EP0002587B1

EP0002587B1 - Valley gutter covering and roof with such valley gutter

Info

Publication number: EP0002587B1
Application number: EP78300766A
Authority: EP
Inventors: Dieter Spath; Karl-Heinz Hofmann
Original assignee: Braas GmbH
Current assignee: Cambio Ragione Sociale braas GmbH
Priority date: 1977-12-09
Filing date: 1978-12-07
Publication date: 1982-10-20
Also published as: DK144628C; EP0002587A1; DK554478A; DE2862067D1; ATA754978A; AT364509B; DE2755011A1; DK144628B

Description

The invention relates to a valley gutter covering for valleys formed between two intersecting pitched surfaces of roofs covered with roofing slabs or tiles, comprising a deformable valley strip in the form of at least one band made of plastics material for fastening to the roof structure and whose longitudinal edges have a barrier which prevents the ingress of water, dust and/or driven snow, on which barrier rest in use the roofing tiles adjoining the valley and overlapping the lateral zones of the valley strip, which band of the valley strip comprises on both sides of a centre line a relatively non-distortable central zone.
One proposal for a valley strip made of plastics is known from DE-A-2315610. The known valley strip is designed as a relatively rigid flat strip which has a corrugation extending longitudinally along the centre line, which corrugation separates two flat areas from one another. The barrier along each longitudinal edge is formed by a double-over layer of the strip, so that a hollow fold is formed for receiving clips or nails.
Furthermore, a series of variously shaped metal valleys are known for roof covering (cf. "Deutsches Dachdecker-Handwerk," 1964, pages 205-206). Here there is described, for example, a valley sheet or flashing having a web extending along the centre line in longitudinal direction, which web serves as a splash-guard and prevents rain water streaming down off of one roof surface from running under the covering of the other roof surface.
Finally, in the case of plastics gutters it is known, for example from GB-A-1 248204, to provide longitudinally extending ribs over their entire inside, which ribs assist in improving the flow conditions, counteract any clogging of the gutter caused by the accumulation of leaves or the like and assist in stiffening and strengthening the gutter.
The object on which the invention is based lies in providing for a valley channel or gutter covering of the aforementioned type a valley strip which can be easily installed, which can be adapted to valley gutters of various shapes, which after installation forms a stable and durable valley gutter, and which enables the mechanical stresses caused by temperature variations and/or expansion and contraction of the roof structure to be taken up without visible distortion.
The achievement of this object according to the invention is reflected in the characterising features of Patent Claim 1.
Further features and preferred embodiments of the valley gutter covering of the invention appear in the sub-claims.
This invention provides a valley strip made of flexible and deformable plastics. To effect installation it is merely necessary to fit the valley strip, which thus undergoes flexible deformation, to the valley boarding and to fasten it in the edge zones by means of nails or the like. In this way there is provided a valley strip which can be readily installed and which can be adapted to almost all valley gutters existing in practice. Even the ribbed central area of the valley strip can be deformed flexibly to a small extent but, because of the ribs, is so strong that a stable and durable lining is obtained. In the ribless lateral zones between the edge zones and the central area, the valley strip merely has sufficient strength for these lateral zones to be capable of taking up, with possibly visible distortion, the mechanical stresses caused by temperature variations and/or the expansion and contraction of the roof structure. Since the chiselled ends of the roofing tiles overlap these lateral zones, such distortions are not visible on the finished roof. Accordingly, only the ribbed central area of the valley strip is visible from the exterior, which in view of its strength is not subject to any distortion. Consequently, an easily installed and stable valley gutter covering is obtained, which can be fitted to match a variety of valley gutter shapes and which always offers a neat and aesthetically attractive appearance.
A preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 shows a valley strip in cross-section;
Figure 2 shows a diagrammatic and isometric illustration of the valley strip according to Figure 1;
Figures 3 and 4 show a diagrammatic sectional view of a valley strip installed in a finished roof covering;
Figure 5 shows an isometric illustration of the covering of a valley gutter with individual pieces of valley strip;
Figure 6 shows diagrammatically the formation of possible distortions in an installed valley strip;
Figures 7 and 8 show a diagrammatic top view of a finished roof with the valley gutter covering according to the invention.

As illustrated in Figures 1 and 2, the valley strip 10 consists of a flexible band 11 with a smooth underside and having ribs 12, 13, 14 and bulbous thickened portions 15 on the upper side. The ribs and thickened portions are formed integrally with the band. As material for the valley strip 10 there may be used rot-resistant, weatherproof plastics materials which are flexibly deformable. Preferably, the valley strip consists of moderately hard, flexibly deformable polyvinyl chloride (PVC) and is manufactured by extrusion.
The width e of the valley strip 10 is preferably between 40 and 80 cm. It is possible for the valley strip 10 to be produced practically endlessly with a length of 10 m or more and is then sufficiently flexible that the endless valley strip can be rolled up into a roll. According to an alternative embodiment, the valley strip 10 consists of separate pieces of determinate length, preferably between 100 and 250cm. These valley strip pieces have at one end a ribless zone 17 (see Figure 2) across the entire width, which zone ensures reliable overlapping when the individual pieces are juxtaposed, so that an absolutely watertight valley strip covering is obtained. Preferably, the linear extension of this ribless zone 17 is about from 10 to 30 cm. The thickness of the valley strip is chosen depending on the respective material and its flexural rigidity so that, on the one hand, satisfactory stability is ensured and, on the other hand, it is possible for the zones not strengthened with ribs to take up the mechanical stresses caused by temperature variations and/or the expansion and contraction of the roof structure by undergoing deformation but without splitting. If the valley strip consists, for example, of moderately hard polyvinyl chloride (PVC), the flat band 11 has a uniform thickness of preferably 1.0 to 1.5 mm over its entire width e.
Ribs are formed in the central zone b on either side of the centre line a on the upper side of the flat band 11. This central zone b preferably extends over 1/4 to 1/2 of the entire width e of the valley strip 10. The ribs are arranged parallel at a distance from one another and extend without interruption in the longitudinal direction of the valley strip 10.
It is preferable to provide first narrow ribs 12, second broad ribs 13 and third low ribs 14. The majority of all the ribs is designed in the shape of the narrow ribs 12. Only the rib extending along the centre line a and also two outlying ribs adjacent the edges of the central zone b are designed as broad ribs 13. The broad centre rib facilitates the determination of the centre line a when installing the valley strip 10 and assists in improving its cross-sectional rigidity. The broad ribs 13 at the edge of the central profiled portion also ensure increased cross-sectional rigidity and they delimit those areas of the flat band 11 into which the distortion 18 (see Figure 6) can extend in a controlled manner. The ribs 12 also assist in increasing the cross sectional rigidity of the strip 10. The narrow ribs 12 and the broad ribs 13 have substantially the same height which corresponds approximately to between 2 and 5 times the thickness of the flat band 11. Additionally, a small number of low ribs 14 can be provided in the edge zone of the central region b. the low ribs 14 essentially have a visual purpose and are intended to make less harsh the transition from the central zone b into the ribless lateral zones c and they do not allow these ribless lateral zones to appear so wide. Preferably, about 16 to 24 ribs are formed in the central zone b, an equal distance being provided between each rib. Although the number and dimensions of the ribs are so chosen that, on the one hand, the valley strip 10 is also deformable in the central zone b and can be fitted to match the shape of the respective valley gutter, while, on the other hand, a durable valley gutter covering is obtained which enables relatively small gaps in the valley boarding to be readily spanned.
On the valley strip 10 the ribbed central zone b is adjoined on either side by a ribless lateral zone c. As evident from .Figures 3 and 4, these lateral zones c are each overlapped on the finished roof by the roofing slabs or tiles 20 bordering on the valley. In the lateral zones c the valley strip 10 merely has the thickness of the flexible band 11, so that these lateral zones c are more flexible and more readily deformable than the central zone b. The lateral zones c are intended, in particular, to take up the mechanical stresses caused by temperature variations and/or the expansion and contraction of the roof structure, in which case it is possible for distortions 18 to develop, which are plainly visible (see Figure 6).
The lateral zones c are adjoined in each case by the edge zones d. In these edge zones d a barrier is formed which in the finished roof prevents the ingress of water, dust and/or driving snow beneath the roof covering. For the formation of this barrier it is possible, for example, to fold over the flat band 11 inwards, so that a hollow fold is formed in the edge zones d. Preferably, however, the barrier is designed as a bulbous thickened portion 15 of the valley strip 10 in the edge zones d. As evident from figures 3 and 4, the underside of those roofing tiles 20 bordering on the valley rests directly on this bulbous thickened portion 15. Preferably, a longitudinally extending nailing groove 16 is recessed in the bulbous thickened portion 15, through which groove nails 21 are driven into the underlying valley boarding 22 or into a support batten 23 mounted thereon. The height of the bulbous thickened portion 15 corresponds, preferably, to the height of the ribs 12 and 13.
Figures 3 and 4 each illustrate diagrammatically a valley gutter covering according to the invention. The valley strip 10 rests in each case on the valley boarding 22. The valley boarding 22 is mounted on a valley beam 24; alternatively, the valley boarding 22 can be fastened to the rafters 25 or can be lowered between them. For fastening the valley strip 10, nails 21 are driven into the valley boarding 22, or into the support batten 23 resting on the valley boarding 22, in the vicinity of the bulbous thickened portion 15 along the nailing groove 16; the additional use of the support batten 23 (Figure 4) is recommended particularly for roofs with shallow pitch. The roofing tiles 20 bordering on the valley rest with their underside on the bulbous thickened portion 15, so as to form a tight seal which reliably prevents the ingress of water, dust and/or driving snow beneath the roofing. Adjacent to the thickened portion 15, the roofing tiles 20 overlap the ribless lateral zones c of the valley strip 10, so that any distortions 18 which may be formed here are not visible to an observer. In that region of the valley not overlapped by the roofing tiles only the ribbed central zone b of the valley strip 10 is visible, which zone is in close contact with the valley boarding 22, has no distortions and, therefore, always presents a neat and aesthetically attractive appearance.
Figure 5 illustrates diagrammatically the installation of a valley strip 10 composed of separate pieces. The valley boarding 22 is fastened to the valley beam 24 and to the rafters 25. An individual valley strip piece 10 is placed on the valley boarding 22, fitted to match the shape thereof and fastened by means of nails 21 in the vicinity of the bulbous thickened portion 15 along the nailing groove 16. As shown, the individual valley strip piece 10 has at one end a ribless zone 17 which extends across the entire width and in which a fluidtight overlap with the underside of the adjacent valley strip piece 10 is possible, so that a fluidtight valley gutter covering is obtained.
Figure 6 illustrates diagrammatically the formation of distortions in the valley strip. After the valley strip 10 has been fitted to match the valley gutter shape, the fastening is effected merely by means of nails 21 which in the vicinity of the bulbous thickened portion 15 along the nailing groove 16 are driven through the valley strip 10 into the valley boarding 22. In the event of shrinkage of the valley boarding 22 or thermal expansion of the valley strip 10, it is possible for the illustrated distortions 18 to develop between the fastening points. These distortions 18 develop by design in the ribless lateral zones c which in both directions exhibit relatively small moments of resistance. The spatial extension of the distortions 18 is in any case limited by the broad ribs 13 in the edge region of the central zone b, since the cross-sectional rigidity of the valley strip 10 increases considerably in the region of these broad ribs 13. Since the lateral zones c are overlapped by the roofing tiles in the finished roof, the distortions 18 develop in a controlled manner in a region which is not visible to an observer. Accordingly, even after many years under the usual stresses, the valley gutter covering of the invention still presents a neat and aesthetically attractive appearance. Finally Figures 7 and 8 each illustrate a finished roof with the valley gutter covering according to the invention. In conventional manner the roofing tiles 20 approach the valley gutter obliquely, so that the tiles have to be cut at this point and an edge composed of chiselled ends is formed. This edge overlaps with the chiselled ends the ribless lateral zones c of the valley strip 10. Accordingly, only the central zone b provided with ribs 12, 13 is visible to an observer, said central zone being free of distortions, as a result of its increased cross-sectional rigidity. The central zone b forms a stable and durable lining, so that the roof can be walked on without danger in the region of the valley, even if the valley boarding 22 has small gaps.

Claims

1. A valley gutter covering for valleys formed between two intersecting pitched surfaces of roofs covered with roofing slabs or tiles, comprising a deformable valley strip (10) in the form of at least one band (11) made of plastics material for fastening to the roof structure and whose longitudinal edges (d) have a barrier (15) which prevents the ingress of water, dust and/or driven snow, on which barrier (15) rest in use the roofing tiles adjoining the valley and overlapping the lateral zones (c) of the valley strip (10), which band (11) of the valley strip (10) comprises on both sides of a centre line (a) a relatively non-distortable central zone (b) characterised in that the band (11) is flexible, the central zone (b) is provided on its upper side with a plurality of spaced ribs (12, 13, 14) extending longitudinally of the band for strengthening the band, and there is a lateral zone (c) adjacent each central zone (b) which lateral zone (c) is to be situated in a region substantially covered by the tiles (20) said lateral zone (c) being ribless so that deformations caused by expansion and contraction are taken up by flexing of the lateral zone (c) preferentially to the central zone (b).

2. A valley gutter covering according to claim 1 characterised in that the central zone (b) provided with ribs (12, 13, 14) constitutes 1/4 to 1/2 of the width (e) of the valley strip (10).

3. A valley gutter covering according to claim 1 or claim 2, characterised in that first ribs (12) and second ribs (13) of greater thickness than the first ribs (12) are provided, the ribs along the centre line (a) and a rib near each edge of the central zone (b) being second ribs (13).

4. A valley gutter covering according to claim 3 characterised in that the first and second ribs (12, 13) are substantially of equal height and this height corresponds to between 2 and 5 times the thickness of the flexible band (11). ).

5. A valley gutter covering according to either of claims 3 or 4, characterised in that between 16 and 24 first and second ribs (12, 13) are provided.

6. A valley gutter covering according to one of claims 3 to 5, characterised in that third ribs (14) of lesser height than the first and second ribs are formed adjacent to the second ribs (13).

7. A valley gutter covering according to one of claims 1 to 6, characterised in that the barrier takes the form of a bulbous thickened portion (15) in the edge zone (d) of the valley strip (10).

8. A valley gutter covering according to claim 7 characterised in that a nailing groove (16) is recessed into bulbous thickened portion (15).

9. A valley gutter covering according to one of claims 1 to 8, characterised in that the thickness of the flexible band (11) is about 1.0 to 1.5 mm.

10. A valley gutter covering according to one of claims 1 to 9, characterised in that the width (e) of the valley strip (10) is about 40 to 80 cm.

11. A valley gutter covering according to one of claims 1 to 10, characterised in that the valley strip (10) is formed in lengths of 10 m or more and can be rolled up into a roll.

12. A valley gutter covering according to one of claims 1 to 10 characterised in that the valley strip (10) is composed of pieces of determinate length from 100 to 250 cm, which have at one end a ribless zone (17) extending across the entire width (e).

13. A valley gutter covering according to one of claims 1 to 12 characterised in that the valley strip (10) consists of moderately hard, flexible and deformable PVC and have been produced by extrusion.

14. A roof with a valley gutter and comprising a roof structure, a valley gutter covering fastened to the roof structure and a plurality of roof slabs or tiles covering the roof and overlying edge portions of the valley gutter covering characterised in that the valley gutter covering is as claimed in any one of the preceding claims.