GB2178773A

GB2178773A - Improvements in roof tiles

Info

Publication number: GB2178773A
Application number: GB08618053A
Authority: GB
Inventors: Paul Roger Sargeant
Original assignee: Redland Roof Tiles Ltd
Current assignee: Redland Roof Tiles Ltd
Priority date: 1985-08-02
Filing date: 1986-07-24
Publication date: 1987-02-18
Also published as: GB8618053D0; GB2178773B

Abstract

A concrete roof tile is generally rectangular in plan view and includes underlying and overlying side lock portions 12, 18 at opposed edges thereof. The underlying side lock portion 12 is cut-away at the lower end of the tile so that, in use, the lower end portion of the tile may lie over the upper surfaces of adjacent tiles down the roof. The upper surface of the tile is convexly curved so that when viewed from the lower end 16 of the tile, the lower end portion of the tile appears thinner than a central portion of the tile. <IMAGE>

Description

SPECIFICATION Improvements in roof tiles This invention is concerned with improvements in roof tiles.

The invention provides a concrete roof tile generally rectangular in plan view and comprising un denying and overlying side lock portions at opposed edges thereof, the underlying side lock portion being cut away at the lower end of the tile, in use, so that the lower end portion of the tile may lie over upper surfaces of adjacent tiles down the roof, in use, and in which the upper surface of the tile is convexly curved so that, when viewed from the lower end of the tile, the lower end portion of the tile appears thinner than the central portion of the tile.

In a conventional roof made of concrete tiles the lower portions-of the tiles overlap upper portions of adjacent tiles down the roof. The tiles usually have interlocking side lock portions which generally extend for the full length of the tile. Thus, when the roof is viewed from its lower edge, one sees the ends of the side locks and the thickness of the tiles when viewed from their lower end is the full thickness of the tile at its lower edge portion where it overlaps. This thickness (that is, the height difference between upper surfaces of adjacent tiles up and down the roof) is governed by the amount of material required to provide the side locks.It is an advantage of the tile according to the invention that the side locks are not visible when the tile is viewed from its lower end, and furthermore, by virtue of the curvature of the upper surface of the tile, the tile appears thinner at its lower end portion than at a central portion of the tile. Thus the roof has the appearance that it is made of thinner tiles than a roof formed with conventional tiles.

provided with side locks. When the roof is viewed from the ground, it appears much more like a roof made with plain tiles than a roof made with the traditional concrete tiles with side locks.

Preferably the roof tile further comprises at least one hanging nib adjacent an upper end of the tile for hanging the tile on a roof. There may be two such hanging nibs.

The upper surface of the tile is preferably curved from its upper end to its lower end and the radius of curvature of the upper surface, in a preferred embodiment, is an order of magnitude greater than the linear dimensions of the tile.

The lower end portion of the tile beyond the underlying side lock portion may be tapered to further enhance the appearance that the lower end portion of the tile is thinner than the central portion of the tile. Furthermore, the underneath surface of the tapered portion may also be curved (concavely) so that this portion lies closely on the upper surface of an adjacent underlying tile. The radius of curvature may be the same as that of the upper surface.

The central portion of the underside of the tile may be hollowed out to reduce the weight of the tile and the amount of material in the tile.

The upper surface of the tile may be convexly curved in two directions, this is from one side lock portion to. the other as well as from the upper end of the tile to the lower end. In further variations, the tile may be approximately twice as wide as it is long and may include two curved surface portions on its upper surface to give the appearance of two tiles lying side by side.

Further features and advantages of the invention will become apparent from the following description, by way of example, of some preferred embodiments of the tile according to the invention, the description being read with reference to the accompanying drawings in which: Figure 1 is a plan view of a roof tile according to the invention; Figure 2 is a section along the line 2-2 of Figure 1; Figure 3 is a perspective view from the upper side of the tile of Figures 1 and 2; Figure 4 shows the tile of Figures 1 to 3 in position on a roof and is a section along the line 4-4 of Figure 1; Figure 5 is a perspective view from the upper side of a modified tile; Figure 6 is a perspective view from the upper side of a further embodiment of roof tile according to the invention; Figure 7 is a plan view of a still further embodiment of the invention;; Figure 8 is a section along the line 8-8 of Figure 7, Figure 9 is a view similar to Figure 6 of a still further embodiment of a roof tile, and Figure 10 is a plan view of a still further embodiment of a roof tile.

Referring first to Figures 1 to 4, a moulded concrete roof tile 10 is generally rectangular in plan view. The tile 10 is shown in figure 1 in the orientation in which it is generally used on a roof and in the following description the expressions left hand edge, right hand edge, upper end and lower end will refer to the tile in the orientation shown in Figure 1.

The tile 10 comprises, at the left hand side thereof, an underlying side lock portion 12 which faces upwardly and extends from an upper end 14 of the tile for about three quarters of the length of the tile towards the lower end 16 thereof.

At the right hand side of the tile there is an overlying side lock portion 18 which extends from the upper end 14 of the tile for a distance slightly greater than the length of the underlying side lock portion 12. The overlying side lock portion 18 and underlying side lock portion 12 are shaped in cross-section so that they interlock when adjacent tiles are laid with the overlying side lock portion of one tile lying over and engaging the underlying side lock portion of the adjacent tile.

Adjacent to the upper end 14 of the tile are a pair of hanging nibs 20 which extend from the underside of the tile, one adjacent each side lock portion. In use of the tile on a roof, as shown in Figure 4, the tile is hung from a roof batten 22 by engaging the nibs 20 with the roof batten.

As can be seen in Figure 1 and as shown more clearly in Figures 2 and 4, the under side of the tile 10 has its central portion 24 hollowed out so that the thickness of this central portion is less than the thickness of the side portions of the tile, the upper end portion and the lower end portion immediately adjacent to the central portion 24. Typically, the thickness of portion 24 may be approximately half the thickness of the other portions referred to above.

As can be seen in Figure 3 and most clearly in Figure 4, the lower end portion of the tile beyond the lower ends of the side lock portions is tapered from a maximum thickness adjacent the ends of the side lock portions to a minimum thickness at the lower end 16 of the tile. This tapered section 28 includes a recess 30 extending across the full width of the tile 10. The recess 30 acts as a weather bar.

The upper surface of the tile 10 is convexly curved, the curvature being from the upper end 14 of the tile to the lower end 16. This curvature can be seen in Figure 3 and most clearly in Figure 4.

The radius of curvature is several times larger than the linear dimensions of the tile and may typically be an order of magnitude greater. For example in one embodiment of the tile in which the length and width of the tile were of the order of 300mm, the radius of curvature was approximately 3 metres. It will be appreciated from a consideration of Figure 4 that when the tile 10 is laid on a roof with its lower end portion 28 overlying an adjacent tile down the roof, the effect of the curved upper surface of the tile is that the upper surface of the central portion of the tile appears higher than the upper surface of the lower end 16 of the tile so that it appears that the thickness of the central portion of the tile is greater than the thickness of the lower end portion.When viewed from the ground, the tiles thus appear thinner at their lower ends than conventional interlocking concrete roof tiles.

This appearance is enhanced by the tapered end portion 28 of the tile 10 which still further reduces the thickness of the lower end portion 16. It will further be appreciated that, because the side lock portions 12, 18 do not extend to the lower end 16 of the tile, these side lock portions are not visible from the lower end when the tiles are laid on a roof.

Figure 5 shows a modified form of the tile of Figures 1 to 4. In Figure 5, the upper surface 35 of the tile 34 is convexly curved In two perpendicular directions. Thus, as well as being curved from the upper end 14 of the tile to the lower end 16 (as in Figures 1 to 4) the upper surface 35 is also convexly curved from one edge portion of the tile to the other edge portion. The radius of curvature from edge to edge will generally, in this embodiment, be of the same order of magnitude as the radius of curvature from the upper end to the lower end.

Figure 6 shows a further embodiment of roof tile 40. The tile 40 is approximately twice the width of the tile 10 and of the same length. Thus, the tile 40 covers an equivalent area to two tiles 10 laid side by side. The upper surface 42 of the tile 40 has two curved portions 44 and 46. The upper surface as a whole is curved from an upper edge to a lower edge of the tile as has been described above. Furthermore, the tile 40 is curved from one edge portion to its centre to form the double cambered surface 44 and from the centre to the other edge portion to form the double cambered surface portion 46. Thus, it will be appreciated that the tile 40 when laid on a roof has the same appearance as two tiles 34 laid side by side. The tiles 40 also in dude on their undersides, two projecting water bars 48, one at the mid-point of each half portion of the tile.The tiles 40 are particularly designed for use in quarter-bond arrangement and it will be apappreciated that, in such arrangement the water bar 48 of one tile lies in the join between surfaces 44, 46 of an adjacent underlying tile 40.

Figures 7 and 8 show a still further embodiment of roof tile 50. It will be seen that the tile 50 has many similarities to the tile 10 and like parts have the same reference numerals. The major differences are that the tile 50 is rather longer in relation to width than the tile 10. As can be seen in Figure 7, the central hollowed out portion 24 of the tile 50 is rather larger than the equivalent portion of tile 10 and furthermore the overlying side lock portion 18 extends closer to the lower end 16 of the tile than the equivalent portion of the tile 10.

At the lower end of tile 50, the underside is formed with two ribs 52, 54 which strengthen the lower end of the tile and also act as weather bars when the tiles 50 are arranged in overlapping arrangement on a roof.

As can be seen in Figure 8, the upper surface of tile 50 is curved in a similar fashion to tile 10, and furthermore, the lower surface 57 of the tapered lower end portion 56 of the tile is also curved, the radius of curvature being, in a preferred embody ment, the same as that of the upper surface of the tile. The tiles 50 are used on a roof in exactly the same way as tiles 10, and it will be appreciated that the curvature of surface 57 helps to ensure that the tiles 50 lie closely on adjacent tiles down the roof.

Figure 9 shows a further embodiment of "double tile" 60 similar to the tile of Figure 6. The tile 60 is again approximately twice the width of the tile 10 and of the same length. Thus, the tile 60 covers an equivalent area to two tiles 10 laid side by side.

The upper surface 62 of the tile 60 has two portions 64 and 66 separated by a longitudinal groove 65. The upper surface 62 as a whole is curved from an upper edge to a lower edge of the tile as has been described above. Thus, it will be appreciated that the tile 60 when laid on a roof has the same appearance as two tiles 10 laid side by side.

Figure 10 is a plan view of a further embodiment of "double tile" 70 similar in many respects to the tile 60 of Figure 9. The tile 70 is again approximately twice the width of a standard tile. Thus, the tile 70 covers an equivalent area to two tiles 10 laid side by side. The upper surface 72 of the tile 70 has two portions 74 and 76 separated by a longitudinal groove 75. The upper surface 72 as a whole is again curved from an upper edge to a lower edge of the tile as has been described above. However in this case the lower ends of portions 74, 76 are curved as shown in Figure 10 to simulate tiles of a type popular in Germany. The lower end curved portions are also tapered when viewed from the side.

The invention is not limited to the preferred embodiments described above and various modifications may be made within the scope of the invention as defined by the appended claims. For example, the length and width of the tiles may be varied to produce different sizes of tile. In particular, double tiles1 half tiles and three-quarter tiles may be produced.

Claims

1. A concrete roof tile generally rectangular in plan view and comprising underlying and overlying side lock portions at opposed edges thereof, the underlying side lock portion being cut away at the lower end of the tile, in use, so that the lower end portion of the tile may lie over the upper surfaces of adjacent tiles down the roof, in use, and in which the upper surface of the tile is convexly curved so that, when viewed from the lower end of the tile, the lower end portion of the tile appears thinner than a central portion of the tile.

2. A roof tile as claimed in claim 1 in which the lower end portion of the tile beyond the underlying side lock portion is tapered.

3. A roof tile as claimed in claim 2 in which the underneath surface of the tapered portion is concavely curved.

4. A roof tile as claimed in claim 3 in which the radius of curvature of the said underneath surface is the same as that of the upper surface.

5. A roof tile as claimed in any one of the preceding claims further comprising at least one hanging nib adjacent an upper end of the tile for hanging the tile on a roof.

6. A roof tile as claimed in any one of the preceding claims in which the upper surface of the tile is curved from its upper end to its lower end.

7. A roof tile as claimed in Claim 6 in which the radius of curvature of the upper surface is an order of magnitude greater than the linear dimensions of the tile.

8. A roof tile as claimed in any one of the preceding claims in which the central portion of the underside of the tile is hollowed out.

9. A roof tile as claimed in any one of the preceding claims in which the upper surface of the tile is convexly curved in two directions.

10. A roof tile as claimed in any one of the preceding claims in which the upper surface of the tile includes two surface portions, each surface portion being convexly curved.

11. A roof tile as claimed in claim 10 in which the tile surface portions are separated by a line or groove extending from an upper end of the tile to a lower end.

12. A concrete roof tile substantially as hereinbefore described with reference to and as shown in the accompanying drawings.