Concrete roof tiles are produced by machine, using the principle of extrusion. Moulds (also called pallets) which form the underneath profile of the roof tile, are coated with a release agent prior to being fed into the extrusion machine.
A mortar mix is delivered from a mixing system to the extrusion head of the machine. This mix is extruded between the pallets and a roller. The roller forms the top surface of the roof tile.
A slipper is mounted behind the roller and this serves to further compact the tile and produce a smooth and level surface finish.
The final operation of the tile machine is to cut the tiles to length and shape using a vertical cutting knife.
The freshly extruded tiles, still on their own individual pallets, are loaded into racks and placed in a curing chamber where the tiles are hardened by the reaction between cement and water. The curing chamber is not a furnace or oven.
After curing, the tiles are separated from the pallets and the pallets are fed back into the extrusion machine. The tiles are packaged and placed in the stock yard for after curing and waiting for delivery.