EP1584768A1

EP1584768A1 - Roof tiles

Info

Publication number: EP1584768A1
Application number: EP05252150A
Authority: EP
Inventors: Martin Oldridge; John Dinsdale
Original assignee: Sandtoft Roof Tiles Ltd
Current assignee: Sandtoft Roof Tiles Ltd
Priority date: 2004-04-06
Filing date: 2005-04-06
Publication date: 2005-10-12
Also published as: GB2413567A; GB2413567B; GB0407835D0

Abstract

The present invention aims to provide a tile having a projection to impede water entry between the tile and an adjacent tile, but permit variable overlap of tiles. In particular the present invention relates to roof tiles for pitched roofs. Preferably the tile is a clay tile, although it is envisaged that the tile could be manufactured from a variety of common roof tile materials known by the skilled person. According to a first aspect of the invention, there is provided a tile having a projection and a projection contact region, the projection being for, when the tile overlaps a similar or identical adjacent tile, contacting the projection contact region of the adjacent tile and inhibiting water entering therebetween, wherein the shape of the projection, and the shape of the projection contact region, permits variable overlap of the tiles.

Description

The present invention relates to roof tiles for forming pitched roof coverings.
In this specification, references to a 'side' direction refer to the direction which would beacross the pitch of a roof when the tiles are laid corrrectly, and references to an 'up/down' direction refer to the direction which would be up and down the pitch of such a roof.
Roof tiles may be single or double overlap tiles. Double overlap tiles abut side by side on a roof and rely on a tile below to prevent water that enters between them passing through the roof. Single overlap tiles interlock side by side such that water cannot enter between them.
Single overlap tiles normally have interlocking ribs down a side edge, commonly known as side interlocks or sidelocks, so that they can interlock with tiles to their sides. Furthermore, some tiles have ribs across a top edge, known as head interlocks or headlocks. These allow interlocking of tiles one above the other on a roof, i.e. interlocking of adjacent tiles with different spacings in an up/down direction.
An example of a headlock tile 4 is shown in Fig. 1b. It can be seen that a ribs 41, 42 protruding from the top face 43 of a lower tile 4 are interleaved between two ribs 44 and 45 protruding from the bottom face 46 of an upper tile 4. Thus the tiles are 'interlocked'. In this case, the interlocking restricts movement of the tiles relative to each other in a direction 'A', i.e. the up/down direction of the roof. Furthermore, the ribs act as barriers to 'weather', in particular to water entering between the two tiles.
The general rule is that clay tiles are made with both sidelocks and headlocks (double interlocking tiles), whereas concrete tiles are made only with sidelocks (single interlocking tiles). The difference has arisen due to two different methods of tile construction. Clay tiles are press formed, and can be designed to assume any shape. Concrete tiles are formed by extrusion, so can only be made with raised ribs in the direction of the extrusion, i.e. in one direction only.
Concrete tiles are much easier than clay tiles to "set out" on a roof, since one tile is substantially slidable over another in the up/down direction. The tiles are slidable because there are no headlocks to obstruct up/down movement. The advantage of the tiles being slidable over one another in this manner is that a roofer can more easily calculate the number of courses of tiles required to reach from the lower edge of a roof to the top ridge of that roof.
In contrast, double interlocking tiles, such as clay tiles, can not significantly slide in an up/down direction over one another, due to the headlock. Thus, when setting out a roof, it may be impossible for the roofer to finish up with a whole tile at the top ridge. In such a case, the roofer has to cut each tile along the whole length of the top ridge to fit properly. This is time consuming, expensive and demands considerable skill. Furthermore, it can cause roofing contractors to shy away from using double interlocking tiles in favour of single interlocking tiles, such as concrete tiles.
At its most general, the present invention proposes a tile having a projection to impede water entry between the tile and an adjacent tile, but permit variable overlap of tiles. In particular the present invention relates to roof tiles for pitched roofs. Preferably the tile is a clay tile, although it is envisaged that the tile could be manufactured from a variety of common roof tile materials known by the skilled person.
According to a first aspect of the invention, there is provided a tile having a projection and a projection contact region, the projection being for, when the tile overlaps a similar or identical adjacent tile, contacting the projection contact region of the adjacent tile and inhibiting water entering therebetween, wherein the shape of the projection, and the shape of the projection contact region, permits variable overlap of the tiles.
The projection may be a rib, the projection preferably being at the bottom face of the tile (the surface of the tile that faces towards the ground when set on a roof), whilst the tile projection contact region is at the top face of the tile. It is understood that the positions of these two features could be reversed to serve the same purpose, i.e. the projection may be at the top face of the tile, with the projection contact region at the bottom face of the tile.
The tile may have a nail hole at one end, such that the tile can be fixed by a nail to a roof batten.
Preferably, the profile of the projection should conform to the profile of the projection contact surface so that good water tightness can be achieved. It is understood that a plurality of projections could be placed side by side on the tile to further increase water tightness.
Preferably the projection contact region is a smooth outer surface of the tile with no obstructions such as recesses and/or protuberances over its full extent. This provides for a continuous degree of overlap within the limits of the variable overlap and allows tiles to be slid easily into position. It is understood, however, that the projection contact region could have protuberances or recesses that would provide for discrete degrees of overlap within the full amount of the variable overlap, whilst allowing the tile to rest truly in position. In such a scenario the tile may have to be placed, rather than slid, into a desirable position.
Preferably the amount of variable overlap permitted is close to the full length of the tile. However the minimum amount of variable overlap permitted may be up to 1/8, 1/4, 1/3, 1/2, 3/4, or 4/5 of the length, or the width, of the tile.
Preferably, the variable overlap is permitted in the up/down direction of the roof, i.e. along a line running between the lower edge of the roof and the upper ridge of the roof. In this case it is preferable that the projection contact region extends in an up/down direction, perhaps from adjacent a nail hole at the top end of the tile, to the bottom end of the tile. Furthermore, the tile may comprise a side protrusion and a side recess and/or side abutment, the side protrusion being for contacting the side recess and/or side abutment of a similar or identical tile located to its side on a roof, thus side-interlocking the two tiles and restricting sideways movement of the tiles with respect to each other. The side protrusion and the side abutments are both preferably ribs. Furthermore the side protrusion is preferably at one side of the top face of the tile with the side abutment and/or side recess at the opposite side of the bottom face of the tile. It is understood that the positions of these two features could be reversed to serve the same purpose, i.e. the side protrusion may be at one side of the bottom face of the tile with the side abutment, and/or side recess, at the opposite side of the top face of the tile.
The shape of the side protrusion and the side recess or abutment may permit up/down sliding of side-interlocked tiles with respect to each other. To allow this, the side protrusion may be a rib of uniform cross-sectional area, and the side recess may be a channel of corresponding shape, preferably having at least one open end.
Preferably the tile is a clay tile made by press-forming. Press-forming allows a tile with any number of surface formations to be produced. In the present invention it may be the omission of certain surface features traditionally included in e.g. a press-formed clay tile, such as a headlock, that permits the variable overlap.
The present invention can apply to pantiles, and may also apply to other styles of roof tiles, known by a person skilled in the art.
Embodiments of the invention will now be described with references to the accompanying drawings, in which:
Fig. 1a shows a side view of overlapping tiles according to a first embodiment of the present invention;
Fig. 1b shows a prior art tile that permits no variable overlap;
Fig. 2 shows an oblique top view of a tile according to the first embodiment;
Fig. 3 shows a top view of the first embodiment;
Fig. 4 shows a bottom view of the first embodiment;
Fig. 5 shows an oblique bottom view of the first embodiment;
Figs. 6 and 7 show an oblique view of a plurality of overlapping and interlocking tiles of the first embodiment.
Fig. 1a shows two overlapping tiles 1 located on roof battens 2. The tiles 1 are essentially hooked on the roof battens 2 via nibs 11 located at the top end 12 of the bottom face 13 of each tile 1. The tiles 1 have a projection 14 located at the bottom end 15 of the top face 16 of the tiles. Fig. 1a shows the projection 14 of the upper tile in contact with a projection contact region 17 of the lower tile. This contact forms a barrier to water entering between the two tiles 1. The projection contact region 17 is a smooth surface of a portion of the top face 16 of tile 1 extending from adjacent the top end 12 of the tile 1 to the bottom end 15 of the tile 1.
Due to the shape of the projection 14 and the nature of the projection contact region 17, a variable degree of overlap of the tiles 1 can be accommodated with the tiles still resting truly. Therefore, when a roofer sets out the battens 2, the roofer has considerable leeway when choosing an appropriate distance ('gauge') between the roofing battens 2. In the present example, the tiles 1 could overlap by up to approximately 4/5 of their overall length if the battens 2 were placed closer together accordingly.
Contrastingly, for the overlapping prior art tiles 4 shown in Fig. 1b, variable overlap is restricted as described above.
Figs. 2 and 3 show top views of the tile 1 according to the present invention. This tile is a clay pantile. Figs. 2 and 3 show the projection 14 is a rib extending along the width of the bottom end 15 of the tile 1. At the top end 12 of the top face 16 of the tile 1 is a depression 121 that forms, inter alia, one or more nib(s) 11, for hooking the tile 1 on roof battens, and also for assisting the stacking of a plurality of tiles 1. Furthermore, the depression 121 may serve as a trap for any water that enters between the projection 14 and projection contact region 17.
Within the depression 121 is a nail hole 122. The nail hole 122 permits a nail to be driven therethrough such that the tile 1 can be nailed to a roof batten if required. The projection contact region 17 extends between a plurality of ribs 123, which is/are optional and some or all may be omitted, and the bottom end 15 of the top surface 16 of the tile 1. The plurality of ribs 123 define a minimum overlap for the tile 1 and any similar or identical tile overlapping from above. For pantiles, the minimum degree of overlap is usually 75 mm.
The tile 1 comprises a rib-shaped side protrusion 51 at a side edge 52 of the top surface 16 of the tile 1. The tile 1 further comprises a rib-shaped side abutment 54 at a side edge 55 of the bottom surface 13 of the tile 1. A side recess 53 is defined between the side abutment 54 and an edge of the projection 14.
The side protrusion 51 is for contacting the side abutment 54, and lying in the recess 53, of a similar or identical tile located to its side when it is set out on a on a roof, thus side-interlocking the two tiles and restricting sideways movement of the tiles with respect to each other.
Figs. 4 and 5 show bottom views of the tile 1. The side abutment 54 can be seen more clearly as a rib running along the side edge 55 of the bottom surface 13 of the tile 1, between the top end 12 and bottom end 15 of the tile 1. The side recess 53 is essentially a channel running alongside the rib. In this embodiment the channel has open ends. This allows two or more side-interlocked tiles 1 to slide in an up/down direction with respect to each other.
Figs. 6 and 7 each show three tiles 1a, 1b, 1c, according to the present invention, interlocked and overlapping in a manner appropriate to a roof covering.
Fig 6. shows the projection 14 of the upper tile 1a contacting the projection contact region 17 of the tile 1b below. It can be seen that the profile of the projection 14 substantially corresponds to the profile of the projection contact region 17, leaving little or no gap therebetween and thus giving good water tightness. In this example the projection 14 of the upper tile 1a is contacting a portion of the projection contact region 17 of the lower tile 1b adjacent the ribs 123, and is thus overlapping the lower tile 1b by approximately the minimum amount permissible for this tile.
Fig. 7 shows the same arrangement of tiles 1a, 1b, 1c as in Fig. 6, but with the upper tile 1a overlapping the lower tile 1b in the up/down direction by a greater amount. Essentially, the upper tile has been moved, by sliding, placing or otherwise, from its position shown in Fig. 6 to the position shown in Fig. 7. This is made possible by the smooth nature of the projection contact region 17 presenting no obstruction to variable positioning of the projection 17 of the upper tile 1a between the ribs 123 and the bottom end of the tile.
Figs. 6 and 7 show two tiles 1b, 1c side-interlocked. The side protrusion 51 of the right hand tile 1c is contacting the side abutment 54, and lying in the recess 53, of the left hand tile 1b, hence restricting sideways movement of the tiles 1b, 1c with respect to each other. This type of interlocking forms a good seal, preventing water entering between the tiles 1b, 1c.
It should be noted that once correctly postioned, by sliding, placing, interlocking or otherwise, tiles 1a, 1b, 1c according to the present invention may each be fixed to roof battens via one or more nail(s) driven through one or more nail hole(s) 122.
A person skilled in the art will appreciate that the ideas expressed in the embodiment can be achieved in ways other than those specifically described; the scope of the present invention is not intended to be limited by the examples.

Claims

A tile having a projection and a projection contact region,

the projection being for, when the tile overlaps a similar or identical adjacent tile, contacting the projection contact region of the adjacent tile and inhibiting water entering therebetween,

wherein the shape of the projection, and the shape of the projection contact region, permits variable overlap of the tiles.
The tile according to claim 1, wherein the amount of variable overlap is up to ⅛, ¹/₅, ¼, ½, or ¾ of the length of the tile.
The tile according to any one of the preceding claims, wherein the profile of the projection corresponds to the profile of the projection contact region.
The tile according to any one of the preceding claims, wherein the projection contact region is a smooth surface of the tile.
The tile according to any one of claims 1 or 4, wherein the tile is a roof tile.
The tile according to claim 5, wherein the projection is on the bottom face of the tile, and the projection contact region is on the top face of the tile.
The tile according to claim 6, wherein the adjacent tiles are tiles one above the other on a pitched roof, and the variable overlap is in an up/down direction.
The tile according to claim 7, further comprising a side protrusion and a side recess and/or side abutment, the side protrusion being for interlocking with the side recess and/or side abutment of a similar or identical tile at its side.
The tile according to claim 8, wherein the interlocking does not preclude substantial sliding of the tile with respect to the tile at its side in an up/down direction.
The tile according to a one of the preceding claims, wherein the tile is a clay tile.
A tile as herein described with reference to, and as illustrated in, Figs. 1a and Figs. 2 to 7.