GB2576782A

GB2576782A - Wall weep

Info

Publication number: GB2576782A
Application number: GB1814268.7A
Authority: GB
Inventors: Louis Shillabeer John
Original assignee: Cavity Trays Ltd
Current assignee: Cavity Trays Ltd
Priority date: 2018-09-03
Filing date: 2018-09-03
Publication date: 2020-03-04
Anticipated expiration: 2038-09-03
Also published as: GB201905023D0; GB2576807A; GB201814268D0; GB2576782B; GB2576807B

Abstract

A building construction 30 having a cavity wall with inner 31 and outer 33 skins and a cavity, and an opening 35 in the wall, for example for a window or door, a drainage element 37 located at the upper edge of the opening to cover an exposed part of the cavity and having a drainage surface for collecting liquid in the cavity above the opening, and a drainage conduit 10 for conveying liquid from the drainage surface to the outside of the wall without passing out of a front face of the outer skin. The drainage element may be a lintel, damp proof course or cavity tray and the conduit may be a wall weep being a pipe which may be integral with the cavity tray or may have apertures for receiving water from the drainage surface. Also claimed is the wall weep which may be a PVC pipe and have a U-shaped portion for extending around the edge of the drainage surface such that the opening to the pipe is below the surface and may be concealed in a masonry block at the side of the window/door.

Description

WALL WEEP

Field of the Invention

The invention relates to a wall weep, and to a cavity wall construction incorporating such a wall weep.

Background

Buildings are now commonly constructed using a cavity wall construction, wherein the exterior walls of the building have an inner skin and an outer skin which are separated by an air cavity. The air cavity may hold an insulating material to minimise heat loss from the building. As well as providing insulation, a cavity wall helps to reduce water ingress into the building.

Cavity wall construction typically comprises a damp proof course such that any moisture reaching the cavity through the outer skin, or condensing within the cavity, runs down a cavity-facing surface of the outer skin or the inner skin and is directed to weep holes where the water is drained to the exterior surface of the cavity wall. Weep holes may in some cases be provided by wall weeps in the form of spacers which sit between bricks to provide an aperture through the outer skin of the cavity wall.

Cavity wall constructions may contain openings, for example for doors and windows. A lintel is typically provided above these openings to maintain structural integrity and strengthen the cavity wall at the opening. The openings provide points of entry for moisture, and so the damp proof course above an opening is provided with stopends so that rain or moisture is held by the damp proof course and lintel arrangement and does not penetrate either to the interior of the building, or into the cavity either side of the opening. Within the outer skin of the cavity wall where the damp proof course meets the outer skin, wall weeps are provided so that any trapped water is able to drain away from the damp proof course and lintel to the exterior of the cavity wall.

Render may be applied to the outside surface of a cavity wall construction. In some cases render may have water resistant properties to help ensure that water does not penetrate the outer skin. Rendering the outer skin of a cavity wall is also performed in order to enhance aesthetics of the building. For example, a rendered surface may be aesthetically textured or decorated. Weep holes can disturb or spoil the aesthetics of such rendered surfaces. Advances in rendering means that wall weeps are not always required for certification as the render itself may be considered water resistant to such a degree that minimal water is able to penetrate through the render to the outer skin of the cavity wall underneath. In such cases aesthetics are maintained as wall weeps may not be required.

However, render is typically only certified to provided adequate waterproofing for a short period of time compared with the lifetime of the building construction (e.g. 25 years), and so fissures and cracks will inevitably appear where water is not able to drain from the cavity. When this happens the outer skin of the cavity wall may become vulnerable to penetrating rain or moisture, and without any wall weeps water becomes trapped at a damp proof course leading to damp banding, patching and staining as the water soaks into masonry. These effects are particularly apparent above openings, where water is retained by a lintel and damp proof course.

Summary of the Invention

The present invention aims to address the problems associated with known wall weeps, and also overcome problems of commonly used renders, in particular water resistant renders .

According to a first aspect of the invention, there is provided a building construction comprising an upstanding cavity wall having an inner surface and an outer surface with a cavity therebetween; an opening through the cavity wall from the inner surface to the outer surface, wherein the cavity is exposed at a top face of an intersection between the opening and the cavity; a drainage element mounted to cover the exposed cavity at the top face of the intersection, the drainage element including a drainage surface for collecting liquid in the cavity above the intersection; and a drainage conduit for conveying liquid away from the drainage surface to an outside of the cavity wall along a flow path that does not penetrate the outer surface. The cavity wall may be formed by an inner skin and an outer skin, which may each be made of suitable building materials such as brick and mortar or the like, wherein the drainage conduit does not penetrate through the outer skin of the cavity wall. In this way, any water which penetrates the outer surface or which condenses within the cavity may be conveyed out of the cavity through the drainage conduit, without negatively impacting the aesthetics of the outer surface of the cavity wall. That is, the outer surface of the cavity wall construction is not disturbed or spoiled by weep holes as water drains from a hidden aperture, and no aperture is required in the outer surface. For example, in some embodiments the outer surface of the cavity wall may have a rendered surface wherein the drainage conduit does not penetrate through the render. A building construction according to the present invention does not require any weep holes to be present in the outer surface of a cavity wall about an opening.

The drainage element may be any one of a lintel, a damp proof course, or a cavity tray. The drainage surface may be an upper surface of any one of a lintel, a damp proof course, or a cavity tray. However, it is envisaged that any combination of these may also be used in some embodiments to ensure that water or other liquid does not penetrate into the building or into the cavity either side of the opening. In some examples, stop ends may also be provided to contain liquid above the opening and prevent leaking of liquid into the cavity beside the opening.

The drainage conduit conveys liquid to an outside of the cavity wall. In particular, liquid may exit the drainage conduit at a location within the opening through the cavity wall. Preferably the drainage conduit conveys liquid away from the drainage surface to an underside of the drainage element. For example, an underside of the drainage element may be at a top face of the intersection between the opening and the cavity. Fluid is thereby conveyed to an outside of the cavity wall, but the flow path through the drainage conduit does not penetrate through the outer surface of the cavity wall, ensuring that there are no weep holes in the outer surface of the cavity wall and pleasing aesthetics are maintained. For example, in some embodiments the drainage conduit may be provided to pass through the drainage surface of the drainage element.

Optionally, the building construction may further comprise a wall weep, wherein the wall weep comprises a tubular body forming the drainage conduit. Advantages of the present invention may therefore be applied to any building construction using existing lintels, damp proof courses, cavity trays etc. The drainage element may therefore be any appropriate structure, typically having an elongate body, which is used to cover exposed cavity in a cavity wall. Wall weeps may be provided in any dimensions suitable for any type of building construction having a cavity wall. Preferably the wall weep may comprise a curved portion, such as a U-shaped bend, which is configured to wrap around an edge of the drainage surface. For example, this may be a lateral edge of the drainage surface such that liquid is drained from a top face of the intersection between the opening and the cavity, or it may be an end edge of the drainage surface such that liquid is drained at or about a side face of the intersection. In this way the wall weep is able to provide a drainage conduit which conveys liquid away from the drainage surface along a flow path which does not penetrate through the outer surface of the cavity wall, the wall weep being suitable for use with any lintel, damp proof course or cavity tray, as discussed above, without penetrating through the drainage surface. To ensure that a good flow rate of water through the wall weep can be achieved, and that liquid may be drained from a large area of the drainage surface, the wall weep may comprise a plurality of openings proximate a first end of the tubular body through which liguid can flow. For example, the plurality of openings may be in a first elongate section of the tubular body, wherein the first elongate section of the tubular body may be arranged, in a building construction, parallel to a longitudinal axis of the cavity wall.

The wall weep may be made of any suitable material, preferably a plastics material. For example, the wall weep may be made of unplasticised polyvinyl chloride (uPVC) which is durable and which is easy to form into a suitable wall weep, e.g. by injection moulding or any other process.

The cavity may also be exposed at a bottom face of the intersection between the opening and the cavity. In some embodiments, therefore, the building construction may further comprise a sill mounted to cover the exposed cavity at the bottom face of the intersection. By providing a sill in this way, liquid which has been conveyed away from the drainage surface is not able to enter the cavity at the bottom face of the intersection. This may be particularly advantageous where liquid is conveyed to an underside of the drainage element.

According to a second aspect of the invention there is provided a wall weep for draining liquid from a portion of a cavity in a cavity wall located above an opening through the cavity wall, wherein the wall weep allows liquid to drain from a cavity wall without penetrating through the outer surface. The wall weep comprises a tubular body, wherein the tubular body provides a drainage conduit for conveying liquid, in particular water, and wherein the tubular body has a curved portion which is configured to wrap around an edge of a drainage surface for collecting liquid in the portion of the cavity. For example, the curved portion may form a U-shape. The wall weep may wrap around a lateral edge or an end edge of the drainage surface. For example, this may be a lateral edge of the drainage surface such that liquid is drained at a top face of the opening, or it may be an end edge of the drainage surface such that liquid is drained at or about a side face of the opening.

The term 'tubular' as used herein may refer to a hollow elongate body having any suitable cross-sectional shape. For example, the cross-sectional shape of the tubular body may be rectangular or triangular. Preferably the cross-sectional shape is circular, such that the tubular body is substantially cylindrical. A wall weep provided in this way is thus able to be used with any kind of lintel, damp proof course, cavity tray etc. which may be provided at an opening through a cavity wall so as to allow water to drain out of the cavity from the drainage surface without penetrating through the outer skin of the cavity wall. No weep holes are therefore required in the outer skin of the cavity wall, and so the aesthetics of a cavity wall and a building construction are maintained.

Preferably the wall weep comprises a number of openings proximate a first end of the tubular body through which liquid can flow. In this way, a high flow rate through the wall weep can be maintained and a large amount of water may be conveyed away from the drainage surface. For example, the plurality of openings may be provided in a first elongate section of the tubular body to ensure that water may be drained from a large area of the drainage surface.

Optionally, the curved portion may be perpendicular to the first elongate section of the tubular body. This arrangement may allow for the first elongate section to lie parallel to the longitudinal axis of the drainage surface, for example, to maximise the area from which liquid may be drained from the drainage surface. Preferably the curved portion is perpendicular to the first elongate section such that water conveyed away from the drainage surface is conveyed to an underside of a lintel, damp proof course or cavity tray which provides the drainage surface. In some embodiments, in particular where the wall weep is configured to wrap around an end edge of the drainage surface, the wall weep may be incorporated within or extend through a stop end provided at an end of the drainage surface.

Any suitable material may be considered for the wall weep. Preferably, the wall weep may be made from a plastics material. In some embodiments, this may allow the wall weep to be formed by injection moulding or any other plastics forming process. For example, the wall weep may be made of unplasticised polyvinyl chloride (uPVC).

The diameter of the tubular body may be selected to allow the wall weep to be positioned within the mortar of a cavity wall. For example, the tubular body of the wall weep may have a diameter of less than 1 cm to ensure that the wall weep does not protrude through the outer surface of a cavity wall.

Brief Description of the Drawings

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 shows a wall weep which is an embodiment of the present invention;

Figure 2 shows a cross-section view of a building construction which is an embodiment of the present invention;

Figure 3 shows a schematic view of a building construction which is an embodiment of the present invention.

Detailed Description and Further Optional Features of the Invention

Fig. 1 shows a wall weep 10 which is an embodiment of the present invention. The wall weep 10 comprises a tubular body which may be made of any suitable material, such as plastic or metal. In particular, the wall weep 10 may be made of unplasticised polyvinyl chloride (uPVC). The term 'tubular' as used herein may refer to a hollow elongate body having any suitable cross-sectional shape. For example, the wall weep 10 may have a circular or rectangular cross-section. The tubular construction of the wall weep 10 provides a fluid drainage pathway through which liquid trapped within the cavity may pass in order to drain to an outside of a cavity wall.

The wall weep 10 is preferably formed from a single piece of material which may be moulded or otherwise shaped to take the form described herein. The wall weep 10 is shaped to convey liquid towards an underside of a damp proof course and lintel which may lie across an opening in a cavity wall and thereby provide a drainage surface. The wall weep 10 operates to provide a flow path that does not pass through the outer surface of the cavity wall as is the case with conventional weep holes. As a result, aesthetics of the cavity wall construction may be maintained as water drains from a hidden aperture, and no aperture is required in the outer surface.

To achieve this, the wall weep 10 may have the shape shown in Fig. 1. A first section 11 of the wall weep 10 is elongate, and has a number of openings 13 through which water may pass to be conveyed away from a drainage surface by the wall weep 10. The plurality of openings 13 in the first section ensures that a good flow rate of liquid can be achieved and also that liquid is drained away from a large area of a drainage surface. In use, the first section 11 may lie parallel to a longitudinal axis of a cavity wall, atop a damp proof course or lintel, in order to collect water and convey it away from the drainage surface. A second section 15 of the wall weep 10 is provided such that, in use, the flow path is directed towards an outside surface of the cavity wall, in particular to a lateral edge of a drainage surface provided by a damp proof course or lintel as discussed below with respected to Figs. 2 and 3. The second section 15 is provided at an end of the first section 11 and is in the same horizontal plane as the first section 11 but at a right-angle to it. The second section 15 of the wall weep may extend to any length suitable for the flow path to reach the outer edge of the drainage surface. Of course, it is not necessary that the angle between the first section 11 and the second section 15 is a right-angle, and any suitable angle may be chosen.

At an outer end of the second section 15, the wall weep 10 forms a curved portion 17, which is a U-shaped bend turning 180° in a vertical plane such that the fluid flow path turns back on itself. In this way, the wall weep 10 may wrap around a lateral edge of a drainage surface as shown in Figs. 2 and

3. The wall weep 10 and fluid flow path therefore do not terminate at an outer surface of a cavity wall, but instead water is conveyed away from the drainage surface to drain from an underside of a lintel or damp proof course to maintain building aesthetics. In other embodiments, the wall weep 10 may be provided to wrap around an end edge of a lintel or damp proof course. The corner section 17 ensures that the wall weep 10 does not penetrate the outer surface of the cavity wall, but may be contained within a layer of render, or within mortar between adjacent bricks in the outer skin. The diameter of the tubular body from which the wall weep 10 is formed is preferably selected to allow the wall weep 10 to be hidden in this way. For example, the tubular body may have a diameter of less than 1 cm.

The flow path through the wall weep 10 terminates at an opening in a second end 19, which in use is situated at an outside of the cavity wall, e.g. an underside of a damp proof course or lintel. The wall weep 10 comprises an additional downward turn between the corner section 17 and the second end 19 to ensure that water is directed downwards from a top face of the opening.

Figure 2 shows a cross-section view of a building construction 20 across an opening through a cavity wall. The cavity wall has an inner skin 21 and an outer skin 23 with a cavity therebetween. An outer surface of the outer skin 23 is provided with a layer of render 25 which may provide an aesthetically pleasing surface of the building construction

20. There is an opening in the cavity wall from the inner surface to the outer surface which intersects the cavity, and within the opening a door or window 100 is mounted.

The cavity is exposed along a top face of the intersection between the opening and the cavity but, as can be seen in Fig. 2, a lintel 27 is arranged to cover the cavity at the top face and also provide strength to the building 20 construction at and around the opening. The lintel 27 may be made of any suitable material, though a metal lintel (e.g. made of steel) may be particularly preferred. The lintel 27 may have an angled upper face such that a separate damp proof course 29 is not always necessary. An angled upper surface may direct fluid within the cavity towards the outer skin 23 where it may be drained by a wall weep 10 in a manner substantially as described below. The lintel 27 thus acts as a drainage element. In some embodiments, a main supporting body of the lintel 27 may be incorporated into the inner skin 21 or the outer skin 23, with a base of the lintel extending across the cavity at the opening. In such embodiments it may be particularly preferable to include a damp proof course, such as damp proof course 29, which may then act as the drainage element and provide a drainage surface.

The damp proof course 29 is laid within the mortar of both the inner skin 21 and the outer skin 23 of the cavity wall, with a drop between the inner section and the outer section of the damp proof course. The damp proof course 29 may be provided as a membrane of flexible material or may be provided in the form of a rigid tray. The upper surface of the damp proof course 29 provides a drainage surface. In embodiments where a damp proof course is not present, the drainage surface is provided by an upper surface of the lintel

27. The damp proof course 29 is provided to ensure that water (e.g. from rain penetrating the outer skin 23) or moisture within the cavity does not also penetrate the inner skin 21 as it collects within the area of the cavity above the lintel 27. Instead, fluid is directed towards the outer skin 23 by the sloped section of the damp proof course 29.

In a conventional cavity wall construction, water may be directed out of the cavity by wall weeps through the outer skin. However, where a layer of render is provided wall weeps spoil the aesthetics of the outer skin and so may not be used, which can lead to damp problems such as banding, patching and staining of the cavity wall both in the inner and outer skins even where a water resistant render is used.

The construction 20 according to the present invention provides a wall weep 10, such as a wall weep as described above with reference to Fig. 1, for draining liquid from a portion of the cavity above the opening. The wall weep 10 provides a fluid flow path which curves around the lateral edge of the drainage surface, and the base of the lintel 27, but does not penetrate or protrude beyond the outer surface of the outer skin 23 and/or render 25. By curving back on itself at a curved portion 17 the fluid flow path may be directed downwards at the opening such that the render 25 is unbroken. The wall weep 10 thus provides a fluid drainage conduit for conveying liquid away from a drainage surface of the damp proof course 29 and lintel 27 within the cavity to outside the building construction, without spoiling the aesthetics of the cavity wall. At the base of the opening, water draining from the cavity through the wall weep 10 may be arrested and directed outwards by a sill, e.g. a window sill or door sill, to ensure that liquid does not penetrate the cavity wall at the base of the opening. The wall weep 10 may be secured within the mortar used in the building construction 20 between the outer skin 23 and the lintel 27.

Figure 3 shows a schematic view of a building construction 30 which is an embodiment of the present invention. The building construction 30 incorporates the wall weep 10 described above with respect to Fig. 1. The building construction 30 comprises an upstanding cavity wall having an inner skin 31 and an outer skin 33 with a cavity therebetween. The cavity is exposed along the longitudinally extending top edge of the opening but, as can be seen in Fig. 3, a lintel 37 is arranged to cover the cavity at the opening and also provide strength to the building construction 30 at and around the opening 35. The inner skin 31 and the outer skin 33 continue above the opening such that the lintel 37 is incorporated into the construction 30. The upper section of the outer skin 33 is omitted for clarity.

In this embodiment the upper surface of the lintel 37 is a drainage surface. The lintel 37 has a sloped upper surface such that the lintel 37 is able to direct fluid within the cavity towards the outer skin 33. However, in other embodiments, the building construction 30 may comprise a damp proof course, such as a damp proof course 29 described above with reference to Fig. 2, which provides the drainage surface. At each longitudinal end of the lintel 37 a stopend may be provided to ensure that any water which is trapped by the lintel 37 does not leak into the cavity wall at each side of the opening 35. To enable water to drain out of the cavity, the wall weep 10 is provided within the building construction at the base of the lintel 37, which conveys water away from the drainage surface without penetrating the outer surface of the cavity wall. The first section 11 of the wall weep 10 lies parallel to the lintel 37 and to the longitudinal axis of the cavity wall such that fluid is collected by openings 14 within the first section 11. Fluid may then flow through the tubular body of the wall weep 10, where it is drained out of the cavity wall at a lower face or underside of the lintel 37. The wall weep 10 thus provides a fluid drainage conduit to convey liquid away from the drainage surface and out of the cavity to the outside of a building construction 30 which does not penetrate the outer surface of the cavity wall. In some embodiments, the wall weep 10 may wrap around an end edge of the lintel 27 in preference to a lateral edge. In such embodiments, the wall weep 10 may convey water to drain from a side face of the opening 35, in the reveal masonry, and may be incorporated within or pass through a stop end at the end of the lintel 37.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims .

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purposes, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclose is one example only of a generic series of equivalent or similar features .

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A building construction comprising:

an upstanding cavity wall having an inner surface and an outer surface with a cavity therebetween;

an opening through the cavity wall from the inner surface to the outer surface, wherein the cavity is exposed at a top face of an intersection between the opening and the cavity;

a drainage element mounted to cover the exposed cavity at the top face of the intersection, the drainage element including a drainage surface for collecting liquid in the cavity above the intersection; and a drainage conduit for conveying liquid away from the drainage surface to an outside of the cavity wall along a flow path that does not penetrate the outer surface.

2. A building construction according to claim 1, wherein the drainage conduit conveys liquid away from the drainage surface to an underside of the drainage element.

3. A building construction according to claim 1 or claim 2, further comprising a wall weep, wherein the wall weep comprises a tubular body forming the drainage conduit.

4. A building construction according to claim 3, wherein the tubular body of the wall weep comprises a curved portion configured to wrap around an edge of the drainage surface.

5. A building construction according to claim 4, wherein the curved portion is a U-shaped bend.

6. A building construction according to any one of claims 3 to 5, wherein the wall weep comprises a plurality of openings proximate a first end of the tubular body through which liquid can flow.

7. A building construction according to claim 6, wherein the plurality of openings are in a first elongate section of the tubular body, wherein the first elongate section of the tubular body is arranged parallel to a longitudinal axis of the cavity wall.

8. A building construction according to any one of claims 3 to 7, wherein the wall weep is made of a plastics material.

9. A building construction according to claim 8, wherein the wall weep is made of unplasticised polyvinyl chloride (uPVC).

10. A building construction according to any one of claims 1 to 9, wherein the building construction comprises render on the outer surface, wherein the flow path does not penetrate through the render.

11. A building construction according to any one of the preceding claims, wherein the cavity is exposed at a bottom face of the intersection between the opening and the cavity, the building construction further comprising a sill mounted to cover the exposed cavity at the bottom face of the intersection.

12. A building construction according to any one of the preceding claims, wherein the drainage conduit has an exit aperture between the top face and a bottom face of the intersection between the opening and the cavity.

13. A building construction according to any one of the preceding claims, wherein the drainage element is a lintel.

14. A building construction according to any one of claims 1 to 12, wherein the drainage element is a damp proof course.

15. A building construction according to any one of claims 1 to 12, wherein the drainage element is a cavity tray.

16. A wall weep for draining liquid from a portion of a cavity in a cavity wall located above an opening through the cavity wall, the wall weep comprising a tubular body, wherein the tubular body provides a drainage conduit for conveying liquid, and wherein the tubular body has a curved portion configured to wrap around an edge of a drainage surface for collecting liquid in the portion of the cavity.

17. A wall weep according to claim 16, wherein the curved portion is a U-shaped bend.

18. A wall weep according to claim 16 or claim 17, wherein the wall weep comprises a plurality of openings proximate a first end of the tubular body through which liquid can flow.

19. A wall weep according to any one of claims 16 to 18, wherein the plurality of openings are in a first elongate section of the tubular body.

20. A wall weep according to claim 19, wherein the curved portion is perpendicular to the first elongate section of the tubular body.

21. A wall weep according to any one of claims 16 to 20, wherein the wall weep is made of a plastics material.

22. A wall weep according to claim 21, wherein the wall weep is made of unplasticised polyvinyl chloride (uPVC).

23. A wall weep according to any one of claims 16 to 22, wherein the tubular body has a diameter of less than 1 cm.