Tiles comprising a mating surface and a roofing surface, wherein the roofing surface is elevated above the mating surface and is shaped to guide or direct a liquid to flow from an upstream first end to a downstream second end under the influence of gravity when the mating surface rests on a leveled surface, and wherein the mating surface comprises a mating or coupling means which is adapted to make complementary mating or coupling engagement with a support member or a support surface having a complementary mating or coupling means.