To provide a method for roofing clay tiles equipped with a disaster preventing function, which is effective for preventing shattering of the flat clay tiles forming a clay tile roof in the event of strong winds or a typhoon, and to provide the flat clay tiles for use in implementing the method.

A sidewise protruding projection is formed on an overlap face or an underlap stepped face at a location closer to a top side thereof. Further, a hole portion is formed in the underlap stepped face or the overlap face at a location closer to the top side thereof and conforming to the projection. The projection is fitted into the hole portion, and they are connected together, which leads to superposing of the overlap and the underlap on each other, to thereby achieve roofing of the clay tiles.