterboard and suspended ceilings from ceiling tiles. In the former, plasterboard sections are secured on either side of a supporting structure or framework to make a dry wall. In the latter, a supporting structure in the form of frame members form a grid and the ceiling tiles are located such that their peripheries are supported by the grid. Both of these may be termed ‘dry constructions’.

The supporting structure for dry constructions may be formed from one or more metal profiles or sections, those typically being shaped lengths of metal formed by bending sheet material to the desired shape.

Typically, to make a dry wall a length of track profile is secured to both the floor and the ceiling and plural vertical stud members (lengths of stud profile) are located therebetween with one end of each stud member located within the floor track and the other end within the ceiling track. Horizontal members may be provided between vertical stud members. A track profile or section is typically called a U-section with an elongate base and a pair of parallel sides extending away from either side of the base. As shown in Figure 1, a prior art stud member 1’ (i.e. profile), which is typically called a C-section, has a web 2’ with a pair of parallel flanges 3’, 4’ extending from either side of the web 2’. Each flange 3’, 4’ generally has at its distal portion an in-turned ledge or lip 3a’, 4a’ which overlies the web 2’. The in-turned ledges or lips 3a’, 4a’ act to rigidify the stud member T. Each flange 3’, 4’ may comprise a longitudinal rib 3b’, 4b’ extending along its length and rebated such that it overlies the web 2’, wherein each rib 3b’, 4b’ has a form depth F’ (which is a measurement of the size of the formation on the stud member T). The web 2’ has a width d’, whilst the two flanges 3’, 4’ may be of different widths bT, b2’ such that stud members 1’ may be placed in facing and abutting relations to form a rectangular ‘box section’. The formation of such box sections leads to a reduced volume for storage and/or transport of stud members T, with a consequential reduction in expense thereof. It can also lead to the formation of stronger parts. With stud members 1’ made from plain sheet steel it is known that the two parts (stud members T) of a so-formed box section are able to slip longitudinally with respect to one another.

With stud members T extending between upper and lower track members, plasterboard sections are secured to the stud members T by screws or other securing means driven through the board and into a facing portion of a stud member T, i.e. one of the flanges 3’, 4’. It is usual to use a stud member T to support the terminal edges of adjacent, preferably abutting, plasterboard sections. Thus, an edge of a first plasterboard section typically overlies a portion, say first half, of the facing flange 3’, 4’ of a stud member T and an edge of a second plasterboard section overlies a further, e.g. second half, portion of the flange 3’, 4’ of the stud member T. In this way, with the edges of the plasterboard sections in close proximity, and preferably abutting, a stud wall is formed. The or any gap between adjacent plasterboard sections may be filled by plaster or other jointing compounds and/or the whole construction may be plaster skimmed and/or otherwise surface-treated (painted, wall papered etc.) to provide a usable and/or desired surface finish.

In order to support plasterboard sections, stud members T are located at regular intervals, with typical distances between the centre of adjacent studs being 600mm, 400mm and 300mm, where the typical width of a plasterboard section is 1200mm.

Companies which assemble dry constructions and/or supply component parts operate in highly competitive marketplaces wherein economic advantage vis-a-vis competitor companies is of paramount importance. Accordingly, it is imperative to reduce, where possible, the expense of completed dry constructions and/or of the components from which they are assembled. In this way, a company assembling such dry constructions or supplying component parts therefore may maintain or improve its market position.

Furthermore, extraction and processing of the metal used in stud members T and track members along with manufacture and transport of the completed stud members 1 ’ and track members, is expensive and any reduction in the amount of metal used will be financially and environmentally beneficial. As will be appreciated, stud members T, by their nature, describe a large internal volume and thus transport entails shipping a great deal of empty space.

Accordingly, it will be beneficial to reduce the number of stud members T used to construct a wall. A reduction in the number of stud members T will improve construction time, reduce fabrication and transport costs and reduce weight as well as being environmental beneficial.

It is therefore a first non-exclusive object of the invention to provide a stud member which at least partially mitigates one or more of the above-identified problems.

Accordingly a first aspect of the invention provides a stud member or profile for a dry wall, the stud member or profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, where the ratio of the width of the longitudinal central web to the width of one or both of the longitudinal flanges, e.g. an average width of the longitudinal flanges, is between 1.56 and 2.04.

In this field it is known that profiles are elongate and often provided by the manufacturer in lengths of 3000mm or longer. Hence, when using the term ‘width’ it is intended to refer to a dimension measured orthogonal to the principal (elongate) axis of the profile.

The ratio of the width of the longitudinal central web to the width of one or both of the longitudinal flanges may be between one of 1.56, 1.57, 1.58, 1.59, 1.60, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69 or 1.70 and one of 2.04, 2.03, 2.02, 2.01, 2.00, 1.99, 1.98, 1.97, 1.96, 1.95, 1.94, 1.93, 1.92, 1.91, 1.90, 1.89, 1.88, 1.87, 1.86, 1.85, 1.84, 1.83, 1.82, 1.81 or 1.80, preferably between 1.67 and 2.03.

For the sake of expediency a stud member or profile will hereinafter be referred to as a stud profile.

The width of one or both of the longitudinal flanges may be less than 48mm, say less than 45mm, for example less than 40mm. The average width of the longitudinal flanges may be less than 48mm, say less than 45mm, e.g. less than 40mm. The width of one or both of the longitudinal flanges may be between 35mm and 48mm, say between 35, 36, 37, 38, 39,40, 41 or 42mm and 48, 47, 46, 45, 44 or 43mm. The average width of the longitudinal flanges may be between 35mm and 48mm, say between 35, 36, 37, 38, 39, 40, 41 or 42mm and 48, 47, 46, 45, 44 or 43mm. The width is preferably between 37mm and 42mm for one longitudinal flange and between 34mm and 39mm for the other longitudinal flange. The flanges may have different widths, in one embodiment the width of one flange is 2 mm or greater than the width of the other flange, for example the difference in flange width may be 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0 mm greater and preferably will be 5.0 or 4.0mm or less than 4.0 mm greater.

The width of the longitudinal central web may be between 51mm and 74mm, say between 55mm and 74mm, e.g. between 60mm and 74mm, for example between 65mm and 74mm, preferably between 68mm and 72mm. The width of the longitudinal central web may be between 35mm and 60mm, say between 40mm and 55mm, for example between 45mm and 53mm, e.g. between 46mm and 52mm.

In one embodiment the width of the web is 70mm and the width of the first and second flanges is 37mm (e.g. 36.6mm) and 40mm (e.g. 39.6mm), respectively. In another embodiment the width of the web is 48mm and the width of the first and second flanges is 37mm (e.g. 36.6mm) and 40mm (e.g. 39.6mm), respectively. In another embodiment the width of the web is 70mm and the width of the first and second flanges is 32mm (e.g. 31.6mm) and 48mm, respectively. In another embodiment the width of the web is 70mm and the average width of the flanges is 48mm.

The web may have a central portion and a first and second edge portion. The central portion may be parallel to the first and second edge portion. The central portion may extend in one plane from the first edge portion to the second edge portion. The flanges may extend from the respective first and second edge portions. The web may extend from one flange to the second flange in a direction which is orthogonal to each flange. The plane defined by the central portion may be displaced from a plane defined by the edge portions. The web is preferably free of any array of apertures, holes or slots extending adjacently along the length of the web, although it may be provided with punch outs for cabling or other facilities.

The stud profile may be formed from metal, for example formed from steel. The stud profile may be formed by cold rolling. The stud profile may be formed from a strip, e.g. a strip of metal, having a base gauge or thickness G of between 0.2mm and 1.2mm, for example between 0.4mm and 1.0mm, for example 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 or 1.2mm thick. In an embodiment the base gauge G is from 0.3 to 0.8mm.

One or each of the flanges may comprise one or more longitudinal ribs or beads, e.g. extending along at least part of its or their length. The, some or each longitudinal rib or bead may project inwardly, e.g. may overlie the central web. The some or each longitudinal rib or bead may project outwardly, e.g. may not overlie the central web. In embodiments one longitudinal flange may comprise a first longitudinal rib or bead, e.g. and the other longitudinal flange may comprise a second longitudinal rib or bead. The first longitudinal rib or bead may have a greater form depth F and/or width than the second longitudinal rib or bead. The first longitudinal rib or bead may have a form depth F of between 1.1 and 3 times the form depth F of the second longitudinal rib or bead. The first longitudinal rib or bead may have a form depth F of between 1 and 10G, e.g. between 2 and 8, 7 or 6G. The first and second longitudinal ribs or beads may be configured such that when first and second stud profiles are positioned in a box configuration the first longitudinal rib or bead of one stud profile engages the second longitudinal rib or bead of the other stud profile.

The form depth F is a measurement of the size of a formation on the stud profile. In this specification the form depth F is measured as a linear distance from a first face of the material to the periphery of the second face.

The central web and/or one or each longitudinal flange may comprise an array of projections and depressions.

The central web may be joined to each flange by a joining portion. The stud profile may comprise an array of raised or rebated formations, for example which may extend across one or each joining portion. A second aspect of the invention provides a stud profile for a dry wall, the stud profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, where the width of one or both of the longitudinal flanges, e.g. an average width of the longitudinal flanges, is between 35mm and 48mm, say between 35mm and 45mm, e.g. between 35mm and 40mm.

The profile according to the second aspect may also comprise a ratio of the width of the longitudinal central web to the width of one or both of the longitudinal flanges, e.g. an average width of the longitudinal flanges, of between 1.56 and 2.04, say between 1.56, 1.57, 1.58, 1.59, 1.60, 1.61,1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69 or 1.70 and 2.04, 2.03, 2.02, 2.01, 2.00, 1.99, 1.98, 1.97, 1.96, 1.95, 1.94, 1.93, 1.92, 1.91, 1.90, 1.89, 1.88, 1.87, 1.86, 1.85, 1.84, 1.83, 1.82, 1.81 or 1.80, preferably between 1.67 and 2.03 A further aspect of the invention provides a stud profile for a dry wall, the profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, the central web having a width of from 68mm to 72mm (e.g. 69mm to 71mm) and each flange having a width of from 35mm to 41mm (e.g. 36mm to 40mm). A yet further aspect of the invention provides a stud profile for a dry wall, the profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, the central web having a width of from 68mm to 72mm, one flange having a width of from 37mm to 42mm and the other flange having a width of from 34mm to 39mm. A further aspect of the invention provides a stud profile for a dry wall, the profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, the central web having a width of from 46mm to 50mm, one flange having a width of from 37mm to 42mm and the other flange having a width of from 34mm to 39mm.

The ratio of web width to the flange width (or the average of flange widths if they are of different widths) may be from 1.1 to 1.4, preferably from 1.2 to 1.3.

For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention.

It has been surprisingly found that by increasing the dimensions of a stud profile, and without increasing the thickness or gauge of the metal used, it is possible to reduce the overall number of stud profiles used to construct a dry wall. Thus, by increasing the amount of metal in each stud profile an overall saving is made. This is an entirely contradictory and surprising finding. A yet further aspect of the invention provides a dry lining wall comprising upper and lower track sections and plural stud profiles in accordance with one or more aspects of the invention and at least two plasterboard sections secured to the stud profiles, wherein the plasterboard sections are 1200mm wide, the stud profiles are distanced 400mm or 600mm from one another whereby the amount of metal in the wall is reduced.

Within the scope of this application it is expressly envisaged that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one aspect or embodiment of the invention are applicable to all aspects or embodiments, unless such features are incompatible.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a sectional end view of a prior art C-section stud member;

Figure 2 is a sectional end view of a C-section stud member according to a first embodiment of the invention;

Figure 3 is a plot of the results of calculated net increase of the C-section stud member shown in Figure 2;

Figure 4 is a plot of the results of calculated net increase of the C-section stud member shown in Figure 2;

Figure 5 is a partial perspective view of a C-section stud member according to a further embodiment of the invention; and

Figure 6 is a partial perspective view of a C-section stud member according to a further embodiment of the invention. A prior art stud member (produced by British Gypsum (RTM) of Loughborough, United Kingdom), herein comparative example 1, is commonly in use in the United Kingdom and has a web 2’ width d’ of 70mm and an average flange 3’, 4’ width of 33mm. The calculated flexural rigidity of this stud member requires that, in use, such stud members are located every 300mm across 1200mm wide plasterboard section in an assembled dry wall. Accordingly, four stud members of comparative example 1 may be required across each 1200mm wide plasterboard section.

Referring now to Figure 2, there is shown, according to a first embodiment of the invention, an improved profile 1 (which is a stud member 1 in this embodiment), where like references (absent the prime (j) refer to like features which will not be described herein further. The stud member 1 is cold roll formed from a strip of steel of 0.5mm thickness, in this embodiment.

In this embodiment of the invention the ratio of web width to flange width is between 1.56 and 2.04, say between 1.67 and 2.03, for example between 1.70 and 1.80.

We have surprisingly found that by increasing the volume of metal required in a single stud member 1 according to the invention (with respect to prior art stud members T of comparative example 1) the overall volume of metal required in a subsequently formed dry wall is relatively reduced. Such a result is inherently counterintuitive.

Advantageously, a relatively reduced number of stud members 1 according to the invention are required to support plasterboard sections as compared to the number of stud members of comparative example 1. For example, the number of stud members 1 required may be three or two per 1200mm wide plasterboard section. Accordingly, the number of stud members 1 according to the invention required may be only half as many as the number of stud members of comparative example 1 so required.

Although the amount of material required to form a stud member 1 according to the invention is greater than that required to form a stud member of comparative example 1, the relative reduction in the number of stud members 1 required to support a dry wall results in an overall saving in the amount of metal used. However, were the dimensions of the stud member 1 increased indefinitely then the amount of material required by each stud member would exceed the savings provided by the subsequent use in a dry wall of a reduced number of such stud members. This is because plasterboard sections of 1200mm width cannot be supported by fewer than two stud members. Accordingly, the inventive benefit of stud members 1 according to the invention exists only within maximum dimensional limits.

Furthermore, as will be appreciated by one skilled in the art, stud members 1 should have web 3 widths d and flange 3, 4, widths bi, b2 which are both practically useful and commercially viable.

It has been found that stud members having flange widths of less than a minimal width offer insufficient area for the support of plasterboard sections in assembled dry walls and therefore stud members should not be made with flange widths less than a minimal width.

Moreover, increasing the average width of the flanges of a stud member by 10% results in a 5% decrease in the number of such stud members which can be transported in a similar given volume. For example, 20 of the prior art stud members described above can be transported in a ‘box-configuration’ within a space having a height of about 330mm and a width of about 700mm, however only 18 stud members having 36.3mm wide flanges (i.e. increased by 10%) may be transported in a space with the same dimensions. For further increased average widths of flange the number of stud members which can be transported in a given space is further reduced. Reducing the number of stud members which can be transported and/or stored within a given space results in an increased expense of transport and/or storage.

Accordingly, whilst increasing the flange width relative to the web width (relative to prior art stud members) results in a reduction in the amount of metal required in a subsequently formed drywall the expense of transporting and/or storing the stud members is increased. It will be appreciated that further increases in the relative width of the flanges will result in further reductions in the number of stud members which can be transported in a similar given volume (and hence an increase in the expense of transport). Moreover, larger and heavier stud members become increasingly cumbersome and more difficult to manoeuvre with an associated increase in difficulty and time of dry wall construction, with consequential expense increases.

We have found that there is a trade-off between, on the one hand increasing the rigidity of stud members in order to reduce the volume of metal required in assembled dry walls, and on the other hand increased dimensions of stud members and hence reducing the number which can be transported and/or stored in a given space. The reduced expense associated with reducing the volume of metal used must be balanced against an increased expense resulting from transportation and/or storage cost increases. For stud member dimensions beyond maximum values the balance becomes negative and consequently is not commercially viable.

Furthermore, altering the width of the web of a stud member requires a similarly altered width of associated track members. Accordingly, increased transportation and storage costs associated with the increased size and/or weight of stud members having relatively wider webs will also lead to increased transportation and storage costs associated with increased size and/or weight of corresponding track members.

Moreover, the width of the web must be practical in use. Typically, insulation materials and utilities such as cabling and pipework are located between facing plasterboard sections of a dry wall. Consequently, the web of the stud member should be of sufficient minimum width to accommodate such cabling, pipework and/or insulation materials. Furthermore, it is imperative that the width of web not result in a dry wall which unnecessarily impinges upon the room around which it borders, thereby reducing the useful space within that room.

Accordingly, the width of web must be within practical and commercially viable dimensional limits. In some embodiments it may be beneficial for the width of web to be similar to a standard width so that such formed stud members 1 can be used with prior art track members. However it is possible to increase both characteristics within the ranges to improve the rigidity of a stud member 1 yet further.

We have found that the most beneficial balance is found between a minimum value of 35mm and a maximum value of 48mm for the average width of flanges of a stud member 1. Stud members 1 having average flange 3, 4 widths within this beneficial range balance the benefits of reduced metal use in formed dry walls with the expense of storage and transport of the stud members 1.

In this embodiment of the invention the average flange 3, 4 width is between 35mm and 48mm, whilst the web 2 width d is maintained at 70mm. In embodiments, however, the web 2 width d may be varied so long as the ratio remains within the prescribed range.

We have surprisingly found that when the ratio of the web 2 width d to average width of flange 3, 4 is within the inventive range there is a commensurate saving in overall expense of dry constructions, for example dry walls and of assembly thereof. The improvement is particularly evident within the above-described ratio of web 2 width d to average width of flange 3, 4. Moreover, stud members 1 having average flange 3, 4 widths between 35mm and 48mm are practically useful and also commercially viable.

Without wishing to be bound by any particular theory it is believed that stud members 1 having ratios within the inventive range exhibit increased flexural rigidity Ds relative to the stud member of comparative example 1.

The flexural rigidity of the stud member 1 is directly proportional to the second moment of area Is, as shown in Equation 1, in which Es is Young’s modulus for the metal from which the stud member is formed. DS = ES1S (1)

Accordingly increasing the second moment of area Is results in a corresponding increase in the flexural rigidity Λ of the stud member 1 (assuming it is formed from the same material). A dry wall or other dry construction formed with a stud member 1 according to the invention will also exhibit an enhanced flexural rigidity D relative to a dry wall or other dry construction including a corresponding prior art stud member T, instead. The flexural rigidity D of a dry wall or other dry construction may be calculated as shown in Equation 2 where Ep is the Young’s modulus for the plasterboard section, Ip is the second moment of area for the plasterboard section, n is the number of stud members 1 and Us the width of the dry wall.

(2)

The maximum deflection δ of a dry wall (comprising one or more stud member 1 and one or more plasterboard section) under a uniformly distributed load and secured at its ends may be calculated through application of Equation 3, in which w is the distributed load and L is the height of the dry construction.

(3)

Using a starting assumption that the maximum allowable deflection δ is 1/240th of the height L under a uniformly distributed load n/of 200N/m, Equation 3 can be rearranged to provide a calculation for the maximum allowable height L of a dry wall, as shown in Equation 4.

(4)

The Applicant has found that even when the plasterboard section(s) are maintained at a constant flexural rigidity Dp, by increasing the flexural rigidity Ds of the stud members 1 the maximum allowable height L of a dry wall thus formed may be maintained or even increased

whilst leading to a concomitant decrease in the number of stud members 1 required to support that dry wall.

While stud members 1 according to the invention exhibit a relatively greater second moment of area than do prior art stud members T, the cross-sectional area of stud members 1 according to the invention is also relatively greater. Consequently, relatively greater volume and hence expense of material is required to form stud members 1 according to the invention than is required to form prior art stud members 1. However, the improvement in second moment of area exhibited by stud members 1 according to the invention is greater than is the increased cross-sectional area of those stud members 1. This relative improvement is defined as a ‘net increase’. The effect of altering the width b2 of the flange 4, (whilst maintaining the web width d at 70mm and the width bi of flange 3 at 31 mm) of a stud member 1 on the net increase is displayed in Figure 3.

The effect of altering the ratio of the width of the web to the average width of the flanges for stud member 1 on the net increase is shown in Figure 4. As can be seen, increasing the width of the flange 4, and hence decreasing the ratio of the width of the web to the average width of the flanges, results in greater net increase. Consequently, the increase in the cross-sectional area is outstripped by the concomitant increase in the second moment of area. This effect was found to be particularly beneficial within the inventive range of web width to average width of the flanges.

For example, in a standard dry wall the width of a plasterboard panel is 1200mm, whilst stud members 1 are disposed every 300, 400 or 600mm (requiring, respectively, 4, 3 or 2 stud members 1 to support each plasterboard panel).

By using stud members 1 according to the invention it has been found that a reduced number n are required to support a given width x and height L of dry wall, compared to the number of prior art stud members T so required. Therefore, for a given width x and height L of dry wall the use of stud members 1 according to the invention results in a decrease in the volume of material used and hence in the over-all expense of construction. Moreover, installation time of the dry wall is relatively reduced due to the requirement to install a reduced number of stud members 1.

Whilst the net increase continues to increase at ratios less than those required by the inventive range the increase in cross-sectional area has been found to make manufacture of stud members with such characteristics impractical. This is because, stud members exhibiting such dimensional characteristics: 1) have been found to require an increased volume for transport and storage such that their use is uneconomical; and/or 2) have web widths d and/or flange widths unsuited to the construction of dry walls or dry constructions. In the case of reason 2), it will be appreciated that web widths should be sufficient to provide suitable separation between facing plasterboard sections, for example in order to provide acoustic damping properties and to provide location for electrical, piping and insulation materials whilst not unduly reducing the useful space within a room around which they are located. Accordingly, the web width should be within a useful range. Furthermore, in respect of reason 2), the flanges must be of a minimum size suitable for the connection thereto of the plasterboard sections, which must thereby be supported, and of a maximum size such that their transport does not become uneconomical. Therefore, the flange widths must be within a useful range, also. Hence, ratios of web width to flange width outside of the inventive range of ratios have been found not to display the particular balance of characteristic advantages found in the stud members 1 of this invention.

The invention will now be explained with reference to the following, non-limiting, illustrative, Example:

Example

A wall of a given length and height requires 100 prior art stud members T of comparative example 1 (having web width of 70mm and average flange width of 33mm). For the same height and length of wall it is calculated that only 63 stud members 1 having web width of 70mm and average flange width of 40mm are required. Accordingly, 37 fewer stud members 1 having the above-described dimensions are required than prior art stud members 1’ of comparative example 1. However, each above-described stud member 1 has a 21.2% increase in volume relative to the stud members T of comparative example 1. Consequently, the overall saving in volume of metal in a wall of given height and length using the above-described stud members 1 according to the invention over stud members T of comparative example 1 is 10.3%. Accordingly, using stud members 1 according to the invention reduces the volume of material required for the formation of dry walls and consequently reduces the expense of construction. Furthermore, as will be appreciated, transport of 63 stud members 1 of the above dimensions instead of 100 stud members T of comparative example 1 requires a reduced volume and consequently, stud members 1 according to the invention (within the inventive range of flange widths) also provide a saving on expense of transport and/or storage. Indeed, 63 stud members 1 of the above-described dimensions require 24% less volume for storage or transport than do 100 stud members T of comparative example 1.

Similar savings are found with studs of the invention having 48 mm webs and 38 mm average flange heights, when compared to the prior art studs of 48mm web and 33 mm flange heights.

Referring now to Figure 5, there is shown a stud member 11 according to a further embodiment of the invention, wherein features similar or identical to those of the first embodiment shown in Figure 2 are identified by a preceding T. The stud member 11 differs from the stud member shown in Figure 2 in that embossed formations E are included across the join between the web 12 and each flange 13, 14. Additionally, embossed formations E are included across the join between each flange 13, 14 and their respective lips 13a, 13b. In embodiments, embossed formations E may be provided across only some of the above joins. Without wishing to be bound by any theory it is believed that the array of embossed formations E acts to further increase the flexural rigidity of the stud member 11.

Referring now to Figure 6, there is shown a stud member 21 according to a further embodiment of the invention, wherein features similar or identical to those of the first embodiment shown in Figure 2 are identified by a preceding ‘2’. The stud member 21 differs from the stud member shown in Figure 8 in that the web 22 and flanges 24 (only one of which is shown) include an array A of projections and depressions. Wthout wishing to be bound by any theory it is believed that the array A of projections and depressions acts to further increase the flexural rigidity of the stud member 21. In embodiments the stud member 21 may be absent embossed formations E in one, some or all of its joins.

It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, although the stud member 1 shown in Figure 2 include a single rib in each of the flanges this need not be the case and instead one or both flanges may be free of ribs or may include more than one rib. Additionally or alternatively, although the stud member 1 is described as being cold roll formed from a strip of steel of 0.5mm thickness this need not be the case and alternatively the stud member 1 may be formed by any suitable process and/or may be formed from a strip of steel of greater than 0.5mm thickness, for example 0.6, 0.7, 0.8, 0.9, 1.0, 1.1 or 1,2mm thick or any suitable thickness or may be formed from a strip of steel of less than 0.5mm thickness, for example 0.4, 0.3, 0.2mm thick. Additionally or alternatively, the stud member 1 shown in Figure 2 may comprise the embossed formations E shown in the stud member 11 shown in Figure 5 and/or the array of projections and depressions shown in the stud member 21 shown in Figure 6.

It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.

Claims

1. A stud profile for a dry wall, the stud profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, the central web having a width of from 68mm to 72mm, one flange having a width of from 37mm to 42mm and the other flange having a width of from 34mm to 39mm, and wherein the ratio of width of central web to average width of the flanges is between 1.67 and 2.03.

2. A stud profile for a dry wall, the stud profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, the central web having a width of from 46mm to 50mm, one flange having a width of from 37mm to 42mm and the other flange having a width of from 34mm to 39mm.

3. A stud profile according to Claim 2, wherein the ratio of width of central web to average width of the flanges is between 1.1 and 1.4, preferably 1.2 to 1.3.

4. A stud profile according to Claim 1, 2 or 3, wherein the stud profile is formed from a strip of metal having a thickness G of between 0.2mm and 1,2mm.

5. A stud profile according to any preceding Claim, wherein one or each flange comprises one or more longitudinal rib or bead.

6. A stud profile according to Claim 5, wherein the, some or each longitudinal rib or bead has a form depth F of between 1 and 10 times the thickness of the flange.

7. A stud profile according to any preceding Claim, wherein the central web and/or one or each flange comprises an array of projections and depressions.

8. A stud profile according to any preceding Claim, wherein the central web is joined to each flange by a joining portion and wherein an array of raised or rebated formations extends across one or each joining portion.

9. A stud profile according to any preceding Claim, wherein the web extends from one flange to the second flange in a direction which is orthogonal to each flange.

10. A stud profile according to any preceding Claim, wherein the two flanges differ in width by more than 2 mm and preferably less than 5mm.

11. A stud profile for a dry wall, the stud profile having a longitudinal central web from opposed edges of which longitudinal flanges extend, where the ratio of the width of the longitudinal central web to the width of one or both of the longitudinal flanges is between 1.56 and 2.04.