Method of manufacturing a brick slip

Abstract

A method of manufacturing a brick slip is disclosed comprising extruding a raw material into a shape having front 102 and rear 104 faces, and first 106 and second 108 longitudinal edges. The brick sli

Description

The present disclosure is directed towards a method of manufacturing a brick slip and the resultantly formed brick slip. The brick slip may be incorporated into a brick slip panel. BACKGROUND It is known to clad interior or exterior walls with brick slips. Such brick slips are used where it is not structurally necessary to use bricks, yet a “brick” finish is desired for decorative of aesthetic reasons. Brick slips can be formed by obtaining a thin slice from an outer face of a brick. Brick slips can also be formed by extruding material into the desired brick slip shape. Brick slips are not required to be made from brick and can be made from other materials such as concrete, clay, masonry or a composite material. Brick slips are typically attached to panels or other forms of backing layer. The brick slips are generally required to be precisely positioned to form a desired “brick-like” appearance of ordered rows of slip courses with joint gaps formed between adjacent brick slips and adjacent slip courses. The joint gaps are then typically filled in or pointed with mortar to form a desired final appearance that resembles a real brick wall. The panel can then be mounted on a building structure to form at least a portion of an outer wall or inner wall of a building structure. It is an object of the present disclosure to provide an improved brick slip and method of manufacturing a brick slip using extrusion. SUMMARY According to aspects of the invention, there is provided a method of manufacturing a brick slip and a corresponding brick slip as set out in the accompanying independent claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. According to a first aspect of the present disclosure, there is provided a method of manufacturing a brick slip. The method comprises: (i) extruding a raw material through an extrusion die to produce an extruded product, the extruded product having a front face, a rear face, a first longitudinal edge, and a second longitudinal edge; and in any order: (ii) forming the extruded product to form a brick slip having a first transverse edge and a second transverse edge extending between first and second longitudinal edges; (iii) processing material from the front face to form a tongue running along the first transverse edge of the brick slip; and (iv) processing material from the rear face to form a groove running along the second transverse edge of the brick slip. The tongue of the first transverse edge is configured to engage with a groove of a second transverse edge of another brick slip. Ideally, the method may further comprise forming or cutting the extruded product to form a brick slip having a first transverse edge and a second transverse edge extending between first and second longitudinal edges. Preferably, the method may further comprise processing or removing material from the front face to form a tongue running along the first transverse edge of the brick slip. Preferably, the method may further comprise processing or removing material from the rear face to form a groove running along the second transverse edge of the brick slip. The method relates to manufacturing brick slips using extrusion where typically a long cable of extruded material is formed which is then formed or cut to size to form the desired number of brick slips. The profile of the first and second longitudinal edges is defined by the extrusion die. However, it is not possible to profile the first and second transverse edges of the brick slip during extrusion. Significantly, the present method provides steps of processing or removing material from the front face and rear face after extrusion to form a tongue running along the first transverse edge of the brick slip and a groove running along the second transverse edge of the brick slip. Thus, the present method imparts tongue-and-groove profile on the transverse edges (often called short edges or perp edges) of the brick slip. The tongue may engage with a groove of an adjacent brick slip in the same brick slip course to help ensure that the brick slips are aligned with one another and to help ensure that the brick slips are maintained on the building structure and are not easily dislodged due to wind or movement of the supporting structure. The extruded product may have an integral (one-piece) or homogenous construction. A single extrusion process may form the extruded product. In other words, the extruded product is not assembled together from multiple separate extruded components. The brick slip therefore has an integral (one-piece) or homogenous construction. The tongue running along the first transverse edge and the groove running along the second transverse edge are spaced apart from one another in the transverse direction such that a main body of the brick slip comprising the front face and the rear face are provided between the tongue running along the first transverse edge and the groove running along the second transverse edge. The raw material may comprise a clay composition. The clay composition may comprise materials typically used to form bricks / brick slips using extrusion. Step (ii) may be performed before (iii) and (iv). This means that the extruded product is first formed or cut to form the brick slip and then material is processed or removed from the front face of the brick slip and the rear face of the brick slip to form the tongue-and-groove profile of the transverse edges. Step (ii) may be performed after (iii) and (iv). This means that the material is first processed or removed from the front face of the extruded product and the rear face of the extruded product, and the extruded product is formed or cut to form the brick slip. Steps (iii) and (iv) may be performed at the same or substantially the same time. Advantageously, this reduces manufacturing time. Alternatively, steps (iii) and (iv) may be performed separately and in any order. Steps (ii), (iii), and (iv) may be performed at the same or substantially the same time. Advantageously, the extruded product may be formed or cut, and the material may be processed or removed from the front face and / or rear face in the same operation at the same or substantially the same time to reduce manufacturing time. Steps (iii) or (iv) may comprise controlling a machining process to process or remove the material from the front face and / or the rear face. The machining process may be configured to perform one or more of cutting, milling, grinding, pressing, or shaping operations to process or remove the material. Other machining processes may be used. The machining process comprises a tool which may be a cutting implement such as a knife or wire. Steps (iii) or (iv) may comprise controlling a machining tool to process or remove the material from the front face and / or the rear face. The machining tool may be configured to perform one or more of cutting, milling, grinding, pressing, or shaping operations to process or remove the material. Other machining tools may be used. The machining tool may be a cutting implement such as a knife or wire. Ideally, the steps (ii) and / or (iii) are carried out by pressing and / or machining. The machining tool may be robotically operated. The machining tool may be operated according to preset instructions and / or may use feedback from one or more sensors to control the processing or removal of material from the front face and / or the rear face. Step (iii) may comprise controlling an implement to process or remove the material from the front face. The implement may be controlled to work in the transverse direction. The implement may be controlled to work in the longitudinal direction. Step (iv) may comprise controlling an implement to process or remove the material from the rear face. The implement may be controlled to work in the transverse direction. The implement is controlled to work in the longitudinal direction. In some examples, step (iii) comprises controlling a first machining tool (e.g., cutting implement) to process or remove the material from the front face, and step (iv) comprises controlling a second machining tool (e.g., cutting implement) to process or remove material from the rear face, (iii) and (iv) may be performed at substantially the same time. The first machining tool and second machining tool may be controlled at the same time. The first implement and second implement may both move in the same direction. The same direction may be the longitudinal direction or the transverse direction. Step (iii) may comprise controlling a cutting implement to remove the material from the front face. The cutting implement may be controlled to cut in the transverse direction. The cutting implement may be controlled to cut in the longitudinal direction. Step (iv) may comprise controlling a cutting implement to remove the material from the rear face. The cutting implement may be controlled to cut in the transverse direction. The cutting implement is controlled to cut in the longitudinal direction. In some examples, step (iii) comprises controlling a first machining tool (e.g., cutting implement) to remove the material from the front face, and step (iv) comprises controlling a second machining tool (e.g., cutting implement) to remove material from the rear face, (iii) and (iv) may be performed at substantially the same time. The first machining tool and second machining tool may be controlled at the same time. The first cutting implement and second cutting implement may both move in the same direction. The same direction may be the longitudinal direction or the transverse direction. The method may further comprise (v) heat treating the brick slip. (v) may be performed after (ii), (iii), and (iv). In some circumstances, it is desirable to cut into and remove material from the extruded product / brick slip before heat treating. This simplifies the manufacturing method, (v) may also be performed before (iii), and (iv). (v) may comprise drying the brick slip, ideally before firing; (v) may comprise firing the brick slip. The method may further comprise (vi) colouring the tongue running along the first transverse edge of the brick slip, (vi) may be performed after (ii), (iii), and (iv). (vi) may be performed after a step of heat treating the brick slip. The tongue may be coloured to have a different colour to the front face. The front face may have an appearance that resembles brick. The front face may be for example brick coloured and / or have a brick-like texture. The tongue may be coloured to resemble mortar. In this way, the tongue can form the desired appearance of mortar between adjacent brick slips. The brick slip construction avoids the need for mortar to be filled or pointed in joint gaps between brick slips when assembled on a backing layer. Step (vi) may comprise painting the tongue. The height / length of the tongue running along the first transverse edge may be greater than that of the groove running along the second transverse edge. The brick slip may further comprise: a tongue running along the first longitudinal edge and / or a groove running along the second longitudinal edge. The tongue is formed during the processes of extruding the raw material through the extrusion die. The groove is formed during the process of extruding the raw material through the extrusion die. The tongue of the first longitudinal edge may be configured to engage with a groove of a second longitudinal edge of another brick slip. The height of the tongue running along the first longitudinal edge may be greater than that of the groove running along the second longitudinal edge. The tongue running along the first longitudinal edge and the tongue running along the first transverse edge may be vertically offset from the front face by the same amount. Step (vi) may comprise colouring the tongue running along the first transverse edge of the brick slip; Step (vi) may comprise colouring the tongue running along the first longitudinal edge of the brick slip. Step (ii) may comprise forming or cutting the extruded product to form a plurality of brick slips each having a first transverse edge and a second transverse edge extending between first and second longitudinal edges. The brick slip may comprise one or more structures to accommodate a mounting component such as a rail for fixing the brick slip to a building. The structure may comprise a channel running along the first longitudinal edge. The structure may comprise one or more formations extending from the rear face of the brick slip. The one or more structures may be formed by the extrusion process. According to a second aspect of the present disclosure, there is provided a further method of manufacturing a brick slip. The method comprises: (i) extruding a raw material through an extrusion die to produce an extruded product, the extruded product having a front face, a rear face, a first longitudinal edge, and a second longitudinal edge; and (ii) forming the extruded product to form a brick slip having a first transverse edge and a second transverse edge extending between first and second longitudinal edges; (iii) firing the formed brick slip in a heat treatment area; (iv) processing material from the front face of the formed and fired brick slip to form a tongue running along the first transverse edge of the brick slip; and (v) processing material from the rear face of the formed and fired brick slip to form a groove running along the second transverse edge of the brick slip. Ideally, the method further comprising cutting the extruded product to form a brick slip having a first transverse edge and a second transverse edge extending between first and second longitudinal edges. Ideally, the method further comprising drying and firing the cut brick slip in a heat treatment area. Ideally, the method further comprising removing material from the front face of the cut, dried and fired brick slip to form a tongue running along the first transverse edge of the brick slip. Ideally, the method further comprising removing material from the rear face of the cut, dried and fired brick slip to form a groove running along the second transverse edge of the brick slip. The method comprising rotating the formed or cut and fired brick slip though ninety degrees prior to removing material from the front and rear face. The method further comprising running the two transverse edges of the formed or cut and fired brick slip through a tooling area where the two transverse edges are formed, ideally simultaneously. The method further comprising running the two transverse edges of the formed or cut and fired brick slip through a tooling area where the two transverse edges are formed, ideally simultaneously. The method comprising processing or removing material from the front and rear face by processing the material from the front and rear face to form a tongue and groove respectively. The method comprising processing or removing material from the front and rear face by cutting and / or machining the material from the front and rear face to form a tongue and groove respectively. The method comprising machining by milling, grinding, pressing, or shaping operations. The tongue of the first transverse edge is configured to engage with a groove of a second transverse edge of another brick slip. The method relates to manufacturing brick slips using extrusion where typically a long cable of extruded material is formed which is then formed or cut to size to form the desired number of brick slips. The profile of the first and second longitudinal edges is defined by the extrusion die. However, it is not possible to profile the first and second transverse edges of the brick slip during extrusion. Significantly, the present method provides steps of processing or removing material from the front face and rear face after extrusion, drying and / or firing to form a tongue running along the first transverse edge of the brick slip and a groove running along the second transverse edge of the brick slip. Thus, the present method imparts tongue-and-groove profile on the transverse edges (often called short edges or perp edges) of the brick slip after the brick slips have been formed or cut, dried and / or fired. The tongue may engage with a groove of an adjacent brick slip in the same brick slip course to help ensure that the brick slips are aligned with one another and to help ensure that the brick slips are maintained on the building structure and are not easily dislodged due to wind or movement of the supporting structure. The extruded product may have an integral (one-piece) or homogenous construction. A single extrusion process may form the extruded product. In other words, the extruded product is not assembled together from multiple separate extruded components. The brick slip therefore has an integral (one-piece) or homogenous construction. The tongue running along the first transverse edge and the groove running along the second transverse edge are spaced apart from one another in the transverse direction such that a main body of the brick slip comprising the front face and the rear face are provided between the tongue running along the first transverse edge and the groove running along the second transverse edge. The method comprising colouring the part of the brick slip which will remain exposed when the brick slips are built into a wall or panel in use, ideally the colouring occurring at a colouring station. The method further comprising extruding a tongue running along the first longitudinal edge and / or a groove running along the second longitudinal edge. The tongue is formed during the processes of extruding the raw material through the extrusion die. The groove is formed during the process of extruding the raw material through the extrusion die. The tongue of the first longitudinal edge may be configured to engage with a groove of a second longitudinal edge of another brick slip. The height of the tongue running along the first longitudinal edge may be greater than that of the groove running along the second longitudinal edge. The tongue running along the first longitudinal edge and the tongue running along the first transverse edge may be vertically offset from the front face by the same amount. The method comprises applying an adhesive onto the front facing surface of the tongues running along the first longitudinal edge and tongues running along the first transverse edge of the formed or cut, dried and / or fired brick slips. The method comprising applying a dust onto the adhesive. Advantageously, the dust is a sand corresponding in colour to a traditional mortar. Ideally, the method comprising applying an epoxy layer onto the front facing surface of the tongues running along the first longitudinal edge and tongues running along the first transverse edge of the cut, dried and fired brick slips. The raw material may comprise a clay composition. The clay composition may comprise materials typically used to form bricks / brick slips using extrusion. According to a third aspect of the disclosure, there is provided a brick slip manufactured according to the first or second method of any preceding statement. The brick slip may comprise a front face, a rear face, a first extruded longitudinal edge, a second extruded longitudinal edge, a first cut transverse edge, and a second cut transverse edge. The brick slip may comprise a tongue running along the first cut transverse edge and a groove running along the second cut transverse edge. According to a fourth aspect of the disclosure, there is provided a brick slip assembly comprising a first brick slip according to the second aspect of the disclosure and a second brick slip according to the second aspect of the disclosure. The tongue running along the first transverse edge of the first brick slip is configured to engage with the groove running along the second transverse edge of the second brick slip. The engagement may be an underlap-overlap style engagement. The tongue and groove arrangement may be a movable arrangement such that the first brick slip can move relative to the second brick slip. In other words, the first and second brick slips are overlapping movably couplable to the support structure. Advantageously, relative movement of the brick slips allows the brick slip assembly to adjust in dimension in a commensurate manner relative to a support structure that the brick slip assembly is mounted on. This helps prevent damage to the brick slips as the support structure shrinks and / or is compressed. This is particularly beneficial when the support structure comprises a timber structure such as timber frame of a building. The direction of movement may be in a direction of shrinkage and / or compression, and / or the longitudinal direction, and / or the transverse direction. The first brick slip and / or second brick slip may comprise a tongue running along the first longitudinal edge. The brick slip assembly may further comprise a third brick slip according to the second aspect of the disclosure. The third brick slip may comprise a groove running along the second longitudinal edge. The tongue running along the first longitudinal edge of the first brick slip and / or second brick slip may be configured to engage with the groove running along the second longitudinal edge of the second brick slip. The engagement may be an underlap-overlap style engagement. The tongue and groove arrangement of the longitudinal edges may be a movable arrangement such that the first brick slip and / or second brick slip can move relative to the third brick slip. Advantageously, relative movement of the brick slips allows the brick slip assembly to adjust in dimension in a commensurate manner relative to a support structure that the brick slip assembly is mounted on. This helps prevent damage to the brick slips as the support structure shrinks and / or is compressed. This is particularly beneficial when the support structure comprises a timber structure. The direction of movement may be in a direction of shrinkage and / or compression, and / or the longitudinal direction, and / or the transverse direction. The brick slips of the brick slip assembly may be mounted individually on the support structure or may be mounted on a panel which is then mounted on the support structure. According to a fifth aspect of the disclosure, there is provided a brick slip comprising a front face, a rear face, a first longitudinal edge, a second longitudinal edge, a first transverse edge, and a second transverse edge. The brick slip comprises a tongue running along the first longitudinal edge and a groove running along the second longitudinal edge. The brick slip comprises a tongue running along the first transverse edge and a groove running along the second transverse edge. The tongue running along the first longitudinal edge and the tongue running along the first transverse edge are vertically offset from the front face by the same amount. The brick slip comprises a tongue running along the first transverse edge and a groove running along the second transverse edge being formed after drying and / or firing of the brick. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an example process of extruding a pair of extruded products through an extrusion die according to aspects of the present disclosure. Figure 2 shows a view from above of the extruded products being extruded through the extrusion die according to Figure 1. Figure 3 shows a section view of the extruded products formed by the process of Figures 1 and 2. Figure 4 shows an example process of cutting the extruded products to form brick slips according to aspects of the present disclosure. Figure 5 shows a view from above of the extruded products being cut according to Figure 4. Figure 6 shows an example process of removing material from the front and rear faces of the brick slips according to aspects of the present disclosure. Figure 7 shows a view from above of the brick slips having material removed from the front face and rear face according to Figure 6. Figure 8 shows a side on view of the brick slips after the material has been removed according to Figures 6 and 7. Figure 9 shows a view from above of the brick slips after the material has been removed according to Figures 6 and 7. Figure 10 shows another example process for removing material from the front and rear faces of a brick slip according to aspects of the present disclosure. Figure 11 shows a side-on-view of the other example process for removing material from the front and rear faces of the brick slip according to Figure 10. Figure 12 shows a view from above of the brick slip after the material has been removed in Figures 10 and 11. Figure 13 shows a side-on-view of the brick slip after the material has been removed in Figures 10 and 11. Figure 14 shows a section view of the brick slip of Figures 12 and 13. Figure 15 shows an example process of painting tongues extending along longitudinal edges of brick slips according to aspects of the present disclosure. Figure 16 shows an example process of painting tongues extending along transverse edges of brick slips according to aspects of the present disclosure. Figure 17 shows view of how brick slips in adjacent slip courses may engage with one another. Figure 18 shows a view of how brick slips in the same slip course may engage with one another. Figure 19 shows an isometric view of another example brick slip according to aspects of the present disclosure. Figure 20 shows a section view of the brick slip of Figure 19. Figure 21 shows an elevation view of the brick slip of Figure 19. Figure 22 shows a plan view of the brick slip of Figure 19. Figure 23 shows an isometric view of another example brick slip according to aspects of the present disclosure. Figure 24 shows a section view of the brick slip of Figure 23. Figure 25 shows an elevation view of the brick slip of Figure 23. Figure 26 shows a plan view of the brick slip of Figure 23. In the figures, like reference numerals are used to indicate like components. DETAILED DESCRIPTION The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. The terms and words used in the following description and claims are not limited to the bibliographical meanings but are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents. It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Figures 1 to 15 show example methods of manufacturing a brick slip according to aspects of the present disclosure. Step 1 (Figures 1 to 3) comprises extruding a raw material through an extrusion die 10 to produce an extruded product 100a, 100b. The raw material is delivered by feeder 11 and forced through the extrusion die 10 to produce the extruded product 100a, 100b. The extruded product 100a, 100b is supported on a conveyor belt 12. The raw material is typically a clay composition. The extruded product 100a, 100b has a front face 102a, 102b, a rear face 104a, 104b, first longitudinal edge 106a, 106b, and second longitudinal edge 108a, 108b. Longitudinal refers to the direction of extrusion as indicated by the arrow L. The second longitudinal edge 108a, 108b rests on the conveyor belt 12 in this example. The longitudinal direction extends along the X-axis. This example shows two extruded products 100a, 100b being formed in the same extrusion process. The extruded products 100a, 100b are extruded with their rear faces 104a, 104b facing one another. The extruded products 100a, 100b are connected by sacrificial elements 110a, 110b, 110c, 110d. The sacrificial elements 110a, 110b, 110c, 110d are formed from the same raw material as part of the extrusion process. The sacrificial elements 110a, 110b, 110c, 110d are removed later in the manufacturing process. The cross-sectional profiles (in the Y-Z plane) of the extruded products 100a, 100b are defined by the extrusion die 10. In this example, the extruded products 100a, 100b have the same profile. A single extruded product 100a, 100b can be formed during the extrusion process. More than two extruded products 100a, 100b can be formed during the extrusion process. The profile and number of extruded products 100a, 100b formed is defined by the extrusion die 10. In this example, the extruded products 100a, 100b comprise a tongue 112a, 112b running along the first longitudinal edge 106a, 106b. The tongue 112a, 112b is formed as part of the extrusion process. The extruded products 100a, 100b further comprise a groove 114a, 114b running along the second longitudinal edge 108a, 108b. The groove 114a, 114b is filled with a sacrificial element 110c, 110d to help maintain the shape of the groove 114a, 114b during the manufacturing process and is removed at a later stage in the process. The extruded product 100a, 100b is transported, via conveyor 12, to a cutting station. Step 2 (Figures 4 and 5) comprises cutting, at the cutting station, the extruded product 100a, 100b to form a desired length L1 of brick slip 200a, 200b. The length L1 is less than the overall length of the extruded product 100a, 100b. The cutting is performed in the transverse direction. The transverse direction is perpendicular to the longitudinal edges 106a, 106b, 108a, 108b and indicated by the arrow T. The transverse direction extends along the Y-axis. The cutting is performed using a cutting implement and in particular a knife 13 that moves up and down in the transverse direction T towards and away from the conveyor 12. The knife 13 is controlled to move down towards the conveyor 12 to cut into the extruded product 100a, 100b. The cutting could also be formed by moving the knife 13 forwards and backwards across the conveyor 12. Other cutting implements, such as a wire, can be used. The cutting is typically performed a plurality of times to form a plurality of brick slips 200a, 200b from the extruded product 100a, 100b. Each brick slip 200a, 200b typically has the same length L1. The brick slip 200a, 200b has front face 102a, 102b, rear face 104a, 104b, first longitudinal edge 106a, 106b, and second longitudinal edge 108a, 108b.The brick slip 200a has first transverse edge 116a, 116b and second transverse edge 118a, 118b. At least one of the first transverse edge 116a, 116b and second transverse edge 118a, 118b are formed by the cutting process in Step 2. After the step of cutting, the brick slips 200a, 200b are still joined together by sacrificial elements 110a, 110b, 110c, 110d. The cut brick slips 200a, 200b are transported, via conveyor 12, to material removal station. Step 3 (Figures 6 to 13) comprises removing (at the material removal station) material 120a, 120b from the front face 102a, 102b, of the brick slip 200a, 200b. The material 120a, 120b is removed from the end of the front face 102a, 102b that joins to the first transverse edge 116a, 116b. The removed material forms a recess / step / notch 122a, 122b that extends in from the front face 102a, 102b towards, but not reaching, the rear face 104a, 104b. The recess / step / notch 122a, 122b extends in the transverse direction between the first longitudinal edge 106a, 106b and the second longitudinal edge 108a, 108b. The recess / step / notch 122a, 122b is open to the front face 102a, 102b and, in this example, has a surface that is parallel with the front face 102a, 102b. The recess / step / notch 122a, 122b forms a tongue 124a, 124b that runs along the first transverse edge 116a, 116b. Generally, material across the full height (in the transverse direction) of the front face 102a, 102b is removed but the length (in the longitudinal direction) of the strip of removed material and the depth can be varied as appropriate. The removing of material typically removes only a small part of the material from the front face 102a, 102b. In this example, the removing of material 120a, 120b is performed after the cutting of the extruded product 100a, 100b to form the brick slip 200a, 200b but before the brick slip 200a, 200b is heat treated. The material is removed by controlling a cutting implement, in this example knife 14a, 14b, to cut into the brick slip 200a, 200b. In this example, the knife 14a, 14b moves up and down in the transverse direction T. The cutting is performed while the brick slip 200a, 200b is positioned on the conveyor 12. Movement of the brick slip 200a, 200b on the conveyor 12 may assist in the cutting process. Two knives 14a, 14b are provided in this example. Knife 14a is used to remove material 120a for extruded product 100a. Knife 14b is used to remove material 120b for extruded product 100b. In other examples, the knife 14a, 14b could move in the longitudinal direction as well as the transverse direction to remove the material 120a, 120b. Other forms of cutting implement may be used. Other methods for removing material can be used. Typically, a machining tool is controlled (e.g., robotically) to remove the material. The machining tool may be a cutting implement or other form of machining tool. The machining tool may perform cutting, milling, grinding, pressing, or shaping operations. Step 4 (Figures 6 to 13) comprises removing (at the material removal station) material 126a, 126b from the rear face 104a, 104b of the brick slip 200a, 200b. The material 126a, 126b is removed from the end of the rear face 104a, 104b that joins to the second transverse edge 118a, 118b. The removed material 126a, 126b forms a recess / step / notch 128a, 128b that extends in from the rear face 104a, 104b towards, but not reaching, the front face 102a, 102b. The recess / step / notch 128a, 128b extends in the transverse direction between the first longitudinal edge 106a, 106b and the second longitudinal edge 108a, 108b. The recess / step / notch 128a, 128b is open to the rear face 104a, 104b and, in this example, has a surface that is parallel with the rear face 104a, 104b. The recess / step / notch 128a, 128b forms a groove 128a, 128b that runs along the second transverse edge 118a, 118b. Generally, material across the full height (in the transverse direction) of the rear face 104a, 104b is removed but the length (in the longitudinal direction) of the strip of removed material and the depth can be varied as appropriate. The removing of material typically removes only a small part of the material from the rear face 104a, 104b. The material 126a, 126b removed in Step 4 is thus removed from the opposing end (in the longitudinal direction) to the material 120a, 120b removed in Step 3. A main body of the brick slip 200a, 200b comprising front face 102a, 102b and rear face 104a, 104b separates the groove 128a, 128b running along the second transverse edge 118a, 118b from the tongue 124a, 124b running along the first transverse edge 116a, 116b. In this example, the removing of material 126a, 126b is performed after the cutting of the extruded product 100a, 100b to form the brick slip 200a, 200b but before the brick slip 200a, 200b is heat treated. The material is removed by controlling a cutting implement, in this example knife 15, to cut into the brick slip 200a, 200b. In this example, knife 15 moves up and down in the transverse direction T. The cutting is performed while the brick slip 200a, 200b is positioned on the conveyor 12. Movement of the brick slip 200a, 200b on the conveyor 12 may assist in the cutting process. A single knife 15 performs the cuts to move both material 126a for extruded product 100a and material 126b for extruded product 100b in this example. Other forms of cutting implement may be used. Typically, a machining tool is controlled (e.g., robotically) to remove the material. The machining tool may be a cutting implement or other form of machining tool. The machining tool may perform cutting, milling, grinding, pressing, or shaping operations. Steps 3 and 4 are performed at (substantially) the same time in this example. That is material 120a, 120b is removed using knife 14a, 14b at the same time as material 126a, 126b is removed using knife 15. These steps could be performed one after the other and in any order. In another example as shown in Figures 10 to 14, Steps 3 and 4 may be performed when the brick slip 200a is lying flat on the conveyor 12. In this example, brick slip 200a is lying flat on the conveyor 12 with rear face 104a facing the conveyor 12. Knife 16 moves laterally (in the longitudinal direction) to cut into the brick slip 200a to remove material 120a. Knife 17 moves laterally (in the longitudinal direction) to cut into the brick slip 200a to remove material 126a. Steps 3 and 4 in the above examples are performed after the cutting of the extruded product 100a, 100b in step 2 in this example. This is not required in all examples and the material 120a, 120b and material 126a, 126b can be removed before the cutting of the extruded product 100a, 100b into brick slip 200a, 200b. Steps 2, 3, and 4 may be performed at substantially the same time in the same operation. In some examples, Steps 2, 3 and 4 are performed under robotic control with minimal or no human input. Robotically controlled machining tools are used to cut the extruded product 100a, 100b and remove material the front face 102a, 102b and rear face 104a, 104b. The machining tools may operate according to pre-set instructions and / or may use feedback from one or more sensors to configure their operation. The cut brick slips 200a, 200b are transported, via conveyor 12, to a heat treatment station. Step 5 comprises heat treating (at the heat treatment station) the brick slips 200a, 200b. Step 5 is performed after steps 3 and 4 in this example. Heat treating the the brick slips 200a, 200b comprises one or more heat treatment stations. For example, brick slips 200a, 200b may be transported to a drying station where the brick slips 200a, 200b are dried at a temperature of between 50 and 150 degrees Celsius before being transferred to a firing station where the brick slips 200a, 200b are baked at high temperatures in a kiln. After the heat treatment, the sacrificial elements 110a, 110b, 110c, 110d are removed, typically by knocking them away using a hammer / chisel. The cut brick slips 200a, 200b are transported, via conveyor 12, to a painting station. Step 6 (Figures 15 and 16) comprises painting (at the painting station) the front facing surface of the tongues 112a, 112b running along the first longitudinal edge 106a, 106b and tongues 124a, 124b running along the first transverse edge 116a, 116b. The brick slips 200a, 200b are placed on a conveyor 12 with the rear faces 104a, 104b facing towards the conveyor 12. The brick slips 200a, 200b are arranged such that the tongues 112a, 112b running along the first longitudinal edge 106a, 106b are aligned with the direction of travel of the conveyor 12. Paint is applied to the brick slips 200a, 200b using a suitable painting apparatus (such as an automatic paint sprayer) to spray paint on to the front face surface of tongues 112a, 112b. The brick slips 200a, 200b are then placed on conveyor 12 with the rear faces 104a, 104b facing towards the conveyor belt. The brick slips 200a, 200b are arranged such that the tongues 124a, 124b running along the first transverse edge 116a, 116b are aligned with the direction of travel of the conveyor 12. Paint is applied to the brick slips 200a, 200b using a suitable painting apparatus (such as an automatic paint sprayer) to spray paint on to the front face surface of tongues 124a, 124b. Sand may also be applied to the tongues 112a, 112b, 124a, 124b during or after the painting process. The painting is performed to give the tongues 112a. 112b, 124a, 124b a different visual appearance to the front face 102a, 102b. Preferably, the tongues 112a. 112b, 124a, 124b are painted to resemble mortar. In some examples, rather than painting the brick slips 200a, 200b, a co-extrusion process is used where a first material and a second material are simultaneously delivered to the extrusion die to form the extruded product. Both the first material and second material may be clay compositions but with different colours. The first material forms a first part of the extruded product 100a, 100b (at least the front face) and the second material forms the second part of the extruded product 100a, 100b (at least the rear face and tongue 112a, 112b running along first longitudinal edge 106a, 106b). The second material may have a colour to resemble mortar. Removing material from the front face 102a, 102b to form the tongue 124a, 124b running along the first transverse edge involves removing sufficient material from the front face to expose the second material. In this way, the tongue 124a, 124b is also formed of the second material and provides the desired visual distinction from the front face 102a, 102b. The resultantly formed brick slip 200a, 200b has a front face 102a, 102b, rear face 104a, 104b, first longitudinal edge 106a, 106b, second longitudinal edge 108a, 108b, first transverse edge 116a, 116b, and second transverse edge 118a, 118b. The extrusion process defines a tongue 112a, 112b running along the first longitudinal edge 106a, 106b and a groove 114a, 114b running along the second longitudinal edge 108a, 108b. The removal of material postextrusion forms a tongue 124a, 124b running along first transverse edge 116a, 116b and a groove 128a, 128b running along second transverse edge 118a, 118b. The height (in the transverse direction) and depth of the brick slip 200a, 200b is defined by the extrusion process in Step 1. The length of the brick slip 200a, 200b is defined by the cutting process in Step 2. The front face 102a, 102b is generally planar and extends in the longitudinal-transverse (X-Y) plane. The front face 102a, 102b has a decorative appearance and may be referred to as the decorative face of the brick slip 200a, 200b. The front face 102a, 102b may have an appearance (such as due to the coiour and / or texture) that is reminiscent of brick. The front face 102a, 102b is designed to face away from the material that the brick slip 200a, 200b is attached to in use such that the front face 102a, 102b forms a visible face of the brick slip 200a, 200b. The front face 102a, 102b is rectangular in this example but could also be square in shape. The rear face 104a, 104b is generally planar and extends in the longitudinal-transverse (X-Y) plane. The rear face 104a, 104b is designed to face towards the back layer that the brick slip 200a, 200b is attached to in use such that the rear face 104a, 104b forms a hidden face of the brick slip 200a, 200b. The rear face 104a, 104b is rectangular in this example but could also be square in shape. The rear face 104a, 104b is of similar size to the front face 102a, 102b in the X-Y plane and overlaps with the front face 102a, 102b in the X-Y plane. The front face 102a, 102b and the rear face 104a, 104b are vertically separated from one another in the Z-axis. The vertical separation generally defines the thickness of the brick slip 200a, 200b. The thickness of the brick slip 200a, 200b is typically less than length or height of the brick slip 200a, 200b. In some examples, projections may extend from the rear face 104a, 104b of the brick slip 200a, 200b to facilitate attachment of the brick slip 200a, 200b to the backing layer. In these examples, the overall thickness of the brick slip 200a, 200b is greater than the vertical separation between the front face 102a, 102b and the rear face 104a, 104b. This is not required in ail examples. The tongue 112a, 112b running along the first longitudinal edge 106a, 106b projects away (in the transverse direction) from the front face 102a, 102b such that the tongue 112a, 112b is not covered by the front face 102a, 102b. The tongue 112a, 112b facilitates the alignment of the brick slip 200a, 200b with one or more further brick slips in an adjacent slip course. The tongue 112a, 112b may extend into a groove 114a, 114b running along a second longitudinal edge 108a, 108b of a further brick slip(s) as described in greater detail below. This simplifies the positioning of brick slips 200a, 200b on a backing layer. The tongue 112a, 112b is vertically offset (along the Z-axis) from the front face 102a, 102b. In other words, the tongue 112a, 112b is positioned vertically below the front face 102a, 102b. This helps mimic the effect of mortar applied between brick slips. The tongue 112a, 112b is vertically offset from the rear face 104a, 104b and, in this example, is provided spaced apart from the front face 102a, 102b and the rear face 104a, 104b. The tongue 112a, 112b has a front surface 130a (Figure 14) that is open to the front face 102a, 102b and a rear surface 132a that is open to the rear face 104a, 104b. The front surface 130a is generally parallel with the front face 102a, 102b. The rear surface 132a is generally parallel with the rear face 104a, 104b. The tongue 112a, 112b further comprises a chamfered end 134a that joins the front surface 130a, 130b to the rear surface 132a, 132b. The first longitudinal edge 106a, 106b further comprises a channel 136a (Figure 14) that extends inwardly in a direction towards the second longitudinal edge 108a, 108b. The channel 136a is configured to engage with a rail of a support structure used to support brick slips on a building. The channel 136a is formed as part of the extrusion process. The groove 114a, 114b running along the second longitudinal edge 108a, 108b extends inwardly such that the groove 114a, 114b is covered by the front face 102a, 102b. The groove 114a, 114b is vertically offset from the front face 102a, 102b and the rear face 104a, 104b such that it is provided spaced apart from the front face 102a, 102b and the rear face 104a, 104b. The groove 114a, 114b is aligned with the tongue 112a, 112b. The groove 114a, 114b has a chamfer 138a (Figure 14). The tongue 112a, 112b and groove 114a, 114b have complementary shapes. The height of the tongue 112a, 112b (in the transverse direction) is greater than the depth of the groove 114a, 114b such that there will be a recess between the front face 102a, 102b of one brick slip 200a, 200b and the front face 102a, 102b of another brick slip 200a, 200b. This recess gives the impression of a joint / mortar line. As shown in Figure 17, the tongue 112a, 112b of the first longitudinal edge 106a, 106b is configured to engage with a groove 114a, 114b of a second longitudinal edge 108a, 108b of another brick slip 200a, 200b. The other brick slip 200a, 200b is provided in adjacent brick slip course. In this way, when two similar brick slips 200a, 200b are placed together the tongue 112a, 112b of one fits into the groove 114a, 114b of the other. This provides a convenient mechanism for locating brick slips together and ensuring brick slips are in proper alignment with one another. This makes it easier to achieve the desired visual effect from the brick slips (e.g., neat rows of bricks). The tongue 112a, 112b may interlock with the groove 114a, 114b formed in the further brick slip to form an interlocking arrangement. As the tongue 112a, 112b projects outward by a greater amount than the groove 114a, 114b extends inward, the tongue 112a, 112b is not entirely covered by the front face of the further brick slip. Instead, part of the tongue 112a, 112b is still visible to create the desired visual effect of a line of mortar extending between adjacent brick slips. The tongue 124a, 124b running along the first transverse edge 116a, 118 projects away (in the longitudinal direction) from the front face 102a, 102b such that the tongue 124a, 124b is not covered by the front face 102a, 102b. The tongue 124a, 114b facilitates the alignment of the brick slip 200a, 200b with one brick slip in the same slip course. The tongue 124a, 124b may extend into a groove 128a, 128b running along a second longitudinal edge 108a, 108b of a further brick slip(s) as described in greater detail below. This simplifies the positioning of brick slips 200a, 200b on a backing layer. The tongue 124a, 124b is vertically offset (along the Z-axis) from the front face 102a, 102b. In other words, the tongue 124a, 124b is positioned vertically below the front face 102a, 102b. This helps mimic the effect of mortar applied between brick slips. The tongue 112a, 112b running along the first longitudinal edge 106a, 106b and tongue 124a, 124b running along the first transverse edge 116a, 116b may be vertically offset from the front face 102a, 102b by the same amount. This helps ensure a uniform appearance is provided when brick slips 200a, 200b are positioned together within slip courses and in adjacent slip courses. Moreover, this arrangement helps prevent rattling of the brick slips 200a, 200b when installed on a building such as due to mind or due to movement of the supporting structure that the brick slips are mounted on. The groove 128a, 128b running along the second transverse edge 118a, 118b extends inwardly such that the groove 128a, 128b is covered by the front face 102a, 102b. The groove 128a, 128b is vertically offset from the front face 102a, 102b. The groove 128a, 128b is aligned with the tongue 124a, 124b. The groove 128a, 128b has a complementary shape to tongue 124a, 124b. As shown in Figure 18, the tongue 124a, 124b of the first transverse edge 116a, 116b is configured to engage with a groove 128a, 28b of a second transverse edge 118a, 118b of another brick slip 200a, 200b. In this way, when two similar brick slips 200a, 200b are placed together the tongue 124a, 124b of one fits into the groove 128a, 128b of the other. The height of the tongue 124a, 124b (in the longitudinal direction) is greater than the depth of the groove 128a, 128b (in the longitudinal direction) such that there will be a recess between the front face 102a, 102b of one brick slip 200a, 200b and the front face 102a, 102b of another brick slip 200a, 200b. This recess gives the impression of a joint / mortar line. The tongues 112a, 112b, 124a, 124b are formed, as part of the manufacturing process, to have a different colour of material to the front face 102a, 102b such that tongues 112a, 112b, 124a, 124b have a different visual appearance to the front face 102a, 102b. In preferred examples, the front face 102a, 102b is coloured to resemble brick and the tongues 112a, 112b, 124a, 124b are coloured to resemble mortar. In use, the tongues 112a, 112b, 124a, 124b provide the visual effect of a line of mortar provided between adjacent brick slips 200a, 200b. An installer or manufacturer of the brick slips 200a, 200b therefore does not need to manually apply mortar between brick slips 200a. 200b to achieve the desired visual effect. This greatly decreases the complexity of installing brick slips 200a, 200b. It is not required in all examples that the tongues 112a, 112b, 124a, 124b have a different visual appearance to the front face 102a, 102b but this a preferred arrangement. The brick slip 200a, 200b may have an overall length (in the longitudinal direction) of between 200 and 250 mm. In preferred examples, the brick slip 200a, 200b has an overall length of 228 mm. The brick slip 200a, 200b may have an overall height (in the transverse direction) of between 75 and 90 mm. In preferred examples, the brick slip 200a, 200b has an overall height of 82 mm. The brick slip 200a, 200b may have an overall thickness (in the Z-direction) of between 18 mm and 30 mm. The brick slip 200a, 200b thickness may be between 20 and 25 mm. The tongue 112a, 112b may project outwardly (in the transverse direction) from the front face 102a, 102b by between 10 mm and 20 mm. The tongue 124a, 124b may project outwardly (in the longitudinal direction) from the front face 102a, 102b by between 10 mm and 20 mm. The tongue 112a, 112b and tongue 124a, 124b are vertically offset (along the Z-axis) from the front face 102a, 102b by between 5 mm and 12 mm. Other heights of tongues 112a, 112b, 124a, 124b and vertical offsets are possible and can be selected using the shape of the extrusion die 10 and the amount of material removed in Step 3. The grooves 114a, 114b 128a, 128b project inwardly from the front face 102a, 102b by a lesser amount than the tongues 112a, 112b, 124a, 114b project outwardly. As shown in Figures 17 and 18, the brick slips 200a, 200b are mounted together in a brick slip assembly with overlapping lap-style joints due to the engagement of the tongues and grooves in both longitudinal and transverse directions. These overlap joints are moveable in the sense that individual brick slips 200a, 200b may move relative to one another while still maintain the desired overlap. This allows the brick slips 200a, 200b to move to accommodate changes in the support structure that the brick slips 200a, 200b are mounted to. This is particularly beneficial when the brick slips are mounted on a timber frame of a building as timber frames can shrink and compress over time. The support structure typically comprises a frame and rails extending from the frame. The rails engage with the brick slips 200a, 200b to couple the brick slips 200a, 200b to the building. The rails are received in the T-shaped channeis 142 (Figure 17) formed between brick siips 200a, 200b in adjacent slip courses. The T-shaped channels 142 are partly defined by the channel 136a of the first longitudinal edge 106a of the brick slip 200a as shown in Figure 14. Figures 19 to 22 show another example brick slip 200c that may be manufactured using the brick slip manufacturing process described above. In this example, the tongue 112c running along the first longitudinal edge 106c and the groove 114c running along the second longitudinal edge 108c are not vertically offset from the rear face 104c. This difference in profile of the brick slip 200c is achieved by using a different extrusion die 10 to the brick slip described above in relation to Figures 1 to 18. Figures 23 to 26 show another example brick slip 200d that may be manufactured using the brick slip manufacturing process described above. In this example, the tongue 112d running along the first longitudinal edge 106d and the groove 114d running along the second longitudinal edge 108d are not vertically offset from the rear face 104d. Furthermore, the brick slip 200d comprises lower formations 140a, 140b that extend away, in the Z-axis, from the rear face 104d. The lower formations 140a, 140b are configured to engage with rails of a cladding assembly used to support brick slips on a building. This difference in profile of the brick slip 200d is achieved by using a different extrusion die 10 to the brick slip described above in relation to Figures 1 to 18. The colouring of the joint is achieved by application of a blend of clays, frits, silica / aluminosilicates and other naturally occurring minerals that define how the material will achieve its colour and texture to the unfired clay body before firing. The firing atmosphere can also interact with the mineralogical content to affect the final colouration but once fired the colour will be stable for the life of the product. The application of this type of material (engobe) to the body is widespread in the brick and tile industry. The actual mechanical application method does not affect the longevity of the finished product. Upon firing of the clay body with the joint colourant / finish applied, the materials become ceramically fused in the same way a glaze / semi-glaze does in the normal brick / glass making process. The colourant material is a ceramic and therefore not subject to UV degradation, is vitrified enough so that it should not be subject to degradation due to freeze / thaw cycles and, due to it only containing clays, aluminosilicates and other naturally occurring minerals and having been through the firing process, will be of the same fire classification as other clay products i.e. non-combustible Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A method of manufacturing a brick slip, the method comprises:(i) extruding a raw material through an extrusion die to produce an extruded product, the extruded product having a front face, a rear face, a first longitudinal edge, and a second longitudinal edge; and(ii) forming the extruded product to form a brick slip having a first transverse edge and a second transverse edge extending between first and second longitudinal edges;(iii) firing the formed brick slip in a heat treatment area;(iv) processing material from the front face of the formed, fired brick slip to form a tongue running along the first transverse edge of the brick slip; and(v) processing material from the rear face of the formed, fired brick slip to form a groove running along the second transverse edge of the brick slip.

2. A method according to claim 1, wherein the method comprises cutting the extruded product to form a brick slip having a first transverse edge and a second transverse edge extending between first and second longitudinal edges.

3. A method according to claim 1 or claim 2, wherein the method comprises drying the cut brick slip in a heat treatment area.

4. A method according to any one of the preceding claims, wherein the method comprising removing material from the front face of the formed, fired brick slip to form the tongue running along the first transverse edge of the brick slip; and removing material from the rear face of the formed, fired brick slip to form the groove running along the second transverse edge of the brick slip.

5. A method according to any one of the preceding claims, wherein the method comprising rotating the formed, fired brick slip though ninety degrees prior to removing material from the front face and the rear face.

6. A method according to any one of the preceding claims, wherein the method further comprising running the two transverse edges of the formed, fired brick slip through a tooling area where the two transverse edges are formed.

7. A method according to any one of the preceding claims, wherein the method comprising removing material from the front face and rear face by machining the material from the front face and rear face to form the tongue and the groove respectively.

8. A method according to any one of the preceding claims, wherein the method comprising removing material from the front and rear face by cutting and machining the material from the front face and rear face to form the tongue and the groove respectively.

9. A method according to claim 7 or claim 8, wherein the method comprising machining by milling, grinding, pressing or shaping operations.

10. A method according to any one of the preceding claims, wherein the method comprises forming the tongue of the first transverse edge of one brick slip to engage with the groove of a second transverse edge of another brick slip.

11. A method according to any one of the preceding claims, wherein the method comprises defining the profile of the first and second longitudinal edges by the extrusion die.

12. A method according to any one of the preceding claims, wherein the method further comprising extruding a tongue running along the first longitudinal edge and extruding a groove running along the second longitudinal edge, the tongue being formed during the processes of extruding the raw material through the extrusion die and the groove being formed during the process of extruding the raw material through the extrusion die.

13. A method according to any one of the preceding claims, wherein the method comprising colouring a part of the brick slip which will remain exposed when the brick slips are built into a wall or panel in use.

14. A method according to any one of the preceding claims, wherein the method comprises applying an adhesive onto the front facing surface of the tongues running along the first longitudinal edge and tongues running along the first transverse edge of the formed and fired brick slips.

15. A method according to claim 14, wherein the method comprising applying a dust onto the adhesive, wherein the dust is a sand corresponding in colour to a traditional mortar.

16. A method according to claim 14, wherein the method comprising applying an epoxy layer onto the front facing surface of the tongues running along the first longitudinal edge and tongues running along the first transverse edge of the cut, dried and fired brick slips.

17. A method according to any one of the preceding claims, wherein the method comprises using a clay composition as the raw material.

18. A method according to claim 12, wherein the method comprising configuring the tongue of the first longitudinal edge to engage with a groove of a second longitudinal edge of another brick slip.

19. A method according to claim 12 or claim 18, wherein the method comprising configuring the height of the tongue running along the first longitudinal edge to be greater than that of the groove running along the second longitudinal edge.

20. A method according to claim 12, 18 or claim 19, wherein the method comprising vertically offsetting the tongue running along the first longitudinal edge and the tongue running along the first transverse edge from the front face by the same amount.

21. A brick slip comprising a front face, a rear face, a first longitudinal edge, a second longitudinal edge, a first transverse edge, and a second transverse edge, the brick slip comprises a tongue running along the first longitudinal edge and a groove running along the second longitudinal edge, the brick slip comprises a tongue running along the first transverse edge and a groove running along the second transverse edge, the tongue running along the first longitudinal edge and the tongue running along the first transverse edge being vertically offset from the front face by the same amount, the brick slip comprising a tongue running along the first transverse edge and a groove running along the second transverse edge being formed after drying and / or firing of the brick.

22. A brick slip as claimed in claim 21, wherein the brick slip comprises one or more structures to accommodate a mounting component such as a rail for fixing the brick slip to a panel or a building.

23. A brick slip as claimed in claim 22, wherein the structure comprises a channel running along the first longitudinal edge.

24. A brick slip as claimed in claim 22 or claim 23, wherein the structure comprises one or more formations extending from the rear face of the brick slip, the one or more structures may be formed by the extrusion process.

25. A panel comprising a plurality of brick slips as claimed in any one of or any combination of claims 21 to 24.A

Images