There are two main tiling systems which are currently used on buildings to provide cladding for a pitched roof. Both systems use horizontally extending wooden battens arranged spaced apart one above the other in a slanting plane corresponding to the pitch of the roof. In one of the systems, heavy tiles are moulded from a concrete-like material, the tiles having an overhanging top lip by means of which the tiles are hung on the. battens. To ensure that the tiles do not blow off in windy conditions, it is usual to nail at least some of the rows of tiles to their battens, e.g. the tiles in every third row may be nailed down to their batten. In the second commonly used tiling system, somewhat thinner tiles known as slates are used. Slates do not have an overhanging lip, and each slate is nailed to its batten. This second tiling system is often used in the construction of cladding for an upright wall, in which case the slates are often referred to as shingles. Since natural slate is very expensive, slate tiles are now usually made of a concrete like material.

Both of the systems described above have disadvantages. In the case of the first system, the tiles are very heavy and bulky, so that they are awkward to use and expensive to transport. The tiles are expensive to make, and a major disadvantage is that they are very likely to break. The tiles may break during loading or unloading, or when they are being nailed down. It is also difficult to break the tiles cleanly along a straight line when it is desired to use a "half tile" or "part tile" at the end of a row of tiles.

Another problem is that the tiles fail in use due to weathering. Another major disadvantage is that the nails may corrode away (for example due to "acid rain"). Further, rain can sometimes penetrate tire tiling and rot the wooden battons. The tiles may also be broken by a workman walking on the roof.

Many of the disadvantages mentioned above also apply to the second tiling system using slates or shingles . It is believed that tiling according to this invention will overcome many or all of the disadvantages described above.

According to the present invention there is provided tiling comprising tiles to be supported on battens, in which the tiles are made of plastics material and, in use, the tiles and the battens interlock with one another.

Preferably, the tiles are supported on battens in such a way that the tiles are slidable along the battens during assembly but cannot be readily removed from the battens except by sliding them off an end thereof. With such a system, tiles are either mounted on a batten by being slid onto one end of a batten or snap-fitted onto a batten, and then slid along the batten until the whole batton is occupied by tiles abutting one another. The tiles at the end of each row are then secured aginst sliding off by a suitable adhesive or by an edge strip. The advantages of the invention and further aspects thereof will be explained in the following description.

In order that the invention may be more readily understood, preferred embodiments of tiling according to the invention will be described by way of example and with reference to the accompanying drawings in which:-

Figure 1 is a cross sectional view of a tile and batten combination according to the invention, showing a single tile mounted on a batten; and Figure 2 is a cross sectional view of a pitched roof having a cladding comprised by tiling acccording to the invention.

Figure 1 shows a tile 1 engaged on a batten 2. Both the tile and the batten are formed by extrusion, and are made of a plastics material having suitably properties as regards mechanical strength, resistance to fire, and resistance to corrosion. The cheapest material which we know of which has adequate properties

_ - is U.P.V.C. (Unplasticised polyvinyl chloride). The cross section of the tile 1 is such that it has a relatively wide central region 3 from which the tile tapers towards opposite edges thereof, i.e. a bottom edge 4 which will overlie the top edge of a tile mounted on a lower adjacent batten (not shown in Figure 1), and a top edge 5 by means of which the tile 1 is mounted on the batten 2.

Th tile 1 and batten 2 are formed with mutually interlocking parts. In the embodiment of Figure 1, the top edge of the tile is formed with a flange 6 comprised by a rearwardly directed wall 7 and a downwardly directed wall 8. This wall 8 defines a continous longitudinal groove 9 between itself and the main body of the tile. Spaced from the flange 6 and parallel to it is a second flange 10 which extends from the rear surface of the tile and comprises a rearwardly directed wall 11 and an upwardly directed wall 12 which defines between itself and the main body of the tile a groove 13.

The batten 2 has a main body portion from which there extends an upper rail 14 and a lower rail 15. The spacing between the rails and the size and shape of the rails is such that the only way of mounting the tile 1 on the batten 2 is to slide the tile onto one end of the batten so that the top flange 6 rides on the top rail 14 and the bottom flange 10 rides on ^' the bottom rail 15. The tile 1 may now be slid along the batten 2, being

guided in its movement by the interlocking parts of the rail and batten. Of course, the tile cannot readily be disengaged from the batten except by sliding it off one end of the batten. Figure 2 shows a traditional inverted *V shape pitched roof 20 and only one face 16 of the roof will be described in detail as the other face 17 is identical to it. Roof face 16 comprises tiling constructed of tiles 21 mounted on battens 22. The battens 22 are made as U.P.V.C. extrusions and they extend horizontally one above the other In a slanting plane the angle of which corresponds to the pitch .of the roof. These battens 22 are similar to- the batten 2 of Figure 1, but the battens are 'T' shaped with the head of the 'T' providing upper and lower rails corresponding to the rails 14 and 15 of the batten of Figure 1. The battens 22 are mounted by the stem of the '1' on structural roof members 23.

The extruded U.P.V.C. tiles 21 are of generally the same shape as the tiles 1, having a wide central region which tapers upwardly and downwardly. The shape of the main body of the tiles 21 may be regarded as a flattened parallelogram so that the upper and lower edges of the tiles have an apex angle of about 8°.

A row of tiles 21 is mounted on each of the battens 22 by the process of successively sliding tiles onto the end of the batten in interlocking engagement therewith. The tiles are successively slid along the batten until it is full of abutting tiles, the process being rather

like threading beads onto a string. It is of course necessary to secure the tiles at the two ends of each row against sliding off in order to provide a secure row of tiles which cannot readily be removed from their batten because of the interlocking engagement between tile and batten. The tiles at the end of the row may be secured in place by a suitable adhesive such as expanding polystyrene adhesive foam which will also provide a seal against the weather. The tiles of each row will be staggered by the width of one half tile from the tiles of the next adjacent row. One can use specially made half tiles to achieve this stagger, but one can also cut a U.P.V.C. tile to a desired width using a power operated saw. The advantage of the "flattened parallelogram" cross sectional shape of the tiles may be seen by observing the way in which the tiles of one row overlap the tiles of the next row.

As seen in Figure 2, the lower halves of the tile of one row overlap the upper halves of the tiles of the next lower adjacent row. Because of this "half tile" overlap and because of the "flattened parallelogram" shape of the tiles, the widest part of the tiles of one row meet the narrowest parts of the tiles of the next higher row and also of the next lower row. The effect of this is that the roof faces 16 and 17 are substantially flat as opposed to being "layered".

This presents an attractive appearance and helps keep the weather out.

A roof cap 24 is secured in place by using expanding polystyrene adhesive foam. Advantages of the system described above are that

U.P.V.C. tiles are very sturdy, and are most unlikely to be damaged during transport, during fixing, or by workmen walking on the roof. They are easy to cut to width and are of very light weight. No mortar is needed, and the tiles can be fixed ver quickly and with little skill needed.

Since no nails are used, there is no rust problem, and no holes are made in the tiles to let water through. The tiles are not affected by "acid rain" as are concrete tiles. Also the U.P.V.C. battens will not rot .

The tiling is so easy to use that it will enable "do-it-yourself" construction of garden huts or chalets. The invention is applicable to all tiling applications using battens, and is also applicable to any type of filing in as much as one aspect of the invention relates to a U.P.V.C. cladding tile for a roof or wall.

In the case of the known tiling systems, the tiles do not interlock with the battens. Accordingly to our invention, it is preferred to use an interlock between batten and tile such that the tiles can only be mounted on the battens by sliding them on at one end. However, it is also possible to provide a "snap together"

interlock so that co-operating parts on the tiles and battens snap fit together.

Although it is proposed to secure end tiles by adhesive a preferred alternative is to provide extruded U.P.V.C. edge strips which will hold the tiles in position. Moreover, whilst it is preferred that a batten 2 be provided with rails 14 and 15 and the tile 1 with grooves 9 and 13, alternatively the rails may be on the tile and the grooves on the batten.