GB2371314A - Wall cladding system - Google Patents

Abstract

A system comprises a panel (10) having at least one projection (30), and at least one brick slip (12) having a grooved or recessed rear face (46), where in use, the panel projection locates in the recess to support the brick slip. The projections may also be directed upward so that in order to remove a slip from the panel it is necessary to lift the slip. Preferably a plurality of courses of slips are mounted on each panel and adjacent panel members are joined together by means of interlocking male and female parts (16, 18). Also disclosed is a brick slip which is moulded from a clay based composition and method of manufacturing brick slips by extrusion.

Description

WALL CLADDING SYSTEM This invention relates to a wall cladding system using brick elements, to brick elements for use in wall cladding systems and to a method for the manufacture of brick slips.

It is well-known to use brick slips for the cladding of interior or exterior 1 walls so as to produce a brick finish for decorative or aesthetic reasons and for durability. In combination with a cast concrete backing or substrate, a brick slip cladding may also afford a load-bearing capability.

Brick slips are typically slices of bricks taken from the outer faces thereof, usually the major outer faces, so that one and at most two, slips are obtained from each brick. Brick slips are usually manufactured by producing a conventionally dimensioned brick and then cutting one or more slips from the brick. The remnant brick core may then be broken up, e. g. for aggregate or hardcore.

One known cladding system is disclosed in European Patent No. 275360 (Eurobrick Systems Limited, UK) and involves pressing brick slips onto preformed plastics panels so that they are retained as a friction fit within spaced, raised, channelforming sections of the panel. The slips are glued to the backing panel and, in practice, due to variations in slip dimensions resulting from manufacturing tolerances, the reliability of the friction fit can be variable to the extent that often the slips are held in place solely by the adhesive.

The present invention seeks to provide inter alia an improved cladding system in which brick slips are reliably retained in position even in the event of failure of an adhesive used.

According to one aspect of the present invention there is provided a cladding system comprising a panel for attachment to a wall surface and at least one brick slip having a main front face and a recessed or grooved rear face, the panel being provided with at least one forwardly directed projection for reception within the recess of the brick slip so as to allow the brick slip to be supported in depending relation from the projection.

Although the cladding system will usually be used for cladding of vertical walls, it will be appreciated that the system may be used for walls which are not necessarily vertical.

Typically a cladding system according to the invention will provide a walled appearance corresponding in appearance to that of a normal brick wall and the brick slips will usually be dimensioned in accordance with the standard length and width dimensions of standard bricks as used in the UK building industry. Typically the nominal length of the slip is of the order of 215 mm and its nominal height (when used as a stretcher) is of the order of 65 mm, although it will be understood that there may be small variations due to the nature of the material and the kilning process. For some applications, the slip "height"may be a multiple of 65 mm plus an appropriate allowance of about 10 nun for each joint so for a slip corresponding in height to a pair of"standard"bricks, the height may be 140 mm (viz. 2x 65 mm + 10 mm joint allowance).

The system typically comprises a plurality of substantially identically configured brick slips and each panel is dimensioned so as to support two or more brick slips.

The panel may be provided with more than one projection so that a single panel may be used to support a plurality of courses of brick slips.

The projections may project forwardly and upwardly from the panel and co operate with a substantially correspondingly inclined surface associated with the groove or recess at the rear face of the brick slip whereby gravity assists in retaining the brick slips engaged with the panels. However, we do not exclude the possibility of the projections and the grooves/recesses of the brick slips being otherwise configured so as to utilise gravity to retain the brick slips engaged with the panels, i. e. so that the brick slips have to be physically lifted in order to effect disengagement from the panels.

Thus, the brick slips may be coupled to the panel by means which result in or require a lifting action in order to disengage the brick slips from the panels. Such means may be configured as intergageable male and female portions, with the male portions being provided on the panels and the female portions on the brick slips, or vice versa.

For instance, the projections associated with the panels need not project upwardly ; instead they may project generally horizontally and be provided with a lateral portion for reception in a concavity associated with the recessed or grooved rear faces of the brick slips so that disengagement of the brick slips from the panel involves a lifting action.

The panels may all be of substantially the same configuration and dimensions and they may be arranged to interengage edgewise with each other. To this end, each panel may have at one edge thereof a female formation and at the opposite edge a male formation so that they may be arranged in generally coplanar relation with the female and male formations of adjacent panels interengaged.

According to a second aspect of the present invention, a brick slip for use in a wall cladding system is moulded with a main front face and a profiled rear face

which allows the brick slip to be attached in depending relation from a surface to be clad with its main front face presented outwardly.

The brick slips may be handmade or pressed products. However, they may with advantage be moulded from a clay-based composition suitable for extrusion. The composition may include additives (e. g. a natural additive such as sand or chemical additives) to assist in the manufacturing process and/or for the purposes of final appearance.

The profiling may include a groove or recess.

The groove or recess may extend lengthwise of the brick slip, e. g. in the case of slips which are to be used as"stretchers".

The groove or recess may extend generally transversely of the slip length, as where the slips are to be used as"soldiers".

The groove or recess may include an inclined surface or other formation such that, when engaged with a projection of the cladding system, disengagement of the brick slip from the projection involves or requires a lifting action.

The brick slip may be produced by extrusion moulding.

I In one embodiment of the invention, the rear face may have a profile including a recess, one side wall of which is configured to allow the brick slip to be hung from an upwardly directed projection provided on the surface to be clad in such a way that the brick slip can only be dislodged by displacing it upwardly.

Another aspect of the invention is concerned with a novel process for the production of brick slips, which may reduce the extent of wastage of the brick-making materials.

Thus, while we do not exclude the possibility of manufacturing by extrusion and cutting the extrusion into single slips, according to this aspect of the present invention there is provided a method of manufacturing brick slips in which a clay composition is extruded to form an extrusion comprising at least two brick slips and in which the extrusion is subsequently separated to provide two or more brick slips.

The extrusion typically has a profile corresponding to two or more brick slips which are united by sacrificial sections of the extruded material which can be readily broken or fractured to separate the slips from one another.

The sacrificial sections may be sufficiently robust to retain the extruded profile during post-extrusion processing thereof. Such post-extrusion steps may include severing of the extrusion into lengths corresponding to appropriate brick lengths, moisture removal under conditions controlling shrinkage of the extrusion material and high temperature firing of the extrusions, e. g. in a kiln. In practice, it will be understood that the brick slips will be severed to oversize lengths to allow for subsequent shrinkage to"standard"length following the drying and firing stages.

Each brick slip within the extrusion is typically of right parallelepiped configuration having a front face, side faces and a rear face, the rear face being formed with at least one groove or recess. The front (fair) face will carry the desired aesthetic appearance as this is the face that will be seen in the finished cladding system.

The sacrificial elements which unite the slips may be located between the side faces and/or the rear faces of adjacent slips.

The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is an end view of a backing panel forming part of one embodiment of a system in accordance with the invention; Figure lA is an enlarged view showing the edgewise interlocking of adjacent backing panels; Figure 2 is a side view of the system showing a number of brick slips supported on the backing; Figures 3A to D are cross-sectional views of different slip configurations for the production of stretcher slips; Figures 4A to C illustrate different multi-slip extrusions; Figure 5 is a view similar to that of Figure 2 but showing a slip design for use as a "soldier'" Figure 6 is a view showing a extrusion as used in the production of soldier slips; Figures 7A and 7B are perspective views showing two methods of interconnecting a pair of backing panels located end to end; Figures 8 and 9 are horizontal and/or vertical sectional views showing different forms of comer pieces for returns ;

Figures 10 and 11 are side views showing an upper cover profile for completing the uppermost part of the system, e. g. adjacent a soffit ; Figure 12 is a horizontal sectional view showing a comer piece for use in concealing the junction between two clad walls of a structure; and Figures 13A and 13B illustrate diagrammatically further modifications for the coupling of the brick slips to the backing panels.

Referring to Figures I and 2, the basic elements of a typical cladding system in accordance with the present invention comprise elongated backing panels 10 and brick slips 12, the axis of elongation of both the panels 10 and the slips being normal to the plane of the paper as seen in Figures 1 and 2. In the illustrated embodiment, the backing panels 10 are relatively narrow in the vertical direction (widthwise) and are designed to support two rows of brick slips 12 in well-defined spaced relation so as to leave a gap 14 of substantially constant width for receiving mortar other joint filler (not shown). It will be appreciated however that the width of the panels 10 may be increased or reduced so as to support more or less than two rows of brick slips. In use, the panels 10 are affixed by fasteners and/or a suitable adhesive to a substrate to be clad with the panels aligned in end to end relation in the horizontal direction and located one above the other in the vertical direction. The substrate may for instance be a solid structure such as a wall built using bricks or thermal blocks or it may be fabricated from structural framing members.

The panels are arranged to be interconnected in edgewise relation one above the other and this may be implemented by means of interengaging formations 16,18 (see Figure ira). The formations may interengage in such a way that a shoulder 20 on the male formation 16 abuts edge surface 22 of the female formation 18 so that the upper extremity 24 of the male formation 16 terminates short of the base 26 of the female

formation thereby leaving a small clearance to ensure that there is a consistent location of vertically adjacent panels.

For each course of brick slips to be supported by a panel 10, a rail 30 is provided which projects forwardly from the backing panel, there being two such rails 30 on each panel 10 in the illustrated embodiment. The rails 30 extend lengthwise of, and preferably continuously along, the panel so that when the panel is affixed to the substrate to be clad, the rails are aligned end to end and extend generally horizontally in parallel relation with each other. The rails allow the brick slips in each course to be adjusted in the horizontal direction by sliding to secure substantially uniform gaps between adjacent slips 12 before the gaps are filled to produce"joints"between the slips. In the illustrated embodiment, the rails 30 are so designed that they project both forwardly and upwardly but, as explained below, other configurations are possible. The positioning of the rails 30 is such that the courses of brick slips are supported with substantially uniform horizontal gaps between adjacent courses of brick slips over the full height of the cladding system. In particular, when vertical adjacent panels are assembled one above the other with the formations 16,18 correctly engaged, the rails 30 are substantially uniformly spaced apart from one panel to the next.

Below each rail 30, the panel 10 is provided with a relatively shallow groove 32 to facilitate accurate location of fasteners (not shown) for securing the panels to the substrate, the spacing between the grooves 32 and the adjacent rails 30 being sufficient to accommodate a variety of fasteners, including wide headed fasteners and washers, depending on the nature of the substrate to which the panels are to be affixed.

The grooves 32 are also located with regard to the positioning of the fasteners relative to the slips 12, as explained below. The panels 10 are provided with roughened regions 34, 36 and raised sections 38 extending longitudinally of the panels at strategic locations in relation to the rails 30. The roughened regions 34,36 serve to assist mechanical

bonding when using adhesive to secure the slips 12 to the panel. The regions 34, 36 are conveniently produced by forming the panels 10 with lengthwise grooves or serrations with the advantage that the serration facilitates trimming of the panels in the widthwise direction by providing a cut or snap line or lines when a reduced width panel is needed.

Figure 2 illustrates the assembly of the brick slips to each panel 10. In particular, Figure 2 shows the lower extremity of the cladding system where a bosom strip 40 is interlocked with the lowest panel 10 using male and female formations 16,18 corresponding to those used to couple adjacent panels 10 as in Figure 1. In this embodiment (see Figure 3A also), each brick slip 12 forms a stretcher and comprises a main front face 42 and a contoured rear face 44 formed with a channel 46 with one side wall 48 which is of re-entrant form and an opposite side wall 50 which is substantially perpendicular to the front face 42. The re-entrant side wall 48 is intended to co-operate with the rails 30 so that the slip can in effect be hung from the rail in the manner illustrated in Figure 2 thereby using gravity to resist dislodgement of the slip when so located. The arrangement is such that when the slips 12 are assembled in this way, the zones 52,54 on either side of the channel 46 engage the panel at the locations of the roughened regions 34, 36 with the raised section 38 located between the longitudinal edge surfaces of vertically adjacent slips.

Prior to assembling the slips to the panels, adhesive is applied to the roughened regions 34, 36, e. g. by means of an applicator gun so that, after assembly, in addition to being supported by the rails 30, the bricks are also bonded to the panels by the adhesive. The raised sections 38 serve as a guide during adhesive application so that adhesive application can be limited to the roughened regions thereby economising on adhesive usage. When the slips are assembled to the panels, it will be seen that the grooves 32 register with the channels 46 so that the fasteners are concealed within the channels. Also, at the junction between vertically adjacent panels (or, as illustrated in

Figure 2 between the lowest panel 10 and the bottom strip 40), the joint provided by formations 16, 18 is also accommodated within the channel 46 as the arrangement is such that the joint is bridged by a course of brick slips.

The bottom strip 40 is provided with a groove 32 and optionally a roughened region 34 for the same purposes as those provided on the panels 10. In addition, the bottom strip 40 is provided with a ledge 56 which may be downwardly sloped to serve as a drip to prevent water accumulation at that point. The panels 10 and the bottom strips 40 may be produced as plastics moulding, e. g. from recycled PVC.

If desired, both side walls 48,50 of the channel 46 may be of re-entrant form to allow the brick slip to be assembled to the panels 10 in either of two orientations.

However, if both are made re-entrant there could be a risk of water collecting on the lowermost re-entrant side wall. To prevent this, one side wall may be re-entrant for cooperation with the rails 30 while the other may have a slope which is not re-entrant so as to facilitate drainage of any water that penetrates into the channels 46.

Typically, in use, the cladding process commences by securing the bottom strip 40 by screw, nail or other fixing, to the substrate material to form a horizontal datum for the panels 10. Whilst the bottom strip 40 may be a plastics moulding, it may with advantage be of a rigid, non-corrosive material such as stainless steel or aluminium to avoid any deviation or sagging during setting out. The bottom strip 40 will usually be fixed at a point above ground level corresponding to a normal horizontal damp proof course position.

Following fixture of the bottom strip, the panels 10 are assembled above the bottom strip with the formations 16,18 interlocked, the panels 10 being affixed to the substrate as appropriate. Adhesive is applied, eg. by gun application, to the roughened

zones 34, 36 in continuous strips. Brick slips are then attached course by course, in the desired bonding pattern, with each slip resting on a rail 30 and in contact with the applied adhesive so that, when the latter sets, the slips are firmly bonded in position.

During attachment of the slips, it will be appreciated that the spacing between successive courses is automatically determined by the locations of the rails 30 while the spacing between adjacent stretchers can be adjusted appropriately by virtue of the fact that the slips can slide along the rails in the horizontal direction. After attachment of the slips to the panelling structure formed by panels 10, the gaps between adjacent courses and stretchers can be filled by mortar or like pointing material which may be applied by gun or a traditional method such as trowel application to provide the final finish.

Figures 3A to 3D illustrate a number of possible configurations for the rear face of the brick slips 12. That of Figure 3A corresponds to the brick slip employed in Figure 2 but illustrates the possibility of varying the slope of the re-entrant side wall 48 (e. g. as depicted by numeral 48A). In practice, the angle of the slope is not critical and may be selected with regard to the need to avoid unintentional dislodgement. Figure 3B illustrates a modification in which, instead of the channel 46, the rear face 44 of the slip is formed with an inclined groove 60 for reception of a rail 30. Although not illustrated, the slip of Figure 3B may be modified to incorporate a shallow channel at its rear face to accommodate standard fixing or fasteners if necessary.

I Figures 3C and 3D illustrate alternative slip designs which are of generally E-shaped configuration. The designs of Figures 3B to D are intended for use in situations where the panels 10 are secured to the substrate in such a way that the heads of fasteners (if any) used are shallow and do not unduly affect location of the slips 12, or alternatively where the panels are secured to the substrate by a suitable adhesive or by way of

fasteners which are countersunk into the panels. The central projection of the E-shape affords an additional bearing surface for contact with the panel 10.

A feature of the invention is that the brick slips 12 may be produced by extrusion techniques, e. g. from materials conventionally used in the production of bricks.

The extrusion while still in the green state can then be cut to appropriate brick lengths, e. g. by means of wire, before further processing of the bricks by way of moisture removal using for instance hot air and temperature control, typically in the range of 150 to 180oC, in such a way as to control brick shrinkage followed by firing in a kiln (e. g. at a temperature of the order of 1000 C) to secure strength, durability and colouration.

If required, while still in the green state and before or after the drying step, those faces of the slips which will ultimately be the front faces (and optionally the side faces) may be treated to impart a desired surface finish. For instance, they may have a surface texture or colouring agent applied to such faces, e. g. by spraying liquid pigment or by the application of sand which may be stained, to give a desired appearance in the end product.

The brick slips may be produced as compound extrusions in which two or more slips are produced as a single extrusion. Three such multiple extrusions are illustrated in Figures 4A to 4C. In each case, the individual brick slips 12 are joined to their neighbours by sacrificial elements 62 which serve to interconnect and maintain the multiply-extruded slips as a unit so as to retain shape through the cutting to length,

drying and firing stages of manufacture. Following production in this way, the individual slips can then be separated from each other by snapping them apart at the location of the sacrificial elements 62. Figure 4C illustrates the simultaneous production of more than one extrusion from which it will be seen that those faces which will ultimately comprise the front and side faces of the slips may be readily subjected to any desired surface treatment prior to separation of the slips from one another.

Figures 5 and 6 illustrate the use and production of "soldier" type brick slips 64 for use with the same panels 10 as used for the stretcher slips. As seen in Figure 5, the slips are elongated (standard brick length) in the vertical direction and have a contoured rear face including a transversely extending recess with re-entrant side wall 66 corresponding to the re-entrant side walls 48 of the stretcher slips 12. If necessary, to afford increased stability over the length of the soldier slips, the rear face may include intermediate projections 68 which seat against, and may optionally be glued or otherwise adhered to, the panels 10. In the case where the panels 10 are designed to mount two courses of stretcher slips, a single soldier slip 64 may span the upper and lower joints 16, 18 associated with a panel 10 so that a pair of soldier slips effectively span the width of three panels 10.

The soldier slips 64 may also be manufactured as extrusions, e. g. multiple slip extrusions, in the manner described above. As shown in Figure 6, the extrusion profile is one incorporating a single soldier slip 64 united with a sacrificial base 69 and sacrificial interconnections 70. The purpose of the base 68 is to ensure that the slip profile is maintained throughout the various stages of the manufacturing process.

Following manufacture, the slip may be broken away from the sacrificial base which is then disposed of.

Figures 7A and 7B illustrate alternative endwise arrangements of the panels 10. In Figure 7A, the panels are butted end to end and secured together by means of an adhesive strip 72. In Figure 7B, they are located end to end but in spaced relation to each other using a flexible jointing element 74 so as to accommodate movement.

Referring to Figure 8, this illustrates the use of a vertically elongated comer piece 76 for use at the location of a return in the substrate structure, e. g. at the location of a window opening. The comer piece includes a facing section 80 for attachment to the

substrate in endwise relation to the panels 10 and a return section 82 which overlies the return surface 84 (which extends vertically into the plane of the paper as seen in Figure 8). The section 82 may be formed with a series of serrations on its rear surface to assist cutting or snapping to a length appropriate to the horizontal width of the return. A sealant 88 may be applied at the junction between the inner edge of the return section 82 and the adjacent window or like frame 90. The comer piece 76 also includes a cover portion 92 for concealing the ends of the brick slips and comprises a forwardly projecting section 96 and an overlapping section 98 for this purpose. The end face of the section 98 may be rebated as illustrated for introduction of a sealant at that point.

A modified form of comer piece 76A is shown in Figure 9 in which the front faces of the return section 82A and the forward section 96A are provided with profiling, e. g. for aesthetic purposes, and in which the overlapping section 98A is of a different contour to assist retention of the adjacent slips. In this case, the overlapping section 98A is spaced from the slips except for a terminal portion 100 which bears against the adjacent slips. The comer piece of Figure 9 may also be used for horizontal surfaces, e. g. the horizontal surface above a window opening, in which case, the projections on the front faces of the return section 82A and the forward section 96A may function as drip profiles.

Figures 10 and 11 illustrate termination of the cladding system at the location of the soffit 102 of a building structure. The uppermost panels 10 are trimmed to a suitable length and any gap between the top of the uppermost course of stretcher slips 12 and the soffit above is bridged by a capping piece or pieces 104 which can be adjusted upwardly/downwardly as indicated by the arrows in Figure 10 to accommodate the size of the gap. The capping piece 104 includes a rear wall 106 and a front wall 108 interconnected by top wall 110 which is sufficiently wide to accommodate the depth of the slips 12 and the panel 10 as the capping piece 104 may be assembled with its rear

wall 106 interposed between the panel 10 and the substrate. As illustrated, the rear wall 106 is formed with serrations to facilitate cutting or snapping to length. If desired, the capping piece may be produced with a longer front wall 104 than that illustrated (and the rear wall may also be shorter than the front wall) with the intention that it may be trimmed to length according to requirements. To this end, the front wall may be formed with serrations or the like to assist cutting/snapping to length.

Figure 12 illustrates the use of a vertically extending comer piece 120 at the junction between two walls which have been clad using a cladding system such as that described with reference to Figures 1 to 3. The exposed ends of the slips 12 are concealed by the comer piece 120 which includes a pair of rear walls 122 which seat against the substrate walls and front walls 124 which are spaced from the rear walls to the extent necessary for reception of the slips as illustrated, the front walls being joined to the rear walls by a central web 126. When fitted in place, it will be seen that the front walls 124 overlap and thereby conceal the ends of the slips 12.

The various components used to finish the corners, returns and upper parts of the cladding structure, namely the components of Figures 8 to 12, may all be produced as plastics mouldings, e. g. from recycled PVC.

In the embodiments described above, the brick slips are retained on the panels 10 with the aid of gravity as a result of the upward slope on the rails 30 and the inclined surfaces 48. However, other ways of utilising gravity to assist the retention of the brick slips on the panels are possible. Figures 13A and 13B by way of example only illustrate alternative methods in which the rails 30 need not necessarily slope upwardly but where the arrangement is such that disengagement of the slips from the vertically orientated panels involves or requires a lifting action. In this manner, even if the adhesive fails for any reason, the slips will not readily become dislodged from the backing panels,

especially when the "'joints" between adjacent courses of stretcher slips have been filled with mortar or other filler material.

It will be appreciated that certain features of the invention which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

Claims (29)

1. A cladding system comprising a panel for attachment to a wall surface and at least one brick slip having a main front face and a recessed or grooved rear face, the panel being provided with at least one forwardly directed projection for reception within the recess of the brick slip so as to allow the brick slip to be supported in depending relation from the projection.

2. A system as claimed in Claim 1 in which the nominal length of the slip is of the order of 215 mm and its nominal height (when used as a stretcher) is of the order of 65 mm or a multiple of 65 mm plus an appropriate allowance of about 10 mm for each joint.

3. A system as claimed in Claim 1 or 2 comprising a plurality of substantially identically configured brick slips, each panel being dimensioned so as to support two or more brick slips.

4. A system as claimed in any one of the preceding claims in which the panel is provided with more than one projection so that a single panel may be used to support a plurality of courses of brick slips.

5. A system as claimed in Claim 4 in which the projections project forwardly and upwardly from the panel and co-operate with a substantially correspondingly inclined surface associated with the groove or recess at the rear face of the brick slip whereby gravity assists in retaining the brick slips engaged with the panels.

6. A system as claimed in any one of Claims I to 4, the brick slip or slips being coupled to the panel by means which result in or require a lifting action in order to disengage the brick slip (s) from the panels.

7. A system as claimed in Claim 6, such means being configured as interengageable male and female portions, with the male portions being provided on the panels and the female portions on the brick slips, or vice versa.

8. A system as claimed in any one of Claims I to 4 in which the projections associated with the panels are provided with a lateral portion for reception in a concavity associated with the recessed or grooved rear faces of the brick slip (s) so that disengagement of the brick slip (s) from the panel involves a lifting action.

9. A system as claimed in any one ofthe preceding claims including a plurality of panels all of substantially the same configuration.

10. A system as claimed in Claim 9 in which the panels are arranged to interengage edgewise with each other.

11. A system as claimed in Claim 10 in which each panel has at one edge thereof a female formation and at the opposite edge a male formation so that they may be arranged in generally coplanar relation with the female and male formations of adjacent panels interengaged.

12. A brick slip for use in a wall cladding system moulded with a main front face and a profiled rear face which allows the brick slip to be attached in depending relation from a surface to be clad with its main front face presented outwardly.

13. A brick slip as claimed in Claim 12 moulded from a clay-based composition suitable for extrusion.

14. A brick slip as claimed in 13 in which the composition includes an additive or additives (e. g. a natural additive such as sand or chemical additives) to assist in the manufacturing process and/or for the purposes of final appearance.

15. A brick slip as claimed in any one of Claims 12 to 14 in which the profiling includes a groove or recess.

16. A brick slip as claimed in Claim 15 in which the groove or recess extends lengthwise of the brick slip.

17. A brick slip as claimed in Claim 15 in which the groove or recess extends generally transversely of the slip length.

18. A brick slip as claimed in Claim 15,16 or 17 in which the groove or recess includes an inclined surface or other formation such that, when engaged with a projection of the cladding system, disengagement of the brick slip from the projection involves or requires a lifting action.

19. A brick slip as claimed in any one of Claims 12 to 18 in which the rear face has a profile including a recess, one side wall of which is configured to allow the brick slip to be hung from an upwardly directed projection provided on the surface to be clad in such a way that the brick slip can only be dislodged by displacing it upwardly.

20. A brick slip as claimed in any one of Claims 12 to 18 in which the nominal length of the slip is of the order of 215 mm and its nominal height (when used as a

stretcher) is of the order of 65 mm or a multiple of 65 mm plus an appropriate allowance of about 10 mm for each joint.

21. A system as claimed in any one of Claims I to 11 in which the or each brick slip is as claimed in any one of Claims 12 to 20.

22. A method of manufacturing brick slips in which a clay composition is extruded to form an extrusion comprising at least two brick slips and in which the extrusion is subsequently separated to provide two or more brick slips.

23. A method as claimed in Claim 22 in which the extrusion has a profile corresponding to two or more brick slips which are united by sacrificial sections of the extruded material which can be readily broken or fractured to separate the slips from one another.

24. A method as claimed in Claim 23 in which the sacrificial sections are sufficiently robust to retain the extruded profile during post-extrusion processing thereof.

25. A method as claimed in any one of Claims 22 to 24 in which each brick slip within the extrusion is of right parallelepiped configuration having a front face, side faces and a rear face, the rear face being formed with at least one groove or recess.

26. A method as claimed in Claim 25 when dependent on Claim 23 or 24 in which the sacrificial elements which unite the slips are located between the side faces and/or the rear faces of adjacent slips.

27. A cladding system substantially as hereinbefore described with reference to, and as shown in, any one of the embodiments illustrated in the accompanying drawings.

28. A brick slip substantially as hereinbefore described with reference to, and as shown in, any one of the embodiments illustrated in the accompanying drawings.

29. A method substantially as hereinbefore described with reference to any one of the embodiments illustrated in the accompanying drawings.