Abstract: An integrated set of roof tiles comprises a main roof tile (12) of rectangular shape in plan, which is provided with interlocking side-lock portions (58,60) at opposite side edges thereof. The roof tile (12) also has a flat, bottomed channel (62) with sloping side walls (68,70), the channel (62) extending from a toe to head end of the main roof tile (12). The channel (62) has a widening towards the middle of its length. The set of roof tiles also comprises a ridge tile (2), which is substantially of half round configuration and is provided with a channel (24) having sloping side walls (30,32), the channel (24) extending over the ridge tile to continue the configuration of the main roof tiles (12). The ridge tiles (2) are also provided with protuberances (42) at lower edges that engage in use with upper faces of the topmost roof tiles (12) on either side of an apex (4) of a roof (6), which protuberances (42) define a ventilation opening (41) between the ridge tiles (2) and the topmost roof tiles (12).