Abstract:
A cladding system based on a specially configured base sheet profiled to provide a ship lap expressed joint with an adjacent sheet, which is ideal for use with relatively low-build brushable or rollable texture coatings. The ship lap expressed joint includes within the visible portion of the joint between the outer surfaces of the base sheets, an interface line defined by an inner overlapping edge of one of the base sheets, whereby the interface line is set in from the outer surface of the base sheets. 
     This arrangement enables coated walls, and in particular texture coated masonry look walls, to be created at a much lower cost and using less skilled operators, as it obviates the need to set and finish the joints between adjacent sheets and the problems associated with that process.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a cladding system, particularly of the kind including base sheets which are secured to an underlying structure such as a stud wall, with a thin finish coating being applied to the outer surface of the base sheets. In preferred forms the coating is a texture coating of a kind used to achieve a masonary look finish. 
         [0002]    The invention has been developed primarily for use with base sheets made of fibre cement and will be described primarily with reference to this particular form. However, it will be appreciated that the cladding system of the invention is not limited for use with the fibre cement base sheets and could readily be adapted for use with base sheets made from other suitable materials. 
         [0003]    Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. 
         [0004]    In response to trends for affordable “monolithic” look coated external wall styles, a number of coated wall cladding systems have been developed. The most popular of these systems all involve first applying planar base sheets or panels to fully clad the outer surfaces of a new or existing external wall or wall frame. After the cladding has been installed, it is then usually coated with a relatively high-build trowel-applied texture coating material which results in a monolithic solid textured stone like appearance. 
         [0005]    These systems have the advantage of providing the desired monolithic type masonry appearance at relatively low cost and with more design flexibility than an equivalent full masonry structure. However, the need to carefully set the joints between adjacent abutting base panels makes the installation of the base panels very time consuming. This results in unduly high labour costs compared to the component material costs and also slows the installation process. Furthermore, in order to adequately hide the set joints, a high build trowel applied texture coating needs to be used, which can only be installed by highly trained coating application specialists, again adding significantly to the overall system cost. In addition, if there is movement between the base sheets due to, for example, movement of the frame or poor installation, cracking of the coating may occur along the set joints and repairs are not practical without generally being noticeable. 
         [0006]    It is an object of the present invention to provide a coated or coatable cladding system that overcomes or ameliorates one or more of the above disadvantages of the prior art, or which at least provides a useful alternative 
       SUMMARY OF THE INVENTION 
       [0007]    According to a first aspect of the invention, there is provided a panelised masonry look wall cladding system incorporating broad planar surfaces extending between vertical expressed joints, the wall cladding system including: 
         [0008]    a plurality of broad rectangular base sheets secured in a side by side vertical orientation to an underlying structure; 
         [0009]    each of the base sheets having an inner surface and a planar generally smooth unfinished outer surface, each base sheet being profiled along at least one longitudinal edge to provide, on installation with an adjacent sheet, broad planar surfaces with an intermediate overlapping vertical ship lap expressed joint, a portion of the joint being clearly visible between the outer surfaces of the base sheets and including an interface line defined by an inner overlapping edge of one of the base sheets, the interface line thereby being set in from the outer surfaces of the base sheets; and 
         [0010]    a relatively low build brushable or rollable texture coating applied in situ to the exposed unfinished outer surfaces of the installed base sheets. 
         [0011]    The term ‘ship lap’ joint is used herein to refer to any sheet jointing structure in which a rebate is formed below the outer surface of an edge of one sheet such that an overhang is formed which is adapted to sit on or over a similar or dissimilar rebate formed in the outer surface of an edge of an adjacent joining sheet, whereby there is an overlap region and the outer surfaces of the joined sheets remain in substantially the same plane. The term ‘expressed’ is used to refer to a joint finish and structure which is intended to be a clearly visible feature, as opposed to a minimal or incidental joint line. 
         [0012]    It will be appreciated that the overlap provided by the ship lap joint, in conjunction with the expressed sizing of the joint with recessed interface line, obviates the need for joint setting as was required with the prior art. 
         [0013]    Preferably, the visible portion of the joint defines a channel formation between the outer surfaces of adjacent base sheets, the channel having an outer width between the outer surfaces, and an inner width at a depth set in from the outer surfaces. Preferably, the interface line is set in at the maximum depth of the channel. 
         [0014]    Preferably, the profiled edges of the base sheets include some form of straight or curved chamfer along the edges immediately adjacent the outer surface of the base sheets such that the outer width of the channel is wider than the inner width of the channel. In some preferred forms the channel has a generally ‘V’ shaped or truncated ‘V’ shaped section. Desirably, some or all of the internal corners and edges are curved or chamfered. 
         [0015]    In preferred embodiments, the outer width is up to about 15 mm. Preferably, the outer width is from about 3 mm to about 9 mm. It is preferred that the inner width is up to about 10 mm. Preferably, the inner width is from about 3 mm to about 9 mm, with the inner width, desirably, being less than the outer width. Further, it is preferred that the maximum depth of the channel is up to about 6 mm. Preferably, the maximum depth of the channel is from about 3 mm to 4.5 mm. 
         [0016]    In one particularly preferred form, the sheets are approximately 8.5 mm thick and the channel is of a generally truncated ‘V’ shaped section having an outer width of approximately 7 mm, a depth of around 4 mm and an inner width of about 3 mm. 
         [0017]    There is also an overlap region of approximately 4 to 5 mm. It will be appreciated that this could be varied. For example, in order to increase weatherproofing capacity, it may be useful to increase the overlap region. 
         [0018]    In preferred forms the base sheets are pre-coated with an appropriate sealer or primer to enable texture coating to commence in accordance with the manufacturer&#39;s recommendations. 
         [0019]    Preferably, the cladding system is part of a texture coated cladding system. More preferably, using a relatively low build brushable or rollable coating for application to the outer surfaces of the installed base sheets. 
         [0020]    Preferably, the relatively low-build brushable or rollable texture coating is a roll-on coating for application by a paint roller. Preferably, the relatively low-build brushable or rollable texture coating has a thickness of up to about 300 microns when applied. 
         [0021]    Preferably, the system includes a back sealing tape adapted to span across the inner edge surfaces of adjacent base sheets. Preferably, the system also includes a sealant for application between the overlapping rebated surfaces of the ship lap joints between adjoining base sheets. 
         [0022]    Preferably, each base sheet is profiled on a longitudinal edge. More preferably, each base sheet is profiled on two opposing longitudinal edges. Preferably, the longitudinal edges are installed vertically when used in walling applications. 
         [0023]    According to a second aspect of the invention, there is provided a method of installing a panelised masonry look wall cladding system, the method including the steps of: 
         [0024]    providing a plurality of broad rectangular base sheets, each of the base sheets having an inner surface and a planar generally smooth outer surface, each base sheet being profiled along at least one edge such that on installation with an adjacent sheet, an overlapping vertical ship lap expressed joint is formed, a portion of the joint being clearly visible between the outer surfaces of the base sheets and including an interface line defined by an inner overlapping edge of one of the base sheets which is thereby set in from the outer surfaces of the base sheets; 
         [0025]    securing the base sheets to an underlying structure in a side by side vertical orientation so as to form at least one vertical ship lap expressed joint as described above; and 
         [0026]    applying in situ a relatively low-build brushable or rollable texture coating to the exposed unfinished outer surfaces of the installed base sheets. 
         [0027]    Preferably, the base sheets are secured such that the visible portion of the joint defines a channel between the outer surfaces of adjacent base sheets, the channel having an outer width between the outer surfaces, and an inner width at a depth set in from the outer surfaces. Preferably, the base sheets are secured such that the interface line is set in at the maximum depth of the channel. 
         [0028]    Preferably, where the profiled edges of the base sheets include some form of straight or curved chamfer along the edges immediately adjacent the outer surface of the base sheets, the base sheets are secured such that the outer width of the channel is wider than the inner width of the channel. 
         [0029]    In preferred embodiments, the base sheets are secured such that the outer width is up to about 15 mm. Preferably, the outer width is from about 3 mm to about 9 mm. It is preferred that the base sheets are secured such that the inner width is up to about 10 mm. Preferably, the inner width is from about 3 mm to about 9 mm, with the inner width, desirably, being less than the outer width. Further, it is preferred that the base sheets are secured such that the maximum depth of the channel is up to about 6 mm. Preferably, the maximum depth of the channel is from about 3 mm to 4.5 mm. 
         [0030]    In one particularly preferred form, the sheets are approximately 8.5 mm thick and the channel is of a generally truncated ‘V’ shaped section having an outer width of approximately 7 mm, a depth of around 4 mm and an inner width of about 3 mm. 
         [0031]    There is also an overlap region of approximately 4 to 5 mm. It will be appreciated that this could be varied. For example, in order to increase weatherproofing capacity, it may be useful to increase the overlap region. 
         [0032]    In preferred forms the base sheets are pre-coated with an appropriate sealer or primer to better enable texture coating to commence in accordance with the manufacturer&#39;s recommendations. 
         [0033]    In one example, the step of applying the relatively low-build brushable or rollable texture coating is carried out by rolling on the coating with a paint roller. Preferably, the relatively low-build brushable or rollable texture coating is applied in two coats. Preferably, the relatively low-build brushable or rollable texture coating is applied to a thickness of up to about 300 microns. In all cases, however, the coating must be applied strictly in accordance with the manufacturer&#39;s directions. 
         [0034]    Preferably, the method includes applying a back sealing tape between the underlying structure and the base sheets such that the back sealing tape spans across the inner edge surfaces of adjacent base sheets. Desirably, the method includes applying a sealant between the overlapping rebated surfaces of the ship lap joints between adjoining base sheets. 
         [0035]    Preferably, in walling applications, the base sheets are secured such that the longitudinal edges of the base sheets run vertically. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0036]    Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
           [0037]      FIG. 1  is a front elevation of a texture coated cladding system in accordance with a preferred embodiment of the present invention, with a base sheet shown cut away to reveal the underlying timber stud wall structure; 
           [0038]      FIG. 2  is a cross-sectional view of the texture coated cladding system of  FIG. 1  taken along section line A-A in  FIG. 1 ; 
           [0039]      FIG. 3  is a cross-sectional view of a texture coated cladding system according to another preferred embodiment of the invention, wherein the underlying structure is a steel frame; 
           [0040]      FIG. 4   a  is a side elevation of two base sheets in an installed configuration, in accordance with a first preferred embodiment of the present invention; 
           [0041]      FIG. 4   b  is a magnified fragmentary side elevation of the ship lap joint between the two base sheets shown in  FIG. 4   a;    
           [0042]      FIG. 5  is a side elevation of two base sheets in an installed configuration, in accordance with a second preferred embodiment of the present invention; 
           [0043]      FIG. 6  is a side elevation of two base sheets in an installed configuration, in accordance with a third preferred embodiment of the present invention; 
           [0044]      FIG. 7   a  is a perspective fragmentary view of a texture coated cladding system according to the present invention, showing a back sealing tape being applied over a vapour permeable membrane; 
           [0045]      FIG. 7   b  is a perspective fragmentary view of the texture coated cladding system of  FIG. 7   a , showing the back sealing tape applied over the vapour permeable membrane and between base sheets and an underlying structure, and showing a sealant being applied to the rebated surface of one of the base sheets in preparation for the installation of a second base sheet; and 
           [0046]      FIG. 7   c  is a perspective fragmentary view of the texture coated cladding system of  FIG. 7   a , showing the installation of the second base sheet. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0047]    Referring to the drawings, each of the texture coated cladding systems shown include a plurality of base sheets  1  for securing to an underlying structure  2 . In the embodiments shown in  FIGS. 2 and 3 , the underlying structures are a timber stud wall frame and a steel wall frame respectively. However, the underlying structures are not limited to these, and in other embodiments can be, for example, an existing wall structure with support battens, or a floor frame. 
         [0048]    Each of the base sheets  1  have an inner surface  3  and a planar generally smooth outer surface  4 , with each base sheet being profiled along at least one edge  5  to provide, on installation, a ship lap expressed joint  6  with an adjacent sheet. A portion  7  of the joint is clearly visible between the outer surfaces  4  of the base sheets and includes an interface line  8  defined by an inner overlapping edge  9  of one of the base sheets, the interface line thereby being set in from the outer surfaces of the base sheets. 
         [0049]    In the present embodiments, each base sheet is profiled on two opposing longitudinal edges  5 , with the longitudinal edges preferably being installed vertically to assist drainage along the joint, as best shown in  FIG. 1 . In other embodiments, some base sheets may be profiled on only one edge, which suits situations where the sheets are installed at the edges of the underlying structure and are not required to join to other sheets in a direction beyond the edges of the underlying structure. In other embodiments, the base sheets may be profiled on more than two edges in installations, for example, where horizontal joints as well as vertical joints are desired. The longitudinal edges of the base sheets may also be installed horizontally. 
         [0050]    In the preferred forms, the base sheets are pre-coated prior to installation with a suitable sealer or primer ready to receive a finish coating or coatings in accordance with the coating manufacturer&#39;s recommendations. If that is not the case, it may be necessary to seal or prime the sheets in situ. Choice of sealer will depend on the base sheet material—the type of texture coating to be applied and the coating manufacturer&#39;s requirements. 
         [0051]    The texture coated cladding systems shown also include a relatively low-build brushable or rollable texture coating  10  for application to the outer surfaces  4  of the installed base sheets  1 . Advantageously, these coatings include roll-on texture coatings that are readily available to end consumers and do not require the skills of specialist tradespeople to apply. The present embodiments include a coating of this type for application by a paint roller, which when applied has a preferred thickness of up to about 300 microns. Examples of suitable brushable or rollable texture coatings suitable for this application include Dulux® Fine Texture, Wattyl Granotex® Roll On, and Taubmans™ Armawall Ultrasand. In all cases, it is important that the coatings be applied strictly in accordance with the coating manufacturer&#39;s instructions. 
         [0052]    As best shown in  FIG. 4   b , the visible portion  6  of the joint defines a channel  11  between the outer surfaces  4  of adjacent base sheets  1 , the channel having an outer width  12  between the outer surfaces, and an inner width  13  at a depth set in from the outer surfaces. The interface line is set in at the maximum depth  14  of the channel. 
         [0053]    The profiled edges  5  of the base sheets  1  include some form of straight or curved chamfer along the edges  15  immediately adjacent the outer surface  4  of the base sheets  1  such that the outer width  12  of the channel is wider than the inner width  13  of the channel. The inner overlapping edge  9  of the one base sheet and the inside corner  16  of the rebate of the other base sheet are also curved. In the present embodiments, the various dimensions of these features are as follows: 
         [0000]    
       
         
               
             
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Approximate channel dimensions in preferred embodiments 
               
             
          
           
               
                   
                 Embodiment 
                 Outer width 
                 Inner width 
                 Maximum depth 
               
               
                   
                   
               
               
                   
                 FIG. 4 
                  7.0 mm 
                 3.0 mm 
                 4.0 mm 
               
               
                   
                 FIG. 5 
                 14.0 mm 
                 8.0 mm 
                 4.3 mm 
               
               
                   
                 FIG. 6 
                  4.4 mm 
                 1.0 mm 
                 4.1 mm 
               
               
                   
                   
               
             
          
         
       
     
         [0054]    In preferred embodiments, the outer width is up to about 15 mm. Preferably, the outer width is from about 3 mm to about 9 mm. It is preferred that the inner width is up to about 10 mm. Preferably, the inner width is from about 3 mm to about 9 mm, with the inner width, desirably, being less than the outer width. Further, it is preferred that the maximum depth of the channel is up to about 6 mm. Preferably, the maximum depth of the channel is from about 3 mm to 4.5 mm. It will be appreciated, however, that a variety of dimensions and combinations of dimensions can be achieved depending on the desired appearance of the installed system. 
         [0055]    The presently preferred embodiment is that shown in  FIG. 4 , preferably made from fibre cement, having a sheet thickness of around 8.5 mm (although this could vary), the channel having an outer width of approximately 7 mm, a depth of around 4 mm and an inner width of about 3 mm. Preferably all internal corners and edges are slightly curved as shown. There is also an overlap region of approximately 4 to 5 mm. It will be appreciated that this could be varied. For example, in order to increase weatherproofing capacity, it may be useful to increase the overlap region. 
         [0056]    The base sheets can be made of any suitable material such as, but not limited to, fibre cement, oriented strandboard, engineered wood, plywood, and masonite. In preferred forms, the base sheets are made of a nailable cellulose fibre reinforced cement. The currently preferred base sheet is a medium density fibre cement board designed for an exterior cladding application. 
         [0057]    In preferred forms the base sheets are pre-coated with an appropriate sealant or primer ready to receive a finish coating or coatings in accordance with the manufacturer&#39;s instructions. For fibre cement sheets of the preferred kind mentioned above an acrylic sealer is suitable. 
         [0058]    The preferred fibre cement sheets have the edges formed during manufacture by continuous milling, cutting, machining, pressing, extrusion, embossing, or any other suitable processes. The simple rebated profiles contemplated by the present invention are well suited to continuous manufacturing processes, especially where longitudinal edges are profiled. Hence, base sheets with these profiled edges can be manufactured relatively easily and cost effectively. The presently preferred method of forming the edges is cutting. 
         [0059]    As best shown in  FIGS. 7   a  to  7   c , the texture coated cladding systems of the present embodiments include a back sealing tape  17  adapted to span across the edges of the inner surfaces  3  of adjacent base sheets  1 . The back sealing tape is a 50 mm EPDM foam tape fixed between the studs  18  of the underlying timber frame structure and the ship lap joints  6  that coincide with the studs. The systems also include a sealant  19  for application between the overlapping rebated surfaces  20  of the ship lap joints  6  between adjoining base sheets  1 . The sealant in these embodiments is preferably a continuous 3 mm diameter bead of fluid joint sealant that sets to form a seal between the rebated surfaces  20 . 
         [0060]    The present embodiments also include a vapour permeable membrane  21  between the base sheets  1  and the underlying structure  2 , as best shown in  FIGS. 7   a  to  7   c . In embodiments such as these, where a back sealing tape  17  is included, the vapour permeable membrane is between the underlying structure  2  and the back sealing tape  17 . The vapour permeable membrane is pliable and serves to prevent moisture ingress, by acting as a drainage plane, whilst allowing water vapour build up from the underlying structure to escape. 
         [0061]    The present invention also provides a method of installing texture coated cladding. A preferred embodiment of the method involves installing the texture coated cladding systems described above. 
         [0062]    This preferred method includes the steps of: providing the plurality of base sheets  1  described above; securing the base sheets  1  to the underlying structure  2  such that each or at least one base sheet forms a ship lap joint  6  with an adjoining sheet, whereby, on installation, the portion  7  of the joint is visible between the outer surfaces  4  of the base sheets and includes the interface line  8  defined by the inner overlapping edge  9  of one of the base sheets, the interface line thereby being set in from the outer surfaces of the base sheets; and then applying the relatively low-build brushable or rollable texture coating  10  to the outer surfaces  4  of the installed base sheets  1 . 
         [0063]    The base sheets  1  are secured such that the visible portion  7  of the joint  6  defines the channel  11  between the outer surfaces  4  of adjacent base sheets, the channel having the outer width  12  between the outer surfaces, and the inner width  13  at a depth set in from the outer surfaces. The base sheets are also secured such that the interface line  8  is set in at the maximum depth  14  of the channel. Further, the base sheets  1  are configured and secured whereby the outer width  12  of the channel is wider than the inner width  13  of the channel. 
         [0064]    Furthermore, the base sheets  1  are preferably secured such that the longitudinal edges  5  of the base sheets run vertically. In other embodiments, the base sheets are secured whereby the longitudinal edges run horizontally, or any other orientation depending on the requirements of the installation. For example, the base sheets may be installed with edges running at oblique angles, especially where the sheets meet wall penetrations such as windows, or terminations such as rooflines. 
         [0065]    In all cases, it will be important to also ensure that installation complies with locally applicable building codes and regulations which may dictate certain spacings from ground surfaces and eaves and/or frame fixing requirements etc. 
         [0066]    In the present embodiments, the base sheets are configured and secured to achieve the dimensions detailed in Table 1 above. In other preferred embodiments, the base sheets are secured to achieve the preferred dimensions described above. In most cases the configuration of the ship lap expressed joint is such that adjacent sheets can be fixed with the edge most surfaces in a generally abutting relationship. 
         [0067]    The step in preferred form of the invention of applying the relatively low-build brushable or rollable texture coating  10  is preferably carried out by rolling on the coating with a paint roller. The relatively low-build brushable or rollable texture coating must be applied in accordance with the coating manufacturer&#39;s recommendations. In one form, the coating may be applied in two coats to a thickness of about 300 microns, but may also be applied in any number of coats to a variety of thicknesses according to the requirements of the particular installation and the recommendations of the coating manufacturer. If appropriately pre-sealed or primed base sheets are used, then, subject to the coating manufacturer&#39;s requirements, no other under coating may be required before the texture coating is applied. 
         [0068]    Rolling on or brush applying low-build texture coatings that are readily available to end consumers has the particular advantage of dispensing with the need for specialist relatively high-build trowel-applied texture coatings that require specialist tradespeople to install. 
         [0069]    It will also be appreciated that the cladding structure also enables a wider range of coatings to be applied, which of course do not need to be textured. 
         [0070]    The present embodiment of the method includes the step of applying the back sealing tape  17  between the underlying structure  2  and the base sheets  1  such that the back sealing tape spans across the inner edge surfaces  3  of adjacent base sheets. The present embodiment also includes the step of applying the sealant  19  between the overlapping rebated surfaces  20  of the ship lap joints  6  between adjoining base sheets  1 , as best shown in  FIG. 7   b.    
         [0071]    The present embodiment also includes the step of installing the vapour permeable membrane  21  to the underlying structure  2  before installing the back sealing tape  17 , and then installing the base sheets  1  over the back sealing tape. 
         [0072]    In one preferred form, the vapour permeable membrane  21  is fixed to the underlying structure  2  first, by means such as nailing, stapling, or gluing. The back sealing tape  17  is then positioned over the vapour permeable membrane  21  along the studs  18 . The sealing tape  17  can be glued into place or can have an adhesive coating on the back surface that adheres the sealing tape to the vapour permeable membrane  21 , as shown in  FIG. 7   a . The next step is to secure the base sheets  1  to the underlying structure  1 . 
         [0073]    At the studs  18 , the base sheets  1  are positioned such that suitable fasteners  22 , such as galvanised fibre cement nails, stainless steel brad nails, or screws, can be driven through the base sheets inboard of the profiled edges  5 , through the back sealing tape  17 , and into the stud  18  to secure the base sheets to the underlying structure  2 . The fasteners  22  are driven through until the fastener heads are flush with the outer surfaces  4  of the sheets. Thus, the fasteners  22  pass through the full thickness of the base sheets, and not through the reduced thickness rebated edge  5 . 
         [0074]    As shown in  FIG. 7   b , a bead of the fluid joint sealant  19  is then applied to the outwardly facing rebated surfaces  20  of the profiled edges  5  of the base sheets already secured onto the stud  18 . Next, further base sheets  1  are positioned onto the underlying structure  2  such that the inwardly facing rebated surface  20  of the profiled edges  5  of the further base sheets sit over the outwardly facing rebated surface  20  of the base sheets already secured onto the stud  18 , with the edge most surfaces of each sheet in, or close to, abutment with each other. Thus, the sealant  19  is sandwiched between the rebated surfaces  20  of the adjoining sheets, sealing the ship lap joint  6  formed between the sheets. 
         [0075]    The newly positioned base sheets  1  are then secured to the underlying structure  2  by means of fasteners  22  driven through the sheets at positions inboard of the profiled edges  5 , through the back sealing tape  17 , and into the stud  18 , until the fastener heads are flush with the outer surfaces  4  of the sheets, similar to the previously secured base sheets, and as shown in  FIG. 7   c . Excess sealant  19  is then wiped away from the visible portions  7  of the ship lap joints  6 . The relatively low-build brushable or rollable texture coating  10  is then applied as described above. 
         [0076]    The described embodiments exemplify the various advantages of the present invention. Having a portion of the joints between base sheets that are deliberately designed to be clearly visible, and in particular, having a recessed interface line between the sheets, eliminates or ameliorates the prior art problems of needing to hide joints effectively prior to coating, at the same time enabling a wider range of coating types to be used. 
         [0077]    The configuration of the ship lap joints contemplated by the present invention, and in particular, the configuration of the rebates in the profiled longitudinal edges, are well suited to large scale continuous manufacturing processes. This results in cost-effective manufacture of the base sheets, decreasing the material costs. 
         [0078]    Furthermore, for texture coated applications the present invention allows the use of relatively low-build brushable or rollable texture coatings that are readily available to end consumers. These are typically rolled-on in a convention manner dispensing with the need for specialist tradespeople applying specialist relatively high-build trowel-applied texture coatings. This results in significantly decreased installation costs and time, particularly decreased specialist labour costs and further savings in material costs. 
         [0079]    Finally, it will be appreciated that further variations are possible without departing from the scope of the invention or inventions described herein.