GB2533094A

GB2533094A - Drainage system for a sloping perimeter of a pitched roof

Info

Publication number: GB2533094A
Application number: GB1421804.4A
Authority: GB
Inventors: Fifield John
Original assignee: Forticrete Ltd
Current assignee: Forticrete Ltd
Priority date: 2014-12-08
Filing date: 2014-12-08
Publication date: 2016-06-15
Anticipated expiration: 2034-12-08
Also published as: GB2533094B; GB201421804D0

Abstract

The element includes a batten-engaging formation 220, and a channel 240 for draining precipitation towards an eave, with a first end 242 of the channel being receivable inside a second end 244 of a neighbouring element channel. The first end may be narrower and shallower than the second end and be defined by a stepped profile 252. The batten-engaging portion may include first and second flanges 222, 224, and be located at the second end of the channel on a second side wall 250 which is higher than a first side wall 248. The first flange may be parallel to the channels base 246, and the second flange may be perpendicular to the first. The first and second ends of the channel may have constant widths. Also claimed is a drainage system with a plurality of the drainage elements fixed to battens along a sloping perimeter of a roof.

Description

Drainage system for a sloping perimeter of a pitched roof

TECHNICAL FIELD

The invention relates to a drainage system for a sloping perimeter of a pitched roof, and drainage elements for use in such a system. In particular, but not exclusively, the invention relates to a dry verge roofing system, and verge elements for use in that dry verge roofing system.

BACKGROUND

Figure la illustrates in perspective view a pitched roof 20 for protecting a lower space below the roof from external elements such as wind and precipitation. The pitched roof 20 includes a plurality of parallel load-bearing rafters 22 that slope from a ridge 24 at the top of the roof structure to an eave 26 at a lowermost edge of the roof structure 20, and a plurality of parallel battens 28 disposed on top of, and extending orthogonally with respect to, the rafters 22 from a left-hand verge (not shown) at the left side of the roof to a right-hand verge 30 at the right side of the roof. Each verge defines a sloping perimeter of the roof 20 and overhangs a corresponding gable wall 32. An angle between the rafters 28 and a horizontal plane defines a pitch of the roof 20.

Roof-covering elements such as tiles 34 are affixed along the battens 28 in horizontally-extending rows or courses. As can be seen in Figure la, each course of tiles underlaps the course of tiles directly above and overlaps the course of tiles directly below, such that the files 34 overlap in a ridge-to-eave direction. Precipitation falling on the roof 20 is generally directed down the roof 20 over the tile 34 to a gutter 36 at the eave 26.

Gaps 38 between the tiles 34 and the gable wall 32 can be sealed with cement. This secures the gable end tiles in place, and acts as a barrier against precipitation and rodents that might otherwise enter the loft space via the gaps 38. However, applying the cement is time-consuming, cumbersome, and requires a skilled worker.

So-called 'dry verge' systems have therefore been developed that do not require cement. One example consists of verge caps, usually made from plastic, which can be placed over the side of each tile 34 at the verge 30, to embrace the tile 34 and close off the gaps 38 between the tiles 34 and the gable wall 32. The cap is nailed to the batten or barge board to secure it in place.

The end-caps have a good aesthetic appearance, giving rise to a stepped effect that mirrors the overlapping tiles. However, wind-driven rain can penetrate between the gable end tiles and the verge caps into the interior of the caps. The rain water then tends to leak out of each verge cap at the bottom, where it runs down the gable wall causing staining and potentially giving rise to damp.

Furthermore, where tiles 34 overlap one another, the cap sits between overlapping tiles. As a result, the cap lifts each tile slightly away from the file below, which disrupts the tiles at the gable end, reducing the efficacy of tile interlocks, thereby leaving the roof more vulnerable to leakage. This disruption is particularly significant if the files are profiled files.

An alternative dry verge system 50 is illustrated in Figures lb and lc. This dry verge system 50 is provided as a continuous strip 52 several metres in length that can be fitted to the verge 30 to guard against leakage.

The strip 52 is of constant cross section along its length, and includes a channel portion 54 at the right side of the strip consisting of a U-shaped channel 55 with a top cap 57, a horizontal flange portion 56 that extends leftwards from the channel portion 54 and is coplanar with the base wall of the channel 55, and a vertical flange portion 58 that depends downwardly from the junction between the channel portion 54 and the horizontal flange portion 56, in a plane parallel to the longitudinal axis of the strip.

In use, as shown in Figure lc, the horizontal flange portion 56 is slid between the perimeter wall and the ends of the battens 28, with the vertical flange portion 58 pushed up against the side of the wall, and the channel 54 arranged to the right of the batten ends. The ends of the battens 28 are nailed through the horizontal flange portion 56, thereby fixing the strip 52 in place. The top cap 57 sits over the top of the tiles, such that the strip 52 grips the tiles from the side, and where tiles overlap, the strip 52 sits between the overlapping tiles.

As the strip 52 is only a few metres long, a single strip is insufficient to cover the entire verge 30 of a typical roof. Several strips are therefore arranged end-to-end along the verge 30 to cover its length, with the strip nearest the ridge being trimmed to size to fit the roof. Ends of the strips 52 are joined together using a small connecting piece, sealed with mastic.

The strip 52 is effective in sealing the verge 30 of the roof 20, but due to the continuous nature of the strip 52 and the absence of a stepped profile it has less aesthetic appeal than the verge-caps described above. The system 50 is also more time consuming to install, since strips 52 must be cut to size, and sealed end-to-end. Furthermore, the strip itself is difficult to mould owing to the complex cross section, and requires collapsible mould cores, which make its production costly and time consuming.

A practical disadvantage with both the dry verge systems described above is that, to provide an effective seal, the systems must be designed for specific tile dimensions to fit the sides of the files 34 tightly. For example, in the system of Figures lb and lc, the top cap 57 must sit tightly over the tile to hold the tile in place and to seal against it. If the tile is too high, the cap will not fit, while if the tile is not high enough there will be a gap between the tile and the cap which will allow water to penetrate into the roof.

In practice, however, tile height cannot always be predicted. It is often necessary to truncate a tile 34 at the verge to fit the length of the roof 20, such that the cap must fit over a central portion of the file 34 rather than the side of the file 34. The central portion may be of different shape and dimensions, particularly if the file is a rolled file, and if so the system will not fit properly, leaving the roof particularly vulnerable to leakage, or in some cases prohibiting use of the system altogether.

It would be desirable to provide a dry verge system that addresses at least one of the problems described above.

SUMMARY OF THE INVENTION

Against this background, the invention resides in a drainage element for use in a drainage system for a sloping perimeter of a pitched roof. The drainage system includes a plurality of such drainage elements arranged along the sloping perimeter.

The drainage element includes a batten-engaging formation for fixing the drainage element to a roof batten, and a channel for draining precipitation towards an eave of the roof. The channel is configured such that a first end portion of the channel can be received inside a second end portion of the channel of a neighbouring drainage element when the drainage elements are arranged in the drainage system.

The batten-engaging formation allows the drainage element to be fixed quickly and easily to a batten, so that the drainage element can be held securely in place in a drainage system. Configuring the channel such that a first end portion of the channel can be received inside a second end portion of the channel of a neighbouring drainage element allows a plurality of such drainage panels to be incorporated into a drainage system such that their channels partially overlap along the roof perimeter.

This overlapping provides a continuous channel down the perimeter that allows any precipitation caught in the interior of the drainage elements to run all the way down the channel towards the eave of the roof, where it can be safely directed into a gutter, or otherwise drained away from the perimeter without penetrating into the roof or leaking down the gable wall.

The first end portion of the channel may be narrower than the second end portion of the channel, thereby facilitating insertion of the first end portion of the channel into a second end portion of the channel of a neighbouring drainage element.

Alternatively or additionally, the first end portion of the channel may be shallower than the second end portion of the channel.

To achieve a narrower or shallower first end portion, walls of the channel may have a stepped profile to define the narrower and/or shallower first end portion of the channel. In alternative embodiments, the stepped profile may be omitted, and the channel may instead be tapered, in the one or both of the first and second end portions.

If the channel has a stepped profile, the first end portion and the second end portion may each be of substantially constant width. This constant width allows the first end portion to be received telescopically in the second end portion of a neighbouring drainage element, whilst maintaining a sealing fit, which allows the effective length of each drainage element in the drainage system to be adjusted by sliding one drainage element further into or out of the second drainage element, thereby allowing the system to accommodate different tile dimensions.

The channel may include first and second side walls perpendicular to a base wall, and the batten-engaging formation may be provided on a side wall of the channel.

Preferably, the batten-engaging formation is provided at the top of the sidewall. The batten-engaging formation may be provided at the second end of the channel.

The first side wall of the channel may be higher than the second side wall of the channel. In this case, the batten-engaging formation may be provided on the second side wall of the channel. In this way, when the batten-engaging formation is fixed to a batten, a file that is fixed to that batten may extends over the second, lower sidewall, while the first, higher side wall bay protrude above the tile.

So that the batten-engaging-formation can be easily fixed on top of a batten, the batten-engaging formation may include a first flange that can lie flat against an upper surface of a batten. The first flange may be provided with nail or screw holes.

The channel of the drainage element may include a base wall, and the first flange may be parallel to that base wall. In this way, when the drainage element is fixed to a roof batten with the flange lying flat against a batten, the angle of the channel is fixed by the plane of the upper surface of the batten.

To locate the drainage element in place even more precisely, the batten-engaging formation may further include a second flange perpendicular to the first flange. In use, the second flange may lie against a side of the batten.

The invention also extends to a drainage system for a sloping perimeter of a pitched roof, the system having a plurality of drainage elements fixed to battens of a roof structure along the perimeter, each drainage element including a channel for draining precipitation towards an eave of the roof, the plurality including first and second drainage elements wherein a lower end portion of the channel of the first drainage element is received inside an upper end portion of the channel of the second drainage element.

The first and second drainage elements of the drainage system may be drainage elements as described above. In this case, each drainage element may be fixed to a batten via a batten-engaging formation.

The batten-engaging formation may be arranged at least partially on top of the batten. Arranging the batten-engaging formation on top of the batten in this way minimises disruption to the batten, and hence minimises disruption to tiles or other roof coverings that are laid on the roof.

The channel of each drainage element may be disposed outward of an end of the batten. In this way each channel can be accommodated at the exterior of the roof structure, such that precipitation flowing in the channel does not enter the interior of the roof structure, thereby reducing the risk of leakage.

The channel may include a side wall that lies against the end of the batten.

The roof structure may be a tiled roof, and a tile extends over the channel at the perimeter of the roof structure. In this way, the majority of precipitation falling in the vicinity of the perimeter is caught by the tiles, and the channel acts as a secondary drainage system. Furthermore, the channel, and an precipitation and/or debris flowing in the channel, are shielded from view.

Preferably the tile extends over the channel to meet an outer side wall of channel. A small gap may be left to allow for thermal expansion of the tiles.

The outer side wall of the channel may stand proud of the tile at the perimeter. In this way, the outer side wall acts as a barrier to guard against rainwater overflowing the verge and running down the gable wall.

The plurality of drainage elements may include an eaves element arranged at an eaves end of the drainage system. The eaves element may have a lower end portion that drains into a gutter of the roof structure. A channel of the eaves element may be of substantially constant width.

The channel of the eaves element may have a base wall that is angled towards a horizontal plane at an end of the eaves element that is closest to the gutter. In this way, the channel is arranged at a shallower angle as it approaches the gutter, thereby slowing the flow of water in the channel to guard against water overflowing the gutter at the eave.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures la, lb and lc of the accompanying drawings have already been described above by way of introduction to the invention. Embodiments of the invention will now be described, by way of example only, with reference to the remainder of the accompanying drawings, in which: Figure 2 is a perspective view from the right-hand side of a pitched roof incorporating a drainage system for a sloping perimeter of the roof; Figure 3a is an alternative perspective view of the roof of Figure 2 with the files removed, and Figure 3b is a partial perspective view showing a close-up the drainage system of Figure 2; Figures 4a and 4b are perspective and side views respectively of a drainage element for use in the drainage system of Figure 2; Figures 5a and 5b are perspective and side views respectively of an eaves element for use in the drainage system of Figure 2; Figure 6 is a cross-sectional view of the right-hand side of the roof of Figure 2; Figure 7 is a cross-sectional view of the left-hand side of the roof of Figure 2; and Figures 8a to 8g illustrate stages in the assembly of the roof and drainage system of Figure 2.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The drainage system of the invention is exemplified in the forgoing description as a dry verge system for use at a verge of a pitched roof, the system including a plurality of verge elements. However, the drainage system need not necessarily be used at a roof verge, but may be employed at any perimeter of a roof that is sloping or inclined.

The perimeter may be, for example, a verge, a gable abutment, a hip a valley, or any other suitable sloping perimeter.

Figure 2 illustrates a roof structure 20 that incorporates a drainage system in the form of a dry verge system 100 at a sloping perimeter defined by a right-hand verge 30 of the roof 20. The dry verge system 100 includes a plurality of drainage elements, exemplified here as verge elements 200 arranged along the verge 30 in a ridge-toeave direction. The lower most verge element 200 at the eave 26 of the roof 20 is an eaves element 200a. In the tiled roof, tiles 34 cover the majority of the verge elements 200, such that only a side wall 202 of each element 200 is visible.

Figure 3a shows the roof structure 20 with the tiles 34 removed, and from an angle that reveals the structure of the verge elements 200 underneath the tiles 34. Each verge element 200 includes a batten-engaging formation 220 that, in use, is fixed to a batten 28 of the roof structure 20 to fix the verge element 200 in place, and a channel 240 that, in use, sits outward of the batten 28 and is covered by a tile 34 (see Figure 2). When the verge elements 200 are arranged along the perimeter, the channels 240 partially overlap one another in a ridge-to-eave direction to define a single continuous channel 102 that runs to the eave 26 of the roof 20.

Figure 3b shows the overlap between two adjacent elements 200 in detail, and reveals that the channel 240b of a first or upper element 200b is arranged to overlie the channel 200c of a second or lower element 200c. More specifically, the channel 240b of the upper element 200b has a lower portion 242 that is received in an upper portion 244 of the channel 240c lower element 200c.

The verge elements 200 will now be described in further detail with reference to Figures 3b, 4a and 4b. Figures 3b, 4a and 4b illustrate right-hand verge elements for use with a right-hand verge, having the batten-engaging formation 220 on the left side, and the channel 240 on the right side. It will be appreciated, however, that the verge element may alternatively be a left-hand verge element for use with a left-hand verge, having the batten-engaging formation 220 on the right side, and the channel 240 on the left side.

The channel 240 of is of U-shaped cross-section, and includes a base wall 246 and inner and outer side walls 248, 250 that are upstanding from and substantially orthogonal to the base wall 246. The inner side wall 248 is closest to the battens 28 when in use (see Figure 3a), and supports the batten-engaging formation 220. The outer side wall 250 is furthest from the battens 28 when in use, and defines the side wall 202 of each element that is visible when the element is installed in the roof. The outer side wall 250 is higher than the inner side wall 248, and in the embodiment shown the outer side wall 250 is approximately twice the height of the inner side wall 248.

As best seen in Figure 4a, the lower portion 242 of the channel 240 is narrower than the upper portion 244 of the channel 240. Put another way, outer surfaces of the side walls 248, 250 are closer together in the lower portion 242 than in the upper portion 244.

To this end, the side walls 248, 250 have an inward step 252 that narrows the channel 240 to define the lower portion 242. The width of the step 252 is substantially equal to the width of the side walls 248, 250. In this way, the external width of the lower portion 242 of the channel 240 is substantially equal to the internal width of the upper portion 244 of the channel 240, which allows the lower portion 242 of the channel 240 of one verge element 200 to fit snugly into the upper portion 244 of the channel 240 of another verge element 200.

As best seen in Figure 4b, the lower portion 242 of the channel 240 is also shallower than the upper portion 244 of the channel 240. Put another way, when the verge element 200 is arranged with the base wall 246 horizontal, a lower surface of the base wall 246 (not visible in Figures 4a and 4b) is higher in the lower portion 242 than in the upper portion 244.

To this end, the base wall 246 has an upward step 254 that decreases the depth of the channel 240 in the lower portion 242. The height of the step 252 is substantially equal to the thickness of the base wall 246.

The batten-engaging formation 220 is located towards an upper end 256 of the verge element 200 and is supported on the inner side wall 248 of the channel 240.

The batten-engaging formation 220 includes a first or top flange 222 that meets the inner side wall 248 of the channel 240 at an uppermost edge 258 of the inner side wall 248, and a second or side flange 224 that lies orthogonal to the top flange 222, and depends downwardly from an upper end 226 of the top flange 222. In this way, the top and side flanges 222, 224 define a right-angled bend that can fit snugly against a batten. The top flange 222 is provided with nail or screw holes 228 that facilitate fixing of the batten-engaging formation 220 to a batten.

Figures 5a and 5b illustrate an eaves element 200a in detail. The eaves element 200a also includes a channel 240a having a base wall 246a and inner and outer side walls 248a, 250a that are upstanding from and substantially orthogonal to the base wall 246a, and a batten-engaging formation 220a including a top flange 222a and a side flange 224a.

An upper portion 244a of the eaves element 200a is configured in substantially the same way as the uppermost end 256 of the verge element 200 of Figures 4a and 4b. In particular, the upper portion 244a is configured such that it can receive the narrow lower end portion 242 of the verge element 200 of Figures 4a and 4b.

A lower portion 242a of the eaves element 200a differs from the lower portion 242 of the verge element 200 of Figures 4a and 4b. In particular, the base wall 246a of the channel 240a is sloped at a different angle in the lower portion 242a of the channel 240a than in the upper portion 244a of the channel 240a, so that it can guide water into a gutter 36 at the eave 26 of the roof (see Figure 3a). The lower portion 242a of the channel 240a of the eaves element 200a has two sections: a middle section 260a that is nearest the upper portion 244a of the channel 240a, in which the base wall 246a is more gently inclined relative to the base wall 246a in the upper portion 244a, and a lower section 262a, in which the base wall 246a is more steeply inclined relative to the base wall 246a in the upper portion 244a.

In this way, when the eaves element 200a is angled for use in a roof as shown in Figure 5b, the base wall 246a becomes angled progressively closer to a horizontal plane towards the eaves end. This shallower angling moving down the eaves element slows the progress of water flowing down the channel 240a, allowing it to fall gently into the gutter at the eave of the roof without overshooting.

The arrangement of the verge element 200 in the roof 20 will now be described in further detail with reference to Figures 3a and 6. The verge element 200 is attached to the roof 20 at the end of a batten 28. The batten-engaging formation 220 of the verge element 200 is arranged on top of the batten 28, such that the top flange 222 lies against an upper surface of the batten 28, and the side flange (not visible in Figure 6), lies against a side of the batten 28 that faces the ridge of the roof (see Figure 2).

As best seen in Figure 3a, the inner side wall 248 of the channel 240 lies flat against the end of the batten. In the accompanying Figures, the channel 240 is illustrated schematically as lying against the rafter 22; however, in practice a perimeter wall such as the gable wall may be arranged outward of the rafter and flush with the batten ends, such that the channel 22 may lie against the outer perimeter wall at the verge 30 of the roof. The channel 240 runs along the verge 30, disposed outwardly of both the battens 28 and the perimeter wall.

In the example illustrated in Figures 3a and 6, each batten 28 is neatly cut and lies flush with the rafter 22 or perimeter wall. However, this is not always the case, and the batten 28 may not be precisely flush with the rafter or perimeter wall, and may not been evenly truncated. Advantageously, the batten-engaging formation 220 allows the verge element 200 to be easily fixed to the batten 28 even if the batten 28 is not precisely flush with the rafter 22 or perimeter wall, or evenly cut. In particular, because the top flange 222 fits over the batten 28, rather than between the batten 28 and the perimeter wall, the top flange 222 can be fixed to the batten 28 even if the batten 28 overhangs the perimeter wall at the verge 30.

Referring now to Figure 6, the roof is filed up to and beyond the outer rafter 22. At the verge 30, the gable end tile 34 in each course extends beyond the rafter 22 to define an overhang 266. Although for illustrative purposes a gap is shown between the overhang 266 and the outer wall 250 of the channel 240, in practice the overhang 266 extends right up to the outer wall 250, such that the channel 240 is covered by the tile 34. The outer wall 250 of the channel 240 is sufficiently high that it stands slightly proud of the tile 34 at the overhang 266, so as to block completely any gap below the file 34, thereby preventing the ingress of rain beneath the tile 34.

Referring back to Figures 2 and 3a, when the verge elements 200 are installed in the roof 20 to form the dry verge system 100, each course of tiles 34 has a dry verge element 200 at the verge 30, arranged beneath the overhang 266 of the gable end tile 34. The eaves course has an eaves element 200a arranged at the verge 30 in the same manner, which runs into the gutter 36.The channel 240 of each dry verge element 200 overlaps the channel 240 of the dry verge element 200 below, and underlaps the channel 240 of the dry verge element 200 above, to provide a continuous channel from the ridge 24 of the roof to the eave 26.

When rain falls on the roof 20, the dry verge system 100 prevents rain from penetrating into the roof structure in two ways. Firstly, the outer side wall 250 of the channel 240 blocks the space beneath the tiles 34 to guard against water penetrating beneath the tiles 34 from the side of the roof. Secondly, any rain falling in the vicinity of the verge 30 that runs between the tile 34 and the outer side wall 250 of the channel 240 will fall down into the channel 240, where it will run down the dry verge system 100 into the channel 240 of each verge element 200 in turn, then into the channel 240a of the eaves element 200a, and finally into the gutter 36 at the eave 26 of the roof 20.

A particular advantage of the dry verge system 100 described is that it can accommodate different tile heights. This is particularly important when the width of the roof 20 is not equal to an integer number of tile widths.

Tiles are typically laid from the right side of the roof to the left. At the right hand side of the roof, a whole tile 34 will be laid with the tile 34 overhanging the verge 30 as described, and as shown in Figure 6. The tiler will continue to lay the course of tile moving leftwards. At the left side of the roof, shown in Figure 7, there is often space for only a portion of a tile 34, such that the gable end file at the left side of the roof 20 must be cut to fit the length of the roof 20.

If the tiles 34 are rolled or cambered tiles, this will result in an unpredictable tile height at the left side of the roof 20. In the dry verge system 50 of Figures lb and lc, this unpredictability is problematic, since the dry verge strip 52 must be fitted accurately to the tile height, to provide an effective barrier against rain. In some cases, this problem may prohibit use of the dry verge strip 52 altogether.

However, in the dry verge system 100 of the invention, this unpredictable file height does not affect the performance of the dry verge system 100, since it is intended that the outer wall 250 of the channel 240 stands proud of the tile 34, giving effective weather protection no matter what the height of the cut tile. Thus, the system can accommodate different tile thicknesses with ease.

If the tiles 34 are rolled tiles, at the left side of the roof the tile 34 may finish at the lowest part of the roll, for example as shown in Figure 7. In this case, the roll of the tile 34 would lead steeply downwards at the gable end of the roof, which tends to direct any precipitation falling in the vicinity of the end of the roof towards the verge 30, where it can over-run the tiles 34 and can be directed down the gable wall 32 (see Figure la). By contrast, when the dry verge system 100 according to the invention is employed at the roof verge 30, the protruding side wall 250 of the channel 240 guards against precipitation over-running the tiles 34, so that precipitation is instead guided down the roof over the tiles. Any water that runs between the tile 34 and the side wall 250 of the verge element 200 is easily accommodated in the channels 240, and directed towards the gutter 36 at the eave 26 of the roof 20.

In the embodiments illustrated, the verge elements 200 overlap right up to the steps 252, 254 in the walls of the channels 240 (see Figure 3b), such that the lower portion 242 of each channel 240 is completely concealed from view in the finished roof 20. However, this need not be the case, and a gap may be left between the upper and of a lower verge element 200c and the steps 252, 254 in the walls of the channel 240 of the upper verge element 200b, such that a part of the lower portion 242 of each channel 240 is exposed. In this way, the dry verge system 100 can accommodate a variety of different batten spacings and tile lengths, without the need to trim or otherwise alter the verge elements 200.

Thus, the invention provides a dry verge system that provides an effective means of protecting the verge from the ingress of water, and from infiltration by insects or rodents. Because the dry verge system can be fitted over an end of the batten, the system does not disturb the tiles at the gable end of the roof, and can accommodate overhanging and uneven battens. The dry verge system can also accommodate different tile lengths and overlaps and different tile thicknesses, and can accommodate the need to cut tiles to fit a roof, without adversely affecting the performance of the system.

The dry verge system 100 is typically installed in the roof 20 when the roof 20 is tiled, as will now be explained with reference to Figures 8a to 8g.

The underlying roof structure 20 is first assembled as shown in Figure 8a. The verge elements 200 are then fixed to the roof structure 20 at the verge 30 moving from the eave 26 of the roof towards the ridge 24.

Referring to Figure 8b, the eaves element 200a is first arranged in place at the verge of the roof, protruding over the gutter 36. The batten-engaging formation 220 is arranged over the end of the batten 28 at the verge 30, with the top flange 222 against the upper surface of the batten 28, the side flange (not visible in Figure 8b) against the ridge-facing wall of the batten 28, and the inner side wall of the channel (also not visible in Figure 8b) against the end of the batten. The eaves element 200a is secured in place, by nailing or screwing the element 200a to the batten 28 through the nail or screw holes 228 in the top flange 222.

The next verge element 200c is then slotted into place at the verge 30, as shown in Figure 8c, such that the channel 240 of the verge element 200c overlaps the channel 240a of the eaves element 200a, in the manner illustrated in Figure 3b. More specifically, a lower portion of the channel of the verge element 200c is inserted into an upper portion of the channel of the eaves element 200a. The batten-engaging formation 220 of the verge element 200c is fitted to the end of the batten 28 in the same manner as the batten-engaging formation 220 of the eaves element 200a, and is nailed or screwed in place.

Next, as shown in Figure 8d, the next verge element 200b is then slotted in place and fixed to the batten 28 in the same way, so that the channel 240 of the verge element 200b overlaps the channel 240 of the verge element 200c below. Further verge elements 200 are added, moving upwardly towards the ridge 24 of the roof 20.

Once the verge elements 200 are fixed in place, the roof 20 is tiled. Tiles 34 are arranged in courses across the roof 20 and are nailed or screwed to the battens 28, starting with the eaves course 34a as shown in Figure Be. At the verge 30 of the roof 20, the file 34 closest to the verge 30 is arranged to sit against the outer side wall 250 of the channel 240a.

As shown in Figures 8f and 8g, the tiling continues in the same manner with subsequent courses 34b and 34c. In each course 34b, 34c the gable end file 34 of the course sits against the outer side wall 250 of the channel 240a of the verge element 200b, 200c. Tiling continues up to the ridge 24 of the roof 20, and the roof 20 is finished with ridge tiles, and any other finishing pieces that are required.

In some cases, a further fixing means in addition to nails or screws may be required to fix the gable end tile in place. For example, to comply with British Standard for slating and tiling 5534 2014, gable end tiles must be fixed at least twice, and a dry verge is not necessarily considered to be a fixing. In this case, a standard tile clip may be employed. If the tile clip is a verge clip, it can extend across the channel of the drainage element to secure the tile at the outer side wall of the channel.

The system 100 can also be retro-fitted to an existing roof if required. To retrofit the system 100, the gable end tiles are first removed from the roof to expose the ends of the battens. The eaves element 200a is then fitted over the batten nearest the eave of the roof and nailed in place. Successive verge elements 200 are then slid into place moving towards the ridge of the roof, and fixed to their respective battens. The gable end tiles are then replaced, such that each tile covers its respective verge piece 200 Thus, the invention provides a dry verge system than can be quickly and easily fitted or retrofitted to a roof, without the need for skilled labour.

In an alternative embodiment, not illustrated, the channels of the verge elements may not have a stepped profile, but may instead be gently tapered in the lower portion, or continuously along the length of the verge element, to allow a lower end of the verge element to fit into the upper end of the verge element below.

The batten-engaging formation may comprise only the top flange and the side flange may be omitted, or the batten-engaging formation may comprise only the side flange and the top flange may be omitted. In other embodiments, the batten-engaging formation the need not be a flange at all, but may take any other suitable form.

It will be appreciated that the dry verge system described could be incorporated into any sloped perimeter of a roof. For example, the roof may terminate in an abutment at the top of the roof instead of a ridge with the verge leading from the abutment to an eave, or the roof may include a gable abutment. If the system is to be incorporated into a gable abutment, a lead flashing may be employed at the abutment, and the lead flashing may extend from the abutment wall into the channel of the verge element nearest the abutment The present invention is not limited to the exemplary embodiments described above and many other variations or modifications will be apparent to the skilled person without departing from the scope of the present invention as defined in the following claims.

Claims

CLAIMS1. A drainage element for use in a drainage system for a sloping perimeter of a pitched roof, the drainage system including a plurality of such drainage elements arranged along the sloping perimeter, and the drainage element including a batten-engaging formation for fixing the drainage element to a roof batten, and a channel for draining precipitation towards an eave of the roof, the channel being configured such that a first end portion of the channel can be received inside a second end portion of the channel of a neighbouring drainage element when the drainage elements are arranged in the drainage system.
2. The drainage element of Claim 1, wherein the first end portion of the channel is narrower than the second end portion of the channel.
3. The drainage element of Claim 1 or Claim 2, wherein the first end portion of the channel is shallower than the second end portion of the channel.
4. The drainage element of Claim 2 or Claim 3, wherein walls of the channel have a stepped profile to define the narrower and/or shallower first end portion of the 20 channel.
5. The drainage element of any preceding claim, wherein the channel includes first and second side walls perpendicular to a base wall, and the batten-engaging formation is provided on a side wall of the channel.
6. The drainage element of Claim 5, wherein the batten-engaging formation is provided at the second end of the channel.
7. The drainage element of Claim 5 or Claim 6, wherein the first side wall is higher than the second side wall.
8. The drainage element of Claim 7, wherein the batten-engaging formation is provided on the second side wall of the channel.
9. The drainage element of any preceding claim, wherein the batten-engaging formation includes a first flange.
10. The drainage element of Claim 9, wherein the channel includes a base wall, and the first flange is parallel to base wall.
11. The drainage element of Claim 9 or Claim 10, wherein the batten-engaging formation further includes a second flange perpendicular to the first flange.
12. The drainage element of any preceding claim, wherein the channel is of substantially constant width in the first end portion.
13. The drainage element of any preceding claim, wherein the channel is of substantially constant width in the second end portion. 10
14. A drainage system for a sloping perimeter of a pitched roof, the system having a plurality of drainage elements fixed to battens of a roof structure along the perimeter, each drainage element including a channel for draining precipitation towards an eave of the roof, the plurality including first and second drainage elements wherein a lower end portion of the channel of the first drainage element is received inside an upper end portion of the channel of the second drainage element.
15. The drainage system of Claim 14, wherein the first and second drainage elements are drainage elements according to any of Claims 1 to 13.
16. The drainage system of Claim 15, wherein each drainage element is fixed to a batten via a batten-engaging formation.
17. The drainage system of Claim 16, wherein the batten-engaging formation is arranged at least partially on top of the batten.
18. The drainage system of any of Claims 14 to 17, wherein the channel of each drainage element is disposed outward of an end of the batten.
19. The drainage system of Claim 18, wherein the channel includes a side wall that lies against the end of the batten.
20. The drainage system of any of Claims 14 to 18, wherein the roof structure is a tiled roof, and a tile extends over the channel at the perimeter of the roof structure.
21. The drainage system of Claim 20, wherein the tile extends over the channel to meet an outer side wall of channel.
22. The drainage system of Claim 21, wherein the outer side wall of the channel stands proud of the tile at the perimeter.
23. The drainage system of any of Claims 14 to 22, wherein the plurality of drainage elements includes an eaves element arranged at an eaves end of the drainage system, the eaves element having a lower end portion that drains into a gutter of the roof structure.
24. The drainage system of Claim 23, wherein a channel of the eaves element is of substantially constant width.
25. The drainage system of Claim 23 or Claim 24, wherein a channel of the eaves element has a base wall that is angled towards a horizontal plane at an end of the eaves element that is closest to the gutter.
26. A drainage element substantially as hereinbefore described with reference to Figures 2, 3a and 3b, 4a and 4b, 6 and 7 of the accompanying drawings.
27. A drainage element substantially as hereinbefore described with reference to Figures 2, 3a, 5a and 5b, of the accompanying drawings.
28. A drainage system substantially as hereinbefore described with reference to Figures 2, 3a and 3b, 6 and 7 of the accompanying drawings.