Abstract: Complementary roof tiles for a staggered roof tile layout are provided by: (i) extruding and conveying a composite ribbon; (ii) demarcating the composite ribbon into an alternating succession of a first roof tile type and a second roof tile type by engaging the composite ribbon with an upstream cutting blade and a downstream cutting blade, such that each roof tile type is demarcated at an upstream tile edge by one of the cutting blades and at a downstream tile edge by the other of the cutting blades, and such that a selected one of the roof tile types includes a pair of cut-out portions demarcated along one of the upstream and downstream tile edges on opposite ones of the ribbon side edges; (iii) separating the succession of demarcated roof tile types into distinct roof tiles; and (v) curing the distinct roof tiles to form a set of cured roof tiles.

Abstract: Complementary roof tiles for a staggered roof tile layout are provided by: (i) extruding and conveying a composite ribbon; (ii) demarcating the composite ribbon into an alternating succession of a first roof tile type and a second roof tile type by engaging the composite ribbon with an upstream cutting blade and a downstream cutting blade, such that each roof tile type is demarcated at an upstream tile edge by one of the cutting blades and at a downstream tile edge by the other of the cutting blades, and such that a selected one of the roof tile types includes a pair of cut-out portions demarcated along one of the upstream and downstream tile edges on opposite ones of the ribbon side edges; (iii) separating the succession of demarcated roof tile types into distinct roof tiles; and (v) curing the distinct roof tiles to form a set of cured roof tiles.

Abstract: Complementary roof tiles for a staggered roof tile layout are provided by: (i) extruding and conveying a composite ribbon; (ii) demarcating the composite ribbon into an alternating succession of a first roof tile type and a second roof tile type by engaging the composite ribbon with an upstream cutting blade and a downstream cutting blade, such that each roof tile type is demarcated at an upstream tile edge by one of the cutting blades and at a downstream tile edge by the other of the cutting blades, and such that a selected one of the roof tile types includes a pair of cut-out portions demarcated along one of the upstream and downstream tile edges on opposite ones of the ribbon side edges; (iii) separating the succession of demarcated roof tile types into distinct roof tiles; and (v) curing the distinct roof tiles to form a set of cured roof tiles.

Abstract: A unitary paving block having an exposed surface in use having a multitude of markings to simulate individual, random paving elements has a periphery with a shape which enables the block to be laid with other similar blocks in an irregular, substantially unrepeated paving array. The shape of the periphery of the blocks is such that the blocks can be laid with each block angularly moved with respect to each other and/or laid in staggered relationship with respect to each other.

Abstract: An extruded roof tile (30) has an upper surface (11), which is contoured to give the appearance of a profiled tile and which is, for example, provided by projections (32, 34) extending between the upper and lower edges (13) and (14a) respectively of the tile, and an under surface (12) having a shape which is other than a contoured shape which generally follows that of the upper surface (11) of the tile (30). For example, the under surface (12) may have a shape which corresponds to that of a flat tile.

Abstract: A composite roofing element comprises a first layer of aggregate based material, a second layer of material having a density less than that of the first layer and has a wedge shaped region depending from its underside. The wedge shaped region is preferably integral with the second layer which can be made of an expanded polymer, expanded polystyrene being particularly suitable. Overlapping structure on the side edges and a recess in the thick end of the wedge enable adjacent elements to interlock with each other. By using such lightweight roofing elements the requirement for a substantial load bearing supporting structure is reduced.

Abstract: Roofing elements, particularly suitable for use on flat roof constructions, are provided with co-operating means on each of at least one pair of opposite side edges for co-operation with at least two adjacent elements on each of the side edges. When assembled, movement of any one element involves movement of at least one co-operating element on each of the opposite sides edges. Such bidirectional co-operation results in an interlocked roof construction wherein the uplifting of individual roofing elements by the action of the wind or other forces is substantially eliminated. Uplift pressure caused by wind passing over the roof surface can be further reduced by providing communicating air-flow passages between co-operating elements.

Abstract: A lightweight concrete product in the form of a concrete roof tile is made from a cementitious mixture comprising a porous lightweight aggregate, an hydraulic cement, water, an agent for enhancing, flexural strength and an agent for enhancing the water retention capacity of the lightweight aggregate, the proportions being such that the product has satisfactory impact and flexural strengths.

Abstract: An interlocking roof tile which can be made by extrusion, pressing or moulding has an upper edge; a lower edge which is visible in use when the tile is laid in overlapping relationship with at least one tile of a next adjacent line of the tiles; an upper surface; a lower surface; a supporting understructure; two oppositely facing side edges; an underlock extending along one of the side edges and an overlock extending along the other of the side edges, the underlock having a lower end and an under surface which forms part of the under surface of the tile, and a lower edge portion having an under surface which includes a part of the under surface of the underlock, and which overlaps, in use, at least one tile of the next adjacent line of the tiles, characterized in that the upper surface of the tile extends continuously from the lower edge to the upper edge, in that the upper and lower surfaces are cambered from the lower edge to the upper edge and are substantially flat when considered in cross-section taken a

Abstract: An interlocking roof tile (1) of which the leading end portion (12) at least as far as the lower end of, and including the underlock (6) is tapered in the direction of the leading edge (5) of the tile (1).

Abstract: A roof tile is provided with a pair of batten lugs and a pair of stacking lugs protruding from the bottom side thereof. The batten lugs are positioned very close to and taper to the edge at the head end of the tile so that the thickness of the tail end of the tile may be relatively thin and may be equal to the thickness at the edge of the tile head end. The stacking lugs are positioned longitudinally away from the tail end of the tile so as not to interfere with tile overlapping. The thickness of the tile from the front surface thereof to the tip of each batten lug is substantially equal to the thickness of the tile from the front surface thereof to the tip of each stacking lug such that the tile may be stacked with other similar tiles without need to rotate every other tile by 180.degree..