EP1472422A1

EP1472422A1 - Interlocking of a longitudinal seam and a transverse seam in metal shingles

Info

Publication number: EP1472422A1
Application number: EP03701565A
Authority: EP
Inventors: Pasi Riikonen
Original assignee: Rautaruukki Oyj
Current assignee: Rautaruukki Oyj
Priority date: 2002-02-08
Filing date: 2003-02-07
Publication date: 2004-11-03
Also published as: WO2003066991A1; FI115987B; FI20020262A0; AU2003202613A1; FI20020262A; PL370086A1

Abstract

The invention relates to shingles made of metal sheet comprising a shingle area (5) and longitudinal sides (1,2), which are disposed in the roof substantially in the water flow (F) direction. The first longitudinal side of the shingle comprises a tongue (1) projecting outwardly (Do) and equiped with a grip nose (15) including portions (7a,7b), and the second longitudinal side comprises a groove (2) projecting outwardly and opening inwardly (Di) indluding legs (8a,8b). The tongue and the groove form seams between adjacent shingles. A shingle also comprises U-folds at the edges transverse to the longitudinal sides, the U-folds forming mutually horizontal seams between the upper and lower shingles. Further, at the upper ends of the tongues, there are first notches (9a), which extend from the fixing flange to the area of the grip nose, and at the upper ends (18) of the grooves, there are second notches (9b), which extend from the grip projection in-between the inner leg and the outer leg. These notches provide tight junctions between the seams.

Description

Interlocking of a longitudinal seam and a transverse seam in metal shingles

The invention relates to a shingle made of a metal sheet comprising a panel area, a first longitudinal side and an opposed second longitudinal side, and an upper edge and a lower edge, the longitudinal sides in the roof being disposed substantially in direction of the water flow and the edges being transverse to said sides, in said shingle: on the first longitudinal side a tongue projecting substantially outwardly from the shingle area and on the second longitudinal side a groove projecting sub- stantially outwardly from the shingle area and opening inwardly; as an extension of said tongue a fixing flange, which projects laterally in the direction of the shingle area; said tongue comprising an outer portion projecting between the shingle area and the fixing flange and an outwardly projecting inner portion comprising a grip nose extending towards the panel area; said groove comprising an outwardly pro- jecting inner leg and an outwardly projecting outer leg having at its free edge a grip projection directed towards the groove. The invention also relates to a roof assembled of shingles of this type, in which each single is attached to its support.

US patent specification 5,247,772 describes shingles of vertical seam type, in which the seam between adjacent shingles is formed between mainly parallel wall-like legs, which are moulded from the shingle material and project upwardly and mainly perpendicularly to the shingle at its opposite edges, and whose covering portion seals the seam. The covering portion is formed from the material of the second leg, it extends over the seam formed by the first seam and the second seam of adjacent shingles, and here it extends over the first leg of the adjacent shingle and comprises a suspended flange having a free edge. The shingle further comprises a projection formed of the same material, which projects from the first leg of the shingle below the adjacent shingle. The first vertical leg has greater height than the second vertical leg in order to keep the shingle apart from the projection of the adjacent shingle ex- tending underneath it. In addition, the vertical legs comprise locking means for fixing the free end of the suspended flange of the covering portion of the second vertical leg to the first vertical leg. Said projection comprises fastening holes and the shingles are consequently fixed only in the area of the described vertical seams, i.e. the seams parallel with the water flow. The reference discloses that the shingle is in- tended to extend continuously, i.e. uninterrupted from the ridge of the roof to its cornice. Hence the reference does not describe, nor even mention any shingle extension, i.e. transverse seams. The manufacture and especially transport and storage of such extremely long shingles, which, in addition, need to be individually factory- manufactured to size according to orders, are awkward and increase costs. The proposed shingle involves the problem of having an end edge at the cornice, where the shingle has to be fastened in the area between the legs by fasteners that are visible directly through the shingle, if one wishes to avoid loud noise and risk of loosening of the shingles in windy weather.

On the other hand, ridge leads of roof panel type generally use hooked seam between the upper and the lower ridge lead, the transverse or vertical seams running transversely or often perpendicularly to the water flow direction. One such hooked seam is disclosed by US patent specification 5,799,460. In this reference, all the seams between the ridge leads are hooked seams, adjacent ridge leads being interconnected by separate locking strips, thus forming vertical hooked seam between the ridge leads, and the lower transverse edge of the ridge leads is bent in U-shape downwardly, thus providing together with the upwardly bent zig zag shape of the upper transverse edge of the lower ridge lead a horizontal hooked seam between the ridge leads. In this reference, the horizontal hooked seams comprise a strip serving for the nailing of the ridge leads to the base, with the nailing hidden underneath the lower ridge lead. Thus the ridge leads are fastened only in the area of to the de- scribed horizontal seams, i.e. in the area of the seams transverse to the water flow direction. The reference further shows that the horizontal seams of adjacent ridge leads are all mutually aligned, whereas the vertical seams of the lower and the higher ridge leads are typically overlapping with the vertical seam of two uppermost ridge leads disposed at the centre of the lower ridge lead. A roof consisting of such ridge leads is slow to assemble and requires high professional skill. In addition, the ridge leads have poor pilability, i.e. they cannot be piled overlapping and hence require much space and are exposed to damage during transport. Due to this ridge lead disposition and the flatness of all the seams, the roof of US patent specification 5,799,460 has quite a different aspect than the roof made of the shingles described in US patent specification 5,247,772, which has seams that protrude distinctly in the vertical direction.

The primary objective of the invention is to provide a roof shingle that is easy to manufacture, easy to transport and has the aspect of "a tin roof, so that the roof made of shingles consequently has accentuated vertical seams. A second detailed objective of the invention is to provide such a shingle, which can be extended with horizontal seams, allowing the use of shingles that are relatively short in the water flow direction, such as standard-sized shingles. Thus the purpose of the invention is to try to avoid the necessity of manufacture to order-specific sizes. A third objective of the invention is to provide such a shingle, whose seams are reliably waterproof even in windy conditions. A fourth objective of the invention is such a shingle, al- lowing assembly of the roof to be manufactured with maximum rapidity and ease, without requiring high professional skill.

These problems are resolved and these objectives are achieved by means of the shingle of the invention, which is characterised by the features defined in the char- acterising part of claim 1, and with the roof of the invention, which is characterised by the features defined in the characterising part of claim 6.

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One of the advantages of the invention is that the shingles can be manufactured at the factory into their final shape and with standard dimensions, so that the shingles can be sold to the users as ready-made kits. Assembly of a roof from these shingles is rapid, because the shingles can be joined by fitting and pressing them manually, a tool being required only for the fixing of the base in principle. Only shingles ending at the ridge of the roof may require cutting of their top, however, this is easy to do by means of tin shears or the like, since the cut-off edge is hidden from sight under the ridge plate. When the shingle of the invention is disposed starting from the cornice, its lower edge comprises an inwardly directed fold, which rigidifies the shingle area, so that the shingles need not necessarily be fastened at other points than the fixing flange adjacent to the tongue.

The invention is described in detail below with reference to the accompanying drawings.

Figure 1 is an axonometric projection of the lower edge and the upper edge of two shingles to be joined and the tongues to be fitted in succession, in the area of the first longitudinal sides of the shingles and cut open in the shingle area.

Figure 2 is the same axonometric projection as figure 1 of the shingles of figure 1 pressed together, with the tongue in succession forming a tongue joint and a third shingle of the invention, whose groove is pressed on top of the tongue. Figure 3 is an axonometric projection of the lower edge and the upper edge of two shingles to be connected and the grooves to be disposed in succession, in the area of the second longitudinal sides of the shingles, with the shingle area cut open.

Figure 4 is the same axonometric view as figure 3 of the shingles of figure 3 pressed together, with the grooves in succession to form a groove joint, and a third shingle of the invention, with the groove joint pressed on top of its tongue.

Figures 5A and 5B are cross-sectional views in plane II-II of figure 6 of the tongue joint and the groove on top of this, corresponding to the point shown in figures 1 and 2, along the plane I-I in figure 6, and accordingly, the groove joint and the tongue underneath it, corresponding to the point shown in figures 3 and 4.

Figure 6 is an axonometric projection and a general top view of a roof of the inven- tion assembled from the shingles of the invention.

The invention uses shingles consisting of metal sheet, the vertical seams between them being of the same type as the seams described in US patent specification 5,247,772. Thus, each shingle 10 comprises a shingle area 5, which constitutes the major portion of the entire shingle area. The shingle area may be planar or relatively slightly shaped in some other suitable way, such as corrugated or the like. The shingle comprises a first longitudinal side 11 and an opposed second longitudinal side 12, and an upper edge 3 and a lower edge 4. In the roof, these longitudinal sides 3, 4 are disposed substantially in the water flow direction F and the upper and lower edges 3, 4 are transverse, generally perpendicular to said sides. In this application, reference numeral 10 generally refers to the shingle. Only in the case of successive shingles in the water flow direction F, reference numeral lO refers to the upper shingles and reference numeral 10_L to the lower shingles, considering that the lower and upper shingles are either mutually identical or identical with regard to all other aspects except the length, and that a shingle that is upper relative to one shingle may be lower relative to another shingle, and vice versa. Similarly, reference numeral 10_s denotes shingles that are adjacent in a direction transverse to the water flow direction, considering that all the shingles in the roof in this direction are adjacent relative to one or more other shingles, and vice versa. Relative reference numerals lOu, 10_L and 10_s are thus used as further precisions alone. The definitions upper, upwardly, etc. imply points of the shingle 10, which, mounted on the roof, are opposed to the water flow direction at a reference point, the definitions lower, down- wardly etc. implying points of the shingle 10, which, mounted in the roof, are in the water flow direction from a reference point. The definitions side, laterally, adjacent imply directions transverse or perpendicular to the directions above. The definitions "outwardly Do" and "inwardly Di" imply directions which, when mounted on the roof, are directed towards the outer space and the roof base 30, respectively. This defines a three-dimensional system of coordinates. The total length L of the shingle is the distance between the upper edge 3 and the lower edge 4. In the set of shingles 10 of the invention, there may be one single such length, i.e. length L, or the set of shingles may comprise shingles with a shorter length L = L_s or longer length L = L_L, as explained below. The effective width Wp of the shingles, i.e. the dimensioning width, implying the width formed by adjacent shingles 10_s, joined by tongues and grooves 1 and 2 described below, perpendicularly to the length L; L_s: L_L from a tongue and groove combination to the adjacent tongue and groove combination, is generally formed between the longitudinal side 11 and 12, consisting more precisely e.g. of the distance between the outer portion 7a of the tongue 1 and the inner leg 8a of the groove 2.

The shingle 10 comprises on its first longitudinal side 11 a tongue 1 projecting substantially outwardly Do from the shingle area and on its second longitudinal side 12 a groove 2 projecting substantially outwardly Do and opening inwardly Di. The tongue is extended by a fixing flange 6, which projects in general or average or effective direction of the shingle area 5 into a first lateral direction Dpi, i.e. away from the shingle area 5. The tongue comprises an outer portion 7a projecting between the shingle area and the fixing flange and a projecting inner portion 7b, the top portion 21 of the tongue being located between these portions at a first height HI. The inner portion 7b of the tongue comprises a gripping nose 15 extending towards the shingle area. The groove, again, comprises a projecting inner leg 8a and a projecting outer leg 8b, the top portion 22 of the groove being located between the groove legs at a second height H2, the legs thus pointing inwardly Di from the top portion 22, whereas the groove 2. At the free edge of the outer leg 8b of the groove, there is a gripping projection 16 directed towards the groove, i.e. the gripping projection protrudes to the second lateral direction Dp2, i.e. from the outer leg 8b to the shingle area 5. The distance W2a between the gripping projection of the groove 2 and the inner leg 8a is substantially smaller than the distance Wlb between the gripping nose of the tongue 1, more precisely the top edge 19 of the gripping nose, which in the second lateral direction Dp2 is remote from the outer portion, and the outer portion 7a, but greater than or equal to the distance Wla between the inward curvature 23 of the grip nose and the outer portion 7a. The distance Wb2 between the outer leg of the groove 2 and the inner leg 8 a is substantially greater than the distance Wlb between the grip nose of the tongue 1 and its outer portion. In all, this gives Wla < W2a < Wlb and W2b < Wlb. The height of the tongue from the fixing flange 6, i.e. the first height HI is preferably slightly greater than the height of the groove from the shingle area 5, i.e. the second height, in other words HI > H2 and preferably HI > H2, in order to provide space for the bases 26 of the fasteners 29. The shingles are made of metal sheet, such as aluminium sheet, cupper sheet or steel plate, such as, for instance, preferably by moulding from a plastic-coated steel sheet, such as bending. Aluminium, copper and steel imply any alloy based on these metals that is suitable for the purpose. The outer portions 7a and/or inner portions 7b of the tongue and especially the inner legs 8a and outer legs 8b of the grooves, in particular the outer legs 8b of the groove, are thus allowed to yield resiliently, i.e. reversibly in the lateral directions Dpi, Dp2.

The shingle 10 of the invention comprises additionally the following features in combination. The upper edge 3 of the shingle comprises a first external U-fold 13 opening towards the lower edge, and the lower edge 4 comprises an inner second U- fold 14 opening towards the upper edge. The bent edge portion 25 of the U-fold of the tongue and groove is substantially parallel with the shingle area 5, and hence the bends 13 and 14 are at an angle of 180°. The dimension Ml of the first U-fold 13 in the direction of the length L of the shingle may be equal to or different from the dimension M2 of the second U-fold 14 in the direction of the length L of the shingle. The edge of the U-fold 14 of the lower edge, i.e. the lower edge 4 of the shingle, runs from the lower end 27 of the tongue, i.e. substantially aligned with the lower end 27, and accordingly, the edge of the U-fold 14 of the lower edge runs from the lower end 28 of the groove, i.e. substantially aligned with the lower end 28, not allowing for the small dimension required for the curvature of the bend. At the upper end 17 of the tongue, the invention provides for a first notch 9a, which extends in the direction of the upper edge 4 from the fixing flange to the area of the grip nose 15, i.e. in the second lateral direction Dp2 all the way to the grip nose. At the first notch 9a, the sheet material of the shingle consequently extends from the shingle area 5 to the narrowed point 23 and from there on all the way to the grip nose 15. In accordance with the invention, the upper end 18 of the groove comprises a second notch 9b, which extends in the direction of the upper edge 4 from the grip projection 16 between the inner leg and the outer leg, i.e. in the second lateral direction Dp2 to the top portion 22 between the inner leg and the outer leg. At the second notch 9b, the sheet material of the shingle then extends from the shingle area 5 to the inner leg 8a and from there on to the top portion 22.

The tongue 1 is located between the first notch 9 a and the lower end 4 of the shingle on the distance between the shingle area and the fixing flange 6, i.e. it is intact i.e. continuous in the transverse direction, and accordingly, the groove 2 is intact i.e. continuous between the second notch 9b and the lower end 4 of the shingle, on the distance between the shingle area and the grip nose 16. In shingles 10 of the preferred embodiment, the tongue 1 has the general shape of an Λ and the groove has the general shape of an |^~] . The tongue of the shingles has a general Λ-shape and the groove a general f^~1 -shape. The first notch 9a of the shingles extends in the direction of the length Ll of the tongue over the dimension Ml of the first U-fold and in the same way, the second notch 9b extends in the direction of the length L2 of the tongue over the dimension Ml of the first U-fold. The metal sheet forming the shingle after the first notch 9a has been made extends at least in such a way to the grip nose that principally the same definitions apply to the cut edge 24a of the first notch as those of the actual grip nose 15 and its top edge 19. When the distance between this cut edge 24a and the outer portion 7a of the tongue is marked with reference numeral Wlb', the relation W2a < Wlb' is valid, but also Wlb' < Wlb. The first notch 9a may be limited by the top edge of the grip nose or between this and the top portion 21 of the tongue, in other words, this cut edge 24a may be located between the top edge 19 and the narrowed point 23, yet closer to the top edge, or between the top edge 19 and the top portion of the tongue. After the second notch 9b has made, the metal sheet forming the shingle extends at least in such a way to the top portion 22 of the groove that the cut edge 24b of the second notch is located between the inner leg 8a and the outer leg 8b, in the centre of this top portion 22, for instance.

As stated above, all the shingles 22 may be mutually identical, and then their lengths L are equal. In the second optional embodiment of the invention, the shingles 10 include starting/ending shingles 10' having a shorter length L_s and standard shingles 10 having a greater length L_L in order to form overlapping adjacent shingles. When the mounting of the roof is started from the cornice, the operation comprises fitting in the lateral direction of adjacent shingles alternating standard shin- gles 10, having a greater length L and starting/ending shingles 10', having a smaller length L_s, as shown in figure 6. Accordingly, the mounting of the roof may be terminated at the ridge of the roof by placing laterally to this adjacent shingles al- ternating between standard shingles 10 and starting/ending shingles 10'. In this manner, the roof will have a neat edge at the cornice and the shingles will have ri- gidified lower edges at the cornice. In terms of the invention, the overlapping horizontal seams in adjacent rows of shingles have an even greater impact, as described in the following. The length L of shingles 10 of the two types is typically markedly shorter than the distance between the ridge of the roof and the cornice - except for roof parts having exceptionally small area - so that the roof assembled of such shingles has the aspect of a roof consisting of relatively small elements, as shown in figure 6. The width Wp of the shingles 10 may be in the range 30 cm - 2 m, typi- cally in the range 50 cm - 1 m, or in special cases greater or smaller than this, and the length L may be in the range 0.5 m - 10 m, typically in the range 1 m - 3 m, or in special cases greater or smaller than this. Consequently, the length L of the shingles may be greater than or equal to or smaller than their width Wp, depending on the aspect or ease of transport or storage desired in each case.

In the roof in accordance with the invention, which has been assembled from shingles 10 made of metal sheet, the first U-folds 13 of the lower shingles 10_L are interlacing with the second U-folds 14 of the upper shingles 10_U3 the hooked seam thus formed ensuring tightness of the transverse seams Z between the upper edges 3 and lower edges 4 of the shingles 10. In addition, the tongue 1 of the upper shingles 10u is located on top of the first notches 9a of the lower shingles 10_L, thus forming tongue extensions 31, the areas 20b of the grooves of adjacent shingles 10_s, which are at a distance ΔL from both the upper edge and the lower edge, bearing against the tongue extensions. Further, the groove 2 of the upper shingles 10u is located on top of the second notches 9b of the lower shingles 10_L. forming groove extensions 32, and the areas 20a of the tongues of adjacent shingles 10_s, which are at a distance ΔL from both the upper edge and the lower edge, are laying underneath the groove extensions. In this manner, intact and continuous areas 20b of grooves 2 cover the tongue extensions 31, thus ensuring tightness of the tongue extensions on the first longitudinal sides 11 of the shingles 10. In the same way, intact and continuous areas 20a of tongues 1 are provided inside the groove extensions 32, ensuring tightness of the tongue extensions on the second longitudinal sides 12 of the shingles 10.

The roof in accordance with the invention is assembled with one pane at a time by piling and fixing shingles 10 by means of fasteners 29, such as screws or nails, from the fixing flange 6, which may be perforated in advance for this purpose, to the base

30 supporting the roof. The piling of the shingles is started from the right lower corner and is ended at the left upper corner, with the roof viewed from the outside. If the shingles are made in an opposite hand view, i.e. as a mirror image, compared to the figures, piling is naturally performed from the left lower corner to the right upper corner. The upper shingle lOy is fixed to the lower shingle 10 as follows. For the tongue extension 31, the upper shingle is first pressed inwardly Di in such a position relative to the lower shingle that the second U-fold 14 is lower than the first U-fold 13, the outer portion 7a of the tongue 1 of the upper shingle 10u yielding so as to allow the tongues to overlap, and the bent edge portions 25 of the U-folds bearing against the shingle area 5 of the second shingle, after which the upper shin- gle is pulled in the direction of the length of the tongues and grooves upwardly so that the U-folds are interlacing, forming a hooked seam Z, and the lower end 27 of the tongue of the upper shingle 10u settles at the first notch 9a of the tongue 1 of the lower shingle 10_L. This bi-directional movement is shown with the arrow PI. Next, the groove 2 of the adjacent shingle 10_s> more precisely its continuous area 20b, is pressed inwardly in the direction P3 on top of the tongue extension 31 explained above, thus allowing the outer leg 8b of the groove to yield. When the groove is pressed into its final position, its grip projection 16 is snapped underneath the grip nose 15 of the aligned tongues, thus locking the longitudinal side 12 of one shingle to the first longitudinal side 11 of the adjacent shingle. For the groove extension 32, the mounting steps described above result in the shingle 10 containing the tongue 1 as a free edge bearing against the base 30. At this stage, this shingle is fixed by its fixing flange 6 by means of fasteners 29 to the base. Then the groove 2 of one adjacent and lower shingle 10_s, 10 is pressed inwardly in the direction P2 on top of the tongue 1 described above, more precisely on top of its continuous area 20a, thus al- lowing for yield of the outer leg 8b of the groove. When the groove is pressed into its final position, its grip projection 16 is snapped underneath the grip nose 15 of the tongue, thus locking the second longitudinal side 12 of an adjacent shingle to the first longitudinal side 11 of the previously mounted shingle. Next, a second adjacent and upper shingle 10_s, 10u is taken to be pressed - on top of the same continuous area 20a of the tongue 1 as above - inwardly Di in a position relative to the lower shingle where the second U-fold 14 is lower than the first U-fold 13, and then the outer leg 8b of the groove 2 of the upper shingle 10u yields, thus allowing the tongues to overlap, and the bent edge portions 25 of the U-folds will bear against the shingle area 5 of the second shingle, after which the upper shingle is pulled in the direction of the length of the tongues and grooves upwardly so that the U-folds overlap, forming a hooked seam Z, and the lower end 28 of the groove of the upper shingle lO settles at the second notch 9b of the groove 2 of the lower shingle 10 , at the same time as the grip projection 16 of the groove of the upper shingle 10u will be aligned with the grip projection of the lower shingle and snaps underneath the grip nose 15 of the tongue at least at this stage, thus locking the second longitudinal side 12 of the second adjacent shingle to the first longitudinal side 11 of the shingle mounted previously. This bi-directional movement is indicated with arrow P4.

Additionally, the roof in accordance with the invention requires separate moulding border pieces at the right-hand edge of the pane, or if the shingles 10 have opposite- handed view, separate moulding border pieces at the left-hand edge. Further, a splice moulding can be disposed at the cornice in order to ensure locking of the lower edge 4 of the shingle. The ridge of the roof also calls for a separate cover moulding. The mouldings mentioned above may be of any suitable type and are thus not explained in detail. Usually the horizontal seams are graded, in other words, hooked seams described above are distributed over adjacent shingles covering half of the shingle, so that the lengths of the areas 20a and 20b of tongues and grooves are not only mutually equal but also very short. In the extreme case, a hooked seam Z between upper and lower shingles is achieved exactly halfway of two successive hooked seams Z of two adjacent shingles by defining ΔL = L/2, and in that case, there is reason to dimension the shorter length of the starting/ending shingles 10' relative to the standard shingles as follows L_s = L_L/2. Any other gradation is conceivable, and then ΔL < L/2. Thus, for instance, the chimney may be disposed at the desired shingle by replacing this shingle with feed-through parts.

Claims

1. A shingle made of metal sheet comprising a shingle area (5), a first longitudinal side (11) and a second longitudinal side (12) opposite to this, and an upper edge (3) and a lower edge (4), the longitudinal sides in roofs being disposed substantially in the water flow (F) direction and the edges being transverse to said sides, in said shingle:

- on its first longitudinal side a tongue (1) projecting substantially outwardly (Do) from the shingle area and on its second longitudinal side a groove (2) projecting substantially outwardly from the shingle area and opening inwardly (Di);

- as an extension of said tongue a fixing flange (6), which projects in direction of the shingle area into a first lateral direction (Dpi);

- said tongue comprising, between the shingle area and the fixing flange, a projecting outer portion (7a) and a projecting inner portion (7b), which comprises a grip nose (15) extending towards the shingle area; and

- said groove comprising a projecting inner leg (8a) and a projecting outer leg (8b), whose free end has a grip projection (16) directed towards the groove, characterised in that the shingle (10) further comprises in combination:

- at the upper edge, an external first U-fold (13) opening towards the lower edge, and at the lower edge, an internal second U-fold (14) opening towards the upper edge;

- at the upper end (17) of the tongue, a first notch (9a) which extends in direction of the upper edge from the fixing flange to the area of the grip nose; and

- at the upper end (18) of the groove, a second notch (9b), which extends in direc- tion of the upper edge from the grip projection in-between the inner leg and the outer leg.

2. A shingle as defined in claim 1, characterised in that the tongue (1) has the general shape of an Λ and the groove has the general shape of an |^~l •

3. A shingle as defined in claim 1, characterised in that the first notch (9a) extends in direction of a length (Ll) of the tongue over a dimension (Ml) of the first U-fold and in a direction perpendicular to said length in direction from the fixing flange to the grip nose (15); and in that the second notch (9b) extends in direction of a length (12) of the tongue over a dimension (Ml) of the first U-fold and in a direction perpendicular to said length in direction from the grip projection to the top portion (22) between the inner leg and the outer leg.

4. A shingle as defined in claim 1 or 3, characterised in that the grip nose (15) comprises a top edge (19); and that the first notch (9a) is defined by the top edge of the grip nose or in-between this and a top portion (21) of the tongue.

5. A shingle as defined in any of the preceding claims, characterised in that all the shingles (10) are mutually identical, or the shingles (10) comprise starting/ending shingles (10') having a smaller length (L_s) and standard shingles (10) having a greater length (L ) in order to form overlapping adjacent shingles.

6. A roof assembled from shingles (10) made of metal sheet, each of which comprises: a shingle area (5); a first longitudinal side (11) with an outwardly projecting tongue (1), an opposite second longitudinal side (12) with an outwardly projecting and inwardly opening groove (2), which are substantially in the water flow (F) di- rection; as an extension of the tongue, a fixing flange (6), from which each shingle is fixed to its base (30); a grip nose (15) projecting from the tongue towards the shingle area; a grip projection (16) directed from the groove towards itself and a top portion (22); and an upper edge (3) and a lower edge (4) transverse to said tongue and groove, characterised in that - each shingle further comprises: at its upper edge a first U-fold (13) and at its lower edge a second U-fold (14); at the upper end of the tongue, a first notch (9a), which extends in direction of the upper edge to the area of the grip nose; and at the upper end of the groove, a second notch (9b), which extends in direction of the upper edge to the area of the top portion; - the first U-folds of the lower shingles (10_L) are interlacing with the second U-folds of the upper shingles (10u);

- the tongue (1) of the upper shingles (10u) is disposed on top of the first notches (9a) of the lower shingles (10_L), forming tongue extensions (31), and areas (20b) of the grooves of the adjacent shingles (10_s) remote from both the upper edge and the lower edge bear against the tongue extensions; and

- the groove (2) of the upper shingles (10τj) is disposed on top of the second notches (9b) of the lower shingles (10_L), forming groove extensions (32), and areas (20a) of the tongues of the adjacent shingles (10_s) remote from both the upper edge and the lower edge are laying underneath the groove extensions.

7. A roof as defined in claim 6, characterised in that the shingles are fixed to their base (30) substantially only at their fixing flanges (6) by means of fasteners (29).