GB2613532A

GB2613532A - Drainage system

Info

Publication number: GB2613532A
Application number: GB2113388.9A
Authority: GB
Inventors: Francis Russell; Doouss Callum
Original assignee: Obex Protection Ltd
Current assignee: Obex Protection Ltd
Priority date: 2021-09-20
Filing date: 2021-09-20
Publication date: 2023-06-14
Also published as: WO2023041806A1

Abstract

A drainage system for installing at a corner between first and second wall sections of a building, wherein each wall section comprises an inner wall and an outer wall which together define a cavity therebetween. The drainage system comprises: a first support member configured to extend substantially between the inner and outer walls of the first wall section; a second support member configured to extend substantially between the inner and outer walls of the second wall section; and a flexible membrane suspended between the first and second support members to define a fluid flow path between the inner and outer walls. At least one of the first and second support members comprises: an attachment portion configured to attach the support member to one of the inner wall and the outer wall; and a membrane guiding portion coupled to the attachment portion and configured at a fall angle to guide the flexible membrane across the cavity in a substantially downward direction from the inner wall to the outer wall. The drainage system further comprises a wall attachment configured to attach the flexible membrane to the inner wall, wherein the wall attachment is shaped to conform to the corner between the first and wall sections.

Description

DRAINAGE SYSTEM

FIELD OF THE INVENTION

The present invention relates to a drainage system for a cavity formed between an internal wall and an outer wall of a building, and to a method of installing a drainage system within a cavity formed between an internal wall and an outer wall of a building.

BACKGROUND OF THE INVENTION

It is known to provide drainage systems within an internal wall cavity of a building. An example of a known cavity wall drainage system includes a flexible waterproof membrane which is draped between the inner and outer walls of the building. The membrane is typically held in position by embedding its ends within the inner and outer walls (e.g. by lapping an end of the membrane between vertically adjacent courses of brickwork).

The membrane may be supported by a support framework made of a rigid polymeric material. The membrane support framework is typically arranged beneath the membrane within the cavity and is typically secured in position by embedding its ends within the inner and outer walls. The support framework includes an upper surface which supports the membrane as it drapes across the internal wall cavity. The upper surface is angled to cause the membrane to slope from the inner wall to the outer wall in a downward direction.

Once the drainage system is installed, any water running down the inner wall is directed by the membrane across the wall cavity towards the outer wall. From there, the water is channeled out of the internal wall cavity by one or more weepholes located through the base of the outer wall.

A known problem with such membrane-based drainage systems is that it can be difficult to position the membrane so that it forms a smooth flow path which channels water away from the internal wall cavity. If the membrane is not installed correctly, it may form unwanted folds and sagging portions which allow the water to pool therewithin. This can be a particular problem when installing a membrane at the corner between two wall sections, which requires great skill in order to prevent bunching and/or stretching of the membrane.

An alternative approach to wall cavity drainage involves the use of a cavity tray drainage system, which involves a plurality of overlapping tray sections being arranged within the wall cavity. Each tray section directs water away from the cavity through the outer wall in a similar manner to the membrane drainage systems.

A problem with cavity tray drainage systems is that the individual tray sections must be made off-site using specialist tooling. Also, each tray section can be large and cumbersome to handle and can take up significant space on a building site.

In some situations, a particular tray section may not fit precisely within a wall cavity, and so it must be cut to size in order for it to be installed correctly. This requires specialist tooling to be brought on-site, which can take-up additional space.

A further problem with known cavity drainage systems is that they are typically formed of materials which do not meet the required fire classification standards, as stipulated by BS EN 13501-1.

The present invention aims to address one or more of the above problems with existing drainage systems.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a drainage system for installing at a corner between first and second wall sections of a building, wherein each wall section comprises an inner wall and an outer wall which together define a cavity therebetween, the drainage system comprising: a first support member configured to extend substantially between the inner and outer walls of the first wall section; a second support member configured to extend substantially between the inner and outer walls of the second wall section; and a flexible membrane suspended between the first and second support members to define a fluid flow path between the inner and outer walls; wherein at least one of the first and second support members comprises: an attachment portion configured to attach the support member to one of the inner wall and the outer wall; and a membrane guiding portion coupled to the attachment portion and configured at a fall angle to guide the flexible membrane across the cavity in a substantially downward direction from the inner wall to the outer wall; wherein the drainage system further comprises a wall attachment configured to attach the flexible membrane to the inner wall, wherein the wall attachment is shaped to conform to the corner between the first and second wall sections.

Accordingly, the flexible membrane may be attached to the inner wall at the corner between the two wall sections by the wall attachment. During installation of the drainage system, the wall attachment provides an additional area of contact between the membrane and the inner wall. The wall attachment is conveniently positioned between the first and second support members, and is thereby configured to orientate and stabilise the membrane in position so that it can be more easily supported by the support members. In this way, the wall attachment improves the positioning of the membrane such that it forms a smooth flow path across the cavity.

Further optional features of the invention will now be set out. These may be applied to any aspect of the invention singly or in any combination unless the context demands otherwise.

It will be appreciated that the inner and outer walls together form a section of the wall of the building. The inner and outer walls may extend in a substantially vertical direction to define a height of the wall section. The inner and outer walls may extend in a transverse, or widthwise, direction to define a width of the wall section. The inner and outer walls may be spaced apart in a depthwise direction (e.g. a transverse direction that is substantially perpendicular to the widthwise direction) in order to define a depth of the wall section.

It will be appreciated that the cavity is defined between the inner wall and the outer wall. For example, in a wall section comprising an inner wall and an outer wall, the cavity may be formed by spacing apart the inner and outer walls in the depthwise direction (i.e. a transverse direction that is substantially perpendicular to the widthwise and vertical directions of the inner and outer walls).

As described above, the drainage system may be arranged at a corner between the first wall section and the second wall section. Accordingly, the first wall section may be arranged, e.g. orientated, at an angle to the second wall section, to define the corner between the wall sections. For example, the first wall section may be arranged substantially perpendicular to the second wall section.

The corner between the first and second wall sections may be a convex corner, i.e. the corner extending outwardly. For example, an angle between a cavity facing surface of the inner walls of the respective wall sections may be less than 1800. In some cases this angle may be about 900 Alternatively, the corner between the first and second wall sections may be a concave corner, i.e. the corner extending inwardly. For example, the angle between the cavity facing surfaces of the inner wall sections may be greater than 1800. In some cases this angle may be about 270°.

The wall attachment may be arranged substantially higher than the membrane guiding portion of at least one of the first and second support members (e.g. at a position on the inner wall which is higher than the membrane guiding portions). In exemplary arrangements in which the attachment portion of at least one of the first and second support members is configured to attach the support member to the inner wall, the wall attachment may be substantially level with the attachment portion of the support member (i.e. the wall attachment may be arranged at substantially the same height as the attachment portion of the support member).

The wall attachment in use may be configured to attach the flexible membrane to the inner wall at a position which is substantially higher than the membrane guiding portions of the first and second membrane supports. In this way, the wall attachment allows the weight of the membrane to cause it to drape onto the support members, which thereby helps the user to accurately install the membrane across the cavity.

The wall attachment may comprise a wall facing surface. At least a portion of the wall facing surface may be attachable to the inner wall. The wall facing surface may be attached (e.g. bonded) to the inner wall. A fixing tape may be applied to at least a portion of the wall facing surface. Alternatively, the wall facing surface may be coated (e.g. directly coated) with an adhesive configured to adhere the wall attachment to the inner wall.

The fixing tape may comprise a film which is configured with an attachment means on at least one of its planar surfaces. The attachment means may comprise an adhesive coating, or layer. The film may be coated with an adhesive coating on both of its planar surfaces, for example to define a double-sided fixing tape. The adhesive coating on the fixing tape may be covered with a removable release layer (e.g. release tape) which protects the adhesive, when not in use. The release layer can be removed from the fixing tape before the wall attachment is installed on the inner wall.

The film of the fixing tape may be formed of a polyester fabric (e.g. a polyester scrim). The adhesive coating may comprise an acrylic dispersion. The release layer may comprise a silicone-coated paper. The fixing tape may be self-adhering. Furthermore, the film may be configured to exhibit an initial tackiness to enable installation of the tape. The tape may be configured to form an immediate cold seam, which is extremely strong and protects against draining rainwater.

According to an exemplary arrangement, a portion of fixing tape is provided (e.g. unspooled from a roll and then cut to size) with an exposed adhesive coating on a first planar surface of the fixing tape. The first planar surface may be installed on the wall facing surface of the wall attachment and adhered thereto by the adhesive coating. A release layer may be removed from an adhesive coating on a second planar surface of the fixing tape before the wall attachment is installed on the wall. It will be appreciated that the first and second planar surfaces of the fixing tape may be installed in any order.

The wall attachment and fixing tape may be supplied separately to the installation site Alternatively, the wall attachment may be delivered to the installation site with the fixing tape already attached. For example, the first planar surface of the fixing tape may be pre-installed onto the wall attachment. The release layer may be removed from the second planar surface immediately before installation of the wall attachment onto the inner wall.

The flexible membrane may be attached (e.g. bonded) to a membrane facing surface of the wall attachment. The membrane facing surface may be arranged opposite to the wall facing surface of the wall attachment. At least a portion of the flexible membrane may be attachable to the membrane facing surface of the wall attachment. For example, the membrane may comprise an attachment means configured to attach the membrane to the membrane facing surface of the wall attachment. For example, fixing tape may be interposed between the membrane and the membrane facing surface of the wall attachment. Alternatively, or in addition, at least a portion of the membrane facing surface of the wall attachment may be coated in an adhesive to attach the membrane facing surface to the membrane. Similar to the fixing tape, the adhesive coating may be covered with a removable release layer which protects the adhesive, and which can be removed before the wall attachment is installed.

As described above, the wall attachment is configured to be arranged at the corner between the first and second wall sections. The wall attachment may be deformed, e.g. folded, along a fold line to define a pair of angled flanges, or leaves. A first flange of the wall attachment may be configured to contact the inner wall of the first wall section, and a second flange may be configured to contact the inner wall of the second wall section. When in use, the fold line may be aligned vertically with the corner between the first and second wall sections.

In an exemplary arrangements in which the corner between the first and second wall sections has a convex profile, then the wall attachment may be configured such that an angle between the wall facing surfaces of the first and second flanges is less than 1800, typically corresponding to the angle between the cavity facing surfaces of the inner wall sections. In alternative arrangements in which the corner between the first and second wall sections has a concave profile, then the wall attachment may be configured such that the angle between the wall facing surfaces of the first and second flanges is greater than 180°, typically corresponding to the angle between the cavity facing surfaces of the inner wall sections.

The wall attachment may comprise a metal or metal alloy. For example, the wall attachment may comprise stainless steel. By forming the wall attachment out of a fire-resistant material, such as stainless steel, this enables the drainage system to withstand high temperatures in the event of a building fire. The use of metal or metal alloy materials enables the wall attachment to meet the amended building regulations which require that a cavity drainage system should achieve an A2-s1,d0 fire classification according to BS EN 13501-1.

The wall attachment may be formed of a plastically deformable material. For example, the plastically deformable material may comprise a metal or metal alloy, such as stainless steel.

In this way, the wall attachment may be deformed in use to match the profile of the inner wall at the corner between the first wall section and the second wall section.

The wall attachment may be folded along a fold line to define a pair of angled flanges. A first flange may contact the inner wall of the first wall section, and a second flange may contact the inner wall of the second wall section. When in use, the fold line may be aligned vertically with the corner between the first and second wall sections.

The wall attachment may be configured with one or more perforation(s) at a required fold location. For example, a plurality of perforations may be arranged in a straight line on a surface of the wall attachment to define the fold line. The perforation(s) make it easier to deform the attachment along the fold line. The wall attachment may be prefabricated with the perforation(s) prior to being delivered to the installation site.

At least one, or each, of the first and second support members may be arranged near to the corner between the first and second wall sections in order to provide increased support and structure for the flexible membrane at the corner between the wall sections.

The drainage system may comprise further support members configured to provide further support for the flexible membrane. The further support members may be spaced apart in a width-wise direction along at least one, or each, of the first and second wall sections.

At least a portion of an upper surface of at least one, or each, of the first and second support members may be attachable to the flexible membrane, e.g. to an underside of the membrane. At least a portion of the upper surface may be attached (e.g. bonded) to the flexible membrane. For example, fixing tape may be arranged on a membrane facing surface of at least one, or each, of the support member(s). For example, the fixing tape may be interposed between the membrane and the membrane facing surface of the support member. The fixing tape may be configured as described above in relation to the wall attachment.

Alternatively, or in addition, at least a portion of one side of the flexible membrane may be attached (e.g. bonded) to at least one, or each, of the first and second support members. For example, at least a portion of one side of the flexible membrane may be coated with an adhesive configured to adhere the flexible membrane to at least one, or each, of the first and second support members. Prior to the flexible member being bonded to the support member, the adhesive coating may be covered with a release layer to protect the adhesive coating.

The attachment portion of at least one, or each, of the first and second support members may be configured with a wall facing surface. The wall facing surface may be configured to be attached (e.g. bonded) to a vertical surface of the inner wall or outer wall. For example, at least a portion of the wall facing surface may be coated with an adhesive configured to adhere the wall facing surface to the inner wall or outer wall. Prior to installation of the support member, the adhesive coating may be covered with a release layer.

The attachment portion may be configured to attach the support member to the inner wall.

The support member may further comprise an anchor portion configured to attach the support member to the outer wall. The anchor portion may be configured to be lapped at least partially through the outer wall. This allows the support member to be secured in position relative to the outer wall, and thereby helps to support the flexible membrane across the cavity.

At least one, or each, of the first and second support members may be comprise a metal or metal alloy. Therefore, the support members may provide increased resistance to failure in the event of a fire.

At least one, or each, of the first support member and the second support member may comprise stainless steel. At least one, or each, of the first and second support members may be formed of a plastically deformable material. This enables the attachment and/or anchor portion(s) of the support member to be deformed, relative to the membrane guiding portion, so as to change the fall angle of the membrane guiding portion. At least one or each of the first and second members may be configured with one or more perforation(s) at a respective fold location, as described in relation to the wall attachment.

The drainage system may comprise at least one weep channel, which may be arranged within the outer wall. The at least one weep channel may be fluidly connected to the flexible membrane. In exemplary arrangements in which the flexible membrane is lapped through the outer wall, the at least one weep channel may be arranged at the same vertical position in the outer wall as the lapped flexible membrane. The weep channel may be arranged at the same vertical position as the lapped anchor portion of the support member.

The weep channel may enable water to drain through the outer wall (i.e. away from the cavity). The weep channel may also provide ventilation to the cavity (e.g. to allow air to flow into the cavity).

The flexible membrane may comprise a plurality of flexible membrane portions which are configured to extend across different sections of the cavity. The flexible membrane portions may be arranged, in use, such that they lie adjacent to each other to form a continuous membrane which extends in a transverse, or width-wise, direction along each wall section.

In an exemplary arrangement, the membrane may comprise a first membrane portion which extends along at least a portion of the of the first wall section. The first membrane portion may be supported at one end by the first support member.

A second membrane portion may be configured to extend along at least a portion of the second wall section. The second membrane portion may be supported at one end by the second support member.

A third membrane portion may be configured to extend along at least a portion of the first and second wall sections, so as to cover the corner therebetween. The third membrane portion may be supported by the first and second support members.

A first lateral, or side, edge of the third membrane portion may be arranged on the first to support member, near to (e.g. adjacent to) an opposing lateral edge of the first membrane portion. A second lateral edge of the third membrane portion may be arranged on the second support member, near to (e.g. adjacent to) an opposing lateral edge of the second membrane portion.

The opposing lateral edges of the flexible membrane portions may be arranged to abut, or overlap, with each other in order to form a seam therebetween. The seam may extend in a lengthwise direction along the membrane guiding portion of the respective membrane support. An adhesive, or sealant, may be applied to the seam to prevent ingress of water between the membrane portions. The sealant may be applied with a mastic applicator.

At least a portion of one side of the flexible membrane may be attachable to the inner wall. At least a portion of one side of the flexible membrane may be attached to the inner wall when the drainage system is installed. For example, fixing tape (e.g. a double-sided fixing tape) may be interposed between the membrane and the inner wall. The fixing tape may extend parallel to an upper edge of the membrane. The fixing tape may be configured as described above in relation to the wall attachment and/or support members.

Alternatively, or in addition, at least a portion of one side of the flexible membrane may be coated with an adhesive configured to adhere the membrane to the inner wall. For example, the adhesive coating may extend parallel to an upper edge of the membrane. Prior to the installation of the flexible membrane, the adhesive coating may be covered with a release layer, for example to prevent the adhesive from adhering the membrane to the wrong part of the inner wall.

The flexible membrane may comprise a fibrous material which may be faced on at least one side with a fire-resistant water-resistant material. The fire-resistant water-resistant material (i.e. a material that is both fire-resistant and water-resistant) may comprise silicone. The fibrous material may comprise a plurality of glass fibres. The fibrous material may be a woven fibrous material. A problem with known membrane-based drainage systems is that the membrane can be susceptible to failure in the event of a fire, in view of the typical materials used for the membrane. By forming the flexible membrane out of fire-resistant materials, the present drainage system is able to satisfy stringent fire safety buildings regulations. In the event of a fire, the use of fire-resistant materials prevents the spread of fire to other areas of the building through the wall cavity (e.g. between adjacent floors of a building).

At least one, or each, of the inner and outer walls may be constructed from a plurality of masonry units. For example, the inner wall may be formed of concrete masonry units, e.g. concrete blocks. The outer wall may be formed of bricks. The masonry units can be laid on top of each other to build up the walls, in a manner that would be readily understood by the skilled person. According to an alternative exemplary arrangement, the at least one or each of the inner and outer walls may be formed of panels which, for example, may be made of wood. Furthermore, it will be appreciated that the inner and outer walls may be formed of any number of building materials without departing form the scope of the present invention. According to an exemplary arrangement, at least one, or each, of the inner and outer walls may be formed of any one of concrete, gypsum core board, cement particle board and calcium silicate board.

According to a second aspect, there may be provided a method of assembling the drainage system according to the first aspect. The method comprises: attaching the wall attachment to the flexible membrane; attaching the attachment portion of the first support member to the inner wall or the outer wall of the first wall section; attaching the attachment portion of the second support member to the inner wall or the outer wall of the second wall section; attaching the wall attachment to the corner between the first and second wall sections; and arranging the flexible membrane onto the membrane guiding portion to guide the membrane across the cavity in a substantially downward direction from the inner wall to the outer wall.

The membrane may be cut to size in order to fit within the cavity. For example, the membrane may comprise a plurality of membrane portions wherein at least one, or each, of the membrane portions may be pre-cut to a predetermined size and shape. When on-site, the membrane portions may be further cut to fit the specific dimensions of the cavity.

In exemplary arrangements in which an adhesive coating is applied to a surface of the drainage system, for example the support member, the wall attachment or the flexible membrane, then the adhesive coating may be covered in a release layer, e.g. a release tape.

The method may comprise removing the release layer from the adhesive coating immediately prior to installing the component of the drainage system.

The method may comprise, once the membrane is arranged in place within the wall cavity, applying an adhesive, or sealant, to a seam which may have been formed between the edges of two adjacent flexible membrane portions. In so doing, the seam between the membrane portions may be sealed to prevent ingress of water.

The invention includes the combination of the preferred or optional features described except where such a combination is clearly impermissible or expressly avoided.

BRIEF DESCRIPTION OF THE DRAW NGS

Aspects and embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of a drainage system according to a first embodiment of the present disclosure, the drainage system being configured to direct liquid across a cavity; Figure 2 is a perspective view of a pair of support members and a wall attachment of the drainage system shown in Fig. 1.

Figures 3 to 7 show different stages of a method of installing the drainage system shown in Fig. 1.

DETAILED DESCRIPTION

Aspects and embodiments of the disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

Figs. 1 and 2 show the components of a drainage system 10 installed in the cavity between an inner wall 12 and an outer wall 14 of a building. In particular, the drainage system 10 is arranged at a corner between a first wall section 16a and a second wall section 16b. Each wall section 16a, 16b comprises an inner wall 12 and an outer wall 14, which together define cavities of each respective wall section. As shown in Fig. 2, the cavities extend between the first and second wall sections 16a, 16b to define a single continuous cavity.

The drainage system 10 comprises a flexible membrane 20 which extends between the inner and outer walls 12, 14 of the first and second wall sections 16a, 16b, as shown in Fig. 1. The flexible membrane 20 is supported by a plurality of support members 18a, 18b which also extend between the inner and outer walls 12, 14, as shown in Fig. 2. The flexible membrane 20 is attached to the inner wall 12 by a wall attachment 22 which is positioned at the corner between the two wall sections 16a, 16b.

The wall attachment 22 provides an area of contact between the membrane 20 and the inner wall 12 prior to the membrane 20 being attached to the support members 18a, 18b. The wall attachment 22 helps to orientate and stabilise the membrane 20 in position so that it can be more easily affixed to the support members 18a, 18b. In this way, the wall attachment 22 prevents pooling of water on the membrane 20 and ensures that the membrane 20 forms a smooth flow path for directing water across the cavity.

Each of the inner and outer walls 12, 14 extend in a substantially vertical direction to define a height (H) of each wall section 16a, 16b. The walls 12, 14 also extend in a transverse, or width-wise, direction to define a width (VV) of each wall section 16a, 16b. Also, the inner and outer walls 12, 14 are spaced apart in a depth-wise direction (e.g. a direction which is substantially perpendicular to the width-wise direction) to define a depth (D) of each wall section 16a, 16b, or the depth of the cavity.

In this embodiment, the wall sections 16a, 16b intersect to define a corner having a convex profile (i.e. the corner extends outwardly from the building). The first wall section 16a is substantially perpendicular to the second wall section 16b to form a 90° angle therebetween.

It will be readily apparent on the basis of this disclosure how the embodiment can be modified to be suitable for a concave profile corner.

The inner and outer walls 12, 14 are constructed from a plurality of masonry units. The inner wall 12 is formed from concrete masonry units, e.g. concrete blocks, and the outer wall 14 is formed of bricks. The masonry units are laid on top of each other in order to build up the respective inner and outer walls 12, 14, as would be understood by the skilled person. It will be appreciated, however, that the inner and outer walls 12, 14 may be formed various alternative building materials without departing form the scope of the present disclosure.

The flexible membrane 20 comprises a plurality of membrane portions 20a, 20b, 20c which are arranged adjacently to one another, as shown in Fig. 1. A first membrane portion 20a extends between the inner and outer walls 12, 14 of the first wall section 16a. A second flexible membrane portion 20b is disposed between the inner and outer walls 12, 14 of the second wall section 16b, and a third flexible membrane portion 20c is arranged between the inner and outer walls 12, 14 at the intersection between the wall sections 12a, 12b.

The flexible membrane portions 20a, 20b, 20c are each made from a fibrous woven material which is faced on at least one side with a continuous layer of fire-resistant water-resistant material. The fire-resistant water-resistant material may be a silicone, for example. The fibrous material may be woven glass fibre, for example.

At least a portion of one side of the flexible membrane 20 is covered in a fixing tape configured to adhere the membrane 20 to the inner wall 12. The fixing tape is arranged onto an upper region of the wall facing surface of the membrane 20 to provide a watertight seal between the membrane and the inner wall 12.

The wall attachment 22 is shaped to conform to the corner between the first and second wall sections 12a, 12b. In particular, the wall attachment 22 is folded along a fold line to define a pair of angled flanges. A first flange contacts the inner wall 12 of the first wall section 16a, and a second flange contacts the inner wall 12 of the second wall section 16b. When in use, the fold line is aligned vertically with the corner between the first and second wall sections 16a, 16b.

The wall attachment 22 is formed of a plastically deformable material so that it can be folded to match the profile of the inner wall 12 at the corner between the first and second wall sections 16a, 16b. In an exemplary arrangement, the wall attachment 22 comprised of a metal or metal alloy, such as stainless steel, which increases fire resistance of the drainage system 10.

The wall attachment 22 has a wall facing surface, at least a portion of which is coated with an adhesive configured to adhere the wall attachment 22 to the inner wall 12. The flexible membrane 20 is also bonded to a membrane facing surface of the wall attachment 22, which is arranged opposite to the wall facing surface of the wall attachment 22.

As described above, the wall attachment 22 attaches the flexible membrane 20 to the inner wall 12. In particular, the wall attachment 22 attaches an upper portion of the third flexible membrane portion 20c to the inner wall 12. In this way, the wall attachment 22 allows the membrane to be easily draped from above onto the support members 18a, 18b, which thereby helps the user to accurately install the membrane 20 across the cavity.

The support members 18a, 18b are arranged either side of the corner between the wall sections 12a, 12b, as shown in Fig. 2. The flexible membrane 20 is supported by, and extends between, the first and second support members 18a, 18b to define a fluid flow path between the inner and outer walls 12, 14.

A first support member 18a extends between the inner and outer walls 12, 14 of the first wall section 16a, and a second support member 18b extends between the inner and outer walls 12, 14 of a second wall section 16b.

Each of the first and second support members 18a, 18b includes an upper attachment portion 26a, 26b, by which the respective support members 18a, 18b are attached to the inner wall 12. Each of the attachment portions 26a, 26b is configured with a wall facing surface which, in use, is coated with an adhesive configured to adhere the support member to a vertical surface of the inner wall 12, as shown in Fig. 2.

The fixing tape comprises a film which is coated with an adhesive on both of its planar surfaces to define a double-sided fixing tape. When not in use, the fixing tape is spooled onto a roll for storage, which protects the adhesive coating provided on the first planar surface.

The adhesive coating on the second planar surface is covered with a removable release layer which protects the adhesive, for example when the first planar surface is bonded to component of the drainage system. The release layer can be removed before the second planar surface is of the fixing tape is installed.

The film of the fixing tape is formed of a polyester fabric (e.g. a polyester scrim), which provides structural support for the tape. The adhesive coating comprises an acrylic dispersion. The release layer is a silicone-coated paper. An example of a suitable fixing tape is CORTEX® double sided tape.

A sealant (not shown) is applied to the seams which form between adjacent sections of the flexible membrane. The sealant is configured to prevent ingress of air and/or moisture through the membrane seams. The sealant is applied with a mastic applicator.

Each of the support members 18a, 18b is provided with an anchor portion 28a, 28b which anchors the respective support member 18a, 18b to the outer wall 14. In particular, the anchor portions 28a, 28b are configured to be lapped at least partially through the outer wall 14 as is depicted in Fig. 2.

Each of the support members 18a, 18b further comprises a membrane guiding portion 24a, 24b which is configured to guide the membrane 20 across the internal cavity. Considering the first support member 18a, for example, the membrane guiding portion 24a is configured at a fall angle to its attachment portion 26a and anchor portion 28a. In this way, the membrane guiding portion 24a is configured to guide the flexible membrane 20 across the cavity in a substantially downward direction from the inner wall 12 to the outer wall 14.

The membrane guiding portion 24b of the second support member 18b is configured in a similar manner to that of the first support member 18a, so as to provide a consistent fall angle for the membrane 20 across the cavity.

When in use, the wall attachment 22 is positioned higher than the membrane guiding portions 24a, 24b of the respective first and second support members 18a, 18b, as shown in Fig. 2. In particular, the wall attachment 22 is arranged substantially at the same height on the inner wall 12 as the attachment portions 26a, 26b of the first and second support members 18a, 18b. This ensures that the connection provided by the wall attachment 22 between the membrane 20 and the inner wall 12 is suitable to enable the membrane to drape easily onto the membrane guiding portion of the support members 18a, 18b.

The upper surfaces of the first and second support members 18a, 18b are arttached to the flexible membrane 20 with double-sided fixing tape (not shown). Alternatively, a coating of adhesive may be applied to the support members 18a, 18b and/or the corresponding regions of the underside of the membrane 20 to bond the membrane to the support members 18a, 18b.

Each of the first and second support members 18a, 18b are made of stainless steel, which enables the support members to be deformed so as to provide the desired fall angle for the membrane 20. Forming the support members from stainless steel also ensures their fire resistance.

The drainage system 10 further includes plurality of weep channels (not shown), which are arranged at various points along the outer wall 14. The weep channels are arranged at the same vertical position in the outer wall 14 as the membrane and the anchor portions 28a, 28b of the support members 18a, 18b. In this way, the weep channels are fluidly connected to the membrane portions 20a, 20b, 20c to allow water to drain through the outer wall 14 (i.e. away from the cavity).

A method of installing the drainage system 10 will now be described with reference to Figs. 3 to 7, which illustrate different stages of a method embodiment.

The method commences with the first, second and third membrane portions 20a, 20b, 20c being cut to a predetermined size and shape. The membrane portions 20a, 20b, 20c are cut to approximate dimensions off-site (e.g. in a factory) and then trimmed to the required size on-site.

The first and second membrane portions 20a, 20b are substantially rectangular, whereas the third membrane portion 20c has a tapered profile as shown in Figs. 6 and 7. In particular, the third membrane portion 20c includes a narrower upper end and a wider lower end such that third membrane portion's lateral edges are substantially straight when it is installed between the inner and outer walls 12, 14. Accordingly, the lateral edges of the third membrane portion 20c align with the support members 18a, 18b, as shown in Fig. 6.

The method continues with the method step of attaching the wall attachment 22 to the third membrane portion 20c, as shown in Fig. 3. In particular, the wall attachment 22 is attached to an area of the wall facing surface of the third membrane portion 20c which in use is placed in contact with the inner wall 12. A membrane facing surface of the wall attachment 22 is bonded to the third membrane portion 20c with fixing tape.

The support members 18a, 18b can then be mounted in their respective positions between the inner and outer walls 12, 14 of the first and second wall sections 16a, 16b. Fig. 4 illustrates the first support member 18a being arranged near to the corner between the first and second wall sections 16a, 16b. The second support member 18b is shown in position, mounted between the inner and outer walls 12, 14.

The method step of mounting the support member 18a includes attaching the attachment portion 26a to a vertical surface of the inner wall 12. Fixing tape is applied to the wall facing surface of the attachment portion 26a to form a bond with the inner wall 12. During this method step, the anchor portion 28a of the support member is also arranged onto an upper surface of the outer wall 14. During the subsequent construction of the outer wall 14, further masonry units will be overlaid on top of the anchor portion 28a so that the anchor portion 28a is lapped within the structure of the outer wall 14.

The third membrane portion 20c is then mounted at the corner between the two wall sections to 16a, 16b, as shown in Fig. 5. The wall attachment 22 is first mounted to a position on the inner wall 12 which is located between the attachment portions 26a, 26b of the first and second support members 18a, 18b.

Once the wall attachment 22 is mounted to the inner wall 12, the third flexible membrane portion 20c is then attached to the support members 18a, 18b in turn. Starting with the first support member 18a, a piece of release tape is removed from half of the upper surface of the support member 18a nearest to the corner, to reveal fixing tape. The lateral edge of the third membrane portion 20c is aligned with a centre line of the upper surface of the support member 18a and then overlaid onto the exposed fixing tape. The same method steps are repeated for the second support member 18b.

The wall attachment 22 is supplied to the installation site already attached to the third membrane portion 20c.

Once the third membrane portion 20c is attached to the support members 18a, 18b, an upper portion 30 of the third membrane portion 20c is also bonded to the inner wall 12 to ensure water running down the inner wall 12 is collected by the membrane. This is achieved by way of a fixing tape disposed on the inner wall facing surface of the membrane 20.

A lower portion 32 of the third membrane portion 20c is lapped onto the upper surface of the outer wall 14, as shown in Fig. 6. The lower portion 32 of the third membrane 20c may be bonded to the upper surface of the outer wall 14 using the same fixing tape as is used to attach the upper portion 30 to the inner wall 12.

The method continues with the method step of arranging the first and second flexible membrane portions 20a, 20b into position, as shown in Fig. 6. This involves aligning the lateral edges of the membrane portions 20a, 20b with the respective supporting elements 18a, 18b. A second piece of release tape is removed from the other half of the upper surface of each of the supporting members 18a, 18b to expose fixing tape on to which the membrane portions 20a, 20b are overlaid.

The lateral edges of the first and second membrane portions 20a, 20b are arranged to abut against the opposing lateral edges of the third membrane portion 20c, as shown in Fig. 7.

The upper and lower edges of the first and second membrane portions 20a, 20b are fixed in position in the same manner as described in relation to the third membrane portion 20c.

Once all the membrane portions 20a, 20b, 20c are arranged in position within the cavity, a sealant is then applied to the seams which are formed between the edges of the flexible membrane portions 20a, 20b, 20c.

Once the drainage system is installed between the inner and outer walls 12, 14, the membrane portions 20a, 20b, 20c are each configured with an upper portion 30, a middle portion 34 and a lower portion 32, as shown in Fig. 1. The upper portion 30 is substantially vertical and is attached to the inner wall 12, and the lower portion 32 is substantially horizontal and is lapped through the outer wall 14. The middle portion 34 is angled downwardly between the upper and lower portions 30, 32, and thereby extends across the cavity between the inner and outer walls 12, 14.

The membrane 20 is configured such that a lower end of the upper portion 30 is vertically spaced apart from the lower portion 32 by a minimum distance. The minimum vertical distance may be measured between the lower end of the upper portion 30 and a point at which the lower portion 32 contacts the outer wall 14. The lower end of the upper portion 30 defines the transition between the upper portion 30 and the angled middle portion 34.

Alternatively, the vertical minimum distance may be measured between the lower end of the upper portion 30 and an upper end of the lower portion 32, which defines the transition between the middle and lower portions 34, 32. In some situations, the minimum vertical distance may correspond to the vertical height of the middle portion 34.

According to an exemplary arrangement of the drainage system 10, the vertical distance between the lower end of the upper portion and the lower portion is at least about 150 mm.

The upper portion 30 of the membrane 20 has a height which is defined by the vertical distance between the lower end of the upper portion 30 and an upper end of the upper portion. According to an exemplary arrangement of the drainage system 10, the upper portion 30 has a height of at least about 100 mm. Accordingly, the vertical distance between the upper end of the upper portion 30 of the membrane 20 and the lower portion 32 is at least about 250 mm.

The wall attachment 22 is configured such that its lower end is positioned at substantially the same height as the lower end of the upper portion 30 of the membrane 20.

The membrane supports 18a, 18b are configured such that a lower end of the attachment portions 26a, 26b (e.g. defining a transition between the attachment portions 26a, 26b and the respective membrane guiding portions 24a, 24b) are positioned at substantially the same height as the lower end of the upper portion 30 of the membrane 20.

The membrane supports 18a, 18b are arranged such that a transition between the membrane guiding portions 24a, 24b and the anchor portions 28a, 28b are positioned at substantially the same height as the point at which the lower portion 32 of the membrane 20 contacts the outer wall 14.

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.

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 can be made without departing from the spirit and scope of the invention.

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.

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%.

List of features Drainage system 10 Inner wall 12 Outer wall 14 Wall sections 16a, 16b Support members 18a, 18b Flexible membrane 20 Flexible membrane portions 20a, 20b, 20c Wall attachment 22 Support members, membrane guiding portions 24a, 24b Support members, attachment portions 26a, 26b Support members, anchor portions 28a, 28b Flexible membrane, upper portion 30 Flexible membrane, lower portion 32 Flexible membrane, middle portion 34

Claims

CLAIMS1. A drainage system for installing at a corner between first and second wall sections of a building, wherein each wall section comprises an inner wall and an outer wall which together define a cavity therebetween, the drainage system comprising: a first support member configured to extend substantially between the inner and outer walls of the first wall section; a second support member configured to extend substantially between the inner and outer walls of the second wall section; and a flexible membrane suspended between the first and second support members to define a fluid flow path between the inner and outer walls; wherein at least one of the first and second support members comprises: an attachment portion configured to attach the support member to one of the inner wall and the outer wall; and a membrane guiding portion coupled to the attachment portion and configured at a fall angle to guide the flexible membrane across the cavity in a substantially downward direction from the inner wall to the outer wall; wherein the drainage system further comprises a wall attachment configured to attach the flexible membrane to the inner wall, wherein the wall attachment is shaped to conform to the corner between the first and second wall sections.
2. A drainage system according to claim 1, wherein the wall attachment is configured so that, when the drainage system is installed, the wall attachment is positioned higher than the membrane guiding portion of at least one of the first and second support members.
3. A drainage system according to claim 1 or claim 2, wherein the wall attachment comprises a wall facing surface, wherein at least a portion of the wall facing surface is attached to the inner wall.
4. A drainage system according to claim 3, wherein the flexible membrane is configured to be bonded to a membrane facing surface of the wall attachment, the membrane facing surface of the wall attachment being arranged opposite to the wall facing surface of the wall attachment.
5. A drainage system according to any one of claims 1 to 4, wherein at least one of the first support member, the second support member and the wall attachment comprises a metal or metal alloy.
6. A drainage system according to claim 5, wherein at least one of the first support member, the second support member and the wall attachment comprises stainless steel.
7. A drainage system according to any one of the preceding claims, wherein at least a portion of an upper surface of at least one of the first and second support members is attached to the flexible membrane.
8. A drainage system according to any one of the preceding claims, wherein at least a portion of one side of the flexible membrane is attached to at least one of the first and second support members
9. A drainage system according to any one of the preceding claims, wherein the attachment portion of at least one of the first and second support members is configured with a wall facing surface which is configured to be attached to a vertical surface of the inner wall or outer wall.
10. A drainage system according to claim 9, wherein at least a portion of the wall facing surface is attached to the inner wall or outer wall.
11. A drainage system according to any one of the preceding claims, wherein the attachment portion attaches the support member to the inner wall and the support member comprises an anchor portion configured to attach the support member to the outer wall, wherein the anchor portion is configured to be lapped at least partially through the outer wall.
12. A drainage system according to any one of the preceding claims, wherein at least a portion of one side of the flexible membrane is attached to the inner wall.
13. A drainage system according to any one of the preceding claims, wherein the flexible membrane comprises a fibrous material which is faced on at least one side with a fire-resistant water-resistant material.
14. A drainage system according to claim 13, wherein the fire resistant and water-resistant material comprises silicone
15. A drainage system according to claim 13 or claim 14, wherein the fibrous material comprises a plurality of glass fibres.
16. A method of assembling the drainage system according to any one of claims 1 to 15; wherein the method comprises: attaching the wall attachment to the flexible membrane; attaching the attachment portion of the first support member to the inner wall or the outer wall of the first wall section; attaching the attachment portion of the second support member to the inner wall or the outer wall of the second wall section; attaching the wall attachment to the corner between the first and second wall sections; and arranging the flexible membrane onto the membrane guiding portion to guide the membrane across the cavity in a substantially downward direction from the inner wall to the outer wall.