WO2009013470A2

WO2009013470A2 - Modular building system

Info

Publication number: WO2009013470A2
Application number: PCT/GB2008/002474
Authority: WO
Inventors: Andrew Colin King; George Edward Shaw; Christopher Mark Gooding
Original assignee: Wernick Buildings Limited
Priority date: 2007-07-20
Filing date: 2008-07-18
Publication date: 2009-01-29
Also published as: GB2451193B; GB0714255D0; WO2009013470A3; GB2451193A; GB0813272D0

Abstract

A modular building system having wall panels (1) constructed from a plurality of elongate metal trays (2). Each metal tray has an elongate body section (4) and elongate flanges (3) extending from and along opposed longitudinal edges of the body section. The metal trays are arranged vertically next to each other and are connected along the flanges. The body sections may be arranged adjacent the interior of the building with the flanges extending towards the outside, making the panels particularly suited to use in secure modular custodial accommodation (10).

Description

Modular Building System

The present invention relates to modular buildings and to a new system of constructing modular buildings. In a preferred arrangement, it relates to modular custodial accommodation, in particular custody cells and suites.

Modular buildings are well known in the art. Typically such buildings comprise a number of separate modular sections that are pre- fabricated off-site in a factory, transported to the desired location and assembled on-site. The parts may, for example, comprise individual wall sections, or larger modules (often referred to as volumetric modules) comprising several pre-assembled walls with a roof and/or floor structure, that can be connected together on-site to form a building. For smaller buildings, for example, cabins, studios etc., a complete building may be prefabricated and then transported and simply installed at the desired location.

Modular buildings have a wide variety of uses. They are often used as short or long-term temporary facilities as they are relatively quick and easy to set up and dismantle. They can also be used as permanent structures. Known uses of modular buildings include construction-site buildings, schools and classrooms, hospitals, housing and industrial facilities.

A wall of such a modular building is typically constructed using a number of vertical studs, made of aluminium, steel or timber for example, onto which a weatherproof cladding/membrane is attached to form the outside surface of the wall, and an internal cladding e.g. plasterboard to form the inside surface of the wall. The studs support and space apart the internal and external cladding so, for example, insulation may be provided in the gap therebetween.

However such walls can be time consuming to assemble and install because each stud needs to be correctly aligned and then the cladding affixed thereto for example using screws or other suitable fasteners. If the studs are incorrectly aligned then the positioning of the internal and external surfaces is affected. Furthermore, pre-drilled screw-holes may not line up making assembly difficult. Moreover the number of components and the labour required to construct the wall is not insignificant, and there is always a desire to reduce costs. Similarly floors and ceilings of modular buildings are constructed by setting out joists and then fastening panels, and similar problems arise.

Whilst it may be desirable to use such a traditional wall, floor or ceiling construction in certain applications of semi-permanent or permanent modular buildings, there is an opportunity to simplify the construction of modular buildings, particularly for temporary structures. Temporary modular buildings, in addition to being quick and easy to assemble, usually need to be as inexpensive as possible. Furthermore, some temporary structures (e.g. buildings located on site for less than two years) may not need to comply with building regulations in some jurisdictions, for example in relation to insulation requirements, and thus lower-performance walls and ceilings may be acceptable.

Moreover, a new type of use for modular buildings is emerging, namely as police or prison custody cells, be it either as temporary or permanent custody cells. Traditional cells in permanent police stations can become very overcrowded for example on a Saturday night or if there is an event such as a football match or demonstration nearby. Whilst more permanent cells could be built, this is not an ideal solution in most cases, particularly if the rise in inmates is only temporary or if the cells need to be moved after a period of time. The speed of installation of modular cells makes them an ideal solution for both temporary and permanent custody suites because they are fast to locate and can be moved to meet the needs of demand.

If a modular building is to serve as a temporary or permanent custody cell, it must be secure, i.e. prevent the occupant from escaping. However, standard modular buildings are not built with this requirement in mind, and so modifications are generally required. One of the normal stipulations is a sheet of steel lining in the wall, in some situations a sheet at least 2mm thick is required, applied for example on the inside surface of the wall behind the cladding. However this adds yet more complexity and expense to the conventional methods of constructing modular buildings.

Thus, there is a need for a new type of modular building that is inexpensive and quick to assemble so that it is appropriate for use as both a temporary or permanent building, and in particular one which can function as custodial accommodation, for example, as a prison or custody cell.

According to one aspect, the present invention provides a modular building system in which panels forming a wall, ceiling and/or floor of a modular building are constructed from a plurality of elongate, preferably metal trays, the trays having an elongate body section and elongate flanges extending from and along opposed longitudinal edges of the body section; wherein the trays are arranged adjacent one another, with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, and wherein the trays are connected together along the adjacent flanges to form a panel.

Thus the body section of the tray forms the plane of the wall, ceiling and/or floor panel. Also the flange of a first tray which is connected to the flange of an adjacent second tray creates a structural rib of double thickness material that extends perpendicularly to the body section. In the case of a wall panel, the elongate trays will extend vertically, with the elongate body sections defining the plane of the wall and the connected flanges creating structural ribs that extend vertically, to transfer load from the building vertically and to stiffen the wall panel. Similarly, the body section of the elongate trays forming a floor panel and/or a ceiling panel will extend horizontally (or the ceiling panel may be inclined in the case of a pitched roof) and the connected flanges will create a structural rib extending in the horizontal direction, to distribute floor or ceiling loads in the horizontal direction and to stiffen the floor or ceiling panel.

The structure of this new modular building system therefore essentially replicates the structural function of the traditional construction systems that use vertical studs and panels for the walls, or in the case of floors or ceilings, the joists and panels of the floor or ceiling, but it benefits from a much more simplified construction process and requires fewer components. The trays essentially define a monocoque structure which replaces the studwork, joists and panelling of the conventional construction systems. The trays preferably butt up against one another at the flanges and are permanently joined to one another by a mechanical connection. In one particularly preferred embodiment, holes are formed in the flanges through which fasteners are fitted, in order to create the mechanical interconnection. A suitable fastener could be a two-part fastener such as a nut and bolt, but more preferably a two-part locking fastener is used to provide tamper-proof security. The pin of such a fastener does not have a screw thread so that a collar fitted over it cannot unscrew but is instead locked in place. Such a pin could include parallel rings protruding outwards along the length, which the collar is forced over to lock the pin in place. A particularly suitable type of fastener is a Huckbolt® fastener, described later. Another preferred fastener is a structural blind rivet. In an alternative embodiment, the mechanical interconnection requires no additional components.

The trays of the present invention are preferably of metal, though there may be applications for modular buildings where other materials may be used, for example, plastic trays or trays made from composite materials, where these could be welded or stuck together at the flanges to form a panel, for example a wall panel, floor panel or ceiling panel. The body section of the tray will usually be rectangular in shape with the longitudinal edges extending parallel to one another and the shorter top and bottom edges perpendicular to the longitudinal edges. However it may be desirable in some applications for the top or bottom edge to be inclined or staggered, for example in the case of a wall panel to take account of variations in the roofline or changes in level.

In particular, viewed from one aspect, the present invention provides a volumetric module for a custody cell, the volumetric module having wall panels constructed from a plurality of elongate, metal trays, the trays having an elongate body section and elongate flanges extending from and along opposed longitudinal edges of the body section; wherein the trays are arranged vertically and adjacent one another, and with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, the trays being connected together along the adjacent flanges to form a wall panel. Preferably the volumetric module includes a ceiling panel constructed from a plurality of elongate, metal trays, the trays having an elongate body section and elongate flanges extending from and along opposed longitudinal edges of the body section; wherein the trays are arranged horizontally and adjacent one another, and with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, the trays being connected together along the adjacent flanges to form a ceiling panel. The volumetric module may also include a floor panel constructed from a plurality of elongate, metal trays, the trays having an elongate body section and elongate flanges extending from and along opposed longitudinal edges of the body section; wherein the trays are arranged horizontally and adjacent one another, and with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, the trays being connected together along the adjacent flanges to form a floor panel.

The present invention also extends to a wall panel constructed from a plurality of elongate metal trays, the trays having an elongate body section and elongate flanges extending along and from opposed longitudinal edges of the body section; wherein the trays are arranged to extend adjacent one another and vertically, when the wall panel is in use, with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, the trays being connected together along the adjacent flanges to form a wall panel. Such wall panels may be prefabricated off-site and assembled to form walls of a building, for example a custody cell, on-site.

The present invention further extends to individual ceiling or floor panels constructed from a plurality of elongate metal trays, the trays having an elongate body section and elongate flanges extending along and from opposed longitudinal edges of the body section; wherein the trays are arranged to extend adjacent one another and horizontally, when the ceiling or floor panel is in use, with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, the trays being connected together along the adjacent flanges to form a ceiling or floor panel. Such ceiling or floor panels may be prefabricated off-site and assembled to form ceilings or walls of a building, for example a custody cell, on-site. The ceiling or floor panels may also have application in connection with modular buildings that have a more conventional construction for the walls because they offer a more simplified construction process than the conventional joists and panels.

The present invention is also seen to encompass a complete modular building comprising a plurality of the volumetric modules or panels, for example, wall panels, assembled together to form the building. The volumetric modules may be arranged side by side or stacked on top of one another. The volumetric modules may be open on one or two sides to facilitate joining to an adjacent volumetric module. The modular building may comprise a custody suite made from volumetric modules which define each cell or a set of cells.

Preferably, each metal tray is in the form of a metal C-section, which has been roll-formed or folded into shape from a single sheet of metal. Thus a method of forming a tray for use in the modular building system preferably includes the steps of roll-forming a metal sheet to form elongate strips which extend along the opposed edges of the sheet and perpendicular to the plane of the sheet, and cutting the formed sheet into metal trays having an elongate body section and a pair of flanges. Alternatively the method may include the steps of cutting a sheet of metal to a predetermined length and folding the sheet to form elongate strips which extend along the opposed edges of the sheet and perpendicular to the plane of the sheet, in order to form a metal tray having an elongate body section and a pair of flanges. Most preferably, each method further includes the step of punching holes in the flanges, so that when the trays are installed, holes in adjacent flanges match up to enable fasteners to be fitted therethrough. In both cases the body section is integrally formed with the flanges of the tray. The cross-section of the tray is preferably the same for the whole of its length. There may be an absence of flanges at the ends of the tray, for example at the top and bottom of the tray forming a wall panel when it is arranged vertically in use. In some embodiments, however, it may be desirable to provide the tray with an integrally formed tab, for example, an auto-formed end, at one or both of its ends which can then be joined to a tray of a perpendicular panel, for example, for joining a ceiling or floor panel to a wall panel. Preferably the tab is an element which is separate and spaced from the flanges.

Most preferably, each flange is lipped, creating a lipped C-section. The sheet forming the metal tray may be roll-formed or folded to create four, parallel extending, right angle bends, which define the body section, the pair of flanges and provide a lip on each of the flanges. Preferably, each lip extends from the far end of the respective flange in a direction substantially perpendicular to the flange and substantially parallel to the body section, with the lips of each tray facing towards each other. As such, the region in the vicinity of the interconnection between adjacent trays has a cross-section substantially in the form of an I-beam, with the body sections and lips forming the head and base of the "I", and adjacent connected flanges forming the central portion of the "I". The creation of this I-beam stiffens the connected trays significantly, providing particularly good strength for wind loading and other localised stresses.

According to another aspect, the invention provides a volumetric module for a building comprising at least one wall having a monocoque structure, the wall comprising a plurality of vertically arranged I-beams and an internal or external metal skin that is integral with the I-beams; wherein the skin and I-beams support the structural load of the wall.

According to another aspect the present invention can be seen to provide a modular building or volumetric module having wall panels constructed from a plurality of elongate, vertically extending trays that are arranged to define three or more walls of an enclosure, the trays of each wall panel being joined together along their neighbouring vertical edges and the wall panels being connected together to define a monocoque structure forming the enclosure, wherein the trays comprise a body section which is provided with L-shaped flanges along opposed vertical edges to define trays with a lipped C-section, and the flanges of adjacent trays are connected together to create vertically extending, I-sectioned, structural ribs for the monocoque structure. In one embodiment the modular building or volumetric module is a custody cell.

The lips of the flanges play an important role (i) structurally in terms of stiffening the modular buildings and volumetric modules, and also (ii) because they provide something that cladding/panelling can easily be attached to. Thus each lipped flange serves a dual purpose of creating the I-beams and providing a suitable flat surface for attaching further panels to, again avoiding the need for additional brackets which might otherwise add to complexity and cost of the building.

A particularly suitable material for the metal trays is steel, more preferably steel which has been coated with a weather or decorative finish, for example, galvanised steel, plastic coated steel or colour coated steel. In one embodiment, the trays are arranged such that the elongate body sections are adjacent the interior of the building, with the flanges extending outwardly. Arranging the trays in this manner means that the body sections effectively form a metal 'lining' in the wall, ceiling and/or floor which is one of the security requirements for a building to serve as a custodial environment. Therefore this embodiment of the modular building and/or volumetric module of the invention is particularly suited to use as a custody cell. Also since the walls are comparatively inexpensive and quick to assemble, this embodiment is particularly useful where the custody cell or suite is a temporary building. Compared to known modular custodial accommodation using studs and a steel sheet lining, the present invention provides the advantage that there are no fasteners that hold the steel lining which are accessible to an occupant, because the body section, which also provides the steel lining to the cell, is an integral part of the tray. Alignment of pre-drilled holes is also less of a problem because alignment of the identical factory prepared trays is relatively straight forward and there are no additional components like plates of steel that require alignment to the structure. Therefore preferably, the metal tray is a steel tray at least 1.5mm thick, more preferably 2mm thick, since this provides the desired steel lining required in some circumstances. In order to allow the metal trays to be handled easily the metal trays are preferably no more than 5mm thick. The trays may in fact seem quite flexible during handling. However, once the trays are joined together the structure is significantly stiffened by the creation of the structural ribs. The trays are preferably planar, in order to form a planar side wall, ceiling and/or floor, though there are instances where it may be desirable to incorporate a curve or crease in the body section to create a change in direction. Alternatively, one or more of the flanges may be arranged at an angle greater or smaller than 90° to create a change in direction.

Thus, according to one embodiment, there is provided modular custodial accommodation in which one or more panels of a modular custody suite is/are constructed from a plurality of elongate, metal trays, the trays having an elongate body section and elongate flanges extending from and along opposed longitudinal edges of the body section; where the trays are arranged vertically and adjacent one another, with a vertical flange of one tray arranged parallel and adjacent to a vertical flange of a neighbouring tray, the trays being arranged such that the body sections are adjacent the interior of the building, with the vertical flanges towards the outside, and wherein the trays are connected together along the adjacent flanges to form a panel. Preferably, the wall or other panels of this embodiment further comprise an internal lining for aesthetic purposes, which can be connected to the elongate body sections. Typically such a lining is arranged as a 'skin' directly on the body sections. The lining could be for example a sheet of thin board, wallboard or a plastic laminate covering. It could also comprise an insulating material. Further internal lining layers may be provided as required. In such embodiments where the trays are hidden from view within the structure, the trays are preferably of galvanised steel.

The wall panels of this embodiment also preferably comprise an external cladding on the outside to form the external surface of the building. In the case where the metal trays are lipped, the external cladding can be attached to the lips, avoiding the need for special brackets or clips. The external cladding is typically weatherproof cladding, however, in one preferred use the building of the invention may be erected inside another larger building for example a warehouse, and in this situation a weatherproof cladding (or indeed any sort of cladding) may not be required. Similarly for ceiling panels, the lips of the tray can provide areas where weatherproof roof elements or cladding can be attached.

The wall, ceiling and/or floor panels of the present invention can also be used as a way of constructing a room, for example, a cell, within a modular building of conventional construction. The cells could be provided as volumetric modules which are installed within the confines of a building constructed in a conventional way. Alternatively the volumetric modules could be a composite of wall panels constructed using the modular building system of the present invention and other panels constructed in a more conventional way. In one arrangement, the module comprises a cell constructed using the modular building system of the present invention and a corridor section of conventional construction. In another arrangement the volumetric module comprises two cells constructed using the modular building system of the present invention and arranged on opposite sides of a corridor. In yet another arrangement the volumetric module comprises just part of a cell, for example three of the four walls, which are constructed using the modular building system of the present invention.

In an alternative embodiment, the trays of the wall panels are arranged the other way around, such that the elongate body sections form, or are adjacent to, the exterior of the building, with the flanges extending towards the inside. Arranging the trays in this manner means that the body sections are on the outside of the building and can function as external weatherproofing. Thus, not only are the walls of the building inexpensive and quick to assemble due to the use of trays as the main structural components, but external weatherproof cladding is not required, thus further reducing expense and assembly time. As such, a building according to this embodiment of the invention is particularly useful as temporary accommodation, such as construction-site cabins. However cladding could be attached to the outside of the wall panels if desired, e.g. to provide additional weatherproofing, insulation or for aesthetic purposes. In this case the cladding could be applied as a 'skin' to the elongate body sections of the wall panels and connected thereto. The ceiling panel may also be constructed of trays which are arranged the other way around, with the body sections forming, or being adjacent to, the exterior of the building. As with the wall panels, the body sections may function as the external weatherproofing, or if desired, the ceiling panel may include additional elements, for example additional insulation or weatherproofing. Preferably the trays of the wall panels and ceiling panel are arranged the same way round, but it may be preferable in some instances to provide a modular building with the trays of the wall panels arranged with the body sections disposed outwardly and the trays of the ceiling panel arranged the other way around with the body sections disposed inwardly.

Temporary buildings of this type (and indeed also the first type) may have further applications such as temporary office space, conference or reception space, library space, retail space, workshop space, education facilities, emergency accommodation, asylum/immigration centres, healthcare centres, armed forces accommodation, etc., where there is a need for low cost buildings that can be erected quickly. In many situations, the buildings may not need to comply with all the requirements of building regulations if it is to be deployed for less than two years. The modular building may also serve as a custody cell.

Preferably, the wall panels of this embodiment further comprise an internal lining for aesthetic purposes, which can be connected to the flanges, or if the tray flanges have lips, then ideally to the lips. The lining could be for example a sheet of thin board, for example, plaster board, wallboard or plywood, possibly covered with a skim of plaster, wallpaper or a plastic laminate covering. It could also comprise an insulating material. Further internal lining layers may be provided as required. If the trays are visible, for example, if they form the exterior of the building, preferably they comprise a colour coated or plastic coated steel, or other product which is more aesthetic than galvanised steel.

According to yet another aspect, the present invention provides a modular building, or a volumetric module for such a building, having panels constructed from a plurality of elongate, preferably metal trays, the trays having a elongate body section and elongate flanges along and extending from opposed edges of the body section; wherein the trays are arranged with the body sections forming or being adjacent to the exterior of the building such that the flanges extend towards the interior of the building; wherein the flange of one tray is arranged parallel and adjacent to a flange of a neighbouring tray, the trays being joined together along the adjacent flanges to form a wall panel. Preferably the panels are wall panels and the elongate trays are arranged vertically such that the flanges are on opposite vertical sides of the trays, the trays being arranged and joined together in the manner described to form a wall panel. The panels may also include a ceiling panel such that the flanges are on opposite horizontal sides of the ceiling panel trays, the ceiling panel trays being arranged and joined together in the manner described to form a ceiling panel.

In embodiments according to any of the above described aspects of the invention, the metal trays are at least 200mm wide, preferably 300mm or wider, more preferably 400mm wide or thereabouts. Wider trays can be used though this reduces the density of the structural ribs which stiffen the panels. Preferably the trays are no wider than 800mm, and preferably only 600mm wide or less. The most preferred size of 400mm wide is a size that is wide enough to enable a wall, ceiling or floor to be constructed quickly with not too many mechanical connections required, and provides the desired structural stability and strength. Yet, it is small enough to be practical to deal with while enabling flexibility in creating different panel lengths etc. Windows or skylights may be fitted by removing a section of one or more trays, and such windows/skylights are already conveniently manufactured in 400mm and 800mm wide frames. Doors and other access hatches can also be easily accommodated with this choice of tray width. Clearly other dimensions can also be used and are envisaged within the scope of the present invention. It may be preferable in some instances to have a modular building where one panel, for example, a wall panel, uses trays of one width dimension while another, for example, a different wall panel, a ceiling panel or floor panel, uses trays of another dimension, to accommodate different structural requirements. In some instances, it may be desirable to incorporate different widths of tray within a single panel, for example, to accommodate different structural or dimensional requirements.

The trays of a wall panel are preferably at least 2.2m tall, more preferably around 3m tall and extend the full length of the wall, though they could be taller or shorter depending on the needs of the building. The trays for a ceiling and floor panel may be 2.4m long or thereabouts. The flanges are preferably around 70-80mm deep, and the lips 20mm wide or more for a wall panel. The flanges may be deeper, for example up to 200mm for floor or ceiling panels. The trays are preferably of steel and around 2mm thick, creating structural ribs of around 4mm thick which are arranged vertically and perpendicularly to the plane of the wall in the case of a wall panel, and arranged horizontally and perpendicularly to the plane of the floor or ceiling in the case of a floor or ceiling panel.

It is particularly suitable to join the trays directly to one another by connecting adjacent flanges: i.e. the flange of one tray being connected to the flange of an adjacent tray, though it may be desirable with some arrangements to incorporate an intermediate layer of material or materials for sealing or insulation purposes. The intermediate layer may include an adhesive.

In a preferred embodiment of the invention the flanges are connected together via holes created (for example by punching or drilling) therein. Preferably these holes are created in the factory during manufacture as opposed to on-site during subsequent assembly. This enables the location of the holes to be precisely controlled, e.g., with respect to the base of the tray. A two-piece fastener can be used to connect the flanges, for example a standard nut and bolt. However in a particularly preferred embodiment a two-piece locking bolt, e.g., a Huckbolt® fastener is used, such as the C6L® LockBolt™, readily available commercially for example from Star Fasteners, Gallows Industrial Estate, Furnace Road, Derbyshire, DE7 5EP, UK. This fastener comprises a pin having serrated rings around the outer surface and a collar which fits onto the pin and is locked in place by the rings. Thus the pin is fitted through holes aligned in the flanges to be joined, and the collar is fitted on the far side using a special gun which crimps the collar over the pin. These fasteners provide a very strong fixing, are resistant to vibratory loosening, offer tamper-proof security and are quick to install. Furthermore, because the holes are punched during the forming of the trays, there is no creation of swarf during assembly, for example during a drilling stage as the locking bolts are being fitted. It may be desirable to connect the flanges in a way that does not require pre- drilled holes since such methods require the trays pre-drilled holes to be in exact aligned. Further, drilling holes or widening misplaced holes can be time consuming and creates swarf at the production site.

Therefore it may be preferable to connect the flanges are connected without the use of drilling or fasteners. Self-piercing rivets could be used, for example, but this requires the provision of a consumable (the rivets). Also, whilst adhesive or welding may be an option, in a preferred type of connection, a part of one flange is punched into and deformed with a part of the adjacent flange, thus forming a mechanical interconnection. One such connection system is the Tog-L-Loc® system available from BTM Corporation, Marysville, Michigan, USA. This system utilises a punch and die to join sheets of metal and provides strong, leak-proof joints without the need for drilling, rivets, screws or other fasteners, or any consumables. It also does not create swarf, which together with the lack of consumables, may provide advantages where the trays can be made of thinner, more readily deformable material. According to a further aspect, the present invention provides a modular building system in which panels of a volumetric module or modular building are constructed from a plurality of elongate metal trays, the trays having a body section and elongate flanges along and extending from opposed edges of the body section; wherein the trays are arranged with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, the trays being interconnected along the adjacent flanges to form a panel by a plurality of regions where one flange has been punched into and deformed with a plurality of corresponding regions of the adjacent flange to form mechanical interconnections therebetween. Preferably the panels are wall panels in which the trays are arranged vertically such that the flanges are on opposite vertical sides of the trays and the trays are joined by the mechanical interconnections in the manner described to create a wall panel. The panels may be, or may also be, ceiling and/or floor panels in which the trays are arranged horizontally such that the flanges are on opposite horizontal sides of the trays and the trays are joined by the mechanical interconnections in the manner described to create a ceiling and/or floor panel. The mechanical interconnection is strong enough that preferably this is the only form of mechanical fixing between the adjacent flanges. In most instances where a ductile metal material, such as sheet steel, in particular 2mm thick sheet steel, is connected in this way, the mechanical interconnection is of a comparable strength to the tensile strength of the sheet it is made from.

Preferably, thermal/noise insulation is provided within the metal trays (e.g. in the area between the body section, flanges and lips). Mineral wool is a particularly useful form of insulation, for example Rockwool.

Alternatively any other suitable flooring may be provided for the modular building of the present invention. In one embodiment a steel-cassette floor is used. The wall panels can be connected to the flooring by any suitable fasteners, for example L-shaped brackets and the like. An integral tab could also be provided at the end of a wall tray to provide a connection in place of such a bracket.

Also whilst it is preferred to construct the roof from a plurality of elongate, preferably metal trays in a similar way to the wall panels, any suitable roofing may be provided for the modular building of the present invention if desired.

Preferably the volumetric module or modular building comprises at least three wall panels and a ceiling panel made from metal trays in the manner described. The body sections are arranged either inwardly with the flanges extending outwardly, or outwardly with the flanges extending inwardly. The former arrangement is particularly useful where the building is to be used as a custody cell as the body sections then act as a better barrier to prevent a person escaping. The latter arrangement is particularly suited to other applications where the number of components is desired to be kept at a minimum, since the body sections could then form the exterior of the wall or roof and provide weatherproofing.

Preferably one or more windows are provided in the walls or roof of the modular building. In the case of single storey custody suites, windows or skylights may only be provided in the roof of the structure. In the situation where volumetric modules are likely to be stacked on top of each other to create a two, three or more storey building, the windows or skylights may be fitted at the top of a side wall. As mentioned above, preferably the windows are the same width as the metal trays used to construct the wall panels, since the fitting then simply replaces a section of tray and connects to the flanges. Thus in one embodiment, the panel includes a fitting in the form of a window or skylight and both the metal trays and the fittings are 400mm wide.

In the particular embodiments described above, the walls are described as external walls, i.e. with one side facing towards the interior of the building and one towards the outside of the building. However, of course, the walls of the modular building of the present invention may be internal dividing walls, e.g. being contained within the interior of the building, one side facing one room and one side facing another. In this case a lining suitable for the interior of buildings, such as thin board, wallpaper or plastic laminate may be provided on both sides of the wall panels, hi an alternative embodiment, an internal dividing wall comprises two walls panels of the type described but provided back-to-back. For example, with the body sections being adjacent each other in the centre region of the double- wall and the flanges facing outwards, or alternatively the body sections on the outside and the flanges facing inwards. The latter example is particularly useful if the building is to be used as a custody cell, since the body sections will be towards the interior of the rooms on either side of the wall, and thus better at preventing a person escaping.

The modular building of the present invention may be prefabricated either in full or in part in a factory and then delivered to the desired site as panels or modules for assembly and installation, hi one embodiment, modules comprising a number of interconnected walls and roofing are prefabricated and then assembled on-site into a complete building. In another embodiment, the modules are pre-assembled and delivered to the site as complete buildings or sections of buildings that can then be craned into position. Thus a custody suite might arrive as a plurality of modules providing the cells which are craned into position on-site to form the custody suite. Thus the invention also extends to a kit of parts from which a modular building as described above can be constructed.

Preferred embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a plan- view cross-section of a wall of a modular building, according to an embodiment of the invention;

Figure 2 is a plan view of part of a custody suite that is a modular building according to an embodiment of the invention;

Figure 3 is a plan view cross-section of walls of a custody cell, according to an embodiment of the invention;

Figure 4a is a side elevation cross-section in the direction of arrow A of Figure 3, of a wall and roof panel of a custody suite, according to an embodiment of the invention;

Figure 4b is a side elevation cross-section in the direction of arrow B of Figure 3, of a wall and roof panel of a custody cell, according to an embodiment of the invention;

Figure 5 is a side elevation cross-section of a wall and floor of a custody cell according to an embodiment of the invention;

Figure 6 is a plan view cross-section of a cell dividing wall of the custody cell according to an embodiment of the invention;

Figure 7 is a plan view of one embodiment of a volumetric module for a custody suite;

Figure 8 is a plan view of a custody suite formed from a combination of the volumetric modules of Figure 7; Figure 9 is a plan view cross-section of walls of a modular building according to an alternative embodiment of the invention;

Figures 10a and 10b show enlarged cross-sections of outboard and inboard systems of joining a wall panel to a floor panel;

Figure 11 shows a perspective view of a preferred tray with an autoformed end; and

Figure 12 illustrates a C6L® LockBolt™.

The main structural components of a wall panel of a modular building according to an embodiment of the invention are illustrated in Figure 1. The wall panel 1 comprises a number of lipped C-section steel trays 2. Each tray comprises an elongate body section 4 with a flange 3 at each side arranged at approximately 90 degrees to the body section 4, and at the far end of each flange there is provided an inwardly- facing Hp 5. The lips 5 are therefore substantially parallel to the body section 4. The trays 2 of the wall panel 1 are arranged substantially vertically so that they are elongate in the vertical direction. The trays 2 have a depth corresponding to the width of the flange 3, and are closed on one side and open on the other. Thus, the elongate body sections 4 (i.e. the 'web' of the C) form one 'face' of the wall panel 1, and the lips 5 are arranged on the other 'face' of the wall panel 1, the 'faces' being separated by a depth corresponding to the width of the flange. The trays 2 are positioned adjacent each other and are connected together via joins 6 at the flanges. Although the joins 6 could be any suitable type of joint, for example, rivets, bolts, weld metal, adhesive etc., in the present embodiment the joins are formed using a Huckbolt fastener, such as the C6L® LockBolt™ 80 (see Figure 12). This comprises a serrated pin 81 which is passed through holes formed in the flanges (not shown) and a collar 82 fitted over the far side of the pin by a gun which crimps the collar over the pin to lock the fastener in place. In another embodiment the joins are formed using a consumable-free system, such as the Tog-L-Loc® system that uses a hand unit with an electrically powered hydraulic pump system. The Tog- L-Loc® system comprises a punch and a die. A stripper clamps both flanges to the die as the punch advances. The punch draws the metals into the die and squeezes them against an anvil. The moving die blades allow an outward flow of metal, expanding the diameter to form a strong circular lock. Thus the flanges are securely and mechanically joined together through the punching of one of the pieces of metal into the other, without the need for pre-drilled holes or consumables. A number of the wall panels 1 of Figure 1 can be connected together and/or subsequently have appropriate cladding attached to one or both faces depending on the building context in which it is being used.

Figure 2 is a plan view of part of a modular building according to an embodiment of the invention which is arranged as a custody suite 10. The custody suite 10 comprises a number of custody cells 41 arranged in rows and separated by a corridor 40. The custody suite 10 may comprise a plurality of cells 41, each of which is a volumetric module, that are arranged together to form the custody suite 10, or the volumetric module may comprise two or possibly more cells, which are then joined to similar volumetric modules to form the custody suite 10. A door 42 is provided in a wall of each custody cell 41 opening up onto the corridor 40. Windows may also be provided (not shown). The walls of the custody suite comprise wall panels 1 of the type shown in Figure 1.

A plan-view cross-section of the left corner region of the custody suite 10 of Figure 2 is illustrated in more detail in Figure 3. Two externally facing walls 43 are illustrated, each comprising a wall panel 1 of Figure 1. The walls 43 are arranged with the elongate body sections 4 facing inwards. Thus the body sections 4 replicate the sheet of steel lining stipulated for custody cells as a measure to prevent an occupant from escaping. The metal trays 2 in this example are made of galvanised steel and have body section 4 dimensions of 400mm x 2.0mm x >3m, though other materials and dimensions may also be used. The flanges 3 are 75mm deep extending the length of the 3m or more of trays 2. The lips 5 may be 20 or 30mm deep. The joined flanges 3, the adjoining portions of the body sections 4 and lips 5 create a structural rib in the form of an I-beam that stiffens the side wall. An external insulated cladding system 11 is provided on the outside of the wall 43 and is attached via the lips 5. This cladding system 11 prevents too much heat being drawn out of the cell 41 via the metal body section 4, the flanges 3 and the lips 5. An internal lining 12 is provided on the inside surface of the wall 43 and is attached to the body sections 4. Rockwool or other insulation 13 is provided within the ¹C of each tray 2 for both thermal and sound insulation. Brackets 14 are located around each outside corner of the cell 41 to make the structure robust. These are L- shaped plates which may be 3mm thick and extend the entire height of the corners to prevent a tool being used to prise apart the two panels.

Side views of the custody cell, in which the roofing system can be seen, are illustrated in Figures 4a and 4b. Figure 4a is a side view looking in the direction of arrow A in Figure 3 and Figure 4b is a side view looking in the direction of arrow B in Figure 3.

The roof comprises a number of metal roof trays 20 which are of the same type as used for the wall trays 2, and comprise a body section 22, flanges 21 and lips 23. The roof trays 20 are arranged horizontally above the wall trays 2 and are connected thereto by suitable brackets. Adjacent roof trays 20 are joined 24 in a similar fashion as the wall trays, using the Huckbolt® or Tog-L-Loc® systems. Rockwool or other material 25 which offers sound-proofing and insulation is provided within the ¹C of the roof trays. A further insulated roof panel 28 is arranged on top of the roof trays 20 and is affixed thereto by means of attachment to the lips 23. An angle bracket 26 fixed around the corner of the wall/roof tray arrangement ensures they are robustly connected. A side cross-sectional view of a wall/floor joint of the custody cell described above in relation to Figures 2-4 is illustrated in Figure 5. The floor structure has a floor frame 32 comprising a pair of side beams 35 connected together by transversely extending joists 33. A 3mm steel floor 31 is provided on the floor frame 32, and a 25mm floor deck 30 is mounted on the steel floor 31. A cleat 34 connects the joists 33 with the side beams 35 and the wall trays 2. Similar cleats may be used to connect other panels together in other parts of the structure. Angle brackets 36 are connected to the base of the wall trays 2 and the side beams 35 in order to support the wall trays 2. In embodiments where the custody cell 41 or suite 10 is to be housed on a concrete floor, for example, when it is located within another building, a 'thinner' floor may be suitable. Such floors can be made from further metal trays 2 formed from 2mm thick sheet steel and the modular building system of the present invention.

A plan- view cross-section of a cell dividing wall 44 of the custody suite 10 of Figure 2 is illustrated in more detail in Figure 6. Each cell 41 has walls of the type illustrated in Figure 1. Therefore the walls between adjoining cells, i.e. cell dividing walls 44, comprise two walls arranged back-to-back, with the body sections 4 of the metal trays 2 facing inwardly of the respective cell 41 and the lips 5 arranged in the middle area of the wall 44. An internal lining 12 is provided on either side of the cell dividing wall 44 and is attached to the body sections 4.

Figure 7 shows a plan view of an example room arrangement for a volumetric module 45 which can be used for a custody suite. Example dimensions are 2.4m x 9.6m. The roof height would usually be a minimum of 3m. The volumetric module 45 is shown with a cell 46 of 2.4m x 3.6m floor area arranged on either side of a section of corridor 47 which is 2.4m wide. The volumetric module 45 may have walls formed from trays 2 on two, three or four sides of each cell 46. Where the volumetric module is at the end of the custody suite, the wall formed from trays 2 may continue to join the two cells 46 and close off the end of the corridor 47. Preferably, as shown in Figure 7, a different type of construction is used for the wall which holds the door. This is because of the considerable weight of the doors which can weigh around 300kg. Such doors are too heavy for the metal trays 2 to support by themselves and consequently a more substantial construction is required. Additional diagonal cross- bracing to triangulate forces, compression beams arranged across the corridor 47, etc, may be required to support the torsional forces created when the cell door is opened.

Figure 8 shows an example floor plan of a section of a custody suite made from a plurality of the volumetric modules shown in Figure 7.

A plan- view cross section of part of a modular building 50 according to an alternative embodiment of the invention is illustrated in Figure 9. The walls 51 comprise wall panels 1 of the type illustrated in Figure 1. In this embodiment, in contrast to the custody cell described above, the wall panels 1 are arranged with the body sections 4 facing outwards so that they form the external surface of the wall 51 , with the flanges 3 extending towards the inside of the building. No additional weatherproof cladding is required since this is fulfilled by the body sections 4. The metal trays 2 are made of galvanised steel and have dimensions 400mm x 80mm x 1.5mm, though could be of thicker sheet if desired, and the trays may be at least 2.2m in length, more preferably around 3m in length. The lips 5 are 20mm long or longer. An interior layer 8 is provided on the inside surface of the walls for insulation and aesthetic purposes, and is attached via the lips 5.

The building 50 also comprises floor and roofing systems similar to those described above in relation to the embodiment of Figures 2-6, which are connected to the walls in a similar way.

A number of windows (not shown), each 400mm or 800mm wide (i.e. the same width as the metal trays 2 or integer multiples of the width), are provided in the wall panels. In order to create a window, a portion of a metal wall tray is removed and the window is fitted in the gap and connected to the flanges 3. The modular building 50 is inexpensive and quick to assemble due to its construction from the metal trays 2, and cost is further minimised as it does not require additional weatherproof cladding. Therefore it is particularly useful as a temporary building where for example low cost is more important than external appearance, such as cabins on building sites. Figure 10a shows an enlarged sectional view of the edge detail where a floor panel 62 is mounted outboard of a wall panel 61. The metal trays 2 of the wall 61 overlap the end of and are joined to the metal trays 2 of the floor panel 62 using a cleat 63 or an integral tab autoformed at the end of the tray 2. Figure 10b shows an enlarged sectional view of the edge detail where a floor panel 62 is mounted the other way around, namely inboard of the wall panel 61. The ceiling panel would usually be arranged outboard of the wall panels 61 so that it can rest on top of the wall edge. In both figures, an outer support bracket 64 is provided to protect the corner. Mechanical interlocks 65 can be formed to join the components together. Figure 11 shows a perspective view of the end of a preferred tray 2 which is provided with an autoformed end 70. As shown in the figure, the tray 2 is provided with a tab 70 of material extending from an end of the tray 2, which has been folded to extend at 90° to the plane of the body section 4. The tray 2 may be made from long sections which are roll-formed to create the flanges 3 and lips 5 of the lipped C- section, cut to length with additional material left to provide one or more tabs 70 at one or each end of the tray, and then the tab 70 folded to create the auto-formed end. This structure allows the cleats or other brackets to be dispensed with when joining a wall panel to a floor or ceiling panel. The Tog-A-Loc® or Huckbolt® systems can be used to mechanically fasten the tab 70 of the auto-formed end of the tray 2 of, say, the wall panel to a tray, beam or other component of a floor or ceiling panel, or vice versa.

Claims

1. A modular building system in which one or more panels of a modular building or volumetric module is/are constructed from a plurality of elongate, metal trays, the trays having an elongate body section and elongate flanges extending from and along opposed longitudinal edges of the body section; wherein the trays are arranged adjacent one another, with a flange of one tray arranged parallel and adjacent to a flange of a neighbouring tray, and wherein the trays are connected together along the adjacent flanges to form a panel.

2. A modular building system as claimed in claim 1 wherein the trays are arranged such that the body sections are adjacent the interior of the building, with the flanges extending towards the outside.

3. A modular building system as claimed in claim 2 further comprising an internal lining connected to the body sections.

4. A modular building system as claimed in claim 2 or 3 further comprising external cladding arranged to form the external surface of the building.

5. A modular building system as claimed in claim 4, wherein the metal trays are lipped and the external cladding is attached to the lips of the flanges.

6. A modular building system as claimed in any preceding claim, wherein the panel is a wall panel and the elongate trays are arranged vertically, with a vertical flange of one tray connected to a vertical flange of a neighbouring fray to form a wall panel.

7. A modular building system as claimed in any preceding claim, wherein each flange is lipped.

8. A modular building system as claimed in claim 7 wherein each lip extends from the far end of the flange in a direction substantially perpendicular to the flange and substantially parallel to the body section, the lips of each tray facing each other, such that the region of the connection between adjacent trays has a cross-section substantially in the form of an I-beam.

9. A modular building system as claimed in any preceding claim wherein the metal trays have been roll-formed or folded from steel sheet.

10. A modular building system as claimed in claim 9 wherein the steel sheet is 1 to 5mm thick.

11. A modular building system as claimed in claims 1 , wherein the trays are arranged such that the body sections are adjacent the exterior of the building, with the flanges extending towards the inside.

12. A modular building system as claimed in claim 11 , wherein the metal trays are lipped and an internal lining is attached to the lipped parts of the flanges.

13. A modular building system as claimed in any preceding claim wherein holes are formed in the flanges and the flanges are connected by a two-part locking fastener, wherein a first part is placed through adjacent holes in both flanges and a second part is fixed over the distal protruding part of the first part.

14. A modular building system as claimed in any of claims 1 to 12 wherein the flanges are connected by parts of one flange being punched into and deformed with parts of the adjacent flange to form a mechanical interconnection therebetween.

15. A modular building system as claimed in any preceding claim wherein the trays are around 2mm thick.

16. A modular building system as claimed in any preceding claim wherein the metal trays are approximately 400mm wide.

17. A modular building system as claimed in any preceding claim further comprising insulation contained within each tray.

18. A wall panel for a modular building made in accordance with the modular building system of any preceding claim.

19. A volumetric module for a modular building comprising a floor panel, ceiling panel and at least two wall panels, wherein at least one of the panels has been made in accordance with the modular building system of any of claims 1 to 17.

20. A volumetric module as claimed in claim 19 which has at least three wall panels made in accordance with the modular building system of any of claims 1 to 17 and is arranged as a custody cell.

21. A modular building in the form of a custody suite assembled from volumetric modules of claim 19 or 20 and/or wall panels of claim 18.

22. A kit of parts for constructing a modular building, the parts including a plurality of elongate metal trays which are to be connected together in accordance with the modular building system of any of claims 1 to 17.

23. A modular building system substantially as hereinbefore described with reference to the accompanying drawings.