The present invention relates to interlockable tiles.

There are many types of known tiles. Commonly, they are formed of slate, clay or concrete and are susceptible to breakage during transit and installation. Further, these types of materials mean that the tiles are relatively heavy. In the case of roof tiles, tiles are often carried by roofers on their shoulders, which restricts vision and hinders movement. This can result in accidents, such as if a roofer breaks a batten between rafters after positioning a hand/foot incorrectly due to restricted vision. Further, the cost of transporting such products is also high.

Various types of interlocking roof tiles are available, for example an interlocking roof tile has been proposed in WO2010/01345. However, it remains desirable to provide an interlocking tile which aids alignment and provides a greater degree of flexibility of adjustment between adjacent tiles.

Embodiments of the present invention are intended to address at least some of the abovementioned problems.

According to a first aspect of the present invention there is provided an interlockable tile including:

a plurality of upper surface arrangements; and

a corresponding plurality of underside arrangements, with a first one of the upper surface arrangements and a first one of the underside arrangements being located at or adjacent a first side edge of the tile and a second one of the upper surface arrangements and a second one of the underside arrangements being located at or adjacent an opposite side edge of the tile, wherein in use, the upper surface arrangement of the tile interlocking with a corresponding underside arrangement on an overlapping tile; characterised in that

each of the upper surface arrangements or each of the underside arrangements of the tile provide an elongate slot respectively at or proximal to an upper or lower edge of the tile; and

each of the other of the underside arrangements or the upper surface arrangements of the tile provides a protrusion for engaging the slot;

such that, in use, the slots and corresponding protrusions provide a range of tiling gauges between a predetermined maximum and minimum gauge for the overlapping tiles.

Each elongate slot may extend from a first end at or proximal to the upper or lower edge of the tile to a second end which is distal to the edge, such that the gauge of the tile may vary between a maximum when the protrusion is at the first end of the slot to a minimum when the protrusion is at the second end of the slot. It will be appreciated that the gauge is the length of the exposed part of an underlying tile when the tiles are in use and therefore the maximum gauge corresponds to the minimum overlap between the tiles and the minimum gauge corresponds to the maximum overlap. The slot is typically aligned with the vertical axis of the tile.

Each protrusion may be spaced apart from an upper or lower edge of the tile. The protrusion may be spaced apart from the adjacent tile edge by a greater length than the distance between the distal end of the slot and its adjacent tile edge. Such an arrangement may ensure that the slot is always below the tile overlap regardless of the tile gauge being used.

Each slot may be open at the upper or lower edge of the tile. As such the slot is open at its first end allowing the corresponding protrusion to be slid into place from the edge of the tile.

The slots and corresponding protrusions may be provided with interlocking profiles. For example the protrusion may have an interference fit within the slot. Alternatively or additionally the protrusion and slot may have keyed male and female cross sectional profiles. Such interlocking profiles may be advantageous in ensuring that the protrusion engages the slot and remains in the desired alignment - for example the tiles may be slid into place in use but may then resist unintentional sliding.

The upper surface of the tile may further include at least one datum line proximal to the upper edge of the tile. Such a datum line provides an aid to alignment during installation, for example the datum line may provide an indication of the relative position of overlapping tiles at a given tile gauge. Multiple datum lines may be provided in the form of an index. The datum line may be a continuous or broken line running along the top of the upper surface of the tile. There may be more than one marking running parallel to the top edge of the upper surface and spaced apart along the vertical length of the tile as required.

The tile may further include: a first formation at or adjacent one side edge, and a second formation at or adjacent an opposite side edge that, in use, interlocks with a corresponding said first formation of an adjacent tile.

The first formation can include a first preformed aperture for receiving, in use, a fixing device such as a nail, and the second formation includes a second preformed aperture for receiving, in use, the fixing device such that when, the first formation is interlocked with said second formation of another tile, the first and second apertures are aligned to allow the fixing device to pass through the first and second apertures.

At least one of the first and second apertures may be elongate.

The first side edge formation may include an elongate protrusion and the second side edge formation may include a recess or slot in the opposite side edge. Engagement of the first and second side edge formations, in use, when the tile is interlocked with an adjacent tile, allows an upper surface of the tile to lie flush with an upper surface of the interlocked tile. At least a portion of the elongate protrusion may be angled to form a water run located, in use, beneath a join between side edges of adjacent tiles.

The tile may further comprise a nib that, in use, hooks over a roofing batten. A portion of the nib may be formed on the first side edge formation.

The tile may be generally square or rectangular in plan view. The tile may have a height of 390 mm and a width of 345 mm. A side edge portion of the tile can include an arrangement for receiving/connecting to a verge attachment. In a set of tiles, at least one of the tiles can be around 50% wider than other tiles in the set.

The tile may be formed of a rigid plastic material, which may include recycled plastic. The tile can be formed of a mixture of pulverised fuel ash (PFA) and plastic, such as polyethylene. The tile may comprise around 70% PFA and around 30% high density polyethylene and in some cases additional materials may be used.

The underside arrangement (or another portion/component of the tile) may fit into a clipping device, which may be fitted at a fascia of a building structure. The clipping device may include a pivotable member including an arrangement for receiving the tile underside arrangement (or other portion/component), the member being pivotable so as to allow the tile to be fitted at an angle corresponding to a pitch of a roof.

According to another aspect of the invention there is provided a set of tiles substantially as described herein. According to another aspect there is provided a kit including a set of said tiles and a set of strips of material adapted to fix the tiles to a fascia board.

According to another aspect of the invention there is provided a roof (or a building structure) laid with a set of tiles substantially as described herein.

According to another aspect of the invention there is provided a method of laying a set of tiles substantially as described herein, the method comprising laying a first said tile in the set on a roof batten and laying a next tile in the set such that the formations/arrangements on the tiles interlock.

Whilst the invention has been described above, it extends to any inventive combination of features set out above or in the following description. Although illustrative embodiments of the invention are described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments. As such, many modifications and variations will be apparent to practitioners skilled in the art. Furthermore, it is contemplated that a particular feature described either individually or as part of an embodiment can be combined with other individually described features, or parts of other embodiments, even if the other features and embodiments make no mention of the particular feature. Thus, the invention extends to such specific combinations not already described.

The invention may be performed in various ways, and, by way of example only, embodiments thereof will now be described, reference being made to the accompanying drawings in which:

Figure 1 is a schematic perspective view of an example lockable tile;

Figure 2 is a schematic plan view of the upper side of the tile;

Figure 3 is a schematic plan view of the underside of the tile;

Figures 4A and 4B are schematic side views of the of the tile; and

Figure 5 is a schematic end view of the lower edge of the tile.

Referring to Figures 1 , 2 and 3, an example tile 100 is shown. The tile 100 can be formed of any suitable material, including conventional ones such as concrete, but it is particularly advantageous if the tile is formed of a lightweight material having a long life cycle, such as a rigid plastic. There can be environmental/economic advantages if the plastic material used is recycled. In some embodiments the tile can be formed of re-processed Polypropylene from car batteries, with a smaller percentage of PE extract from reprocessed nappy-waste also compressed shaped. Metal, such as aluminium, may also be used for manufacturing embodiments of the tile, which could accommodate a flush inter-joined solar ray energy collection device (not shown). The texture and design of the tile can be such that it has a similar appearance to conventional (e.g. slate/plain/Shaker) tiles so that it can blend in with existing roofing if needed. Thus, the tile may be considered to comprise a man-made interlocking slate. The tiles can be used for roofing, but also for external (e.g. slate) vertical tiling and versions can be produced that are suitable for floor and wall tiling. It will be appreciated that the tile interlocking arrangements described herein can be modified so that tiles surrounding the tile have flush exposed surfaces.

The tile can be formed by any suitable manufacturing method, e.g. injection moulding when plastic is used. Alternatively, the tile may be formed of a mixture of pulverised fuel ash (PFA) and polyethylene, e.g. around 70% PFA and around 30% high density polyethylene. The PFA can be heated and compounded into granules and then injection-moulded to form the tiles. Additives such as flame-retardants can also be used in some embodiments. It will be appreciated that the dimensions and design of the tile can be varied. In one example, the overall length/width of the main area of the tile is 360 mm (height) x 325 mm (width), which is a size commonly used and preferred by tradesmen in the UK. However, it will be understood that tiles of virtually any reasonable dimensions (e.g. 390 mm x 345 mm, or 600mm x 300mm or 900mm by 300mm may be used for larger areas, or 900 mm x 360 - 1200 mm x 360 mm) can be formed.

The tile 100 is generally rectangular in shape and includes an upper surface 101 A and an underside 101 B. The surface of the tile 100 may have a ridged profile as shown in the figures to provide a plurality of channels in the upper surface 101 A. Alternatively the tile may have a flat surface profile (not shown). An upper edge of the tile is labelled 104A in Figure 1 , whilst its lower edge is labelled 104B. The right-hand side edge of the tile in Figure 1 is labelled 104C and the straight, clean cut left-hand side edge is labelled 104D. At the upper edge 104A there is at least one depending nib 106. In the illustrated example, there are two nibs 106, 106', each nib being located at opposite side edges of the tile. The nibs can be used to hook the tile over a roofing batten 102A. The nibs may include a preformed aperture/bore (not illustrated) for receiving a nail or the like to help fix the tile to the batten, in addition to any abutting tiles. This is especially useful if the tile is to be fitted in a substantially vertical orientation, e.g. the nib being set on an upper surface of the batter and the main surface of the tile being set on a side surface of the batten. In some cases the nibs 106 may comprise snap-off hinges that can solve the problem of crooked batons, or batons having notches, bad workmanship, etc. If a baton is laid crooked then it can hinder the interlocking feature, but snapping off the nibs 106 allows the tile to lay to a true course that would otherwise affect plumbing aspects. Snapping off the hinges 106 can allow the system to be laid to flat plyboard, allowing for another application of laying to a pitched roof.

As can be seen in Figures 1 and 2, towards the upper edge 104A of the tile 100 there is at least one elongate slot 1 1 OA, 1 10B on the upper surface 101 A extending from the upper edge 104A. The slots 1 1 OA, 1 10B are intended to assist the tile 100 with interlocking with another tile that will partially lie on top of it in use. In the illustrated example the upper surface 101 A comprises two elongate slots 1 1 OA and 1 10B, although it will be appreciated that the number, length and appearance of the slots can be varied. The elongate slots 1 1 OA, 1 10B extend from and are perpendicular to the upper edge 104A of the tile 100. The slots 1 1 OA - 1 10B may be oversized by at least 3 mm in size length and width in order to accommodate expansion/contraction of about 1 .5 - 2 mm per tile, which can result from varying heat conditions.

As can be seen in Figure 3, the underside of the tile includes two protrusions 109A, 109B towards the lower edge 104B of the tile. In the example, the underside formations 109A, 109B comprise a rectangular-shaped protrusion that is designed to fit into the elongate slots 1 10A, 1 10B provided by the upper surface 101 A of another tile (not shown). It will be appreciated that variations to the illustrated upper surface and/or underside interlocking formations are possible, e.g. there may be more than two protrusions on the underside and the location, and/or the dimensions and shape of the formations can vary. In the example tile of Figures 1 , 2 and 3 there are two elongate slots 1 10A, 1 10B on the upper surface 101 A and a corresponding pair of projections 109A, 109B on the underside but, again, it will be understood that variations are possible and there may be more, or less, than two channels/interengaging formations on the upper surface and/or the underside of the tile. For instance, the lower surface of the tile may include one or more elongate slots (in addition to, or instead of, such slots on the upper surface) and/or the upper surface of the tile may include one or more formations (in addition to, or instead of, such a set on the lower surface) in order to provide different tile "gauges", as discussed below. The upper/underside arrangements could be located at/near the lower edge 104B of the tile instead of the top edge 104A.

The tile is provided with a receiving portion 1 12 at the left hand side edge 104D. As best seen in figure 4, the receiving portion 1 12 includes a slot 1 16 that is open at the side edge 104D of the tile. The shape of the receiving portion is formed to correspond with a protrusion 1 14 on the opposite side edge of the tile. The slot 1 16 extends from close to the upper edge 104A of the tile to close to the lower edge of the tile 104B. The slot ends close to the upper edge 104A of the tile at a recessed portion 120 which is formed to correspond to an overlapping portion 122 at the upper edge of the protrusion 1 14 on the opposite side of the tile. The skilled person will appreciate that other interlocking arrangements may be used for example an overlapping arrangement may be provided at the edges of the tile.

The protrusion 1 14 may for example have a width of around 30mm and extends from near the upper edge 104A of the tile to near the lower edge 104B. The protrusion is generally rectangular, but is bevelled at the lower right-hand corner (in Figure 1 ) and is designed to engage the receiving portion 1 12. It will be understood that the design of the protrusion (and corresponding receiving portion) can vary, e.g. a set of spaced-apart protrusions/pegs may be provided. The protrusion 1 14 may be provided with a profiled surface 1 16 including a plurality of elongate ridges and or valleys which extend along substantially the entire length of the protrusion. Advantageously such a profiled surface 1 16 may provide at least one valley that can act as a water run in use. Advantageously, this valley is located beneath the join between two interlocked adjacent tiles.

Located at the upper right-hand corner of the tile on overlapping portion 122 is a preformed aperture 1 18 that passes through the upper surface of the tile, its underside and out through the lower surface of the receiving portion. The hole 1 18 is dimensioned so as to allow a nail (e.g. 0.5 mm), screw or the like to pass through it and a depressed area may be formed on the upper surface of the tile around the aperture to accommodate the head of a nail/screw during use.

Located at the upper left-hand corner of the tile, on recessed portion 120, is a preformed elongated slot 1 15 that passes through the upper surface of the tile, its underside and out through the lower surface of the receiving portion. The slot 1 15 is dimensioned so as to allow a nail (e.g. 0.5 mm), screw or the like to pass through it.

In use, when the protrusion 1 14 engages the receiving portion 1 12 of an adjacent tile, the aperture 1 18 will be aligned with the preformed elongated slot 1 15 of the adjacent tile, allowing a nail to pass through both tiles, thereby securing them to the underlying batten. In the example, the slot 1 15 is elongated so as to allow for some sideways relative movement of the tiles, but it will be understood that the apertures can take other forms.

The upper surface of the tile may further include at least one datum line (not shown) proximal to the upper edge of the tile. Such a datum line provides an aid to alignment during installation. For example, the datum line may provide an indication of the relative position of overlapping tiles at a given tile gauge. Multiple datum lines may be provided in the form of an index. The datum line may be a continuous or broken line running along the top of the upper surface of the tile. There may be more than one marking running parallel to the top edge of the upper surface and spaced apart along the vertical length of the tile as required.

In use, the tile 100 is hooked over a batten in the desired location on the roof as outlined above. The next tile to be fitted is then placed on the batten (conventionally to the left of the previous tile) and moved sideways, so that the protruding arrangement 1 14 of the right-hand tile enters the receiving portion 1 12 of the left-hand tile. (It will be understood that side edge locations of the protrusions/receiving portions could be swapped if desired, but roof tiles are conventionally laid in a right to left direction). The left-hand tile is then pushed close to the other tile, and their side edges may contact each other, so that the two nail holes 1 15, 1 18 on each of the tiles are aligned. Engagement of the protrusion and receiving portion in the example allows the upper surface of the tile 100 to be flush with the upper surface of the adjacent interlocked roof tile, although it will be understood that the design can vary so that this is not the case. A nail can then be driven through the holes into the batten below, thereby securing both tiles to the batten (although it may be considered unnecessary to nail down all pairs of tiles). This procedure can continue for an entire row/course of side-by-side tiles.

The next row/course of tiles can then be laid. Part of the upper tile overlaps portions (which include the nail holes) at the upper edges of the underlying interlocked tiles. The length of the exposed part of the underlying tiles is called the "gauge". The underside formation 109 of the upper tile fits into ones of the elongate slots 1 1 OA, 1 1 OB of the lower tile 100. The provision of an elongate slot on the upper surface means that the overlying tile can be adjusted relative to the underlying tile thereby allowing the gauge of the tiling to be adjusted between a minimum and maximum gauge provided for by the slot.

The gauge for roof tiling may be around 300 mm, which in the example tile is selected by inserting the underside projection into the channel 1 1 OA nearest the top edge 102A. By inserting the projection into the channel, the gauge can be varied continuously between a minimum gauge of, for example, 250 mm (at the bottom end of the channel furthest from the top edge 102A) and 280 mm. It will be appreciated that tiles formed to have other dimensions can enable different gauge settings, e.g. anywhere between 240 mm or 280mm to 310mm. The elongate slot allows for a greater variation and increased flexibility of the gauge and the sliding connection is convenient ot use when installing tiles. Such flexibility may be particularly useful for taking into account tolerances between the gauge across the length of a course/row of tiles. It will be understood that the range over which the gauge of the tiling can be varied will depend on the length of the elongate slot.

The underside protrusions of the first course of tiles laid (normally the eaves) can be fixed by providing an arrangement including a set of suitable apertures/bores. These can be provided on strips of material, e.g. recycled plastic, which can be sold in regular lengths, e.g. 1 m. The strips can be fixed, by means of nails or screws, etc, to the top of the fascia board, gable end to gable end.