Roof tiles

Abstract

A roof tile adapted for flat-packing includes on its under surface at least one region spaced from the or each hanging nib where the tile is deeper in cross-section than any other part of the tile. The underside of the or each region is configured so that when the tile is superposed on a second said tile, the tiles lie parallel and the underside lies in substantial contact with the upper surface of the second tile and prevents the hanging nib(s) of the first tile from contacting the upper surface of the second tile. By creating a region that is deeper than the depth at the hanging nibs, no load is borne by the nibs during stacking and the risk of the nibs breaking off during stacking and/or subsequent transportation is significantly reduced. In addition, because the tiles are specifically adapted to be flat-packed, the packs are particularly stable. A method of packing such roof tiles or other roof tiles of the cambered variety involves stacking layers of tiles on their side edges with the orientation of the tiles reversed in adjacent layers.

1 . A flat roof tile comprising an upper edge, a lower edge, two oppositely facing side edges, an upper surface and an under surface provided with at least one hanging nib, wherein the under surface includes at least one region spaced from the or each hanging nib where the tile is deeper in cross-section than any other part of the tile and the underside of the or each region is configured so that when the tile is superposed on a second said tile, the tiles lie parallel and the underside lies in substantial contact with the upper surface of the second tile and prevents the hanging nib(s) of the first tile from contacting the upper surface of the second tile.  
     
     
         2 . A roof tile according to  claim 1 , wherein the underside of the region of deepest cross-section has a contour that is complementary to the contour of upper surface above the region.  
     
     
         3 . A roof tile according to  claim 1 , wherein the or each region encompasses or spans the middle portion of the under surface.  
     
     
         4 . A roof tile according to  claim 1 , wherein the or each region is located symmetrically around the mid-point of the tile's unsupported span in use.  
     
     
         5 . A roof tile according to  claim 1 , wherein the region of deepest cross-section does not extend into the area of the under surface that overlaps in use with the upper surface of an underlying tile in an adjacent row.  
     
     
         6 . A roof tile according to  claim 4 , wherein the or each region extends for between about one third to two thirds of the length or width of the tile or both.  
     
     
         7 . A roof tile according to  claim 1 , wherein the under surface of the tile tapers from the boundary of the region's underside in the direction of the tile edges.  
     
     
         8 . A roof tile according to  claim 1 , wherein the tile is provided with a plurality of ribs on its under surface at least one such rib including along a mid-portion the region of deepest cross-section.  
     
     
         9 . A roof tile according to  claim 8 , wherein a pair of ribs are symmetrically disposed on either side of the mid-point of the unsupported tile span in use and extend longitudinally between the upper edge and the lower edge but not to the said edges.  
     
     
         10 . A roof tile according to  claim 9 , wherein the pair of ribs are spaced equidistant from each other and from the side edges of the tile.  
     
     
         11 . A roof tile according to  claim 1 , wherein the or each region of deepest cross-section has a depth that is sufficient to avoid frictional contact between the hanging nib(s) and the upper surface of another such tile when the tiles are superposed.  
     
     
         12 . A roof tile according to  claim 11 , wherein the depth of the tile at the region is 0.1 mm or more greater than the depth at the hanging nib(s).  
     
     
         13 . A roof tile according to  claim 12 , wherein the depth of the tile at the region is 0.5 mm greater than the depth at the hanging nib(s).  
     
     
         14 . A roof tile according to  claim 1 , wherein the tile has a planar upper surface and the underside of the or each region is planar.  
     
     
         15 . A roof tile according to  claim 1 , wherein the tile has a cambered upper surface and the underside of the or each region is concave having a degree of curvature complementary to the camber.  
     
     
         16 . A roof tile according to  claim 1 , wherein the tile is made of concrete.  
     
     
         17 . A roof tile according to  claim 1 , wherein the tile is made by extrusion.  
     
     
         18 . A roof tile having a substantially planar upper surface and an under surface from which one or more hanging nibs depend, characterised in that the under surface is provided with one or more elongate ribs each having a median portion that depends beyond the depth of the hanging nib(s) and its underside is of complementary configuration to the upper surface lying immediately thereabove.  
     
     
         19 . An array of tiles fixed to a supporting surface, the array including a plurality of tiles according to  claim 1 .  
     
     
         20 . A roof structure comprising a plurality of roof tiles according to  claim 1 , said tiles being laid in side-by-side and overlapping lower edge-over-upper edge relationship on a support structure to form a roof.  
     
     
         21 . A roof structure according to  claim 20 , further including one or more ventilation tiles adapted to co-operate with adjacent roof tiles in the same row in side-by-side interlocking relationship and with roof tiles in an adjacent row in upper edge-to-lower edge overlapping relationship.  
     
     
         22 . A method of forming a pack of cambered roof tiles including: 
 stacking together a first group of said tiles so that each tile in the group is supported on a side edge with their respective upper and lower edges parallel and vertically aligned to form a first layer of said tiles; and    stacking together a second group of said tiles on top of said first group, the tiles in said second group also supported on a side edge with their respective upper and lower edges being parallel and vertically aligned to form a second layer of said tiles;    wherein prior to stacking on the first group, the tiles of the second group are turned through 180° to face the opposite direction to those of the first group.    
     
     
         23 . The method of  claim 22 , wherein the roof tiles are interlocking roof tiles.  
     
     
         24 . The method of  claim 22 , wherein a roof tile in an upper layer is supported on two adjacent roof tiles in the layer beneath.  
     
     
         25 . The method of  claim 22 , wherein said roof tiles comprise tiles according to  claim 1 .  
     
     
         26 . A pack of cambered roof tiles comprising first and second layers of tiles, the tiles in each layer stacked together and supported on their side edges with their respective upper and lower edges parallel and vertically aligned, wherein the orientation of the tiles in the second layer is reversed such that they face the opposite direction to the tiles of the first layer.  
     
     
         27 . The pack of  claim 26 , wherein the roof tiles are interlocking roof tiles.  
     
     
         28 . The pack of  claim 26 , wherein a roof tile in an upper layer is supported on two adjacent roof tiles in the layer beneath.  
     
     
         29 . The pack of  claim 26 , wherein said roof tiles comprise tiles comprising an upper edge, a lower edge, two oppositely facing side edges, an upper surface and an under surface provided with at least one hanging nib, wherein the under surface includes at least one region spaced from the or each hanging nib where the tile is deeper in cross-section than any other part of the tile and the underside of the or each region is configured so that when the tile is superposed on a second said tile, the tiles lie parallel and the underside lies in substantial contact with the upper surface of the second tile and prevents the hanging nib(s) of the first tile from contacting the upper surface of the second tile..