GB2314354A

GB2314354A - Weephole extension devices

Info

Publication number: GB2314354A
Application number: GB9620434A
Authority: GB
Inventors: George Molyneux
Original assignee: G Molyneux
Current assignee: G Molyneux
Priority date: 1996-05-08
Filing date: 1996-10-01
Publication date: 1997-12-24
Anticipated expiration: 2016-10-01
Also published as: GB9620434D0; GB9609542D0; GB2314354B

Abstract

The invention provides an extension device (10) which is suitable for use with a weephole device (48) to provide an extended weephole (47) to provide a fluid flow path between the cavity face (86) of a cavity wall (76) and the outer face of the outer leaf (88) of a cavity wall, (76), thus providing a covered and uninterrupted channel for liquid communication between the inlet at the cavity face (86) and the outlet at the outer leaf face (88) of the cavity wall (76) to disperse any water that may collect, for example, on a cavity tray damp course (84) spanning across the cavity (82) which is part of a cavity wall (76).

Description

IMPROVEKENTS IN AND RELATING TO BXTZMSION DIVICHS Field of the Invention The present invention relates to extension devices and a structural assembly comprising such extension devices. The extension devices are for use with drainage devices for the dispersal of water that may collect, for example, on a cavity tray damp course spanning across the cavity which is part of a cavity wall. Such drainage devices are referred to as weephole devices.

Background of the Invention A commonly used method of dispersing water that may collect, for example, on a cavity tray damp course spanning across the cavity which is part of a cavity wall, has been to omit most or all of the mortar from a perpendicular mortar joint between two units of masonry in the outer wall leaf that forms part of a cavity wall built on top of a part of the cavity tray damp course. Such a method is then said to form a weephole in the form of a water passageway between the vertical mortar joint through which any water collecting on the cavity tray damp course can escape by allowing the water entering the passageway to discharge externally of the outer wall leaf.

However, just omitting the mortar from a perpendicular mortar joint acting as a weephole is no longer deemed acceptable because it is unsightly and there is a risk that mortar splashes will block the fluid channel preventing the flow of water. There are now various preformed weephole devices available which attempt to overcome these difficulties. One such weephole device is "The Molyneux Concealed Weephole," which is the subject of United Kingdom published patent application No.

9415107.2, the content of which is incorporated herein by reference.

Weephole devices should have an overall thickness of no more than lOmm to enable the weephole to be sandwiched in the normally required lomm space that forms a perpendicular joint between the ends of two bricks in a wall.

The weephole devices generally prevent the spread or splashing of mortar during the building of a wall from blocking the weephole water passage. However, this problem can still arise if the weephole device does not extend across the full masonry wall leaf that is part of a cavity wall.

The depth of a masonry wall leaf between its inner to outer faces can vary for numerous reasons, for example, if the masonry units being used are wider than the commonly used basic lOOmm bricks or blocks and also if a cavity wall using the popular.100mm bricks or blocks has cement rendering or the like plastered onto the external face of its outer wall leaf causing a variation in the depth of the wall.

It will therefore be appreciated that a number of weephole lengths have been required to suit all situations but it is impractical for either a manufacturer to make, or an agent to carry stocks to meet all wall depth possibilities. As a result most known weephole devices are lOOmm long and are intended just for use with the lOOmm bricks and blocks. Although the 100mm dimension of either the masonry unit depth or the device length may vary by up to 3mm, this does not prevent such weephole devices from being used with such masonry units.

A known weephole extension device is that of Cavity Trays Limited. This extension device is used with the Cavity Trays Limited Type W weephole, to accommodate use of the weepholes in non-standard wall thicknesses. A problem with this extended weephole believed to be that the extension device interengages with the weephole device by means of a protuberance on the extension device which extends for the full height of the internal walls of the extension device hollow tube. This present a barrier on the internal base wall of the extended weephole which projects into the fluid flow pathway, making it difficult for water to pass from the cavity tray through the extension device and through into the weephole, resulting in the risk of standing water or even of water spilling back into the wall cavity.

It is an aim of a preferred embodiment of the present invention to overcome or obviate at least one problem encountered in relation to the prior art, whether referred to herein or otherwise.

Summary of the Invention According to the present invention in a first aspect there is provided an extension device suitable for use with a weephole device in an outer wall leaf of a cavity wall, said outer wall leaf comprising a cavity face and an external face; said weephole device comprising a channel of fluid communication between an inlet and an outlet, said channel being bounded on its underside by a base wall; said extension device comprising a channel of fluid communication, said channel being bounded at its underside by a base wall; said extension device further comprising means for interengaging with the weephole device; whereby, the interengaging means are such that when the extension device and the weephole device are interengaged to extend the channel of fluid communication, in use, between the cavity face and external face of the cavity wall outer wall leaf, there is no additional barrier along the base walls to impede the flow of fluid from the extension device to the weephole device.

Such a weephole extension device can be used to extend a covered channel for the passage of drainage water across the full depth of a masonry wall leaf that is part of a cavity wall, even when the cavity wall is not of standard dimensions. The extended weephole maintains the continuous channel of fluid communication without interruption at the site of joining the extension device to the weephole device, allowing fluid to flow through the weephole device uninterrupted, without any additional barrier to the flow.

The extension device negates the need to manufacture or stock a number of weephole lengths to suit all wall depth possibilities. Also the extension device provides for an extended weephole arrangement in which the level of the base line water passage of the extended weephole device is not raised or obstructed.

The extended weephole device arrangement could also benefit from features that may exist on a known weephole device, for example, means for preventing the ingress of large insects into the water channel, a restricted size outlet to deter wind driven rain from being forced through the water channel, a water drip and location rib extending below the outlet to accurately locate the outlet against the outer wall external face because the cavity tray dampcourse on which a weephole device is normally sat would prevent such a downward projecting location rib from being included below the cavity drainage water inlet provided by the extension device.

Suitably, a plurality of extension devices may be used in tandem to extend the uninterrupted fluid flow path provided by a weephole device. This arrangement is particularly important for use with masonry wall constructions that are much deeper than the standard 100mm wall and require an extension of more than 25mm.

Suitably, the extension device additionally comprises a main body comprising a side wall, a base wall and optionally a top wall.

Preferably, the extension device main body comprises a hollow, open-ended tube. In use, the hollow tube allows uninterrupted fluid flow from the inner side of the cavity wall through the extension device to the fluid channel of the weephole of the weephole device.

Preferably, the hollow tube has a substantially rectangular transverse cross section. Such an extension device has the advantage that it can fit or abut existing weephole devices, for example, a weephole device of the type described in published United Kingdom patent application number 9415107.2. The extension device is also suitable for placing in the perpendicular mortar joint of a wall making up a leaf of a cavity wall. Also, the rectangular cross section of the extension device body allows a multiplicity of them to be packed flat, optionally slotted together so that they take up less room.

Suitably, the means for interengaging the extension device with the weephole device comprises a protuberance, adapted to fit a weephole device.

Suitably, the protuberance comprises a hollow tube.

Preferably, the hollow tube has at least one open end.

Suitably, the protuberance does not extend from the full height of the extension device. Preferably, the protuberance does not extend from the region of the extension device which provides the base wall of the channel of fluid communication with the weephole device.

Preferably, the protuberance only extends between the top of the extension device and a level less than mid-way down the extension device.

Suitably, the protuberance comprises a cross wall which is substantially tapered from where it connects to the top of the extension device to its end. Preferably, the cross wall is truncated before it joins the top of the extension device. Preferably, the protuberance comprises a top wall which extends from where the cross wall is truncated, to the extension device. All of these features provide a protuberance that is a substantially truncated rectangle in shape. Such an arrangement may be found to be of some help with the manufacture of the extension device and may also be of assistance during the assembly operation of attaching the extension device to a weephole device, in particular to a weephole device of the type described in published United Kingdom patent application number 9415107.2. In particular, as the protuberance neither extends from the top of the extension device nor from the base of the extension device, the extension device may still be of use even if inserted upside down, as there will still be no additional barrier to impede the flow along the base of the extended weephole. Preferably, the cross wall of the extension device comprises a lip.

Preferably, the extension device comprises one or more region(s) adapted for cutting or breaking, along its length. When the extension device is cut or broken at one of these regions the length of the extension device is reduced. Preferably, such regions are on the main body of the device. Preferably, the regions adapted for cutting or breaking are each in the form of a groove, preferably on the outer surface of the main body. Preferably, each region extends along the base wall of the extension device. Preferably, each region is substantially continuous around the outer surface of the extension device. Each region is adapted to provide a guide line for cutting the extension device to a certain length and is preferably also shaped to more readily accept a blade for cutting.

It is also preferred that in order to further assist cutting or breaking the main body at designated points, the regions adapted for cutting or breaking may only leave a thin membrane to be cut and there also may be no membrane at all at certain parts along the length of the region, providing perforations in the extension device body.

It is also further preferred that the regions adapted for cutting or breaking on the main body of the device may each be marked, normally numerically, to indicate the length that the extension device will provide when cut or broken at any particular designated region. Preferably, the regions adapted for cutting or breaking are 5mm apart on the main body. Such 5mm intervals allow a number of sizes of invention device to be produced from one master design.

Suitably, the protuberance is narrower than the main body. Preferably, the protuberance projects inside the main body. Preferably, the protuberance projects inside the main body up to a point adjacent the first region adapted for cutting or breaking. This strengthens the extension device construction so that the protuberance is not easily broken off.

Preferably, the main body comprises an internal ridge which extends from the bottom wall of the protuberance.

Preferably, the main body further comprises a second ridge which extends from the top wall of the protuberance.

Preferably, the wall of the main body above the second ridge is thickened. Such ridges can act to abut the walls of a protuberance of a further extension device to allow a plurality of extension devices to cooperate, keeping the base horizontal channel of fluid communication uninterrupted.

Preferably, the main body has substantially the same external transverse cross section as the weephole device with which it is adapted to cooperate. This allows the protuberance to be inserted inside the weephole device whilst keeping the external faces of the main body of the extension device and the weephole device flush.

Preferably, the extension device is a one-piece construction, preferably a single plastic moulding.

Suitably, the extension device is provided as a 25mm standard size. Such an extension device is capable of being cut or broken at the adapted regions to provide an extension device that will fit a variety of wall depths, with the extension device extending the weephole device by between 10mm and 25mm, with intervals of 5mm. If an extension of over 25mm is required a plurality of extension devices may be used in tandem. Alternatively, the extension device is provided in a 50mm size, providing an extension of between 10mm and 50mm, also in 5mm intervals.

According to the present invention in a second aspect there is provided an extended weephole device, the device comprising a plurality of elements, including a weephole device and an extension device according to the first aspect of the invention; whereby the elements are interengaged to extend the length of the weephole device to provide a fluid flow pathway between the weephole device and the extension device with no additional barrier to impede the flow of fluid from the extension device to the weephole device.

Suitably, the weephole device may additionally comprise an internal bar. Such internal bar provides a rest for the protuberance of the extension device to abut when in cooperation with the weephole device.

The extended weephole device according to the second aspect of the invention has the advantageous features that the internal width of the extended weephole device base line water passage is not reduced, nor is the external width (thickness) of the extended weephole device increased. Also the level of the base line water passage of the extended weephole device is not raised or obstructed.

According to the present invention in a third aspect there is provided a structural assembly comprising a cavity wall formed by an inner leaf and an outer leaf separated by a cavity, the outer leaf having an external face, the outer leaf comprising at least one perpendicular mortar joint within which there is a drainage device comprising a weephole device and an extension device according to the first aspect of the invention, thereby providing an inlet on the cavity side of the outer leaf, an outlet on the external side of the outer leaf and a channel of liquid communication between the inlet and the outlet comprising no additional barrier along the base wall of the channel to impede the flow of fluid from the extension device to the weephole device.

Suitably, the extended weephole does not project substantially beyond the external face of the outer leaf of the structural assembly.

According to present invention in a fourth aspect there is provided a method of extending a weephole device comprising interengaging an extension device according to the first aspect of the invention with a weephole device, such that the fluid flow pathway along the base walls of the channel provided by the extended weephole device comprises no additional barrier to impede the flow of fluid from the extension device to the weephole device.

According to the present invention in a fifth aspect there is provided a weephole extension device comprising one or more regions adapted for cutting or breaking.

Cutting or breaking the extension device at such regions reduces the length of the extension device. The feature of being a able to reduce the length of the extension device allows one type of extension device to be used in cavity wall construction for cavity walls of different depths, as one extension device can be cut or broken to the size required.

Preferably, such regions are on the main body of the device. Preferably, such regions extend along the base wall of the extension device. Preferably, the region(s) adapted for cutting or breaking are each in the form of a groove, preferably on the outer surface of the extension device. Preferably, each region extends along the base wall of the extension device. Preferably, each region is substantially continuous around the outer surface of the extension device. Each region is adapted to provide a guide line for cutting the extension device to a certain length and is preferably also shaped to more readily accept a blade for cutting.

It is also preferred that in order to further assist cutting or breaking the extension device at designated points, the regions adapted for cutting or breaking may only leave a thin membrane to be cut and there also may be no membrane at all at certain parts along the length of the region, providing perforations in the extension device.

It is also further preferred that the regions adapted for cutting or breaking on the extension device may each be marked, normally numerically, to indicate the length that the extension device will provide when cut at any particular designated region. Preferably, the regions adapted for cutting or breaking are 5mm apart on the main body. Such 5mm intervals allow a number of sizes of extension device to be produced from one master design.

Brief Descrintion of the Dravinas The invention will now be described, by way of example only, with reference to the drawings that follow, in which: Figure 1 is a perspective view of a weephole extension device according to an embodiment of the first aspect of the invention.

Figure 2 illustrates a front view of the extension device illustrated in Figure 1.

Figure 3 illustrates a side view of an extended weephole device according to an embodiment of the second aspect of the invention, with the extension device being as shown in Figures 1 and 2.

Figure 4 illustrates the open cavity inlet end of an assembled extended weephole device as shown in Figure 3.

Figure 5 illustrates the external wall face outlet end of an assembled extended weephole device as shown in Figure 3.

Figure 6 illustrates a section through a structural assembly according to an embodiment of the third aspect of the invention.

Figure 7 is a perspective view of a weephole extension device according to an alternative embodiment of the first aspect of the invention.

Figure 8 illustrates a front view of the extension device illustrated in Figure 8.

D-scriDtion of the Preferred E bodLments Referring to Figure 1 and Figure 2 of the drawings that follow, there is shown a preformed plastic moulded weephole extension device 10 having a main body 12 from which projects a protuberance 14.

The main body 12 is in the form of a length of rectangular hollow tube 16 having a top wall 18, a base wall 20 and two substantially parallel opposed side walls, 22, 24. The hollow tube 16 has a front end 26 (from which the protuberance 14 projects) and a rear end 28, both of which are completely open. The main body 12 is of the same height and width as the weephole device to which it is to be attached (see Figures 3 and 6 of the drawings that follow).

The main body 12 has a number of recessed grooves 30, 32 extending around all its external faces, groove 32 being the closest groove to the protuberance 14. The purpose of the grooves 30, 32 is to reduce the thickness of the walls 18, 20, 22, 24 forming the hollow tube 16 to facilitate the easy cutting to length of the hollow tube 16 at designated points along its length, whilst also functioning to assist in the keying of the extension device 10, in use, to mortar in a perpendicular mortar joint. To further assist the user to identify the position at which the extension device 10 should be cut in order to achieve the desired length of extension, numbered millimetre markers 33, at intervals of 5mm, are moulded in the outer faces of the hollow tube 16, e.g as shown on the side wall 22 of the hollow tube 16. To further assist in identifying to which recessed groove 30, 32 each number applies arrows 34, 36 may be used. The recessed grooves 30, 32 also act as a guide in which to insert a blade, to assist in cutting the extension device.

The protuberance 14 of the extension device 10 projects from the upper part of the otherwise open end 26 of the hollow tube 16. The protuberance 14 consists of a horizontal base cross wall 38 and a sloping cross wall 40 joined and bridged apart by a vertical side wall 42. It must be appreciated that a second side wall could be used.

To assist with the manufacture of the extension device 10 and also with its insertion into a weephole device, the cross wall 40 of the protuberance 14 terminates at a line 44 before it reaches the top wall 18 at the front open end 26 of the hollow tube 16.

The base wall 38 and the side wall 42 of the protuberance 14 are connected to the side walls 22 and 24 of the main body 12 where they form the open end 26 of the hollow tube 16. Furthermore, the base wall 38 projects some distance inside the hollow tube 16, with the base wall 38 projection being indicated by a broken line 46 projecting into the hollow tube 16. However, it will be noted that the broken line 46 indicates the base wall 38 as only projecting into the hollow tube 16 as far as first designated cutting groove 32 on the hollow tube 16 in order that extension of the base wall 38 does not hinder the purpose of the designated cutting grooves 30, 32 while still providing some structural stability between the side walls 22 and 24 of the hollow tube 16.

The protuberance 14 as described herein may help to overcome problems that can arise if the extension device 10 is being inserted into a weephole device in outdoor building site conditions, when extraneous matter such as wind blown grains of sand or particles of mortar may accidentally gain access into the protuberance or weephole device insertion area. It should also be noted with reference to Figure 1 that either the hollow tube 16 or the protuberance 14 may include simple instructions or indicators impressed onto any of their outer surfaces to assist the user when the extension device is being attached to a weephole device.

Referring now to Figures 3 to 5 of the drawings that follow, there are illustrated three views of a plastic moulded weephole 48 (generally according to patent application number 9415107.2 as described in relation to Figures 12-15 of that application) to which has been attached the preformed plastic extension device 10, as illustrated in Figures 1 and 2 of the drawings herein. In Figure 3 of the drawings that follow, there is shown an extended weephole 47 comprising an extension device 10 and a weephole device 48. The weephole device 48 has a generally triangular side shape, with a base wall 50, and a sloping top wall 52 having a peak 54 at the rear inlet end 56 of the weepholedevice 48 and tapering to a front outlet end 58. The weephole device 48 is a rectangular cross sectioned hollow tube that provides a covered channel for liquid communication between the inlet end 56 and the outlet end 58. Of some relevance to the present invention is that the weephole 48 has an internal horizontal wall, indicated here by a broken line 62, which horizontal wall acts, for example, to provide an internal wind baffle and also provides for stable interengagement between the protuberance 14 of the extension device 10 and the weephole device 48.

The rectangular open end 26 of the extension device 10 from which projects the protuberance 14, and the rectangular rear inlet end 56 of the weephole device 48 are substantially identical in size. To clarify this description and all others with similar reference to Figure 3, a broken line 64 will indicate the outline of the protuberance 14 of the extension device 10.

To attach the extension device 10 to the weephole device 48 the extension device protuberance 14 is inserted inside the upper part of the rear inlet end 56 of the weephole device 48 so that the base wall underside 38 of the protuberance 14 sits on top of the weephole internal horizontal wall as indicated by broken line 62. The attachment is complete when the open end 26 of the extension device 10 closely abuts the rear inlet end 56 of the weephole device 48.

It is desirable that the external dimensions of the protuberance 14 provide an interference fit into the internal dimensions of the weephole device 48 for handling purposes when assembled, because there can be no expected forces present to force them apart when the completed assembly is built into a masonry wall. However, although it is not envisaged to be necessary, a suitable adhesive could be included during assembly if so desired.

Upon completion of the described assembly procedure, the external surface of the sloping top wall 40 on the protuberance 14 will closely abut the internal surface of the sloping top wall 52 on the weephole device 48 and thereby align the peak 54 of the weephole device 48 with the top wall 18 of the extension device 10. Likewise, with the underside of the base wall 38 of the protuberance 14 also sitting on top of the weephole internal horizontal wall, as indicated by broken line 62, this aligns the base 20 of the extension device 10 with the base 50 of the weephole device 48. These top and bottom alignments prevent any vertical movement between the extension device 10 and the weephole 48 after they have been assembled together. Furthermore, if the cross sectional width of the base wall 38 of the protuberance 14 and the cross sectional width of the sloping top wall 40 of the protuberance 14 provide a reasonably tight sliding fit between the internal faces of the weephole device 48 side walls, this will accurately align the side walls of the extension device 10 with the side walls of the weephole 48.

From the foregoing description it will be appreciated that by utilising the horizontal internal wall as indicated by broken line 62 on the weephole device 48 this allows internal engagement to be achieved between the protuberance 14 of the extension device 10 and the weephole device 48. The interengagement between the protuberance 14 and the weephole device 48 provides accurate alignment of the two components, thereby providing a channel of fluid communication through the extended weephole 47 which does not comprise an additional barrier to impede the flow of water along the base walls 20, 50 of the extended weephole device 47.

The interengagement of the weephole device 48 and the extension device 10 provides an extended weephole water passage without intruding into the lower cross sectional internal area of the original water passage when provided by just the weephole. In addition, this arrangement also avoids increasing the external cross sectional size at any point along the length of the attached products above that which would have been provided by just the weephole without an extension.

Figure 4 of the drawings that follow illustrates the rear view of the tall cavity drainage water rear open end 28 of the extension device 10 which is seen as a side view in Figure 3. It should be appreciated that like the front open end 26 of the extension device 10 the rear open end 28 is also the same size and shape as the rear inlet end 56 of the weephole device 48.

Figure 5 of the drawings that follow illustrates an end view of the front outlet end 58 of the weephole device 48. Here it can be seen that the front outlet end 58 offers protection against the ingress of large insects by way of a circular insert 66 supported by yokes 68, 70 and 72. Also, projecting from the underside of the front outlet end 58 of the weephole device 48 there is a location/drip feature 74. One of the purposes of the location/drip feature 74 is to locate accurately the weephole 48 along with the attached extension device 10, relative to the thickness of a wall leaf that is part of a cavity wall, and with the correct position being achieved by simply abutting the back face of the location/drip feature 74 against the external face of a cavity wall outer wall leaf.

Figure 6 of the drawings that follow shows a section through a structural assembly which includes an extension device 10 in accordance with the present invention. The structural assembly comprises a cavity wall 76 having an outer masonry wall leaf 78 and an inner masonry wall leaf 80 separated by a cavity 82. A cavity tray dampcourse 84 spans the cavity 82. The dampcourse 84 is sandwiched within the inner wall leaf 80 at a higher level than it is sandwiched within the outer wall leaf 78 directly underneath an extended weephole 47 which consists of an extension device 10 attached to a weephole device 48, with the extended weephole 47 being as illustrated and described with reference to Figure 3 of the drawings that follow.

In the structural assembly shown in Figure 6 of the drawings that follow, there are times when under certain climatic conditions the cavity face 86 of an outer wall leaf 78 can run with water, and when for a number of reasons it is required to arrest the downward progress of such water, a cavity tray damp course is inserted to both arrest and guide the water to an extended weephole device 47 through which the water can pass and be discharged at the external wall face 88 of the outer wall leaf 78.

It should be appreciated that with reference to Figure 6 of the drawings that follow, by way of example only, the inner wall leaf 80 is represented as being a standard 100mm thick masonry wall, but the outer masonry wall leaf 78 is represented here as being 150mm thick.

This shows the need for a standard 100mm long weephole device 48 to be extended on this occasion by a 50mm long extension device 10 to provide a covered and uninterrupted channel for liquid communication between a tall open inlet end 28 provided at the cavity face 86 by the extension device 10 and a small outlet end 58 at the opposite end of the channel provided by the weephole device 48. It should also be appreciated that should on other occasions the weephole device 48 be required to be extended by less than the 5Omm shown here, then the extension device 10 could be reduced in length by cutting at provided designated grooves 30, 32 and still provide the same sized tall cavity wall face inlet as the tall cavity open inlet end 26. It should also be appreciated that should on other occasions the weephole device 48 be required to be extended by more than 50mm, two or more extension devices may be used in tandem.

The extended weephole 47 is installed by it being sat on top of the lower horizontal part 90 of the cavity tray dampcourse 84 and then it is embedded in a perpendicular mortar joint 92 when the outer wall leaf 78 is being constructed. To assist with the correct cross wall alignment of the extended weephole 47 the location/drip feature 74 below the outlet end 58 is placed with its rear face abutting the outer wall face 88. In this arrangement the extended weephole device 47 is correctly aligned with its outlet end 58 being aligned with the outer wall face 88 and its inlet end 28 being aligned with the outer wall cavity face 86. To complete the installation of the extended weephole device 47 in the perpendicular mortar joint 92, the triangular area 94 above the extended weephole device 47 is filled with mortar. The location/drip feature 74 also serves as a drip feature as it projects from the wall face 88 to encourage water discharging from the weephole outlet end 58 to discharge away from the wall face 88.

Figures 7 and 8 of the drawings that follow show a preformed plastic moulded weephole extension device 10 substantially as shown in Figures 1 and 2 of the following drawings, with additional features according to further embodiments of the first aspect of the invention.

An alternative protuberance 14 is shown, comprising an additional lip 41 on the sloping cross wall 40, which lip is substantially parallel with side wall 42. The alternative protuberance 14 further comprises a horizontal top wall 45 extending from the sloping cross wall 40 to where the protuberance 14 joins to the main body 12 of the extension device 10. Both the lip 41 and the top wall 45 act to enhance the cooperation of the extension device 10 with a weephole device 48, or the extension device 10 with a further extension device 10, to provide perfect alignment of the extension device 10 with a weephole device 48 or a second extension device 10, and to give a flush and secure fit, whilst providing a channel of fluid communication with a level and uninterrupted base.

A further embodiment according to the invention shown in Figures 7 and 8 of the drawings that follow is a horizontal ridge on the internal face of the main body 12 of the extension device 10, projecting from the horizontal base wall 38 of the protuberance 14. The internal ridge is shown represented by the double broken lines 43. The ridge provides a ledge on a first extension device 10 for the horizontal base 38 of the protuberance 14 of a second extension device 10 to abut, when two or more extension devices 10 are used in tandem. Such a ridge can also be used to guide the protuberance 14 of a second extension device 10 into the main body 12 of a first extension device 10.

A further feature shown on Figures 7 and 8 of the drawings that follow is a thickened internal wall 39, indicated externally in Figure 7 by the broken line 37 and shown more clearly as a thickened line in Figure 8. The thickened internal wall 39 projects on the internal face of side wall 22 from where it meets the top wall 18, to a ridge extending from the top wall 45 of the protuberance 14. This internal thickened wall 39, along with the ridge indicated by double broken lines 43, act to position a protuberance 14 of an extension device 10 in the main body 12 of an extension device 10, resulting in alignment of the two extension devices 10, without any vertical movement. When one or more extension device(s) 10 are fitted together and interengaged with a weephole device 48, the cooperation is such that the internal horizontal base wall(s) 20 provided by the extension device(s) 10 and the horizontal base wall 50, provided by the weephole device 48 are perfectly aligned to provide a channel of fluid communication between the inlet end 28 of the extension device 10 and the outlet end 58 of the weephole device 48, with no additional barrier to impede the flow of fluid.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

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 combinations 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 purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed 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

Claims:

1. An extension device suitable for use with a weephole device in an outer wall leaf of a cavity wall, said outer wall leaf comprising a cavity face and an external face; said weephole device comprising a channel of fluid communication between an inlet and an outlet, said channel being bounded on its underside by a base wall; said extension device comprising a channel of fluid communication, said channel being bounded at its underside by a base wall; said extension device further comprising means for interengaging with the weephole device; whereby, the interengaging means are such that when the extension device and the weephole device are interengaged to extend the channel of fluid communication, in use, between the cavity face and external face of the cavity wall outer wall leaf, there is no additional barrier along the base walls to impede the flow of fluid from the extension device to the weephole device.

2. An extension device according to Claim 1, comprising a main body comprising a side wall, a base wall and optionally a top wall.

3. An extension device according to Claim 1 or Claim 2, in which the extension device comprises a hollow tube.

4. An extension device according to Claim 3, in which the hollow tube is open-ended.

5. An extension device according to Claim 3 or Claim 4, in which the hollow tube has a substantially rectangular cross section.

6. An extension device according to any one of the preceding Claims, in which the interengaging means comprises a protuberance, adapted to fit a weephole device.

7. An extension device according to Claim 6, in which the protuberance comprises a hollow tube.

8 An extension device according to Claim 6 or Claim 7, in which the protuberance has an open end.

9. An extension device according to any one of Claims 6 to 8, in which the protuberance does not extend from the full height of the extension device.

10. An extension device according to Claim 9, in which the protuberance does not extend from the base wall of the extension device.

11. An extension device according to Claim 9 or Claim 10, in which the protuberance only extends between the top of the extension device and a level less than mid-way down the extension device.

12. An extension device according to any of Claims 6 to 11, in which the protuberance comprises a cross wall which is substantially tapered from where it connects to the top of the extension device to its end.

13. An extension device according to Claim 12, in which the cross wall is truncated before it joins the top of the extension device.

14. An extension device according to Claim 13, in which the protuberance comprises a top wall which extends from where the cross wall is truncated to the extension device.

15. An extension device according to any one of the preceding Claims, in which the extension device comprises one or more region(s) adapted for cutting or breaking, along its length.

16. An extension device according to Claim 15, in which the regions adapted for cutting or breaking are in the form of a groove.

17. An extension device according to Claim 16, in which the grooves are on the outer surface of the extension device.

18. An extension device according to any one of Claims 15 to Claim 17, in which the regions adapted for breaking or cutting extend along the base wall of the extension device.

19. An extension device according to Claim 15, in which the regions adapted for cutting or breaking are substantially continuous around the outer surface of the extension device.

20. An extension device according to any one of Claims 15 to 19, in which the regions adapted for cutting or breaking comprise a thin membrane on the extension device.

21. An extension device according to Claim 20, in which the regions adapted for cutting or breaking are perforated.

22. An extension device according to any one of Claims 15 to 21, in which the regions adapted for cutting or breaking are marked to indicate the length that the extension device will provide when cut or broken at that region.

23. An extension device according to any one of Claims 15-22, in which the regions adapted for cutting or breaking are at 5mm intervals.

24. An extension device according to any one of Claims 6 to 23, in which the protuberance is narrower than the extension device.

25. An extension device according to Claim 24, in which the protuberance projects inside the extension device.

26. An extension device according to Claim 25, in which the protuberance projects inside the main body up to a point adjacent to the first region adapted for cutting or breaking.

27. An extension device according to any one of Claims 6 to 26, comprising an internal ridge extending from the bottom wall of the protuberance.

28. An extension device according to any one of Claims 6 to 27, comprising an internal ridge extending from the top wall of the protuberance.

29. An extension device according to Claim 28, in which the side of the extension device above the internal ridge is thicker than the side of the extension device below the internal ridge.

30. An extension device according to any one of the preceding Claims, in which the external cross section of the extension device is substantially the same as the external cross section of the weephole device with which it is intended to cooperate.

31. An extension device according to any one of the preceding Claims, in which the extension device is a one-piece construction.

32. An extended weephole device comprising a plurality of elements, the extended weephole device comprising a weephole device and an extension device according to any one of the preceding Claims, whereby the elements are interengaged to extend the length of the weephole device to provide a fluid flow pathway between the weephole device and the extension device with no additional barrier to impede the flow of fluid from the extension device to the weephole device.

33. An extended weephole device according to Claim 32, in which the weephole device additionally comprises an internal bar.

34. A structural assembly comprising a cavity wall formed by an inner leaf and an outer leaf separated by a cavity, the outer leaf having an external face and a cavity face, the outer leaf comprising at least one perpendicular mortar joint within which there is a drainage device comprising a weephole device and an extension device according to any one of Claims 1-31, thereby providing an inlet on the cavity face of the outer leaf and an outlet on the external face of the outer leaf and a channel of liquid communication between the inlet and the outlet comprising no additional barrier along the base wall of the channel to impede the flow of fluid from the extension device to the weephole device.

35. A structural assembly according to Claim 34 in which the extended weephole does not project substantially beyond the external face of the outer wall leaf.

36. A method of extending a weephole device comprising interengaging an extension device according to any one of Claims 1-31 with a weephole device, such that the fluid flow pathway along the base walls of the channel provided by the extended weephole device comprises no additional barrier to impede the flow of fluid from the extension device to the weephole device.

37. A weephole extension device comprising one or more region(s) adapted for cutting or breaking.

38. A weephole extension device according to Claim 37, in which the regions adapted for cutting or breaking are each in the form of a groove.

39. A weephole extension device according to Claim 38, in which the grooves are on the outer surface of the extension device.

40. A weephole extension device according to Claim 37, in which the regions adapted for cutting or breaking extend along the base wall of the extension device.

41. A weephole extension device according to any one of Claims 37 to 39, in which the regions adapted for cutting or breaking are substantially continuous around the outer surface of the extension device.

42. A weephole extension device according to any one of Claims 37 to 41, in which the regions adapted for cutting or breaking comprise a thin membrane on the extension device.

43. A weephole extension device according to Claim 42, in which the regions adapted for cutting or breaking are perforated.

44. A weephole extension device according to any one of Claims 37 to 43, in which the regions adapted for cutting or breaking are marked to indicate the length that the extension device will provide when cut or broken at that region.

45. A structural assembly substantially as described herein and as shown in Figure 6 of the accompanying drawings.

45. A weephole extension device according to any one of Claims 37 to 44, in which the regions adapted for cutting or breaking are at 5mm intervals.

46. An extension device substantially as described herein and as shown in any one or more of Figures 1, 2, 7 or 8 of the accompanying drawings.

47. An extended weephole device substantially as described herein and as shown in any one or more of Figures 3 or 4 of the accompanying drawings.