Cavity Wall System

Abstract

A cavity wall system and a method of forming a cavity wall including: a wall structure ( 1 ); a plurality of outer wall cladding panels ( 2 ); and a plurality of discrete mounting elements ( 4, 5, 6 ) for mounting the cladding panels a predetermined distance away from the wall structure ( 1 ) so as to form a substantially flat exterior wall surface ( 7 ) and a substantially uninterrupted internal wall cavity ( 8 ) between the cladding panels ( 2 ) and the wall structure ( 1 ); the mounting elements ( 4, 5, 6 ) being sized and arranged so as to allow substantially uninterrupted fluid flow throughout the cavity ( 8 ); and the system further including moisture control means defining a moisture control plane to minimise migration of liquid moisture from the cavity ( 8 ) into the wall structure ( 1 ). The invention also provides a mounting member ( 4 ) and a termination member ( 5 ) for use as mounting elements in the cavity wall system and method.

1 . A cavity wall system including:
 a wall structure;   a plurality of outer wall cladding panels; and   a plurality of discrete mounting elements for mounting the cladding panels a predetermined distance away from the wall structure so as to form a substantially flat exterior wall surface and a substantially uninterrupted internal wall cavity between the cladding panels and the wall structure;   the mounting elements being sized and arranged so as to allow substantially uninterrupted fluid flow throughout the cavity; and   the system further including moisture control means defining a moisture control plane to minimize migration of liquid moisture from the cavity into the wall structure.   
   
   
       2 . A cavity wall system according to  claim 1  wherein a lower periphery of the cavity includes an opening to permit drainage of liquid from the cavity and venting of the cavity. 
   
   
       3 . A cavity wall system according to  claim 1  wherein an upper periphery of the cavity includes a vent to permit venting of the cavity. 
   
   
       4 . A cavity wall system according to  claim 1  wherein the mounting elements include at least one mounting member and at least one termination member. 
   
   
       5 . A cavity wall system according to  claim 4  wherein the mounting member is a mounting member as defined in  claim 52 . 
   
   
       6 . A cavity wall system according to  claim 4  wherein the termination member is a termination member as defined in  claim 62 . 
   
   
       7 . A cavity wall system according to  claim 1  wherein the cladding panels define an exterior wall surface a substrate supporting at least one outer finishing layer. 
   
   
       8 . A cavity wall system according to  claim 7  wherein the outer finishing layer conceals edges between adjacent cladding panels and any exposed portions of the mounting elements to provide a monolithic finish over the exterior wall surface. 
   
   
       9 . A cavity wall system according to  claim 7  wherein the outer finishing layer is applied by rendering or textured coating. 
   
   
       10 . A cavity wall system according to  claim 7  wherein the outer finishing layer is sealed, primed or painted to produce an outer surface finish resembling that of monolithic masonry construction. 
   
   
       11 . A cavity wall system according to  claim 7  wherein the outer finishing layer includes a sub-layer of render, a reinforcing mesh layer over the sub-layer, and an external finishing layer over the reinforcing layer. 
   
   
       12 . A cavity wall system according to  claim 1  wherein the cladding panels are formed substantially from fibre cement sheet. 
   
   
       13 . A cavity wall system according to  claim 12  wherein an exterior surface of each cladding panel is coated with an outer finishing layer, and an interior surface of each cladding panel is covered with a carbonation reducing coating, so as to reduce differential carbonation within the fibre cement panel. 
   
   
       14 . A cavity wall system according to  claim 1  wherein the cladding panels are formed substantially from EPS. 
   
   
       15 . A cavity wall system according to  claim 1  wherein the wall structure is formed from concrete or masonry, and the moisture control plane is formed by a coating of sealant or moisture resistant paint on the cavity side of the structure. 
   
   
       16 . A cavity wall system according to  claim 1  wherein the wall structure is formed from a relatively dense or moisture-impervious concrete such that an additional coating of sealant or paint is not required to form the moisture control plane. 
   
   
       17 . A cavity wall system according to  claim 1  wherein a substantially waterproof pliable building membrane is used to cover and seal the wall structure, the membrane forming the moisture control plane. 
   
   
       18 . A cavity wall system according to  claim 1  wherein the wall structure is formed from a timber frame, and the moisture control plane is formed by a substantially waterproof pliable building membrane covering the outer or cavity side of the frame. 
   
   
       19 . A cavity wall system according to  claim 18  wherein the building membrane is formed from a plurality of overlapping membranes. 
   
   
       20 . A cavity wall system according to  claim 17  wherein the building membrane is permeable to moisture vapour. 
   
   
       21 . A cavity wall system according to  claim 17  wherein the building membrane includes an outer reflective surface to enhance the thermal insulation characteristics of the wall system. 
   
   
       22 . A cavity wall system according to  claim 1  further comprising a supplementary sarking membrane having a reflective outer surface to enhance the thermal insulation characteristics of the wall system. 
   
   
       23 . A cavity wall system according to  claim 1  wherein outwardly directed reflective surfaces are applied to both the cavity side of the cladding panels and the cavity side of the wall structure to enhance the thermal insulation characteristics of the wall system. 
   
   
       24 . A cavity wall system according to  claim 23  wherein the reflective surfaces are provided by paints, coatings, sarkings, membrane materials, or any combination thereof. 
   
   
       25 . A cavity wall system according to  claim 17  further comprising supplementary spacers to maintain the internal wall cavity between any one of the membranes and the cladding panels such that wind-induced movement of the membranes is minimized. 
   
   
       26 . A method of forming a cavity wall including the steps of:
 forming a wall structure;   providing a plurality of outer wall cladding panels; and   mounting the cladding panels a predetermined distance away from the wall structure with a plurality of discrete mounting elements to form a substantially flat exterior wall surface and a substantially uninterrupted internal wall cavity between the cladding panels and the wall structure;   sizing and arranging the mounting elements so as to allow substantially uninterrupted fluid flow throughout the cavity; and   providing moisture control means to define a moisture control plane adapted to minimize migration of liquid moisture from the cavity into the wall structure.   
   
   
       27 . A method according to  claim 26  further comprising the step of providing an opening at a lower periphery of the cavity to permit drainage of liquid from the cavity and venting of the cavity. 
   
   
       28 . A method according to  claim 26  further comprising the step of providing a vent at an upper periphery of the cavity to permit venting of the cavity. 
   
   
       29 . A method according to  claim 26  wherein the mounting elements include at least one mounting member and at least one termination member. 
   
   
       30 . A method according to  claim 29  wherein the mounting member is a mounting member as defined in  claim 52 . 
   
   
       31 . A method according to  claim 29  wherein the termination member is a termination member as defined in  claim 62 . 
   
   
       32 . A method according to  claim 26  further comprising the step of applying at least one outer finishing layer to the exterior wall surface defined by the cladding panels. 
   
   
       33 . A method according to  claim 32  wherein the at least one outer finishing layer conceals joins between adjacent cladding panels and any exposed portions of the mounting elements to provide a monolithic finish over the exterior wall surface. 
   
   
       34 . A method according to  claim 32  wherein the at least one outer finishing layer is applied by rendering or textured coating. 
   
   
       35 . A method according to  claim 32  including the step of sealing the outer finishing layer, priming the outer finishing layer or painting the outer finishing layer to produce an outer surface finish resembling that of monolithic masonry construction. 
   
   
       36 . A method according to  claim 32  wherein the step of applying the outer finishing layer includes the steps of applying a sub-layer of render, applying a reinforcing mesh layer over the sub-layer, and applying an external finishing layer over the reinforcing layer. 
   
   
       37 . A method according to  claim 26  wherein the cladding panels are formed substantially from fibre cement sheet. 
   
   
       38 . A method according to  claim 37  including the step of coating an exterior surface of each cladding panel with an outer finishing layer, and covering an interior surface of each cladding panel with a carbonation reducing coating, so as to reduce differential carbonation within the fibre cement panel. 
   
   
       39 . A method according to  claim 26  wherein the cladding panels are formed substantially from EPS. 
   
   
       40 . A method according to  claim 26  wherein the wall structure is formed from concrete or masonry, and the moisture control plane is formed by applying a coating of sealant or moisture resistant paint on the cavity side of the structure. 
   
   
       41 . A method according to  claim 26  wherein the wall structure is formed from a relatively dense or moisture-impervious concrete such that applying an additional coating of sealant or paint is not required to form the moisture control plane. 
   
   
       42 . A method according to  claim 26  including the steps of covering and sealing the wall structure with a substantially waterproof pliable building membrane, the membrane thereby forming the moisture control plane. 
   
   
       43 . A method according to  claim 26  wherein the wall structure is formed from a timber frame, and the moisture control plane is formed by covering the outer or cavity side of the frame with a substantially waterproof pliable building membrane. 
   
   
       44 . A method according to  claim 43  wherein the building membrane is formed from a plurality of overlapping membranes. 
   
   
       45 . A method according to  claim 42  wherein the building membrane is permeable to moisture vapour. 
   
   
       46 . A method according to  claim 42  wherein the building membrane includes an outer reflective surface to enhance the thermal insulation characteristics of the cavity wall. 
   
   
       47 . A method according to  claim 26  including the step of providing a supplementary sarking membrane having a reflective outer surface to enhance the thermal insulation characteristics of the cavity wall. 
   
   
       48 . A method according to  claim 26  including the step of applying outwardly directed reflective surfaces to both the cavity side of the cladding panels and the cavity side of the wall structure to enhance the thermal insulation characteristics of the cavity wall. 
   
   
       49 . A method according to  claim 48  wherein the reflective surfaces are provided by paints, coatings, sarkings, membrane materials, or any combination thereof. 
   
   
       50 . A method according to  claim 42  including the step of providing supplementary spacers to maintain the internal wall cavity between any one of the membranes and the cladding panels such that wind-induced movement of the membranes is minimized. 
   
   
       51 . A cavity wall formed by the method as defined in  claim 26 . 
   
   
       52 . A mounting member for use in the cavity wall system as defined in  claim 4  or in the method of forming a cavity wall as defined in  claim 29 , the mounting member including:
 a mounting portion adapted for attachment to a wall structure;   a spacing portion adapted to space at least one associated cladding panel outwardly from the mounting portion by a predetermined distance corresponding to an intended depth of the internal wall cavity;   and at least one positioning portion adapted for connection to the associated cladding panel;   the mounting member being adapted, in conjunction with a plurality of like members, to support and position a plurality of cladding panels in substantially contiguous each to edge relationship at the predetermined distance away from the wall structure, thereby to form a substantially flat exterior wall surface and a substantially uninterrupted internal wall cavity between the cladding panels and the wall structure.   
   
   
       53 . A mounting member according to  claim 52  wherein the mounting portion is adapted for attachment to the wall structure over the moisture control plane. 
   
   
       54 . A mounting member according to  claim 52  in the form of a mounting block wherein the mounting portion is defined by an inner face of the block, the spacing portion is defined by a main body of the block, and the positioning portion is defined by an outer face of the block. 
   
   
       55 . A mounting member according to  claim 54  adapted for positioning in spaced apart relationship with a plurality of like blocks to support and position a plurality of the cladding panels by means of fasteners driven into the cladding panels, through the respective blocks, and into the wall structure. 
   
   
       56 . A mounting member according to  claim 52  in the form of a mounting bracket, wherein the mounting portion includes a mounting plate, the spacing portion includes a spacing web, and the bracket further includes:
 a first pair of spaced apart substantially parallel positioning surfaces interconnected by an orthogonal web, both first positioning surfaces being substantially parallel to the mounting plate and located at one end of the spacing web opposite the mounting plate; and   a second pair of spaced apart substantially parallel positioning surfaces interconnected by an orthogonal web, both second positioning surfaces being substantially parallel to the mounting plate and located at the end of the spacing web opposite the mounting plate;   the first pair of positioning surfaces and the second pair of positioning surfaces and their respective interconnecting webs forming oppositely directed substantially U-shaped positioning channels, the positioning channels being adapted to receive and locate adjacent edges of adjoining cladding panels, to retain the panels in substantially contiguous each to edge relationship, outwardly of the wall structure.   
   
   
       57 . A mounting member according to  claim 56  wherein the mounting portion includes a perforation for a fastener. 
   
   
       58 . A mounting member according to  claim 56  wherein the spacing web includes a spacing plate extending substantially normally to the mounting plate by a predetermined distance corresponding to the intended depth of the wall cavity. 
   
   
       59 . A mounting member according to  claim 56  wherein the positioning surfaces are located on respective positioning plate flanges. 
   
   
       60 . A mounting member according to  claim 52  being profiled to allow substantially uninterrupted fluid flow around or through the member. 
   
   
       61 . A mounting member according to  claim 52  formed from a material or materials of sufficient strength to support the intended dead and imposed live loads, being selected from a group comprising metal, plastics, fibre cement, timber and composite materials. 
   
   
       62 . A termination member for use in the cavity wall system as defined in  claim 4  or in the method of forming a cavity wall as defined in  claim 29 , the termination member including:
 a mounting portion adapted for attachment to a wall structure;   a spacing portion extending outwardly from the mounting portion by a predetermined distance corresponding to an intended thickness of the internal wall cavity;   a positioning portion connected to the end of the spacing portion opposite the mounting portion, the positioning portion being adapted for connection to at least one associated cladding panel;   the termination member being adapted to support and position the associated cladding panel at the predetermined distance away from the wall structure, and to define an edge of the exterior wall surface;   the termination member further including a drainage portion adapted to permit drainage of liquid from the wall cavity.   
   
   
       63 . A termination member according to  claim 62  wherein the mounting portion is adapted for attachment to the wall structure over the moisture control plane. 
   
   
       64 . A termination member according to  claim 62  in the form of a starter strip wherein the mounting portion includes a mounting plate, the drainage portion includes a drainage surface extending outwardly from the mounting plate, and the positioning portion includes:
 an inner positioning surface extending in one direction from the drainage surface parallel to the mounting plate;   a support surface extending outwardly from the inner positioning surface; and   an outer positioning surface extending from the support surface parallel to the mounting plate;   whereby the inner positioning surface, support surface and outer positioning surface together form a substantially U-shaped channel adapted to receive and locate a peripheral edge of the associated cladding panel.   
   
   
       65 . A termination member according to  claim 64  wherein the drainage surface is configured to drain away from the mounting plate. 
   
   
       66 . A termination member according to  claim 64  wherein the drainage surface drains towards the support surface. 
   
   
       67 . A termination member according to  claim 64  wherein the drainage surface includes perforations for drainage or ventilation. 
   
   
       68 . A termination member according to  claim 64  wherein the support surface includes a drainage groove to permit drainage of liquid from the interior surface of cladding panels and away from the wall cavity. 
   
   
       69 . A termination member according to  claim 64  wherein the outer positioning surface is located on an outer positioning flange having perforations for keying with an over-coating render. 
   
   
       70 . A termination member according to  claim 64  including an alignment flange extending generally outwardly from the outer positioning flange for supporting and aligning an applied exterior wall surface coating. 
   
   
       71 . A termination member according to  claim 64  including a perforated flange extending away from the U-shaped channel generally orthogonally from the support surface for providing ventilation or drainage along an edge of the exterior wall surface. 
   
   
       72 . A termination member according to  claim 62  in the form of a top strip wherein the mounting portion includes a mounting plate, the spacing and ventilation portion includes a perforated spacing surface extending outwardly from the mounting plate, and the positioning portion includes:
 an inner positioning surface extending in one direction from the perforated spacing surface parallel to the mounting plate;   a support surface extending outwardly from the inner positioning surface; and   an outer positioning surface extending from the support surface parallel to the mounting plate;   whereby the inner positioning surface, support surface and outer positioning surface together form a substantially U-shaped channel adapted to receive and locate a peripheral edge of the associated cladding panel.   
   
   
       73 . A termination member according to  claim 72  wherein the outer positioning surface is located on an outer positioning flange having perforations for keying with an over-coating render. 
   
   
       74 . A termination member according to  claim 72  including an alignment flange extending generally outwardly from the outer positioning flange for supporting and aligning an applied exterior wall surface coating. 
   
   
       75 . A termination member according to  claim 72  including a perforated flange extending upwardly away from the U-shaped channel generally orthogonally from the support surface to provide ventilation along an edge of the exterior wall surface. 
   
   
       76 . A termination member according to formed from a material or material of sufficient strength to support the intended dead and imposed live loads, being selected from a group comprising metal, plastics, fibre cement, timber and composite materials