A cantilevered leaf spring is biased against the upper edge of a roofing tile to prevent the tile from sliding upward beneath an overlying upper row of roofing tiles. The leaf spring can be formed as a part of a tile fastener which includes a hooked portion for receiving and holding the lower edge of a roofing tile on a roof. A series of tile fasteners is mounted to a layer of roofing material to facilitate installation of tiles without the need for installation tools. Damaged tiles can be easily replaced without the need for installation or removal tools. With this system, each row of underlying tiles is locked in place by the combined effect of an overlying and overlapping row of tiles and a spring awl on an upper fastener pushing the upper edge of a tile downwardly so that the lower edge of the tile is forced into the mouth of a lower fastener.