Building component and method for its manufacture

Abstract

A method of manufacturing a building component (1). The method includes the steps of providing a sheathing board (4) having a first planar surface (5) and a second planar surface on opposite sides of the sheathing board (4), bonding a breather membrane (2) to the first planar surface (5) of the sheathing board (4), and fitting the breather membrane (2) to the sheathing board (4) to provide a planar area of the breather membrane (2) confined by an outer edge (4a, 4a) of the first planar surface (5) of the sheathing board (4). Also provided are methods of constructing a building (100), building components (1) for mounting onto a building frame (20), and a building (100) comprising a cavity wall, a building frame (20) and a plurality of said building components (1).

Description

[0001] BUILDING COMPONENT AND METHOD FOR ITS MANUFACTURE

[0002] This application claims priority from GB2312006.6 filed 4 August 2023, the contents and elements of which are herein incorporated by reference for all purposes.

[0003] Field of the Invention

[0004] The present invention relates to a building component, a method of manufacturing the building component, a building constructed with the building component, and a method of constructing the building. In particular, although not necessarily exclusively, the building component relates to a sheathing board for building a cavity wall.

[0005] Background

[0006] A known method of building construction involves assembling a frame (e.g. a steel frame) and mounting an array of sheathing boards to the frame. The sheathing boards perform a number of functions such as providing weather resistance, fire resistance, thermal performance and acoustic performance. After the sheathing boards are applied, a breather membrane is wrapped around the construction, covering an outward facing surface of the sheathing boards. The breather membrane is typically flexible and is generally resistant to most weathering during the construction phase. Typically the breather membrane remains in position even when the outer layer of the building is constructed. It is therefore important that the breather membrane allows water vapour to permeate therethrough so that moisture can escape from the building.

[0007] The sheathing boards provide a mounting / support surface, e.g. for insulation, brackets and fagade items. An external facade may be constructed from bricks, render, or cladding panels, for example. A wall cavity may be provided between the external fagade and the sheathing boards. This can for example be filled with insulation material. Accordingly, even after the external fagade has been built, the breather membrane still has a function to repel any water that enters the cavity in order to shield the sheathing boards.

[0008] However, applying the breather membrane correctly during the construction phase can be difficult. In particular, it is necessary for the breather membrane to completely cover the outward facing surface provided by the array of sheathing boards. Accordingly, large quantities of the breather membrane, which is often supplied on a large roll or in strips, must be lifted against the array of sheathing boards and joined to the outward facing surface. This can be difficult to accomplish accurately in windy conditions. Any gaps between breather membrane sections must also be covered. Accordingly, it is natural for construction workers to use large amounts of breather membrane for this purpose, in order to ensure that all of the sheathing board surface is covered. This can be inefficient. Furthermore, preparing the outward facing surface for attaching the breather membrane can be time consuming. For example, double-sided tape is usually applied to the sheathing boards to hold the breather membrane in place. A sufficient amount of double-sided tape is required to ensure that the breather membrane is attached securely, at the expense of increased costs and construction time.

[0009] The present invention has been devised in light of the above considerations.

[0010] Summary of the Invention

[0011] According to a first aspect, the present invention provides a method of manufacturing a building component, the method including the steps: providing a sheathing board having a first planar surface and a second planar surface on opposite sides of the sheathing board; bonding a breather membrane to the first planar surface of the sheathing board; and fitting the breather membrane to the sheathing board to provide a planar area of the breather membrane confined by an outer edge of the first planar surface of the sheathing board.

[0012] The method of the first aspect differs from known manufacturing methods in that the breather membrane is fitted to the sheathing board. As a result, the known method of building construction may be simplified by eliminating the step of wrapping the breather membrane around a building frame in order to cover an array of sheathing boards. More specifically, building components may be manufactured at an off-site location, e.g. a factory, and transported to a building construction site.

[0013] According to a second aspect, the present invention provides a building component for mounting onto a building frame, the building component comprising: a sheathing board having a first planar surface and a second planar surface on opposite sides of the sheathing board; and a breather membrane bonded to the first planar surface of the sheathing board via an adhesive component formed therebetween, wherein a planar area of the breather membrane, defined by an outer edge of breather membrane, is confined by an outer edge of the first planar surface of the sheathing board.

[0014] The building component of the second aspect may be manufactured according to the method of the first aspect.

[0015] The fitting step may include reducing a width of the breather membrane to be less than or equal to a width of the first planar surface of the sheathing board.

[0016] The first planar surface may have a uniform width in a longitudinal direction. The planar area of the breather membrane may have a uniform width in the longitudinal direction. Accordingly, the planar area of the breather membrane and the first planar surface of the sheathing board may comprise parallel longitudinal edges. Alternatively, or additionally, the first planar surface may have a uniform width in a transverse direction perpendicular to the longitudinal direction. The planar area of the breather membrane may have a uniform width in the transverse direction. Accordingly, the planar area of the breather membrane and the first planar surface of the sheathing board may comprise parallel transverse edges.

[0017] The first planar surface of the sheathing board and / or the planar area of the breather membrane may be rectangular.

[0018] The planar area of the breather membrane may be defined by an outer edge of breather membrane. For example, the fitting step may include removing an edge portion of the breather membrane in order to reduce the planar area.

[0019] The breather membrane may be provided on a roll. For example, the longitudinal direction of the breather membrane may correspond to its roll / unroll direction. Reducing the width of the breather membrane may involve removing an end section of the roll e.g. by slicing through a cross-section of the roll perpendicular to its width.

[0020] The edge portion may be a projecting edge portion of the breather membrane. For example, the fitting step may include removing an edge portion of the breather membrane which projects, or would otherwise project, from the outer edge of the sheathing board when the breather membrane is bonded to the first planar surface of the sheathing board. The projecting edge portion may be determined by placing the breather membrane over the first planar surface of the sheathing board and identifying where the breather membrane overlaps the outer edge of the sheathing board.

[0021] Determining the planar area of the breather membrane may include measuring one or more spatial dimensions of the first planar surface of the sheathing board. As such, the planar area of the breather membrane may be determined before placing the breather membrane on the sheathing board.

[0022] The planar area of the breather membrane and the first planar surface of the sheathing board may be coextensive in at least one of the longitudinal direction or the transverse direction of the sheathing board.

[0023] Alternatively, or additionally, the width of the breather membrane may be reduced such that the planar area of the breather membrane is separated from at least one longitudinal edge or at least one transverse edge of the first planar surface of the sheathing board by a predetermined distance. The predetermined distance may be not less than 17 mm, e.g. not less than 18 mm, e.g. not less than 19 mm, e.g. not less than 20 mm. The predetermined distance may be not more than 18 mm, e.g. not more the 17.5 mm, e.g. not more than 17 mm. The outer edge of the breather membrane may provide a guide for a user to install fastening elements. For example, the fastening elements may be inserted into the sheathing board proximal the outer edge of the breather membrane.

[0024] The bonding step may include applying an adhesive component to a first major surface of the breather membrane and / or the first planar surface of the sheathing board. Subsequently, the first major surface of the breather membrane may be contacted to the first planar surface of the sheathing board. The adhesive component may comprise an acrylic polymeric material. The adhesive component may comprise one or more flame retardant compounds, which are configured to prevent the spread of fire at the interface between the breather membrane and a surface to which the breather membrane is attached.

[0025] The adhesive component may be applied to the first major surface of the breather membrane to provide a self-adhesive breather membrane having an adhesive coating. A release member, e.g. a release paper, may be configured to cover the adhesive coating. Advantageously, the release member enables the self- adhesive breather membrane to be more easily stored, i.e. before the breather membrane is eventually applied to the sheathing bond. The self-adhesive breather membrane may therefore be stored on the roll.

[0026] For example, the adhesive coating may be arranged on an inward-facing surface or an outward-facing surface of the breather membrane with respect to the roll.

[0027] When applied to the breather membrane or the sheathing board, the adhesive component may form an adhesive layer comprising an average area density of at least 75 g / m2, or at least 100 g / m2, or at least 125 g / m2, or at least 150 g / m2. The thickness of the adhesive layer may be approximately equal to the thickness of the breather membrane. For example, the thickness of the adhesive layer may be not less than 80%, e.g. not less than 90%, e.g. not less than 95%, of the thickness of the breather membrane.

[0028] For example, the thickness of the breather membrane may be not less than 80%, e.g. not less than 90%, e.g. not less than 95%, of the thickness of the adhesive layer.

[0029] The bonding step may be performed before or after the fitting step is performed.

[0030] The sheathing board may comprise at least one of cement, calcium silicate, and gypsum.

[0031] When the sheathing board comprises at least one of cement and calcium silicate, the sheathing board may satisfy the standard BS EN 12467:2012.

[0032] The sheathing board may be reinforced by fibres, e.g. discrete fibrous elements which are randomly dispersed, continuous strands or tapes, or nets or webs. When the sheathing board comprises cement, the sheathing board may further include a fibre-reinforced facer, e.g. a glass fibre mesh.

[0033] When the sheathing board comprises gypsum, the sheathing board may satisfy the standard BS EN 15283-1 :2008.

[0034] Preferably, the sheathing board comprises a substantially uniform thickness. The thickness of the sheathing board may be not less than 8 mm, e.g. not less than 10 mm, e.g. not less than 12 mm, e.g. not less the 14 mm, e.g. not less than 16 mm. The thickness of the sheathing board may be not more than 25 mm, e.g. not more than 23 mm, e.g. not more than 21 mm, e.g. not more than 19 mm, e.g. not more than 17 mm.

[0035] When the first planar surface of sheathing board is rectangular, the first planar surface may have a maximum height in the range 2900-3100 mm, e.g. in the range 2950-3050 mm, e.g. approximately 3000 mm. Alternatively, when the first planar surface of sheathing board is rectangular, the first planar surface may have a maximum height in the range 2300-2500 mm, e.g. 2350-2450 mm, e.g. approximately 2400 mm. When the first planar surface of sheathing board is rectangular, the first planar surface of sheathing board may have a minimum width in the range 1100-1300 mm, e.g. 1150-1250mm, e.g. approximately 1200 mm.

[0036] Preferably, the breather membrane comprises a substantially uniform thickness. The thickness of the breather membrane may be not more than 0.8 mm, e.g. not more than 0.5 mm, e.g. not more than 0.4 mm, e.g. not more than 0.3 mm. The thickness of the breather membrane may be not less than 0.15 mm, e.g. not less than 0.3 mm.

[0037] The building component may have a reaction to fire classification of B or above, a smoke generation classification of s1 , and a flaming droplets classification of dO, as defined in Fire Classification Standard BS EN 13501-1 :2018.

[0038] The breather membrane may be configured with a water vapour permeability (Sd) of less than 0.12 m, when tested according to BS EN ISO 12572:2016.

[0039] The breather membrane may be configured with an air permeation / thermal performance of less than 0.05 m3m-2h'1, when tested according to BS EN 12114:2000, with a relative pressure differential of 100 Pa.

[0040] The breather membrane may be configured to resist water penetration for up to 2 hours, when tested according to BS EN 1928:2000.

[0041] According to a third aspect, the present invention provides a method of constructing a building, including: manufacturing a plurality of building components using the manufacturing method of the first aspect; assembling a building frame; mounting the plurality of building components to the building frame to define at least part of an inner wall of a cavity wall, the breather membrane of each building component partially defining a cavity facing surface of the inner wall.

[0042] According to a fourth aspect, the present invention provides a building comprising a cavity wall, a building frame and a plurality of building components according to the second aspect, wherein the building components are mounted to the building frame to define at least part of an inner wall of the cavity wall, each breather membrane partially defining a cavity facing surface of the inner wall.

[0043] The building of the fourth aspect may be constructed according to the method of the third aspect.

[0044] The manufacturing step may include manufacturing a first building component and a second building component. The mounting step may include positioning the first building component adjacent the second building component on the building frame.

[0045] When the first building component is positioned adjacent to the second building component, the method of the third aspect may further include applying a first sealing element to the breather membranes of the first and second building components, respectively. The first sealing element may be configured to cover a joint gap between the first building component and the second building component for sealing the cavity facing surface of the inner wall. The joint gap may have an average width of not more than 10 mm, e.g. not more than 8 mm, e.g. not more than 6 mm, e.g. approximately 3 mm.

[0046] The first sealing element may comprise a strip of material having the same or similar properties to the breather membrane. For example, the first sealing element may be a self-adhesive strip of the breather membrane. The first sealing element strip may have a length approximately equal to the length of the joint gap, e.g. equal to total height or total width of an integer number of adjacent sheathing boards. The strip may have a width not less than 10 mm, e.g. not less than 20 mm, e.g. not less than 30 mm, e.g. not less than 40 mm. The strip may be supplied from a breather membrane roll (not shown).

[0047] The method of the third aspect may include attaching the one or more building components to the building frame by inserting a plurality of fastening elements through the / each sheathing board and into the building frame. Each fastening element may be inserted at a position having a minimum distance from the outer edge of the first planar surface of the / each sheathing board. This may reduce the risk that a fastening element tears through the outer edge of the sheathing board. The minimum distance may be not less than 15 mm, e.g. not less than 16 mm, e.g. not less than 17 mm, e.g. not less than 18 mm. The minimum distance may be predetermined based on the strength properties, e.g. tear strength, of the sheathing board. The strength properties may be determined by the material composition and the dimensions of the sheathing board.

[0048] The fastening elements may be screws, e.g. self-drilling screws having a drill point for drilling a hole into the building frame.

[0049] As mentioned above, the outer edge of the breather membrane may provide a guide for inserting the fastening elements. The minimum distance may therefore correspond to the predetermined distance separating the edge of the breather membrane from the edge of the first planar surface of the sheathing board. The fastening elements may be inserted between the breather membrane and outer edge of the first planar surface of the sheathing board.

[0050] Inserting the plurality of fastening elements may include penetrating the / each breather membrane from the cavity facing surface with the fastening elements. The method of the third aspect may further include applying a second sealing element to the / each breather membrane to cover locations where the / each breather membrane is penetrated by a respective fastening element for sealing the cavity facing surface of the inner wall.

[0051] The second sealing element may comprise a strip of material having the same or similar properties to the breather membrane. For example, the second sealing element may be a self-adhesive strip of the breather membrane. The second sealing element strip may have a length approximately equal to the maximum height of the sheathing board. The strip may have a width not less than 5 mm, e.g. not less than 8 mm, e.g. not less than 10 mm. The strip may be supplied from a breather membrane roll (not shown).

[0052] The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided. Summary of the Figures

[0053] Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which:

[0054] Figure 1 shows a schematic of an example building component in a front view.

[0055] Figure 2A shows a schematic of an example building component in a perspective view.

[0056] Figure 2B shows an enlarged section of the building component depicted in Figure 2A, illustrating the arrangement of the breather membrane, the adhesive layer and the sheathing board.

[0057] Figure 3A shows a schematic of example building components which are positioned adjacently.

[0058] Figure 3B shows a schematic of a first sealing element applied to the building components of Figure 3A to seal the breather membrane.

[0059] Figure 4A shows a schematic of an example building component with a plurality of fastening elements inserted therein.

[0060] Figure 4B shows a schematic of a second sealing element applied to the building component of Figure 4B to seal the breather membrane.

[0061] Figure 5 shows a schematic of a partly constructed building in a front view.

[0062] Figure 6 shows a schematic perspective view of a testing rig for fire resistant properties of a building component.

[0063] Detailed Description of the Invention

[0064] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0065] Figures 1-5 illustrate variants of building components 1 , 11 , 21 , 21 ’ which are interchangeable.

[0066] Figure 1 shows a schematic front view of a building component 1 for mounting onto a building frame 20 (see Figure 5). The building component 1 includes a breather membrane 2 with a planar area 3 bonded to a first planar surface 5 of a sheathing board 4. The sheathing board 4 has a second planar surface (not shown) on an opposite side of the sheathing board 4 to the first planar surface 5. The sheathing board 4 is rectangular, having a width A of approximately 1200 mm and a height B of approximately 2400 mm. In a variant of the building component (not shown), the height B may be approximately 3000 mm e.g. for use in the modular industry.

[0067] The planar area 3 of the breather membrane 2 is defined by a rectangular outer edge 6 of the breather membrane 2. The breather membrane 2 and the sheathing board 4 have approximately the same height B. Accordingly, the planar area 3 of the breather membrane 2 and the first planar surface 5 of the sheathing board 4 are coextensive in the longitudinal direction of the sheathing board 4. In other words, the outer edge 6 of the breather membrane 2 coincides with the transverse edges 4b of the sheathing board 4.

[0068] On the other hand, the breather membrane 2 has a width C which is narrower than the width A of the sheathing board 4. Specifically, the planar area 3 of the breather membrane 2 is separated from each longitudinal edge 4a of the first planar surface of the sheathing board by a predetermined distance D.

[0069] The predetermined distance D is approximately 17.5 mm. By using a separation around 17.5 mm, a user (i.e. a builder) mounting the building component 1 onto the building frame 20 can use the outer edge 6 of the breather membrane 2 as a guide for installing fastening elements 14. Details of mounting the building component 1 are discussed below (see Figures 3A to 5).

[0070] Accordingly, the outer edge 6 of the breather membrane 2 and therefore its planar area 3 are confined by an outer edge 4a, 4b of the sheathing board 4.

[0071] Preferably, the sheathing board 4 comprises at least one of cement, calcium silicate, and gypsum. The sheathing board 4 may be reinforced by fibres, e.g. glass fibres. The fibres may be discrete elements which are randomly dispersed, continuous strands or tapes, or nets or webs. The sheathing board 4 may include a fibre-reinforced facer.

[0072] The cement and calcium silicate sheathing boards 4 are preferably in accordance with the BS EN 12467:2012 standard. The gypsum sheathing boards 4 are preferably in accordance with the BS EN 15283-1 :2008 standard.

[0073] The sheathing board 4 may be a Cortex 0270 Class A1 Score’N’Snap Board.

[0074] Figures 2A-B show a schematic perspective view of a building component 11 according to another variant. In this building component 11 , the breather membrane 2 has the same height and width as the rectangular sheathing board 4 which are therefore coextensive. Figure 2B shows an enlarged section of the building component 11 of Figure 2A, illustrating the arrangement of the breather membrane 2 and the sheathing board 4 with respect to an adhesive layer 10 which is formed therebetween. All variants of the building component 1 , 11 , 21 , 21 ’ have the adhesive layer 10 which bonds the breather membrane 2 to the sheathing board 4.

[0075] Normally, the adhesive layer 10 is formed by applying an adhesive component (e.g. an acrylic polymeric material) to a first major surface (not shown) of the breather membrane 2 to provide a self-adhesive breather membrane 2. Preferably, a release paper (not shown) is applied to cover the adhesive side of the breather membrane 2 for ease of storage. For example, the breather membrane 2 can be stored on a roll (not shown) until it is required for bonding to the sheathing board 4. The adhesive layer 10 can also be formed by applying the adhesive component onto the first planar surface 5 of the sheathing board 4. Typically, the adhesive layer 10 has an average area density of approximately 150 g / m2. The inventors have found that loading at least 75 g / m2of the adhesive component is sufficient to form a strong bond.

[0076] Subsequently, the first major surface of the breather membrane 2 is contacted to the first planar surface 5 of the sheathing board 4. Thereafter, the building components 11 may be stacked onto a pallet for storage and transportation.

[0077] Figure 2B illustrates the relative layer thicknesses (not to scale) of the building component 11 . The sheathing board 4, the breather membrane 2 and the adhesive layer 10 each have substantially uniform thicknesses, respectively. The thickness Ts of the sheathing board 4 is typically in the range 8 to 25 mm, preferably about 12.5 mm. The thickness Tb of the breather membrane 2 is typically in the range 0.15 to 0.80 mm, e.g. 0.3 to 0.4 mm. The thickness Ta of the adhesive layer is preferably not less than 80% of the thickness of the breather membrane Tb, and vice versa. For example, the thickness Ta of the adhesive layer 10 may be approximately equal to the thickness Tb of the breather membrane 2.

[0078] Figures 3A-B show a schematic front view of two adjacent building components 21 , 21 ’ according to another variant. When building components 1 , 11 , 21 , 2T are mounted to the building frame 20 (see Figure 5) and positioned adjacently, a joint gap 12 is formed therebetween. Generally, the size of the joint gap 12 is minimised by forming an abutment between the respective outer edges 4a, 4b of adjacently mounted building components 1 , 11 , 21 , 21 ’. Typically, the joint gap has an average width of not more than 10 mm, e.g. preferably about 3 mm.

[0079] Notwithstanding this, the joint gap 12 naturally forms a discontinuity between adjacent building components 1 , 11 , 21 , 21 ’, which affects the weather resistant properties otherwise provided by the breather membranes 2. This can be mitigated by applying a first sealing element 16 to the breather membranes 2 to cover the joint gap 12 along the adjacent outer edges 4a, 4b.

[0080] Figure 3A illustrates the joint gap 12 formed between adjacent longitudinal edges 4b of a first building component 21 and a second building component 21 ’. In this case, the adjacent longitudinal edges 4b of each sheathing board 4 are configured in contact to reduce the size of the joint gap 12. Figure 3B shows a schematic of the first sealing element 16 applied to the building components 21 , 2T to seal the breather membrane 2. As shown in Figure 3B, the first sealing element 16 preferably comprises a self-adhesive strip of breather membrane material having approximately the same length as the length of the joint gap 12. Preferably, the strip has a width not less than 40 mm to ensure that the first sealing element overlaps the breather membranes 2 of the adjacent building components 21 , 2T. The strip may be supplied from a breather membrane roll (not shown).

[0081] Turning back to Figure 3A, two vertical arrangements of fastening elements 14 which are inserted through the sheathing boards 4 of the first and second building components 21 , 2T are shown. The fastening elements 14 are used for attaching each building component onto the building frame (see Figure 5). The fastening elements 14 are preferably located between the longitudinal edge 4b and the outer edge 6 of the breather membrane 2 for each building component 21 , 21 ’. This arrangement ensures that the fastening elements 14, which are typically exposed on the first planar surface 5, are completely covered by the first sealing element 16.

[0082] Prolonged and / or substantial stress on the sheathing boards 4 caused by the fastening elements 14 can lead to the fastening elements 14 tearing through the outer edge 4a, 4b. To mitigate this, each fastening element 14 is preferably inserted at a position having a minimum distance from the outer edge 4a, 4b of the sheathing board 4 not less than 15 mm. As mentioned, the outer edge 6 of each breather membrane 2 can function as a guide for positioning the fastening elements 14 for insertion into the sheathing boards 4.

[0083] Figure 4A shows a front view schematic of the building component 11 with a plurality of fastening elements 14 inserted therein. In this arrangement, the fastening elements 14 penetrate the breather membrane 2 as well as the sheathing board 4 and are partly exposed. As a result, the weather resistant properties of the breather membrane 2 are diminished and the fastening elements 14 may also be vulnerable to weather damage. As shown in Figure 4B, this can be mitigated by applying a second sealing element 18 to the building component 11 . The second sealing element 18 is configured to cover the exposed fastening elements 14 and seal the breather membrane 2.

[0084] Like the first sealing element 16, the second sealing element 18 preferably comprises a self-adhesive strip of breather membrane material. Preferably, the strip has a width not less than 10 mm to ensure that the second sealing element 18 completely covers the fastening elements 14. The strip preferably has a length approximately equal to the height B of the sheathing board 4 to cover a vertical arrangement of fastening elements 14. The strip may be supplied from a breather membrane roll (not shown).

[0085] Figure 5 shows a schematic front view of a partly constructed building 100. The partly constructed building 100 comprises a building frame 20 and a plurality of building components 1 mounted to the building frame 20. For illustrative purposes, the building components 1 are shown during different construction stages. Specifically, six adjacent building components 1 are mounted to the frame 20 and configured across a bottom row 22 and a middle row 24. In the bottom row 22, the breather membranes 2 are sealed by first sealing elements 16 and second sealing elements 18. A variant of the first sealing element 16’ extends horizontally across the building 100 covering a joint gap (not visible) between the adjacent transverse edges (not visible) of the building components 1 in the bottom row 22 and the middle row 24, respectively. In a top row 26, a single building component 1 is mounted to the frame 20 on a left hand side position. Therefore, the top row 26 has two vacant positions on the right hand side. In the middle row 24 and the top row 26, the breather membranes 2 have yet to be sealed at the joint gaps 12 and the locations of the fastening elements 14 using sealing elements 16, 16’, 18.

[0086] The plurality of building components 1 define part of an inner wall of a cavity wall (not shown). Therefore, each breather membrane 2 partially defines a cavity facing surface of the inner wall, which is sealed by the sealing elements 16, 16’, 18.

[0087] The frame 20 is preferably a steel frame with a thickness of 100 to 150 mm. The frame 20 comprises vertical struts 28 spaced approximately 600 mm apart. Therefore, each building component 1 having a width A of approximately 1200 mm is attached to the frame 20 using fastening elements 14 inserted along a vertical centre line and its longitudinal edges 4b. The fastening elements 14 may be screws. Preferably, the fastening elements 14 are self-drilling screws having a drill point (not shown) for drilling a hole (not shown) into the steel frame 20 to provide an increased grip of the steel frame by the screw thread as the fastening elements 14 are inserted. The building component 1 , 11 , 21 , 21 ’ may have a reaction to fire classification of B or above, a smoke generation classification of s1 , and a flaming droplets classification of dO, as defined in Fire Classification Standard BS EN 13501 -1 :2018.

[0088] Details of the testing procedure used to obtain these parameters will now be described. The testing procedure involves two parts, each requiring the test specimen to be prepared in accordance with BS EN 13238:2010.

[0089] In a first part of the testing procedure, three length and three width specimens of the building component 11 are prepared and tested according to BS EN ISO 11925-2:2020, which describes a standard method of testing vertically oriented test specimens under thermal attack from a single flame source. The specimens are mounted vertically in the specimen holder so that one end and both sides are exposed. The exposed end is positioned 30 mm from the end of the frame. Filter paper is placed beneath the specimen holder and replaced between tests. The flame burner is inclined at an angle of 45° and the flame height was set at 20 mm. A marker is placed 150 mm above the upper end of the burner. For 30 seconds, the flame is configured to impinge a vertical centre line of the specimen 40 mm above the bottom edge. The total test duration is 60 seconds after application of the flame.

[0090] The test found that no ignition occurred for each specimen of the building component. As such, it was determined that the building component 11 has a reaction to fire rating of at least E.

[0091] Figure 6 illustrates a schematic perspective view of a testing rig used during a second part of the testing procedure. A test specimen 50 of the building component 11 is tested according to BS EN 13823:2020. The test specimen 50 consists of two vertical wings 50a, 50b forming a right-angled corner, which is exposed to the flames 52 of a burner 54 placed at the bottom of the right-angled corner. The flames 52 are formed by the combustion of propane gas, injected through a sandbox to give a heat output of 30.7 ± 2.0 kW. The performance of the test specimen 50 is evaluated over a period of 20 minutes.

[0092] During testing, the testing specimen 50 is placed in a testing chamber (not shown), which is connected to a gas exhaust system capable of removing heat and gases from the test site. The exhaust system is operable, throughout the test, with an exhaust volume flow rate of 0.60 ± 0.05 m3 / s. Each of the vertical wings 50a, 50b are mounted to a specimen holder (not shown) formed of a fire-resistant material. The specimen holder includes two rectangular supporting frames to which the vertical wings 50a, 50b are attached, respectively. The burner 54 is angled at 45° to a substantially vertical join 56 between the two vertical wing portions 50a, 50b. The flow of propane to the burner 28 is configured so that the flame height is around 20 mm above the end of the burner.

[0093] The test specimen 50 is required to achieve a set of classifications, namely: (a) a reaction to fire rating, (b) a smoke generation rating, and (c) a flaming droplet rating. The ratings (a), (b), and (c) are determined by measuring a set of parameters including the heat release rate (HRR), and the smoke production rate (SPR). HRR is measured using an oxygen calorimeter arranged in the gas exhaust system, based on the principle that the amount of oxygen consumed in a fire is proportional to the amount of heat produced. SPR is measured by a light attenuation instrument mounted in the gas exhaust system. From the measured parameters, a series of classification indices are calculated, including a fire growth rate index (FIGRA), a lateral flame spread (LFS), a total heat release (THReoos), a smoke growth rate index (SMOGRA) and a total smoke production (TSPeoos).

[0094] The FIGRA and SMOGRA indices are calculated as follows:

[0095] FIGRA = 1000 .

[0096] SMOGRA = 1000 where HRRav is the heat release rate (measured in kW) averaged over 30 s, SPRav is the smoke production rate (measured in m2s-1) averaged over 60 s, and t (measured in s) is the time elapsed following the start of the test (e.g., the ignition of the burner). The units of FIGRA and SMOGRA are Ws-1and m2s-2, respectively. It will be appreciated that different heat release related threshold values for the FIGRA calculation are used in different classes to obtain FIGRAO.OMJ and FIGRAO,4MJ values.

[0097] The THReoos and TSPeoos values are calculated over the first 600 seconds of the test as follows: where HRR(t) is the heat release rate as a function of time, and SPR(t) is the smoke production rate as a function of time, and At is the data acquisition interval (measured in s) of the measurement. The units of THReoos and TSPeoos are MJ and m2, respectively.

[0098] In addition to the quantitatively measured parameters, a series of visual observations are also made during the test in order to identify flame spread and the subsequent falling of flaming droplets or particles. Specifically, filter paper is placed beneath the specimen holder to catch any flaming droplets from the test specimen 50. The lateral flame spread rating comprises a measure of whether the flame reaches an outer edge 58 of the wings 50a, 50b at a height between 500 mm and 1000 mm measured from the base of the test specimen 50.

[0099] The results of the second part of the testing procedure are presented in Table 1 as follows. Table 1

[0100] A reaction to fire rating of B is achieved if the FIGRAO,2MJ value is up to 120 Ws-1, if the THReoos value is up to 7.5 MJ, and if the lateral flame spread is observed to not reach the edge of the specimen. A smoke generation rating s1 corresponds to a SMOGRA value of up to 30 m2s-2and a TSPeoos value of up to 50 m2. A flaming droplets rating of dO is achieved if no flaming droplets / particles are observed within 600 seconds of the film specimen being exposed to thermal attack from the flame.

[0101] The breather membrane 2 preferably has a water vapour permeability (Sd) of less than 0.12 m when tested according to Standard Test Method BS EN ISO 12572:2016. This means that, when installed in the walls of a building, the breather membrane 2 is configured to allow water vapour to escape from the building to prevent the damp which can lead to the formation of mould.

[0102] The breather membrane 2 is preferably configured with an air permeability of less than 0.05 m3m-2h'1, when tested according to Standard Test Method BS EN 12114:2000 (modified according to BS EN 1026:2016). This property enables the breather membrane to reduce air flow through the walls of the building, which thereby improves the thermal performance of the building. In an exemplary arrangement, testing the air permeability of the breather membrane 2 involves providing a square film specimen of the breather membrane 2 having side lengths of 1 .3 m, which is mounted to a rectangular frame to form an exposed central test area of 1 .23 m2. During the test, the film is exposed to a relative pressure differential of up to 100 Pa.

[0103] The breather membrane 2 may be configured to resist water penetration for at least 2 hours, when tested according to Standard Method BS EN 1928:2000. Advantageously, the breather membrane 2 is therefore capable of reducing water leaks into the building. Testing resistance to water penetration requires that the breather membrane 2 is conditioned prior to testing for a minimum of 6 hours at 23 ± 5°C. The testing procedure involves providing a plurality of film specimens of the breather membrane 2, each forming a circular cut-out of film having a diameter of 150 mm. Each film specimen is arranged onto a separate piece of filter paper which is used to indicate water passage through the film. A cover plate is placed over each film specimen to prevent the film material lifting from the filter paper during the test. Each specimen is then subjected to a hydrostatic head of 200 mm for a period of 2 hours. The test is undertaken in an atmosphere of 65 ± 5% relative humidity, at a temperature of 20 ± 2°C, and with each film specimen being subjected to a water pressure differential of 2 kPa. The film specimens are then inspected for any discolouration of the filter paper. The test is satisfied if no discolouration of the filter paper is observed. ***

[0104] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

[0105] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

[0106] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

[0107] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0108] Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0109] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example + / - 10%.

Claims

Claims:1 . A method of manufacturing a building component, the method including the steps: providing a sheathing board having a first planar surface and a second planar surface on opposite sides of the sheathing board; bonding a breather membrane to the first planar surface of the sheathing board; and fitting the breather membrane to the sheathing board to provide a planar area of the breather membrane confined by an outer edge of the first planar surface of the sheathing board.

2. The method according to claim 1 , wherein the fitting step includes reducing a width of the breather membrane to be not more than a width of the first planar surface of the sheathing board.

3. The method according to claim 2, wherein the fitting step includes removing an edge portion of the breather membrane which projects, or would otherwise project, from the outer edge of the sheathing board when the breather membrane is bonded to the first planar surface of the sheathing board.

4. The method according to claim 2 or claim 3, wherein the width of the breather membrane is reduced such that the planar area of the breather membrane is separated from at least one longitudinal edge of the first planar surface of the sheathing board by a distance not less than 17 mm, optionally not more than 18 mm.

5. The method according to any preceding claim, wherein the bonding step includes: applying an adhesive component to a first major surface of the breather membrane and / or the first planar surface of the sheathing board; and contacting the first major surface of the breather membrane to the first planar surface of the sheathing board.

6. A method of constructing a building, including: manufacturing a plurality of building components using the manufacturing method of claims 1 to 5; assembling a building frame; mounting the plurality of building components to the building frame to define at least part of an inner wall of a cavity wall, the breather membrane of each building component partially defining a cavity facing surface of the inner wall.

7. The method according to claim 6, wherein: the manufacturing step includes manufacturing a first building component and a second building component; the mounting step includes positioning the first building component adjacent the second building component on the building frame; andthe method further includes applying a first sealing element to the breather membranes of the first and second building components, respectively, to cover a joint gap between the first building component and the second building component for sealing the cavity facing surface of the inner wall.

8. The method according to claim 6 or claim 7, including: attaching the one or more building components to the building frame by inserting a plurality of fastening elements through the / each sheathing board and into the building frame, wherein each fastening element is inserted at a position not less than 15 mm from the outer edge of the first planar surface of the / each sheathing board.

9. The method according to claim 8, wherein inserting the plurality of fastening elements includes penetrating the / each breather membrane from the cavity facing surface with the fastening elements, wherein the method further includes applying a second sealing element to the / each breather membrane to cover locations where the / each breather membrane is penetrated by a respective fastening element for sealing the cavity facing surface of the inner wall.

10. A building component for mounting onto a building frame, the building component comprising: a sheathing board having a first planar surface and a second planar surface on opposite sides of the sheathing board; and a breather membrane bonded to the first planar surface of the sheathing board via an adhesive component formed therebetween, wherein a planar area of the breather membrane, defined by an outer edge of breather membrane, is confined by an outer edge of the first planar surface of the sheathing board.11 . The building component according to claim 10, wherein the planar area of the breather membrane and the first planar surface of the sheathing board are coextensive in a longitudinal direction of the sheathing board.

12. The building component according to claim 10 or claim 11 , wherein the planar area of the breather membrane is separated from at least one longitudinal edge of the first planar surface of the sheathing board by a distance not less than 17 mm, optionally not more than 18 mm.

13. The building component according to any one of claims 10 to 12, wherein the sheathing board comprises at least one of cement, calcium silicate, and gypsum.

14. The building component according to claim 13, wherein the sheathing board comprising cement includes a fibre-reinforced facer, the facer optionally comprising a glass fibre mesh.

15. The building component according to claim 14, wherein the sheathing board comprising at least one of cement and calcium silicate satisfies the standard BS EN 12467:2012.

16. The building component according to claim 14, wherein the sheathing board comprising gypsum satisfies the standard BS EN 15283-1 :2008.

17. The building component according to any one of claims 10 to 16, wherein the sheathing board has a thickness of not less than 8 mm, and optionally not more than 25 mm.

18. The building component according to any one of claims 10 to 17, wherein the breather membrane has a thickness of less than 0.5 mm.

19. The building component according to any one of claims 10 to 18, wherein the first planar surface of sheathing board is rectangular having a maximum height in the range 2900-3100 mm, or alternatively in the range 2300-2500 mm.

20. The building component according to any one of claims 10 to 19, wherein the first planar surface of sheathing board is rectangular having a minimum width in the range 1 100-1300 mm.

21. A building comprising a cavity wall, a building frame and a plurality of building components according to any one of claims 10 to 20, wherein the building components are mounted to the building frame to define at least part of an inner wall of the cavity wall, each breather membrane partially defining a cavity facing surface of the inner wall.

22. The building according to claim 21 comprising a first building component and a second building component, wherein the first building component and the second building component are positioned adjacently, wherein the building comprises a first sealing element applied to the respective breather membranes of the first and second building components and configured to cover a joint gap between the first building component and the second building component for sealing the cavity facing surface of the inner wall.

23. The building according to claims 21 or 22, wherein the building components are attached to the building frame via a plurality of fastening elements extending through each sheathing board and into the building frame, wherein each fastening element is positioned not less than 15 mm from the outer edge of the first planar surface of each sheathing board.

24. The building according to claim 23, wherein each breather membrane is penetrated by the fastening elements, the building further comprising: a second sealing element applied to the / each breather membrane and configured to cover locations where the / each breather membrane is penetrated by a respective fastening element for sealing the cavity facing surface of the inner wall.

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