GB2452745A

GB2452745A - Coping with rain gutter

Info

Publication number: GB2452745A
Application number: GB0717862A
Authority: GB
Inventors: Liam Clear
Original assignee: Wembley Innovation Ltd
Current assignee: Wembley Innovation Ltd
Priority date: 2007-09-13
Filing date: 2007-09-13
Publication date: 2009-03-18
Also published as: GB0717862D0

Abstract

A coping unit 10 comprises an upper surface which defines a longitudinal rainwater channel 12. The unit may comprise a channel 12 configured to lead the rainwater over a side edge or it may comprise an aperture in its upper surface to lead rainwater into conduit or pipe work built into a wall below the coping. The aperture may have a depending rim and may be fitted with a leaf guard or grating. The unit 10 may be solid or hollow. Coping units 10 may be laid end to end to form a coping, for example on a parapet. Joints 18 between adjacent coping units 10 may be sealed with grout, mortar or mastic or may have an elastomer gasket.

Description

I

WALL COPING WITH RAINWATER CHANNEL

Field of the Invention

This invention concerns wall copings for the collection and channelling of rainwater.

Background of the Invention

Copings are used on walls to protect the masonry below from weathering and in the case of parapet walls for buildings, to prevent damp penetration into the wall and the building interior. A masonry unit well known for use as a wall coping is substantially rectangular in plan with a generally flat underside dimensioned to jut out slightly beyond both faces of the wall below. The overhanging underside portions of the unit are often provided with a drip channel running parallel to and spaced from the adjacent wall face. The top surface of the unit may slope symmetrically from a raised centre portion towards lower side edges so as to shed water evenly to either side, or may slope wholly or predominantly to one side, so as to direct water from a parapet wall onto an adjacent roof or into a gutter, for example.

With this type of construction water falling from the projecting edges of the parapet can still be blown against or otherwise fall onto the face of the wall below. Prolonged wetting can lead to spalling and erosion of the wall surface as well as problems of damp penetration into a building, in the case of a parapet wall. Also the water shed from the parapet is not collected and therefore caimot be used e.g. for watering plants or as part of a "grey" water recycling system.

Summary of the Invention

The present invention addresses these problems by providing a coping unit comprising an upper surface that defines a longitudinal rainwater channel. A series of such units may therefore be laid end to end on top of a wall, with joints formed between them, to conduct rainwater along the top of the wall to a suitable point for disposal or recycling. For example, the rainwater may be led from an endmost coping unit into a hopper and downpipe.

Additionally or alternatively, the coping unit may comprise a channel configured to lead the rainwater over a side edge for similar collection or recycling, or an aperture in or towards a central region that can lead the rainwater into a conduit or pipework built into the wall below the coping. For example the aperture may have a depending rim at its lower end, for positioning over an upwardly open end of a downpipe or of a roof outlet body built into the wall below the coping unit. The upper end of the aperture can be fitted with a leaf guard or grating, similar to those used in conventional roof gutters and roof outlets. Special units can be provided for carrying the longitudinal channel around corners. Different combinations of the various coping units just described can be used to form a parapet drainage system.

The coping unit may be solid; made from natural or artificial stone or concrete. Alternatively it may be hollow; formed from sheet metal or plastics.

The joints between adjacent coping units may be sealed in any suitable way. For example they may be filled with grout or mortar. Preferably however, they are sealed by a bead of mastic. In the case of solid coping units, the joints may also be formed as shown in UK patent application no. 0623889.3. Any moisture penetrating the seal will therefore be directed laterally outwardly of the wall, reducing the likelihood of damp penetration. In the case of sheet metal or other hollow coping units, lap joints may be formed between adjacent units, which may be sealed by an elastomer gasket, as well as or instead of mastic.

The coping units may be laid to an appropriate fall, similar to that used in roof gutters.

Different units of successively different height may be provided to achieve the necessary fall.

Alternatively or in addition, the fall can be built into the top of the underlying wall.

Illustrative embodiments of the invention and some of their preferred features and advantages are described below with reference to the drawings.

Brief Description of the Drawings

Figure 1 is a perspective view from one end of a coping unit embodying the invention; Figure 2 shows a series of units as in Figure 1, laid end-to-end, in three quarter view from the opposite end; Figure 3 shows an endmost coping unit fitted with a hopper and downpipe; Figure 4 shows a modified coping unit, providing a side runoff channel; Figure 5 shows a further modified coping unit, with a drainage aperture in a central region; Figure 5a shows the unit of Figure 5 in use with a cavity wall and concealed drain pipe; Figure 6 shows a sheet metal coping unit embodying the invention, and Figure 7 shows a securing bracket for the coping unit of Figure 6.

The coping units 10 shown in Figures 1 and 2 have a gently curved, concave upper surface which forms a longitudinally extending drainage channel 12 for rainwater. A bead of mastic 14 approximately 2mm wide is applied along the upper edge of the end face of each unit as it is laid. The next unit is butted up against the first to compress the mastic and form a water seal. The units also have an underlying projection 16 at one end, which is received in a complementary recess 18 formed in the opposite end of the next unit. Longitudinal drip strips 20 may be let into the lower side edges of the units, extending along the main body of each unit and continuing along the projection 16. A transverse channel (not shown) may be formed across the upper surface of each projection 16, with ends terminating at the lower side edges of the projection, outwardly of the drip strips 20. Any small quantities of water penetrating into the joints between adjacent units 10 past the mastic 14 is therefore directed away from a cavity wall 22 received between the drip strips 20 on which the coping units 10 are supported.

Figure 3 shows a "bespoke" leadwork rainwater hopper 24 arranged to catch the runoff from an endmost coping unit 10 and direct the flow into a downpipe 26. Any suitable rainwater hopper may however be used for this purpose, e.g. standard off-the-shelf hoppers of plastics, cast iron or cast aluminium. The free end of the endmost coping unit 10 is made to slightly overhang the end of the wall 22 and the hopper 24.

Figure 4 shows a modified coping unit 100 including a depression 28 formed in its upper surface which is shaped to direct water running along the channel 12 over one side edge of the unit 100, as represented by the flow arrows 30, 32. The flow over this side edge is contained between a pair of projecting ridges 34 extending downwardly in parallel, on either side of the depression 28. A hopper (not shown) can then be attached to the wall beneath and between the ridges 34 to catch the rainwater flow and direct it into a downpipe (not shown).

Figure 5 shows an alternative modification in which a coping unit 200 is provided with a drainage aperture 36 towards a central region of its upper surface. The lower end of the aperture has a depending rim 38 that directs water running into the aperture 36 from the channel 12 into the upper end of a drainpipe or roof outlet body (not shown). This pipe or body is built into the wall supporting the coping unit 200. Where a wall cavity of sufficient width is provided, as shown in Figure 5a, the drainpipe can be concealed within the cavity.

There is thus no need for guttering or external pipework. The drain pipe (whether within the cavity or external) can be connected to ground level drainage, or to a soft water storage tank.

The water collected by the rainwater channel can alternatively or in addition be used in heating and cooling systems for the building below, or for irrigating a green roof or plants within the building, or it can be fed to a "grey" water recycling system, so as to reduce the demand for mains water.

The coping unit shown in Figure 6 is formed from sheet metal such as stainless steel, copper or aluminium. A longitudinal channel 12 is formed on its upper surface, defined by upstanding side edges or rims 40. Brackets 42 (Figure 7) secured to the top of the wall by suitable fasteners (not shown) are snap engaged or slidably received between a pair of inwardly directed lower flanges 44 to secure the unit in place on top of the wall. One end 46 of the unit is of reduced height and width to form a lap joint with the next unit. An elastomer gasket (not shown) may be bonded to the end 46 so as to seal the lap joint in the region of the channel 12 in a similar manner to conventional roof guttering. Alternatively or in addition, a bead of mastic may be used to seal this joint.

Other profiles for the channel 12 are of course possible besides those illustrated in Figures 1 -5a and 6: for example V or U shaped profiles. Profiles having higher raised edges help to retain deeper water flows and also are more resistant to water being blown out of the channel in high winds. Different features of the various embodiments may be combined in ways not specifically illustrated, but within the scope of the claims.

In advantageous embodiments, the coping with a longitudinal rainwater channel in its upper surface eliminates mortar joints between adjacent units that can deteriorate over time. There is also no need for the usual damp proof course below the coping, which can be prone to damp penetration through deterioration over time andlor bad workmanship. Eliminating the damp proof course removes a slip plane in the masonry which is particularly vulnerable to cracking and movement, due to lack of any significant weight of masonry above. By reducing or eliminating wetting of the parapet wall faces, spalling and weather stains are also reduced. Unlike external guttering, the coping system channel can be accessed from the building roof area, thus avoiding the requirement for costly access equipment, such as an external scaffold.

Claims

1. A coping unit comprising an upper surface that defines a longitudinal rainwater channel.

2. A coping unit as defined in claim I and further comprising a channel configured to lead the rainwater over a side edge.

3. A coping unit as defined in claim 1, comprising an aperture in or towards a central region of its upper surface that can lead the rainwater into a conduit or pipework built into a wall below the coping.

4. A coping unit as defined in claim 3, in which the aperture comprises a depending rim at its lower end.

5. A coping unit as defined in claim 3 or 4, in which the aperture is fitted with a leaf guard or grating.

6. A coping unit as defined in any preceding claim and which is solid.

7. A coping unit as defmed in any preceding claim and which is hollow.

8. A coping unit as defined in any preceding claim, in which the joints between adjacent coping units are sealed.

9. A coping unit as defined in claim 8, in which the joints are filled with grout or mortar

10. A coping unit as defined in claim 8 or 9, in which the joints are sealed by a bead of mastic

11. A coping unit as defined in any of claims 8 -10, in which the joints are sealed by an elastomer gasket

12. An assembly of coping units as defined in any preceding claim or claims, comprising a parapet drainage system.

13. An assembly as defined in claim 12, in which the coping units are laid to an appropriate fall.

14. A coping unit substantially as described with reference to or as shown in Figures 1 - 3, Figure 4, Figure 5 and 5a or Figure 6 of the drawings.

15. A parapet drainage system substantially as described with reference to or as shown in the drawings.