GB2046808A - Tiles - Google Patents

Abstract

An anti-capillary device is disclosed for use at the head lap of lion two overlapping tiles at either of two amounts of overlap. The upper tile 1 has at least one rib 8 on its lower surface at its lower edge and the lower tile 2 has at least two grooves 9 at its upper surface at its upper edge. A nib 7 acts to space apart the rib 8 and groove 9 of the or each cooperating rib and groove pair. At least one rib 86 can cooperate with two different grooves 9 at respective differing amounts of overlap L1 or L2. Enables effective anti-capillary device to be formed at either amount of overlap for use on roofs of differing pitch. <IMAGE>

Description

SPECIFICATION Tiles This invention relates to tiles, which term hereinafter includes slates.

Dead weight tiles are conventionally laid on roofs having rafter pitches varying e.g. from 17+' to 55". It is also possible to hang vertically overlapping on a vertical wall. The minimum pitch practicable is dependent upon the tendency of the tiles to absorb moisture and also upon the ability of the tile to exclude rain and snow.

A further factor of importance is the amount of head lap of the tiles. As the pitch of a roof is reduced, the amount of overlap has to be increased in order to obviate the effects of wind and rain. British Standard Specification Bs 5534 lays down various recommendations regarding the relationship between the amount of head lap and the pitch. For slates, e.g. concrete slates, at a pitch of 30 , the amount of lap is to be at least 75 mm (about 3 inches) whereas at, for example, 20 pitch, the amount of lap is to be at least 11 5 mm (about 4.6 inches). However, for single-lap concrete tiles manufacturers may make their own requirements. Normally at 1 7+' pitch a single lap-concrete tile is to over lap by at least 100 mm.

A further requirment for single-lap concrete tiles laid down by British Standards is that below 30 pitch an effective anti-capillary device at the head lap should be used.

A known commonly used type of anti-capillary device is described in U.K. Patent No.

840,179. In this device, at the head lap of two adjacent tiles the lower tile is provided with two horizontal channels and the upper tile is provided with two horizontal ribs above respective channels. The ribs are spaced from the channels so that the ribs function as drip collectors whilst the channels function as water collection channels. Obviously this arrangement will only function correctly when a particular amount of overlap exists between the tiles: the ribs mustte'located substantially directly above their respective channels. It is possible to position the channels and/or grooves for the maximum amount of overlap which is likely to be necessary in practice, but this conflicts with requirements for economical use of tiles.It is clearly undesirable to provide a large amount of overlap when other conditions, e.g. the pitch of the roof, do not make this neccessary.

According to one aspect of the invention, there is provided a tile having at least one rib extending along its under surface at its lower edge and at least two grooves extending along its upper surface at its upper edge, the spacing between said grooves being such that the tile can cooperate with another similar tile at either of two amounts of overlap, one being about 75 mm or less and the other being substantially greater than 75 mm, with the or at least the lower rib cooperating with a or a respective said groove at each of said amounts of overlap, there being provided spacing means on the tile to space apart in use the rib and groove of the or each cooperating rib and groove pair.

According to a further aspect of the invention, there is provided a tile having at least two ribs extending along its under surface at its lower edge and at least three grooves extending along its upper surface at its upper edge, the spacing between said grooves being such that the tile can cooperate with another similar tile at either two amounts of overlap, with each rib cooperating with a respective said groove at each of said amounts of overlap, there being provided spacing means on the tile to space apart in use the rib and groove of each cooperating rib and groove pair.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which Figure 1 shows in schematic cross-section two tiles in overlapping position on a roof; Figures 2a and 2b show two alternative positions of a first embodiment of the invention; and Figures 3a and 3b show two alternative positions of a second embodiment of the invention.

Fig. 1 shows two concrete tiles 1 and 2 in overlapping mutual engagement on respective battens 3 and 4 which are mounted on a rafter 5. The tiles are provided with side lock which is conventional and so will not be discussed further. Each tile is also provided with a main nib or nibs 6 and a subsidiary, spacing nib 7. Tile 1 is provided with one or more ribs 8 less proud than nib 7, and tile 2 has at least two channels 9, there being a channel 9 cooperating with the or each rib 8 to receive any water dripping therefrom. The area of overlap of tiles 1 and 2 is shown in greater detail in Figs. 2 and 3.

Figs. 2a and 2b show two alternative positions of a first embodiment.

Fig. 2a is for use on a normal pitched roof, say 30 , when overlap L, will be about 75 mm. Nib 7 of tile 1 rests on the upper surface of tile 2 so that rib 8, seen in cross-section, is suspended over one of channels 9 of tile 2.

Rib 8 acts as a drip collector and the channel 9 therebeneath as a water collector to carry surface water from the tile surface to its lateral periphery. The channels 9 may be given a degree of lateral fall to assist this process.

Thus the rib and channel pair cooperate as a so-called anti-capillary device.

When the tiles are to be used on a low pitch roof, say 17+ , the tiles must overlap further, in this case about 4 inches or 100 mm, i.e. L2 = 100 mm as shown in Fig. 2b.

In this Figure, rib 8 is positioned above the lower of the two channels 9 and spaced therefrom by nib 7. Thus in this case L2 - L1 equals 25 mm which is also the distance between the centre lines of channels 9. Of course, this spacing may be varied to suit individual circumstances and pitches of roof.

However, it a fact that the "creepage" of water by capillary action becomes an acute problem with roofs having a pitch angle about 30 and below and so it is with such roofs that this specification is chiefly concerned. A pitch of 30 corresponds to a head overlap of about 75 mm and a pitch of 17T to a head lap of about 100 mm, and pitches of 17 > and 30 are commonly used in the building trade.

Figs. 3a and 3b show an alternative embodiment in which the essential difference from that of Figs. 2a and 2b is the provision of a further rib 8 and a further channel 9. Thus at both relative positions of the tiles 1 and 2, both ribs 8 are able to cooperate with respective channels 9. The provision of further rib 8 provides a further safeguard against capillary seepage. In this case the difference in lap D2 - D, is equal to the rib spacing. Clearly the spacing between rib 7 and the lower rib 8 should be somewhat greater than the rib spacing so that rib 7 does not rest in the lowest channel 9 in the position shown in Fig.

3a. As in the embodiment of Figs. 2a and 2b, channels 9 are preferably given a degree of lateral fall to assist in water drainage.

The tiles hereinbefore described may thus be designed for use on roofs of any pitch and also vertical walls.

It will be appreciated that the tile may be of any conventional shape, ornamental or otherwise. It may be flat tile or slate as shown in U.K. Patent No. 840,1 79 or a ridge tile as shown in U.K. Patent No. 978,577. Flat tiles/slates and ridge tiles may be laid together on the same roof alternating along a horizontal course, or in any other regular pattern. If this is done, however, it is necessary to ensure that the flat tiles and ridge tiles are of the same thickness so that the side lock between the tiles functions correctly to exclude moisture.

It is also important, to comply with British Standards Specification, to ensure that the depth of the main rib 6 is sufficiently large.

B.S. 473 specifies in clause 3.1 3 that the nibs of Group B products (single-lap interlocking concrete tiles and slates) shall be not less than 12.5 mm.

Within the scope of the invention, it is also possible to provide a tile with two ribs 8 and two grooves 9. The spacing between the ribs and grooves would be so chosen that at least one of the ribs 8 cooperated with a respective groove 9 at each of two amounts of overlap, e.g. 75 mm and 100 mm. Preferably, at one amount of overlap both ribs would cooperate with respective grooves.

Claims (11)

1. A tile having at least one rib extending along its under surface at its lower edge and at least two grooves extending along its upper surface at its upper edge, the spacing between said grooves being such that the tile can cooperate with another similar tile at either of two amounts of overlap, one being about 75 mm or less and the other being substantially greater than 75 mm, with the or at least the lower rib cooperating with a or a respective said groove at each of said amounts of overlap, there being provided spacing means on the tile to space apart in use the rib and groove of the or each cooperating rib and groove pair.

2. A tile having at least two ribs extending along its under surface at its lower edge and at least three grooves along its upper surface at its upper edge, the spacing between said grooves being such that the tile can cooperate with another similar tile at either of two amounts of overlap, with each rib cooperating with a respective said groove at each of said amounts of overlap, there being provided spacing means on the tile to space apart in use the rib and groove of each cooperating rib and groove pair.

3. A tile according to claim 1 wherein there is provided a single said rib.

4. A tile according to claim 1 or 3 wherein there are provided two of said channels.

5. A tile according to claim 1 or 4 wherein there are provided two said ribs.

6. A tile according to claim 5 wherein there are provided three said channels.

7. A tile according to any one of the preceding claims wherein said spacing is such that one of said amounts of overlap corresponds to the minimum necessary for use on a roof pitch of 17+'.

8. A tile according to any one of the preceding claims wherein said spacing is such that one of said amounts of overlap corresponds to the minimum necessary for use on a roof pitch of 30 .

9. A tile according to any one of claims 1 to 6 where said spacing is such that said amounts of overlap are respectively 75 mm and 100 mm.

10. A tile substantially as hereinbefore described with reference to Figs. 1, 2a and 2b or to Figs. 1, 3a and 3b of the accompanying drawings.

11. A building roofed with tiles according to any one of the preceding claims.