WO2000047836A1

WO2000047836A1 - Wall construction system

Info

Publication number: WO2000047836A1
Application number: PCT/AU2000/000091
Authority: WO
Inventors: Morris Nankin; Robert Hamilton Wilson
Original assignee: Morris Nankin; Robert Hamilton Wilson
Priority date: 1999-02-12
Filing date: 2000-02-10
Publication date: 2000-08-17
Also published as: AUPP873499A0

Abstract

A wall element is disclosed that is suitable for constructing the walls of building structures, perimeter fences, tanks, piers and other structures. In one form the wall element (10) may include a frame (12) that has fixed to it a corrugated sheet metal module or core (18) in which the corrugations (22) are roll formed so as to be of trapezoidal or re-entrant shape. The exterior of core sheet (18) is covered with a layer of rendering (20) that is keyed and retained in place by the re-entrant nature of the corrugations (22).

Description

TITLE: WALL CONSTRUCTION SYSTEM

TECHNICAL FIELD

This invention relates to wall elements and to wall construction methods, means and apparatus. The elements and methods are suited for use as external walls and cladding for domestic and light-commercial buildings, as well as to internal walls, partitions, acoustic barriers and high fire-rated walls.

The wall elements of this invention may be self-supporting or affixed to timber, steel or other types of building framing. The wall elements and methods may be used for water tanks, non-rectangular structures, perimeter or garden walls and for the construction of piers, posts or similar structures.

BACKGROUND TO THE INVENTION

Domestic and light commercial timber-framed buildings in Australia are commonly of the 'brick vernier' type in which a single-brick wall is used to clad the exterior of the building walls to provide maintenance-free weatherproofing and an attractive finish. However, the cost of bricks and bricklayers is now such that this method of cladding comprises a substantial proportion of the total cost of a domestic building. Reversion to 'weather-board' cladding is not a cost-effective alternative because of the shortage of timber, the cost of installation, the need for painting and the high maintenance of the cladding. Fire risk is also a concern for many householders.

An alternative cladding system common in the US, and now increasingly common in Australia, employs plywood sheeting that is covered with a sprayed-on stucco or render material. Because Australian timber prices are considerably higher than in the US, this alternative is not so economically attractive. Moreover, cracking of the stucco over time allows the ingress of moisture to the underlying ply that, in turn, causes the outer layer of the ply to rot and peel off with the stucco.

For commercial buildings, the cost of external wall construction has been reduced by the use of precast or site-cast steel-reinforced concrete wall units that are tilted into place. The technique is referred to as 'tilt-slab construction' and the walls are often called 'tilt-slab walls'. Such wall units may be load bearing or non load bearing, they may be attached to building frames as cladding or erected as essentially free-standing elements that are suitably braced and joined. While tilt- slab wall construction offers important economies in the construction of commercial buildings, the wall units are heavy (being made of reinforced concrete and being designed to stand the significant bending stresses associated with tilting) and they require heavy cranes and other equipment for handling. In general, tilt-slab construction is impractical for internal partition-like walls.

OUTLINE OF INVENTION

From one aspect, the present invention comprises a wall element for use in building construction or partitioning comprising a core or backing of corrugated sheet material covered on one side with a rendering that forms a substantially coherent and water-impervious external surface layer, the corrugations of the sheet material being of re-entrant form so as to be adapted to key the rendering in place thereon. The core may be of any desired shape, though it is preferable to avoid sharp radii, which crumple or otherwise distort the corrugations. Usually, as in most common buildings, the wall elements will be planar and the exposed surface will be substantially flat. The core sheeting maybe built up from a plurality of modules for ease of transport, the modules being overlapped and secured together along the overlap to form an integral core, if desired.

The wall element may include, incorporate or be attached to a frame to provide support or strength. Alternatively, the wall element may simply comprise a corrugated sheet material core of the type indicated above, which is rendered and coated on both sides to form an integral self-supporting wall or partition. Such walls or partitions can be formed in situ or preformed off-site or on-site. When preformed, the rendering of the wall elements may be cast onto the core sheet and tilted or lifted into position on site. Normally the sheet material will be roll-formed sheet steel that can be perforated or otherwise treated to improve adherence of the render or to inhibit corrosion. Where the core is rendered on one side only, the other side can be formed with a decorative or protective finish. If the finish is decorative, that side can be the internal face of the wall element that is exposed on the inside of the building. If the finish is protective, it could be used as the external surface of the wall element.

From another aspect, the invention concerns a method of constructing a wall element comprising the steps of erecting or otherwise forming a core of sheet material having corrugations of re-entrant form, applying a render to at least one surface of the core to completely cover said core and then allowing the render to dry or set so as to create a substantially rigid wall element. The method may include the additional step of rendering the second side of the sheet material to cover said second side and allowing that rendering to dry or set.

From another aspect the invention comprises a method of forming a wall or partition in situ, particularly (but not solely) where the wall or partition requires a high fire rating or a high acoustic rating. Such a method may include the steps of erecting a core of sheet material, having re-entrant corrugations formed therein, on a frame-like jig so that one surface of the core is exposed, releasably engaging the other surface of the core by clamping or holding means that enter the corrugations therein, rendering the exposed side of the core to cover it and to so form a continuous integral coating thereon, allowing the render to dry or set, releasing the core from the jig by disengaging the clamping or holding means from the corrugations, removing the jig and rendering the other side of the core to cover it and to so form a continuous integral coating thereon, and allowing the render on the other side to dry or set. Preferably, the jig with the core in place is positioned so that the core stands vertically in the position where the wall or partition is required and the respective sides of the core are rendered from floor to ceiling and from sidewall to sidewall.

Considerations of cost, strength, durability and convenience will generally dictate that the material of the core is sheet steel, whether galvanised or otherwise coated for decoration or durability. However, aluminium, other metals or plastic sheeting may be employed if desired. The sheeting can be arranged so that the corrugations are horizontal or angled to the horizontal, the latter having the advantage of improved bracing qualities where framed walls are involved. Various channel-like members can be clipped into the corrugations of the core to form cores for cornices, sills, cappings and the like that are covered when the render is applied and then finished by shaped trowels. Preferably such channel-like members are heavily perforated to allow them to be substantially filled by the render. Means may also be provide to lock the channel-like members in place before the render is applied.

The term 'rendering' is used to cover a wide variety of cement or plaster based materials that can be formed into a paste or slurry, which is suitable for spraying in heavy layers onto vertical surfaces and or trowelled. Such renderings usually contain particulate materials such as sand, small stones, expanded mineral substances such as vermiculite, basalt and pumice stone; and, sometimes containing fibrous material such as cellulose, mineral wool or glass fibres. Various clays and plaster-like materials may also be included. If desired, a pigment or die may also be included to give the rendering an attractive colour. Such material can be readily formulated for extruded or air-propelled application to a vertical wall under pressure through a flexible hose and a hand-held nozzle, or for casting onto a horizontal surface. If formulated for spray-application, the material will generally be sufficiently fluid for it to penetrate the perforations of the metal sheeting and to key itself onto that sheeting. The use of expanded mineral substances in the rendering is generally preferred because it is light in weight and has good thermal and sound insulation properties, and can have an excellent fire rating

As an additional optional feature, internal lining material (eg drywall cladding, plaster-board or the like) may be applied to the inner face of the sheet-material core or to the inner face of a framed core before or after the outer cladding has been applied. The walls formed as indicated above can be mounted on bearers in the conventional manner, set on brick footings, affixed directly to a rendering slab floor or extended to the ground. In any case, conventional damp courses may be applied in the normal manner before the walls are set in place. Preferably, a channel-like plastic foot may be used to space the sheet metal core from the ground or a damp situation and, also preferably, the foot may be incorporated in the render at the base of the wall element.

DESCRIPTION OF EXAMPLES

Having broadly portrayed the nature of the present invention, some examples will now be described by way of illustration only. In the following description, reference will be made to the accompanying drawings in which:

Figure 1 is a part sectional perspective view of an example of an external framed-wall element.

Figure 2 is a sectional elevation of two separated corrugated sheet-metal modules that may be used to form the wall elements of Figure 1 or 3, Figures 2A, 2B and 2C being enlarged details of respectively identified portions of Figure 2.

Figure 3 is a sectional elevation of an example of a self-supporting frameless wall incorporating the sheet-metal modules of Figure 2, Figure 3A being a detail of the portion of Figure 3 marked A.

Figure 4 is a series of three diagrammatic elevations, identified as (a), (b) and (c), illustrating three stages in constructing the wall of Figure 3.

Figure 4A is an enlarged detail of portion of the jig of Figure 4 showing the manner in which the core modules can be clamped or support by the jig frame. Figure 5 is an external elevation of a window opening in an external wall constructed in accordance with the present invention.

Figure 6 is a an enlarged sectional end elevation of the wall and window of Figure 5 taken on section line 6-6 of Figure 5.

Figure 7 is a sectional elevation of a framed wall element illustrating one form of wall capping that may be used.

Figure 8 is a sectional plan of one form of external corner between two framed wall elements.

Figure 9 is a sectional plan of an alternative form of external corner between two framed wall elements.

Figure 10 is a perspective view of a partially constructed pier or post formed using four wall elements

Referring to Figure 1 , a wall 10 comprises (i) a timber or metal frame 12 having a top plate 14 and studs 16, and an external cladding consisting of strips of roll- formed corrugated sheet steel 18 fixed to the studs 16 and to top plate 14, (ii) an external layer of rendering 20 and an internal lining plaster-board 21. Sheeting 18 is corrugated with longitudinal corrugations 22 of re-entrant or generally trapezoid shape having flat outer faces 24 and flat inner faces 26. In this example, sheeting 18 is formed in modules of between 1000 and 1200 mm high and to a length suitable for transportation. The sheeting modules are cut to length on-site and nailed to the studs 16 by nails 28 that pass through the inner faces 26 of corrugations 22, the bottom edge of one module overlapping the top edge of the lower module. [The modules are not separately identified or shown in Figure 1.] Optionally, outer faces 24 can be perforated with holes 30 that help to key the rendering layer 20 in place. However, the rendering is also held in place by integral keystone like strips 32 that are formed in the re-entrant recesses of corrugations 22 when the rendering is applied.

Wall 10 can be formed by constructing the frame 12 in the conventional manner, fixing the corrugated sheeting to the external face of the frame, applying the rendering 20 to the external face of the sheeting 18, trowelling the rendering (if needed) to form the generally planar external face of the wall, and allowing the rendering to set. Alternatively, the frame 12 and sheeting 18 of wall unit 10 can be pre-formed in a factory (or on-site) and the rendering can be cast or otherwise applied while the unit is horizontal, with or without the use of edge mouldings to confine the rendering. If the internal lining board 21 is to be applied to the frame in the factory, the necessary wiring and plumbing can be installed first and, after the lining board has been applied, the windows may installed and the architraves applied to the inside of the walls. After the wall unit 10 has been delivered and fixed in place, the lining board joints and corners can be finished by a plasterer and the electricity and plumbing outlets installed.

In the example of Figure 1 , the aforementioned wall element may be taken to be wall assembly 10 or only the combination of the corrugated sheeting 18 and the rendering 20. Also referring to the above Outline of the Invention, sheeting 18 can be referred to as the 'core' of the wall element.

In conventional brick-vernier external wall construction, it is necessary to provide concrete footings to support the external brick wall. The use of external wall elements of the present invention avoids the need for footings and bricking-in to floor level where raised wooden floors supported by stumps and bearers are used. For, in that type of construction, the corrugated sheeting modules can extend down to ground level and be rendered in-situ. Lateral support for the wall element below floor level can be provided by the perimeter stumps or rails nailed to those stumps. Such a wall construction provides for both vertical circulation of air from below floor level to above ceiling level and horizontal air movement along the inner corrugations of the metal sheeting. Figure 2 is an edge-on view of a pair of corrugated sheet-metal core modules comprising an upper module 40 and a lower module 42 arranged in vertical alignment. Though still of re-entrant form, the corrugations 44 of modules 40 and 42 are more rectangular than those of sheeting 18 and have rounded corners 43. This shape of corrugation is more amenable to roll-forming. The re-entrant character of the corrugations 44 is illustrated more clearly in the detail of Figure 2A, which is an enlargement of the portions marked A on Figure 2. To facilitate overlapping of modules, the upper edge 46 of each module is flat while the lower edge 48 of each module is formed with a return or lip 48. Figure 2B is an enlargement of portion B of Figure 2 showing the lip 48.

Figure 3 is a sectional elevation of a frameless, or self-supporting, internal wall or partition that comprises a wall element 50, which extends between a floor 52 and a ceiling 54. Element 50 incorporates modules 40 and 42 shown in Figure 2, the upper edge of lower module 42 overlapping the lower edge of upper module 40. Again, for the sake of clarity of illustration the detail of the overlap has not been shown in Figure 3. In this example, rendering 55 is applied to both sides of wall element 50 and sprayed or trowelled to form substantially planar left and right faces 56 and 58. It will be appreciated that the rendering 55 will seal all gaps between the wall and the floor 52 and ceiling 54 (as well as all gaps between the ends of element 50 and the sidewalls of the room (not illustrated). This permits the wall element to have high ratings as an acoustic and fire barrier.

If floor 52 is a concrete slab cast upon the ground, or for other reasons may be a source of moisture migration, it will be preferable to ensure that the lower edge 48 of the bottom module does not contact the floor surface. A preferred way of achieving this is to sit lower edge 48 of lowermost module 42 in an extruded or folded plastic channel or foot 59 that contacts the floor 52. Normally, foot 59 will be fully incorporated into the wall element and will not be visible externally. If desired, however, foot 59 may be dimensioned to form a skirting along one or both lower edges of wall element 50. One method of forming partition-wall element 50 in situ in a manner that ensures high acoustic and fire ratings is illustrated by Figure 4, parts (a), (b) and (c) of Figure 4 representing three steps in the process. First, as shown in (a), corrugated sheet-metal modules 40 and 42 are fitted to a wheeled jig 60 at the position where the wall 50 is to be erected. Jig 60 is conveniently a collapsible open frame structure comprising a vertical frame 62, a horizontal base 64 mounted on wheels 65, and diagonal bracing 66. A weight 68 may be carried by base 64 to give the structure stability. A preferred way of clamping modules 40 and 42 to vertical frame 62 is by the use of four rows of levers 70, 72, 74 and 76 affixed to frame 62, upper and lower rows 70 and 72 being employed to hold upper module 40 and upper and lower rows 74 and 76 being employed to hold lower module 42. Each row may comprise two or more levers at the same horizontal level.

The enlarged detail of Figure 4A illustrates the manner in which lever rows 74 and 76 can be used to hold lower module 42 in place on frame 62. [Module 40 is held in place in essentially the same manner that will not be separately described.] Each upper row lever 74 is pivotally mounted to frame 62 by a pin or bolt 78 and has a short upwardly facing hook 79 on one end and an extended handle 80 on the other end. Each lower row lever 76 has is pivotally mounted to frame 62 by a pin or bolt 82 and has a short downwardly facing hook 84 on one end and an extended handle 86 on the other end. Handle 80 of lever 74 can be secured to a hook 87 on frame 62 by a downwardly extending chain 88, while handle 86 of lever 76 can be secured to a hook 89 on frame 62 by an upwardly extending tension spring 90.

To fit and hold lower module 42 in place on frame 62, upper levers 74 are secured by chains 88 to hooks 87 so that handles 80 are substantially horizontal and the module is hung by the appropriate corrugation 44a on the upwardly facing hooked ends 78 of levers 74. The lower part of module 42 is first pulled away from frame 62 to allow the channel-like foot 59 to be laid on the floor 52 and positioned over the lower edge 48 of module 42. The lower portion of module 42 is then pushed against frame 62 so that lower edge 48 and foot 52 are moved into approximately correct position and, then, so that the downwardly facing hooked ends 84 are first deflected upwards (against the tension of springs 90) and then allowed to snap (under the tension of springs 90) into lower corrugation 44b. This is the position illustrated by the enlargement of Figure 4A. Upper module 40 is then clamped to frame 62 in a similar manner, taking care to overlap the lower edge 48 of upper module 40 with upper edge 64 of lower module 42 This position is illustrated in Figure 4 part (a).

After placing wheeled jig 60 correctly in position (a) of Figure 4, it is immobilised so that it cannot move during the first rendering operation. As shown in diagrammatically in Figure 4, part (b), the exposed sides of modules 40 and 42 are coated with rendering mix by the use of a spray-head 92. If necessary, the rendering is smoothed with a trowel or the like to form a smooth flat surface and it is allowed to set or to dry. After rendering 55 has set the chains of upper hooks 74 and the springs of lower hooks 76 are released to uncouple jig 60 and allow it to be moved aside while leaving the unfinished wall element 50 in position. This is illustrated in part (c) of Figure 4. The second side of wall 50 is then rendered using spray head 92 in the same way as the first side and allowed to set. The wall may then be painted or decorated in the normal manner.

Referring to Figures 5 and 6, the next example illustrates a framed wall element 110 of the type illustrated in Figure 1 having a window assembly 112, a cornice moulding 114 over the window and a sill moulding 116 below the window. It will be assumed that the building is multi-storey. In the enlarged but truncated sectional elevation of Figure 6, window assembly 112 is of conventional construction having an inner frame 118 in which a window pane 120 is mounted and an outer frame 122 comprising a sill piece 124, a head piece 126 and a pair of sides 128. Assembly 112 is supported in a conventional timber frame 130 comprising horizontal elements 132 (eg, noggins and plates) and vertical elements 134 (ie, studs). Modules 136 and 138 of corrugated sheet steel are nailed to the outside of frame 130, while the inside of frame 130 is lined with dry-wall or plaster board 140. The ceiling lining of the lower storey is shown at 142 and the floorboards of the upper storey are shown at 144.

It will be assumed that, as shown in Figure 5, cornice moulding 114 is largely decorative and extends horizontally along wall 110 over multiple windows 112, while a separate sill moulding 116 is required for each window. Cornice and sill mouldings 114 and 116 are supported and shaped by perforated, roll-formed sheet-steel channels 146 and 148 that clip into the external corrugations of upper and lower modules 136 and 138, respectively. The lower face of channel 146 that forms cornice 114 is step-like, this being largely for decorative purposes, though this shape also helps to shed any rainwater that runs down wall 110 above the windows 112. Lower longitudinal edge of channel 146 is retained by the lower out- turned lip (48, Figure 2B) of upper module 136, allowing its upper edge to be snapped into the lower re-entrant part of one of the upper corrugations of upper module 136. Spring steel retainers 150 are clipped in to that corrugation to lock the cornice channel 146 firmly to module 136.

In a similar manner, elongate sill channel 148 is snap-fitted into the upper corrugations of lower module 138. Locking retainers 152 are also used to retain sill channel 148 in place but, in this case, are fitted into the open ends of the channel from each end to lock the upper and lower runs of channel 148 to ensure that they cannot move together and be released from the corrugations of lower module 138. After channels 136 and 138 have been positioned, the exterior of the corrugated core modules is sprayed with render, care being taken to fill the interior of cornice and sill channels 146 and 148 by directing the render material through the perforations in the channels. The exterior of the wall is the trowelled flat and appropriately-shaped moulding tools are run horizontally along the exterior of channels 146 and 148 to form an outer layer of render to the desired finished shape, thus forming an attractive and weather-proof surface. The rendered coating is indicated at 154. Figure 7 shows a method of proving a capping cornice for the top of a wall. Here, the lower horizontally-extending edge 160 of a stepped channel-like, roll-formed and perforated sheet-steel core 162 is clipped into a corrugation of a wall core module 164. The upper edge 166 of core 162 extends horizontally sufficiently to cover the top of the building sidewall 167 and to include a short return flange 168. As with the window cornice and sill of the previous example, the capping cornice is both filled with render and covered with a layer of render.

Figure 8 is a sectional plan of the corner of a building at which two framed wall elements 180 and 182 meet, the bottom plate 184 and stud 186 forming part of the frame 188 of element 180 and the bottom plate 190 and stud 192 forming part of the frame 194 of element 182, stud 192 forming the corner of the walls. A folded Y-shape flashing strip 196 is nailed to corner stud 192 and extends the full vertical length the stud and covering both faces thereof. Flashing strip 196 is preferably formed from stainless steel and is unperforated, the central leg 198 of the strip is preferably folded double so as to include some internal space that allows for linear thermal expansion and contraction of the wall elements 180 and 182. Figure 9 shows the same building corner with the same wall elements but, instead of using an Y-shape flashing strip, the example of Figure employs an angle-strip 196a. This is less preferable because it does not allow for differential thermal expansion and contraction of wall elements 180 and 182.

It will be appreciated that the wall elements of this invention need not be exclusively employed in the walls of domestic or office buildings. They can also be used in much smaller building projects, such as the construction of boundary walls and even piers in such walls. One method of constructing a pier 200 of square or rectangular section is illustrated in Figure 10. Pier 200 can be constructed on a concrete foundation 201 from four wall elements having corrugated core panels 202 fixed to vertically spaced internal metal frames 204. If desired four corner posts (not shown) could be used instead. A cap or finial 206 is supported on the posts or on the core of sheet steel before the application of render by spraying and/or trowelling. It will be appreciated that the examples described and illustrated are only a small sample of the many ways in which the present invention may be implemented. Many variations thereon are possible without departing from the general principles of the invention disclosed herein. For example, the walls and methods of this invention are eminently applicable to the formation of cylindrical, conical or other shaped structures, provide the radii are not so sharp as to cause buckling or other distortion of the core sheets.

Claims

CLAIMS A wall element for use in building construction, or for use in the partitioning of buildings, comprising corrugated sheet material having a first side face and a second side face opposite said first side face, said sheet material being covered on said first side face with a rendering that forms a substantially planar first external surface of the wall element, the corrugations of the sheet material on said first side being of re-entrant form so as to be adapted to key the rendering in place on the first side of the corrugated sheet material.

A wall element according to claim 1 wherein said corrugated sheet material is covered on said second side face with a rendering that forms a substantially planar second external surface of the wall element, the corrugations of the sheet material on said second side being of re-entrant form so as to be adapted to key the rendering in place on the second side of the corrugated sheet material.

A wall element according to claim 1 wherein the corrugations of said sheet material extend substantially horizontally when said planar surface of the wall element is disposed substantially vertically.

A wall element according to any preceding claim having a frame comprising a plurality of studs and fixing means securing said studs to the second side of the corrugated sheet material, wherein the corrugations of said sheet material extend across the studs and, together with said fixing means, serve to brace the studs against racking movement.

A wall element according to claim 4 having lining board affixed to said studs so as to form a planar lining surface of the wall unit.

A wall element according to claim 4 wherein the second side of the corrugated sheet material is rendered so as to cover said studs and to form a planar surface of the wall element. A wall element according to any preceding claim wherein the corrugated sheet material is formed from at least two modular elongate sheets each having re-entrant longitudinal corrugations formed therein, each sheet having first and second longitudinal edges that are substantially parallel to one another, and wherein the first edge of a first one of said modular sheets is adapted to overlap and engage the second edge of a second one of said modular sheets.

A wall element according to any preceding claim having an elongate cornice, sill, or capping extending from one surface thereof, said cornice sill or capping including a channel-like base member formed from sheet material and having flexible walls adapted to be clipped into the corrugations of the core, the core and the member being covered and encased by said render.

A wall element according to claim 8 wherein said channel-like member is perforated to allow it to be substantially filled by the render.

A wall element according to claim 8 or 9 having means fitted within the relevant corrugations to lock said channel-like member in place before the render is applied.

A method of constructing a wall element comprising the steps of erecting or otherwise forming a core of corrugated sheet material having corrugations of re-entrant form, applying a render to at least one surface of the core to completely cover said core and then allowing the render to dry or set so as to create a substantially rigid wall element.

A method according to claim 8 including the step of rendering the second side of the sheet material to cover said second side and allowing that rendering to dry or set. A method of forming a wall or partition in situ including the steps of erecting a core of sheet material having re-entrant corrugations formed therein on a frame-like jig so that one surface of the core is exposed, releasably engaging the other surface of the core by clamping or holding means that enter the corrugations therein, rendering the exposed side of the core to cover it and to so form a continuous integral coating thereon, allowing the render to dry or set, removing releasing the core from the jig by disengaging the clamping or holding means from the corrugations, removing the jig and rendering the other side of the core to cover it and to so form a continuous integral coating thereon, and allowing the render on the other side to dry or set.

A method according to claim 10 wherein the jig with the core in place is positioned so that the core stands vertically in the position where the wall or partition is required and the respective sides of the core are rendered from floor to ceiling and from side wall to side wall.