GB2372268A - Cladding resembling brick wall - Google Patents

Abstract

A cladding panel resembling a brick wall comprises slips 1 attached to a substrate, e.g. board 21, by means of clips 10 which engage in grooves 7 to restrain movement of the slip away from the substrate. As shown, the clips may be generally T - shaped, and engage in a mortice 7 which is cut into the side and bottom edges of the slip at each lower corner: alternatively a clip with a circular head may engage in a recess in the side only of the slip. Gaps 27,28 between the slips may be filled with mortar: in addition to the clips, adhesive may be used to attach the slips.

Description

Prefabricated Building Components

The present invention relates to improvements in and relating to prefabricated building components. In particular, the invention relates to techniques for attaching decorative slips of, for example, concrete, or reconstituted stone or clay brick to a supporting structure during prefabrication of cladding panels.

A task force was set up by the UK Government in 1998 to advise upon improving the efficiency of the UK construction industry. The task force was chaired by the industrialist Sir John Egan, and led to a report entitled Rethinking Construction that is now universally known in the UK construction industry as the'Egan Report'. Further details of the Egan Report can be obtained from the website of the UK Government's Department of the Environment, Transport and the Regions at www. construction. detr. gov. uk A key recommendation of the Egan Report was a move toward standardisation in the UK construction industry and, especially, greater use of prefabricated or'factorybuilt'building components. Consequently, the UK Government is encouraging innovation in the design and assembly of prefabricated building components and the development of a range of standard building components that can be used in different buildings.

Prefabricated building components such as cladding panels have advantages of speed of construction and a reduction in defects and waste, and hence lower cost.

Specifically, components and sub-assemblies can be produced off-site and delivered to a building site exactly when needed, in the right order, without defects. This therefore reduces the need for on-site storage, and overcomes the major problem of material waste. For example, traditional bricks and other discrete decorative building elements are heavy, are time consuming and expensive to lay, require skilled labour (so-called'wet trades'), and are particularly prone to wastage, notably by theft, breakage and inadvertent burial on site. Cladding panels provide a quick and costeffective alternative that offers the durability and aesthetic characteristics of

traditional brick or other decorative building elements, while mitigating or avoiding their associated drawbacks.

Whilst cladding panels are typically designed to emulate traditional brick and stonework for external walls, they may also or alternatively incorporate marble, slate, concrete and other architectural and decorative masonry elements. Also, decorative elements can be applied to both sides of a cladding panel and may be for internal or external use. For example, whilst the decorative elements of a cladding panel are typically applied to the external side of the panel, it is possible for such elements to be applied to the internal side as well or for the entire panel to be adapted for internal mounting.

Cladding panels can be made in various ways. In one such method applicable to the manufacture of concrete cladding panels, thin tile-like sections of brick, stone, marble or any other suitable decorative material are pre-arranged in a desired pattern in a generally horizontal mould. These thin sections are commonly known in the construction industry as'slips', which term will be used hereinafter in this specification. Any necessary reinforcements are then arranged over the slips before concrete is poured into the mould over both the slips and the reinforcement to the depth necessary to give the required thickness to the panel. The concrete, once cured, thereby fixes the slips in position, which in effect are embedded in the concrete with only their side that faced the mould exposed to view. In particular, the concrete fills the gaps between the slips giving the impression of mortar between the slips to emulate a traditionally-built wall.

As a cladding panel of essentially solid concrete has a substantial weight that is inappropriate to many buildings and leads to high transport costs, a lightweight, more manoeuvrable alternative has evolved in which slips are attached to a board-fronted metal-framed panel. Specifically, the lightweight cladding panel is made of a ladderlike framework or lattice of metal studs folded from galvanised steel, the studs being arranged in parallel within a frame of similar material. Optionally, cross-members link the studs to increase the stiffness of the panel. The framework supports a board that can be bonded and/or mechanically fixed to the studs by screws, bolts or other

fastenings. The board in turn supports slips that are bonded to the board in a desired pattern using a suitable waterproof adhesive.

A specific example of a cladding system employs slips of, for example, brick that are permanently bonded to a waterproof skin. The skin is supported by a stiff insulating backing panel that can be attached to a substrate or other support such as an existing wall. The substrate can as easily be of metal frame construction as aforesaid.

In that known system, the skin has an array of parallel ribs defining tracks in which slips are arranged in courses, typically in broken bond. Specifically, one or more longitudinal strips of adhesive are applied to the skin along the track for each course of slips. The slips are then offered up to and pressed against the adhesive strips and hence bonded in place. Finally, the gaps between slips are filled by mortar that is piped into the gaps and finished in the manner of traditional pointing.

The ribs on the skin give some mechanical support to the slips. They also define the relative positions of the courses and the gaps between neighbouring courses, so that the courses of slips are reliably and correctly positioned in relation to one another.

However, the ribs do nothing to define the relative positions of slips within a course or the gaps between neighbouring slips in a course. Unless specifically designed otherwise, nor do the ribs allow for patterns of slips other than straight parallel courses.

In extreme climates, the temperature of a building may fluctuate by around 30 to 40 Celsius either side of zero Celsius, with changing seasons and from night to day. This makes known cladding systems susceptible to slips falling off. In other words, the bond between a slip and the attached board or skin or the surrounding concrete can fail, for example as a result of differential expansion. Also, in some systems such as the abovementioned known system that employs strips of adhesive, water may permeate between and behind the slips over time, where eventually it freezes and expands, thereby forcing slips away from the supporting board or skin or the surrounding concrete.

Whilst instances of failure have been mercifully rare, it is totally unacceptable that slips might fall from clad buildings onto people and property below.

It is against this background that the invention has been devised.

From one aspect, the invention resides in a cladding system including a plurality of slips supported by a substrate, wherein each slip is engaged with at least one clip fixed to the substrate, the clip including a slip-engaging formation adapted to engage the slip to restrain movement of the slip away from the substrate.

By means of the invention, inter-engagement between the clips and the slips prevents the slips falling away from the substrate.

Each slip may have at least one recess adapted to receive the slip-engaging formation of a clip. In preferred embodiments, the recess of a slip is a mortise and the slipengaging formation of a clip is a tenon.

For the most secure location of slips, the slips are preferably hung on the clips, suitably by engagement of the slip-engaging formation in the recess.

A slip according to the invention can include a front exposed face and at least one peripheral face facing a peripheral face of a neighbouring slip, in which case the mortise or other recess is preferably set into the peripheral face of a slip. More specifically, the mortise lies in a plane substantially parallel to a generally planar front face of the slip.

In most practical embodiments, the slip will be a cuboid that has four peripheral faces being side, top and bottom faces. Thus, the mortise or other recess is preferably set into a side face of the slip but may also be set into the bottom face of the slip. In that case, the mortise suitably extends from the bottom face of the slip part way up the side face toward the top face, defining an aperture that extends around the comer intersection between the bottom face and the side face.

For optimum location, there are two mortises and one of those mortises is associated with each side face of the slip.

The clip of the invention preferably includes a spacer that spaces the slip-engaging formation of the clip from the substrate. The spacer of the clip can, for example, be a stem extending from the substrate to the slip-engaging formation, which stem is dimensioned to fit in a gap between slips. The stem may have a transverse crosssection that defines at least one flat adapted to bear against a side face of a slip in use.

This helps to locate the clip. Alternatively, the stem may be rounded, for example of circular cross-section.

The clip of the invention preferably has at least two slip-engaging formations and more preferably has two opposed slip-engaging formations situated on and symmetrically disposed about the stem, such that the clip is generally T-shaped. The slip-engaging formations may be generally semi-circular in shape which, being preferably opposed, may define a circular part. The or each slip-engaging formation of the clip is dimensioned to fit in a gap between slips.

In this respect, preferred embodiments of the invention envisage a gap between adjacent peripheral faces of neighbouring slips and that a portion of a clip is accommodated in the gap. The gap can then be filled with mortar so that the mortar conceals the clip and gives a traditionally-built appearance to the panel.

Whilst the clip can be integral with the substrate it is much preferred that the clip is separate from and attached to the substrate. For example, the clip can be attached to the substrate by a fastening extending through the clip and into the substrate, which fastening preferably extends along the stem of the clip.

To cater for limited movement of the slips with respect to the substrate under thermal expansion and other stresses such as ice expansion or freeze-thaw action, the clip is advantageously resilient to permit such movement of the slips with respect to the substrate.

Whilst the invention provides a reliable method of preventing a slip falling away from a substrate, preferred embodiments of the invention also employ an adhesive to attach the slips to the substrate. The adhesive is preferably a continuous layer between the slips and the substrate, to the benefit of strength and waterproofing.

The substrate can take any suitable form but preferably comprises a framework to which a backing board can be attached to support the slips. The backing board may have a plurality of layers. In a preferred'warm frame'system, the backing board advantageously comprises a layer of insulation between the slips and the framework.

The invention can also be expressed in method terms within the embracing inventive concept.

Specifically, one method of constructing a cladding system in accordance with the invention comprises applying a plurality of slips to a supporting substrate in a desired pattern, engaging each slip with at least one clip having a slip-engaging formation adapted to engage the slip and to restrain movement of the slip away from the substrate, and fixing the clip to the substrate.

In this method, the clip can for example be inserted into and moved along a gap between adjacent slips before being fixed to the substrate. The slip-engaging formation of the clip preferably engages the slip during said movement of the clip.

More specifically, in preferred embodiments, the slips define bottom and top faces and the clip is slid from the bottom face toward the top face during said movement along the gap. For example, the slips can be applied to the supporting substrate in parallel courses and the clip can then be inserted into a gap between adjacent courses before being moved along a gap between adjacent slips in a course.

Another method of constructing a cladding system in accordance with the invention comprises applying a plurality of slips to a supporting substrate in a desired pattern while engaging each slip with at least one clip fixed to the substrate, the clip having a slip-engaging formation adapted to engage the slip and restrain movement of the slip

away from the substrate. This method can include the preliminary step of fixing the clips to the substrate in positions defining the desired pattern of the slips.

A yet further method of constructing a cladding system in accordance with the invention comprises applying a slip to a supporting substrate in a desired location, engaging the slip with at least one clip having a slip-engaging formation adapted to engage the slip and to restrain movement of the slip away from the substrate, and fixing the clip to the substrate. Further slips may then be applied by engaging each further slip with the slip-engaging formation of a fixed clip, engaging the further slip with a second clip having a slip-engaging formation, fixing the second clip to the substrate, and so on.

In preferred expressions of the invention, all of the aforesaid methods contemplate hanging the slips on the clips.

Preferably, the clips are fixed to the substrate by fastenings that extend through the clips into the substrate and that are accessible via gaps between adjacent slips. Where the substrate comprises a framework of studs, a strength advantage is gained if at least some of the fastenings extend into the studs. Nevertheless, retainers are contemplated for use where a fastening does not extend into a stud. In all cases, it is envisaged that mortar is applied to fill any gaps between slips and hence to conceal any clips within those gaps.

The invention extends to parts of the system and items for use in the method of the invention, notably the slips and the clips, and also to building components embodying the system or made by the method of the invention, notably cladding panels and other slip-clad structures.

In order that the invention can be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is an isometric drawing of a slip in accordance with the invention, showing mortises set into the slip;

Figures 2 (a) and 2 (b) are perspective views of a clip in accordance with the invention, co-operable with the slip of Figure 1 ; Figure 3 is a perspective view of a cladding panel being either partially constructed in one method of the invention or partially deconstructed to show the disposition of clips and slips on the panel; Figure 4 is a vertical section of the cladding panel of Figure 3, viewed from one side; Figure 5 is a horizontal section of the cladding panel of Figures 3 and 4, viewed from below; Figure 6 is an isometric view of the slip of Figure 1 engaged with a clip of Figures 2 (a) and 2 (b), and showing a retainer for securing a screw that fixes the clip to the substrate of the cladding panel of Figures 3 to 5; Figures 7 (a), 7 (b) and 7 (c) are views of the retainer shown in Figure 6, Figures 7 (a) and 7 (b) showing the retainer in plan and side view respectively and Figure 7 (c) showing the retainer in combination with a screw; Figure 8 is a schematic rear view of the cladding panel of Figures 3 to 5 that omits the backing board for clarity; Figure 9 is an isometric view of an end clip for use at an end of a course of slips; Figure 10 is a perspective external view of a slip in accordance with a second embodiment of the invention ; Figure I I is a perspective view corresponding to Figure 10 but showing the internal shape of mortises set into the slip;

Figures 12 (a), 12 (b), 12 (c) and 12 (d) are views of a clip in accordance with the second embodiment of the invention, co-operable with the slip of Figures 10 and 11, Figure 12 (a) showing the clip in perspective, Figures 12 (b) and 12 (c) showing side views from respective orthogonal directions, and Figure 12 (d) showing the clip from above; Figure 13 is a perspective view of a cladding panel being either partially constructed in one method of the invention or partially deconstructed to show the disposition of clips, as shown in Figures 12 (a) to 12 (d), and slips, as shown in Figures 10 and 11, on the panel; Figure 14 is an isometric view of the slip of Figures 10 and 11 engaged with a clip of Figures 12 (a) to 12 (d), and showing the retainer of Figure 6 for securing a screw that fixes the clip to the substrate of the cladding panel of Figure 13; Figures 15 (a), 15 (b), 15 (c) and 15 (d) are views of a variant of the clip shown in Figures 12 (a) to 12 (d), Figure 15 (a) showing a side view of the clip variant, Figures 15 (b) and 15 (c) showing top and bottom perspective views of the clip variant, and Figure 15 (d) showing the clip variant from underneath ; and Figure 16 is a vertical section of a variant of the cladding panel of Figures 3 and 4, viewed from one side, in which the substrate is of a different layered construction.

Referring firstly to Figure I of the drawings, a slip I in accordance with the invention takes the form of a thin substantially solid cuboidal block defining six oblong faces.

The slip 1 is moulded of any suitable mouldable material such as concrete, which, in the embodiment shown, presents the desired decorative finish on at least one of its faces. Specifically, the slip I has two major parallel opposing faces, a first major face 2 being the visible decorative face of the block in use and a second major face 3 lying against and being bonded to a substrate such as a backing board of a cladding panel in

use. Thus, in use, the first major face 2 becomes the front face of the slip 1 and the second major face 3 becomes the rear face of the slip 1.

The four minor faces are divided into two opposed parallel pairs, one pair being side faces 4 and the other pair being a top face 5 and a bottom face 6. The top face 5 is plain and uninterrupted whereas the other minor faces 4,6 are interrupted by mortises 7. As shown, a pair of oblong mortises 7 is set into the bottom and side faces 6,4 of the slip 1, one mortise 7 being at the comer intersection between the bottom face 6 and one of the side faces 4 and the other mortise 7 being at the comer intersection between the bottom face 6 and the other of the side faces 4. Each mortise 7 extends within the slip I in a plane parallel to the major faces 2,3 and defines an aperture 8 that extends half way along the side face 4 from the bottom face 6 toward the top face 5 and bisects the corresponding lower portion of the associated side face 4. The aperture 8 of each mortise 7 extends around the intersection between the side face 4 and the bottom face 6, extending into and along a minor portion of the bottom face 6 away from the side face 4 and similarly bisecting that minor portion of the bottom face 6.

It will be apparent to those skilled in the art that the demoulding direction of the slip I is from the bottom face 6 toward the top face 5. A slight taper (not shown) may be imparted to the surfaces of the slip I to assist demoulding, in conventional manner.

By way of example, the thickness of the slip I between the major faces 2,3 is approximately 35-40mm depending on the density and weight of the material, each mortise 7 extends into the slip by about 20mm from the associated side face 4, and the aperture 8 defined by each mortise 7 is about 5mm wide. Slips I in concrete or stone can be of any size but typically will be either 390 x 190mm (actual face size) or 440 x 215mm (actual face size) to give a co-ordinated face dimension of 400 x 200mm and 450 x 225mm respectively. It will be appreciated that the exact dimensions of the slip I and the mortises 7, and the location of the mortises 7 within the slip 1, may be tailored to suit particular applications and materials. For example, other slip sizes may be used depending on the specification required by the architect designing the project for which the cladding panels are intended.

A clip 10 in accordance with the invention is shown in Figures 2 (a) and 2 (b). Viewed overall, the clip 10 is substantially T-shaped having a stem 11 and a crosspiece 12 moulded integrally of plastics material, the stem 11 depending centrally and orthogonally from the crosspiece 12. The stem 11 therefore divides the crosspiece 12 to define a pair of opposed tenons 13. More specifically, the crosspiece 12 and hence the tenons 13 are defined by a flat oblong plate having long and short sides 14,15 surrounding major parallel faces 16 that lie in planes orthogonal to the central

longitudinal axis of the stem 11. The major face 16 further from the stem 11 is penetrated by a central countersunk hole 17 that leads into the stem 11.

The stem 11, in turn, is defined by a pair of parallel flat oblong members 18 whose major faces are orthogonal to both the major faces 16 and the long sides 14 of the crosspiece 12. The members 18 defining the stem 11 are disposed symmetrically about the central longitudinal axis of the stem 11 and are integrally conjoined by a tube 19 of square external section and circular internal section that is aligned with and leads to the countersunk hole 17 in the crosspiece 12.

As can be seen clearly in Figure 2 (b), the members 18 defining the stem 11 have a width matching the width of the short sides 15 of the crosspiece 12 whereas the external section of the tube 19 between the members 18 is somewhat narrower, although the length of the tube 19 matches the length of the members 18 and so extends the full length of the stem 11. This reduction in the external section of the tube 19 imparts an H-section to the stem 11 that eases moulding and saves material without significantly compromising the strength of the clip 10.

Turning now to Figure 3 of the drawings, a cladding panel 20 of the invention comprises a substrate 21 to which slips I of Figure 1 are attached by clips 10 of Figures 2 (a) and 2 (b) and a continuous layer of waterproof adhesive (not shown). The substrate 21 can be of any suitable material (even concrete) but in the preferred embodiment illustrated comprises a two-layer backing board 22 of bitumenimpregnated fibre board 23 (such as is sold under the trade mark Bitroc) overlaid with compressed cement bonded particle (CP) board 24 (such as is sold under the trade

mark Viroc) attached to a framework of C-sectioned steel studs 25. The construction of the panel 20 is shown in more detail in the enlarged sectional view of Figure 4.

In a preferred method of constructing the cladding panel 20 of the invention, the slips 1 are arranged on the substrate and are fixed in their respective required positions with adhesive 26, preferably an adhesive layer already applied to the substrate (i. e. to the exposed face of the CP board 24 that forms a layer of the backing board 22).

Typically, the substrate 21 is laid horizontally, say on a factory floor, to facilitate laying the slips I in courses with appropriate gaps 27,28 left between the courses and between the slips 1 that define those courses. Once the desired arrangement of slips 1 has been achieved, a clip 10 is inserted into the gap 27 between adjacent courses of slips I with the stem 11 of the clip 10 facing the substrate 21 and the crosspiece 12 of the clip 10 aligned with the direction of the courses. The clip 10 is then slid in that orientation from the bottom faces 6 of adjacent slips I in a course toward the top faces 5 of the adjacent slips 1, with its stem 11 between the side faces 4 of the adjacent slips 1, such that the opposed tenons 13 of the clip 10 are received in respective mortises 7 of the adjacent slips 1.

When the tenons 13 reach the respective top ends of the mortises 7 and no further movement in that direction is possible, each clip 10 is fixed to the substrate 21 with a fastening 29 such as a self-drilling, self-tapping Tek screw (trade mark) that extends into the countersunk hole 17 in the clip 10, through the tube 19 at the centre of the stem 11, and into the substrate 21. It will be noted that the flat members 18 defining the stem 11 of the clip 10 bear against the opposed side faces 4 of the adjacent slips I and so resist twisting or other movement of the clip 10 while the clip 10 is being fastened or indeed afterwards, in use of the cladding panel 20.

When all the slips 1 of the cladding panel 20 have been retained in this way and so have a clip 10 in each mortise 7, the gaps 28 between the slips are filled with mortar to cover the clips 10 and emulate a traditionally built wall. It will be noted that, overall, just one clip 10 is needed for each slip 1.

In an alternative but currently less preferred method of construction, the clips 10 are fastened to the substrate 21 at the desired spacing before the slips I are engaged with the pre-attached clips 1. Figure 3 shows a cladding panel 20 being made by such a method. It will be noted that the clips 10 are staggered in intersecting diagonal arrays to impose a broken bond arrangement upon the slips 1 engaged with the clips 10.

The arrays of clips 10 intersect in such a way as to define vertical lines of clips 10 whose mutual spacing advantageously coincides with the spacing between studs 25 in the framework underlying the substrate 21. Thus, half of the clips 10 can be aligned with the studs 25 so that their screws or other fastenings 29 can extend into the studs 25 for better fixing strength against withdrawal loads. This is shown in the horizontal sectional view of Figure 5 of the drawings, and it will be appreciated that the screws 29 also help to hold both layers 23,24 of the backing board 22 on the studs 25. Figure 5 also shows how the other half of the clips 10 (i. e. those in intermediate vertical lines) are attached to the substrate 21 : in their case, there is no underlying stud 25, so instead a retainer 30 is used to engage the exposed end of the fastener 29 where it protrudes through the rear face of the backing board 22, namely through the surface of the Bitroc board 23 exposed between the studs 25 at the rear of the backing board 22.

The retainer 30 can also be seen in the rear perspective view of Figure 6 which omits the backing board 22 for clarity, individually in Figures 7 (a) and 7 (b), and in combination with a screw 29 in Figure 7 (c). The retainer 30 is simply a flat oblong 31 of metal having a central aperture 32 defined by opposed tabs 33 pressed out of the general plane of the oblong 31. The tabs 33 form resilient inwardly-and rearwardlyextending jaws that can be pressed in a ratchet-like, irreversible fashion onto the exposed thread of a screw 29 as shown in Figure 7 (c). The retainer 30 is therefore akin to a circlip in its operation and function. It is emphasised that the design of the retainer 30 is still under review and could take any form that provides sufficient resistance to shear.

Once the clips 10 are suitably positioned, the slips 1 are engaged with the clips 10 by aligning each slip 1 between a respective pair of adjacent clips 10 defining a course,

such that the slips I can slide parallel to the exposed face of the substrate 21 and between the stems 11 of the clips 10 while the tenons 13 of the respective clips 10 that face each other are received in the respective mortises 7 of the slips 1. It will be appreciated that this operation can be performed while the substrate 21 is horizontal, as before, but it can just as easily be performed when the substrate 21 is at or near to the vertical. In that case, the slips 1 are, in effect, 'hung'on the clips 10. That hanging relation also applies when the cladding panel 20 is upright in use on a building.

Figure 8 shows the completed cladding panel 20 from behind but omits the backing board 22 for the purposes of illustration, and shows the mortises 7 in dashed lines.

This Figure clearly shows the relationship between the clips 10, the slips 1, the mortises 7 and the studs 25, and also shows the retainers 30 used to fix clips 10 between studs 25.

This latter method of inter-engaging slips 1 and clips 10, that involves engaging slips 1 to a pre-attached array of clips 10, is currently less preferred because of the difficulties it presents in applying and maintaining an adhesive layer 26 at the interface between the rear face 3 of the slip 1 and the front face of the substrate 21.

Although described in relation to this latter method, it is emphasised that the drawings of the cladding panel 20 in Figures 3 to 8 are equally apt to show the general constructional arrangement achieved by the former method in which clips 10 are offered up to pre-positioned slips 1. In other words, the construction shown in those drawings is independent of the method by which that construction is achieved.

In all cases, the clips 10 prevent slips I from falling off a cladding panel 20 in use by providing an auxiliary fixing that holds the slips I to the substrate 21 even if the adhesive bond between the slip I and the substrate 21 should fail. To do so, the clips 10 present a barrier to movement of the slips I away from the substrate 21, by virtue of engagement between the tenons 13 and the mortises 7. This applies even if water gets behind the slips I and freezes: the clips 10 have some resilience that can accept movement of the slips 1 caused by the expansion of ice, without themselves breaking.

In similar fashion, the clips 10 can cater for some differential movement between the slips 1 and the substrate under normal thermal expansion and contraction. It is also

reiterated that the slips I are retained on the clips 10 partially by their own weight, by virtue of being, in effect, hung on the clips 10, even if all other means of support should fail.

Those skilled in the art will appreciate that apart from their structural duties, the clips 10 of the invention can also be used reliably and consistently to determine the positional relationship between the slips I as the cladding panel 20 is constructed.

Referring to Figure 9 of the drawings, this shows an end clip 40 for use at an end of a course of slips 1, where the T-shaped clip 10 of Figures 2 (a) and 2 (b) is not suitable for use as there is only one mortise 7 into which the clip 10 can be received. The end clip 40 of Figure 9 is of folded steel or moulded plastics in a squared C-section having a relatively short tenon arm 41 orthogonal to an intermediate web 42 that is in turn orthogonal to a relatively long securing leg 43 parallel to, but extending beyond, the first arm 41. The securing leg 43 has a hole near 44 its free end.

The tenon arm 41 of the C-section is adapted to fit snugly within the mortise 7 of a slip 1 at the end of a course while the intermediate web 42 of the C-section abuts the associated side face 4 of that slip 1. The securing leg 43 of the C-section loops around the back 3 of the slip 1 behind the backing board 22 and is attached to the rear of the backing board 22 by a screw 29 extending through the hole 44.

Another benefit of the invention is that it permits replacement of damaged slips 1 after the cladding panel 20 has been completed, even when the cladding panel 20 is in situ on a building. Mortar is removed from around a damaged slip 1 to access and remove the clips 10 that hold the slip 1 in place, enabling the slip I to be prised away from its substrate 21 and replaced. A fresh layer of adhesive 26 is applied to the rear face 3 of the replacement slip I which is then pressed into the space left by the removed slip 1, leaving a gap 27,28 around the slip I that enables clips 10 to be inserted into the mortises 7 of the replacement slip 1 as aforesaid, and fixed to the substrate 21. Finally, the gap 27,28 around the slip 1 is filled with mortar to blend in with the surrounding slips 1 and to conceal the clips 10. It must be noted that severe impact pressure would need to be asserted to the damaged slip 1 in order to remove it from the panel 20.

A second embodiment of the invention is shown in Figures 10 to 14. The Figures show a slip, clip and cladding panel which has many similarities in design to the slip 1, clip 10 and cladding panel 20 shown in Figures 1 to 9. Consequently, in the description that follows, like numerals will be used for like parts.

Starting with Figures 10 and 11, it will be noted that, as before, the slip 1 takes the form of a thin substantially solid cuboidal block defining six oblong faces including two major parallel opposing faces defining a front face 2 and a rear face 3. The four minor faces are divided into two opposed parallel pairs, one pair being side faces 4 and the other pair being a top face 5 and a bottom face 6. The top and bottom faces 5, 6 are plain and uninterrupted whereas the side faces 4 are interrupted by mortises 7.

As best shown in Figure 11, there is a pair of semi-circular mortises 7, each mortise 7 being set into a respective side face 4 of the slip 1, the mortise 7 being centrally located in the associated side face 4. Each mortise 7 extends within the slip 1 in a plane parallel to the major faces 2,3 and defines an oblong aperture 8 that bisects the side face 4 and extends approximately a quarter of the way along the side face 4. The mortises 7 can either be moulded or cut into the slip 1.

As before, it will be appreciated that the exact dimensions of the slip 1 and the mortises 7, and the location of the mortises 7 within the slip 1, may be tailored to suit particular applications and materials.

A clip 10 in accordance with the second embodiment of the invention is shown in Figures 12 (a), 12 (b), 12 (c) and 12 (d). Viewed from the side as shown in Figures 12 (b) and 12 (c), the clip 10 is substantially T-shaped having a stem 11 and a crosspiece 12, the stem 11 depending centrally and orthogonally from the crosspiece 12 and dividing the crosspiece 12 to define a pair of opposed tenons 13. In this embodiment, however, the crosspiece 13 is defined by a flat circular plate or disc 46 that lies in a plane orthogonal to the central longitudinal axis of the stem 11 and is divided into two semicircular tenons 13 by the stem 11. The plate 46 is penetrated by a central countersunk hole 17 that leads into the stem 11.

As in the first embodiment, the stem 11 is defined by a pair of parallel flat oblong members 18 whose major faces are orthogonal to the crosspiece 12. The members 18 defining the stem 11 are disposed symmetrically about the central longitudinal axis of the stem 11. While not shown in Figures 12 (a) to 12 (d), the members 18 defining the stem 11 may, like the previous embodiment, be integrally conjoined by a tube that is aligned with and leads to the countersunk hole 17 in the crosspiece 12.

As seen in Figure 12 (b), the members 18 defining the stem 11 have a width approximately one third of the diameter of the crosspiece 12.

Figure 13 shows a cladding panel 20 of the second embodiment that comprises a substrate 21 to which slips 1 of Figures 10 and 11 are attached by clips 10 of Figures 12 (a) to 12 (d). Although not shown, a continuous layer of waterproof adhesive may be included as before between the slips I and the substrate 21. The substrate 21 can be of any suitable material but in the embodiment illustrated comprises a single-layer backing board 22.

In a preferred method of constructing the cladding panel 20, a slip 1 is arranged on the substrate 21 and may be fixed in the required position with adhesive. Preferably an adhesive layer is already applied to the substrate 21, or adhesive may be applied to each individual slip 1 before it is arranged on the substrate 21. For ease of assembly, the substrate 21 is preferably laid horizontally, say on a factory floor, to facilitate laying the slips 1.

Once the slip 1 has been placed on the substrate 21 in the desired position, the semicircular tenon 13 of the crosspiece 12 of a clip 10 is inserted into a mortise 7 of the slip 1 whose aperture 8 will face the next slip 1 in the course. The direction of insertion is parallel to the face of the substrate 21 and toward the side face 4 of the slip 1. When the tenon 13 reaches the base of the mortise 7 and the stem 11 of the clip 10 bears against the side face 4 of the slip 1, no further movement in that direction is possible. The clip 10 is then fixed to the substrate 21 with a fastening 29 such as a

screw that extends into the countersunk hole 17 in the clip 10, between the flat members 18 defining the stem 11, and into the substrate 21.

The next slip 1 in the course is laid by locating within a mortise 7 of that slip 1 the exposed semicircular tenon 13 protruding from the side 4 of a slip 1 already fixed to the substrate 21 by a clip 10 as aforesaid. The newly laid slip I then lies against the substrate 21 which may or may not be coated in adhesive, and is located by fixing a second clip I in the opposite mortise 7 of the newly laid slip 1 as described above.

As with the first embodiment, the flat members 18 of the stem 11 of the clip 10 bear against the opposed side faces 4 of the adjacent slips I and so resist twisting or other movement of the clip 10 while the clip 10 is being fastened or indeed afterwards, in use of the cladding panel 20. Similarly, appropriate gaps 27,28 are left between the courses and between the slips 1 that define those courses. When all the slips I of the cladding panel 20 have been retained and so have a clip 10 in each mortise 7, the gaps 27,28 between the slips I are filled with mortar to cover the clips 10 and emulate a traditionally built wall.

Like Figure 6, Figure 14 shows the arrangement of a clip 10 within a mortise 7 in accordance with the second embodiment of the invention, including the screw 29 and a retainer 30 shown in Figure 7.

As correct orientation of the slip 1 is not necessary, i. e. the top and bottom faces 5,6 of the slip 1 are inter-changeable, this allows speedier construction of the cladding panel 20.

For the purposes of repairing damaged cladding panels 20 or otherwise altering cladding panels 20 by replacing slips 1, a variant of the second embodiment envisages clips 10 adapted to fit within the mortar joint between adjacent slips 1, which joint is typically as narrow as 10mm. Such clips 10 can have an elongate crosspiece 12 akin to that of the first embodiment, but no wider than the mortar joint, and a circular-section

stem 11 that allows the clip 10 to turn when it is situated in the mortar joint between adjacent slips 1. So, when the mortar has been cleared and a new slip 1 has been

located on the substrate, such clips 10 can be inserted into the gaps 27, 28 around the new slip 1 and turned, before or after fixing to the substrate 21, to engage the tenons 13 of the crosspiece 12 in the semi-circular mortises 7 of the adjacent slips 1.

The clip variant 10 shown in Figures 15 (a), 15 (b), 15 (c) and 15 (d) is broadly akin to the clip 10 of Figures 12 (a) to 12 (d) and again, like numerals are used for like parts.

Specifically, the clip variant 10 of Figures 15 (a) to 15 (d) is again substantially Tshaped having a crosspiece 12 and a stem 11 depending centrally and orthogonally from the crosspiece 12 to divide the crosspiece 12 into a pair of opposed semi-circular tenons 13. Those tenons 13, in turn, define a flat circular plate or disc 46 that lies in a plane orthogonal to the central longitudinal axis of the stem 11. Also, as before, a hole 17 penetrates the disc 46 and leads into, along and through the stem 11. However, in Figures 15 (a) to 15 (d), the stem 11 is simply a straight tube of circular cross-section.

As the orientation of the disc 46 with respect to the axis of the stem does not matter,

the flat-sided stem 11 of the preceding embodiments is less important. So, the circular-section stem 11 may be preferred as being cheaper and easier to mould.

Turning finally to Figure 16 of the drawings, a variant of the cladding panel 20 of the invention is of layered construction akin to that shown in Figures 3 to 5 in that the substrate 21 comprises a two-layer backing board 22 attached to a framework of Csectioned steel studs 25. As before, one of those layers-namely the outer layer in use, to which the slips I are attached-is CP board 24 (such as Vioc). However, in this variant, the bitumen-impregnated fibre board 23 (such as Bitroc) is replaced by a layer of rigid board insulation 48 such as polyurethane insulation sold under the trade marks Celotex Double R or Kooltherm K8, for example. That insulation lies between the CP board 24 and the studs 25 to insulate the frame made up of the studs 25, thus classing this variant as a'warm frame'system. The benefit of a'warm frame'system is that the steelwork of the frame is kept wann and protected by the insulation, allowing the user to apply any desired finish to the inside of the frame because it is protected from external weathering.

Many other variations are possible within the inventive concept. For example, the slip need not necessarily be moulded and its faces need not necessarily bear the same

finish. Thus, if the slip is moulded, it can be a composite of a moulded substrate material faced with a decorative material after moulding.

A mortise need not, geometrically-speaking, bisect a side face or a bottom face of a slip: it can be offset toward either of the major faces but preferably is offset toward the first major face, i. e. the decorative front face of the slip. This maximises the thickness of the slip that is engaged by the clip and that therefore resists separation of the clip from the substrate, to the benefit of the ultimate fixing strength. Clearly, in the embodiment illustrated, the stem of the clip must be of appropriate length to align the tenon with the mortise when the clip and the slip are mounted on the substrate.

In a broad view of the invention, slips do not have to be cuboidal or laid in straight parallel courses: they can be of any desired shape and can be disposed in any desired pattern, as may be dictated by the architectural design of the building for which the cladding panel is intended.

In view of these and other variations within the inventive concept, reference should be made to the appended claims and other conceptual statements herein rather than the foregoing specific description in determining the scope of the invention.

Claims (84)

1. A cladding system including a plurality of slips supported by a substrate, wherein each slip is engaged with at least one clip fixed to the substrate, the clip including a slip-engaging formation adapted to engage the slip to restrain movement of the slip away from the substrate.

2. The system of Claim 1, wherein each slip has at least one recess adapted to receive the slip-engaging formation of a clip.

3. The system of Claim 2, wherein the recess of a slip is a mortise and the slipengaging formation of a clip is a tenon.

4. The system of any preceding Claim, wherein the slips are hung on the clips.

5. The system of Claim 4 when appendant to Claim 2 or Claim 3, wherein the slips are hung on the clips by engagement of the slip-engaging formation in the recess.

6. The system of any preceding Claim, wherein a slip includes a front exposed face and at least one peripheral face facing a peripheral face of a neighbouring slip.

7. The system of Claim 6, wherein the mortise is set into the peripheral face of a slip.

8. The system of Claim 6 or Claim 7, wherein the front face of the slip is generally planar and the mortise lies in a plane substantially parallel thereto.

9. The system of any preceding Claim, wherein the slip is a cuboid and has four peripheral faces being side, top and bottom faces.

10. The system of Claim 9, wherein the mortise is set into a side face of the slip.

11. The system of Claim 10, wherein the mortise is also set into the bottom face of the slip.

12. The system of Claim 11, wherein the mortise extends from the bottom face of the slip part way up the side face toward the top face, defining an aperture that extends around the comer intersection between the bottom face and the side face.

13. The system of Claim 10, wherein the mortise defines an oblong aperture that extends part way along the side face.

14. The system of Claim 14, wherein the mortise is semi-circular in longitudinal section.

15. The system of any of Claims 10 to 14, wherein there are two mortises, one mortise being associated with each side face of the slip.

16. The system of any preceding Claim, wherein the clip includes a spacer that spaces the slip-engaging formation of the clip from the substrate.

17. The system of Claim 16, wherein the spacer of the clip is a stem extending from the substrate to the slip-engaging formation.

18. The system of any preceding Claim, wherein there is a gap between adjacent peripheral faces of neighbouring slips.

19. The system of Claim 18 wherein a portion of a clip is accommodated in the gap.

20. The system of Claim 18 or Claim 19, wherein the gap is filled with mortar.

21. The system of Claim 20 when appendant to Claim 19, wherein the mortar conceals the portion of the clip accommodated in the gap.

22. The system of any of Claims 18 to 21 when appendant to Claim 17, wherein the stem is dimensioned to fit in a gap between slips.

23. The system of Claim 22, wherein the stem has a transverse cross-section that defines at least one flat adapted to bear against a side face of a slip in use.

24. The system of any of Claims 18 to 23, wherein the or each slip-engaging formation of the clip is dimensioned to fit in a gap between slips.

25. The system of any preceding Claim, wherein the clip has at least two slip-engaging formations.

26. The system of Claim 25, wherein two opposed slip-engaging formations are situated on and symmetrically disposed about the stem, and the clip is generally Tshaped.

27. The system of Claim 26, wherein the slip-engaging formations are generally semicircular.

28. The system of Claim 27 when directly or indirectly appendant to Claim 17, wherein the stem is of circular cross-section.

29. The system of any preceding Claim, wherein the clip is separate from and attached to the substrate.

30. The system of Claim 29 wherein the clip is attached to the substrate by a fastening extending through the clip and into the substrate.

31. The system of Claim 30 when appendant to Claim 17, wherein the fastening extends along the stem of the clip.

32. The system of Claim 30 or Claim 31 when appendant to Claim 18, wherein the fastening extends through the clip into the substrate and is accessible via the gap between adjacent slips.

33. The system of any of Claims 30 to 32 wherein the substrate comprises a framework of studs and at least some fastenings extend into the studs.

34. The system of any preceding Claim, wherein the clip is resilient to permit limited movement of the slips with respect to the substrate.

35. The system of any preceding Claim, wherein the slips are also attached to the substrate by an adhesive.

36. The system of Claim 35, wherein the adhesive is a continuous layer between the slips and the substrate.

37. The system of any preceding Claim, wherein the substrate comprises a framework.

38. The system of Claim 37, wherein a backing board is attached to the framework and supports the slips.

39. The system of Claim 38, wherein the backing board has a plurality of layers.

40. The system of Claim 38 or Claim 39, wherein the backing board comprises a layer of insulation between the slips and the framework.

41. A method of constructing a cladding system comprising applying a plurality of slips to a supporting substrate in a desired pattern, engaging each slip with at least one clip having a slip-engaging formation adapted to engage the slip and to restrain movement of the slip away from the substrate, and fixing the clip to the substrate.

42. The method of Claim 41, wherein the clip is inserted into and moved along a gap between adjacent slips before being fixed to the substrate.

43. The method of Claim 42, wherein the slip-engaging formation of the clip engages the slip during said movement of the clip.

44. The method of Claim 42 or Claim 43, wherein the slips define bottom and top faces and the clip is slid from the bottom face toward the top face during said movement along the gap.

45. The method of any of Claims 41 to 44, wherein the slips are applied to the supporting substrate in parallel courses and the clip is inserted into a gap between adjacent courses before being moved along a gap between adjacent slips in a course.

46. A method of constructing a cladding system comprising applying a plurality of slips to a supporting substrate in a desired pattern while engaging each slip with at least one clip fixed to the substrate, the clip having a slip-engaging formation adapted to engage the slip and restrain movement of the slip away from the substrate.

47. The method of Claim 46, further including the preliminary step of fixing the clips to the substrate in positions defining the desired pattern of the slips.

48. A method of constructing a cladding system comprising applying a slip to a supporting substrate in a desired location, engaging the slip with at least one clip having a slip-engaging formation adapted to engage the slip and to restrain movement of the slip away from the substrate, and fixing the clip to the substrate.

49. A method of Claim 48, comprising applying a further slip to the supporting substrate in a desired location by engaging the further slip with the slip-engaging formation of a fixed clip, engaging the further slip with a second clip having a slipengaging formation, and fixing the second clip to the substrate.

50. The method of any of Claims 41 to 49, wherein the slips are hung on the clips.

51. The method of any of Claims 41 to 50, wherein the clips are fixed to the substrate by fastenings that extend through the clips into the substrate and that are accessible via gaps between adjacent slips.

52. The method of any of Claims 41 to 51, wherein the substrate comprises a framework of studs and at least some fastenings extend into the studs.

53. The method of any of Claims 41 to 52, wherein mortar is applied to fill the gaps between slips and to conceal the clips.

54. A slip for use in the cladding system of Claims 1 to 40 in which the slip is supported by a substrate and restrained by a clip against movement away from the substrate, the slip comprising at least one recess adapted to receive a slip-engaging formation of a clip fixed to the substrate.

55. The slip of Claim 54, wherein the recess is a mortise.

56. The slip of Claim 55, wherein the mortise is set into a peripheral face of a slip.

57. The slip of Claim 55 or Claim 56, wherein a front face of the slip is generally planar and the mortise lies in a plane substantially parallel thereto.

58. The slip of any of Claims 54 to 57, wherein the slip is a cuboid and has four peripheral faces being side, top and bottom faces.

59. The slip of Claim 58 when appendant to Claim 55, wherein the mortise is set into a side face of the slip.

60. The slip of Claim 59, wherein the mortise is also set into the bottom face of the slip.

61. The slip of any of Claims 58 to 60, wherein the mortise extends from the bottom face of the slip part way up the side face toward the top face, defining an aperture that extends around the comer intersection between the bottom face and the side face.

62. The slip of any of Claims 58 to 60, wherein the mortise defines an oblong aperture that extends part way along the side face.

63. The slip of Claim 62, wherein the mortise is semi-circular in longitudinal section.

64. The slip of any of Claims 58 to 63, wherein there are two mortises, one mortise being associated with each side face of the slip.

65. A clip for use in the cladding system of Claims 1 to 40 and being adapted to restrain a slip against movement away from a substrate, the clip being attachable to the substrate and comprising a slip-engaging formation adapted to engage the slip to restrain movement of the slip away from the substrate.

66. The clip of Claim 65, further including a spacer that spaces the slip-engaging formation of the clip from the substrate.

67. The clip of Claim 66, wherein the spacer is a stem for extending in use from the substrate to the slip-engaging formation.

68. The clip of Claim 67, wherein the stem has a transverse cross-section that defines at least one flat adapted to bear against a side face of a slip in use.

69. The clip of any of Claims 65 to 68, wherein the clip has at least two slip-engaging formations.

70. The clip of Claim 69, wherein two opposed slip-engaging formations are situated on and symmetrically disposed about the stem, and the clip is generally T-shaped.

71. The clip of Claim 70, wherein the slip-engaging formations are generally semicircular.

72. The clip of any of Claims 65 to 71, wherein the clip is attachable to the substrate by a fastening extending through the clip and into the substrate.

73. The clip of Claim 72 when appendant to Claim 67, wherein the fastening extends along the stem of the clip.

74. The clip of any of Claims 65 to 73, and being resilient to permit limited movement of the slips with respect to the substrate.

75. A slip substantially as hereinbefore described with reference to or as illustrated in Figure 1 of the drawings.

76. A slip substantially as hereinbefore described with reference to or as illustrated in Figure 10 or Figure 11 of the drawings.

77. A clip substantially as hereinbefore described with reference to or as illustrated in Figures 2 (a) and 2 (b) of the drawings.

78. A clip substantially as hereinbefore described with reference to or as illustrated in Figure 9 of the drawings.

79. A clip substantially as hereinbefore described with reference to or as illustrated in Figures 12 (a), 12 (b), 12 (c) or 12 (d) of the drawings.

80. A clip substantially as hereinbefore described with reference to or as illustrated in Figures 15 (a), 15 (b), 15 (c) or 15 (d) of the drawings.

81. A cladding system substantially as hereinbefore described with reference to or as illustrated in Figures 3, 4, 5 or 8 of the drawings.

82. A cladding system substantially as hereinbefore described with reference to or as illustrated in Figure 13 of the drawings.

83. A cladding system substantially as hereinbefore described with reference to or as illustrated in Figure 16 of the drawings.

84. A method of constructing a cladding system, substantially as hereinbefore described.