TECHNICAL FIELD

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.

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.

BACKGROUND OF THE INVENTION

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.

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

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.

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

According to a first aspect of the invention, there is provided a texture coated cladding system including: a plurality of base sheets for securing to an underlying structure; 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 to provide, on installation with an adjacent sheet, an overlapping 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.

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

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.

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. 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.

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.

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.

In one particularly preferred form, the sheets are approximately 8.5mm thick and the channel is of a generally truncated 'V shaped section having an outer width of approximately 7mm, a depth of around 4mm and an inner width of about 3mm.

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.

In preferred forms the base sheets are pre-coated with an appropriate sealer or primer to enable fexture coatinp. to commence in accordance with the manuf.ktiϋvr ^" ..

^~ iecυiiimenαauons.

Preferably, the cladding system is part of a texture coated cladding system. More preferably, using a relatively low build brushable or Tollable coating for application to the outer surfaces of the installed base sheets. - A -

Preferably, the relatively low-build brushable or reliable 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.

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.

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.

According to a second aspect of the invention, there is provided a method of installing texture coated cladding, the method including the steps of: providing a plurality of base sheets in accordance with the base sheets described above; securing the base sheets to an underlying structure such that at least one base sheet forms a ship lap joint with an adjoining sheet, whereby, on installation, a portion of the joint is clearly visible between the outer surfaces of the base sheets and includes 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 applying a relatively low-build brushable or rollable texture coating to the outer surfaces of the installed base sheets.

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

outer surfaces. Preferably, the base sheets are secured such that the interface line is set in at the maximum depth of the channel.

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.

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.

In one particularly preferred form, the sheets are approximately 8.5mm thick and the channel is of a generally truncated 'V shaped section having an outer width of approximately 7mm, a depth of around 4mm and an inner width of about 3mm.

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.

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's recommendations.

In one example, the step of applying the relatively low-build brushable or Tollable 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 ctrif tiv m >< ^{• •} >-< >" - ^■ > H Hh the πuπuf v*""v~ ^% ~ (f "cr* ^: "

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. 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

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 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;

Figure 2 is a cross-sectional view of the texture coated cladding system of Figure 1 taken along section line A-A in Figure 1 ;

Figure 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;

Figure 4a is a side elevation of two base sheets in an installed configuration, in accordance with a first preferred embodiment of the present invention;

Figure 4b is a magnified fragmentary side elevation of the ship lap joint between the two base sheets shown in Figure 4a;

Figure 5 is a side elevation of two base sheets in an installed configuration, in accordance with a second preferred embodiment of the present invention;

Figure 6 is a side elevation of two base sheets in an installed configuration, in accordance with a third preferred embodiment of the present invention;

according to the present invention, showing a back sealing tape being applied over a vapour permeable membrane;

Figure 7b is a perspective fragmentary view of the texture coated cladding system of Figure 7a, 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

Figure 7c is a perspective fragmentary view of the texture coated cladding system of Figure 7a, showing the installation of the second base sheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

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 Figures 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.

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.

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 Figure 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 fniKxiinvnK *h« Sπ«e sheet* *Kt ^» > M» ^■ > ^* '_ ^"• * ^{• • " ■} for example, where horizontal joints as well as vertical joints are desired. The longitudinal edges of the base sheets may also be installed horizontally.

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'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's requirements.

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 Tollable 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's instructions.

As best shown in Figure 4b, the visible portion 6 of the joint defines a channel 1 1 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. 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:

Table 1. Approximate channel dimensions in preferred embodiments

! Fmbodiment ¹ Outer width I Inner width Maximum dept' ^» i" i5iuv -T / .u nun j.υ mm 4.U mm

Figure 5 14.0 mm 8.0 mm 4.3 mm

Figure 6 4.4 mm 1.0 mm 4.1 mm

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.

The presently preferred embodiment is that shown in Figure 4, preferably made from fibre cement, having a sheet thickness of around 8.5mm (although this could vary), the channel having an outer width of approximately 7mm, a depth of around 4mm and an inner width of about 3mm. 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.

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 such as or similar to the products Hardiflex™, HardiTex®, Axon™, Matrix™, and Comtex®, as sold by the applicant. The currently preferred base sheet is a medium density fibre cement board designed for an exterior cladding application.

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's instructionsFor fibre cement sheets of the preferred kind mentioned above an acrylic sealer is suitable.

The preferred fibre cement sheets have the edges formed during manufacture by

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. As best shown in Figures 7a to 7c, 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 5 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.

10 The present embodiments also include a vapour permeable membrane 21 between the base sheets 1 and the underlying structure 2, as best shown in Figures 7a to 7c. 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,

15 by acting as a drainage plane, whilst allowing water vapour build up from the underlying structure to escape.

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.

20 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 ^heet^ the interface line therebv heinr «*** ' ^ρ fivm ttv ,I ^; IJ.T >α»rfV« ^ . * ^" 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.

The base sheets 1 are secured such that the visible portion 7 of the joint 6 defines the channel 1 1 between the outer surfaces 4 of adjacent base sheets, the channel having

30 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.

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.

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.

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.

The step in preferrred form of the invention of applying the relatively low-build brushable or Tollable 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'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

recommendations of the coating manufacturer. If appropriately pre-sealed or primed base sheets are used, then, subject to the coating manufacturer's requirements, no other under coating may be required before the texture coating is applied.

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.

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.

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 Figure 7b.

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.

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 Figure 7a. The next step is to secure the base sheets 1 to the underlying structure 1.

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 J " ¹ and into the %hui J S M -^YIMV the ba«e sheets to tV '»n»U^H »r»w ^«- ^, _k * ^, , _r . - m, iasteners 22 ^~ aϊe ^~ 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.

As shown in Figure 7b, 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, abuttment 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.

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 Figure 7c. Excess sealant 19 is then wiped away from the visible portions 7 of the ship lap joints 6. The relatively low-build brushable or Tollable texture coating 10 is then applied as described above.

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.

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.

of relatively low-build brushable or reliable 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. Finally, it will be appreciated that further variations are possible without departing from the scope of the invention or inventions described herein.