Abstract: A tool for laying sequential courses of tiles on an inclined roof, or sidewall the tool including a rail and several arms sized to extend over a previous course of tiles and to position the rail to define a straight edge for the current or new tile course. The arms extend over the current course and their ends are nailed or otherwise secured to the roof or sidewall. After the course is laid, the rail is moved up for the next course. A kit is formed of one or more rails, sets of arms, each set being sized and/or hinged for a corresponding type of tile, and means of interconnecting and aligning the rails. Two rails may also be used to provide roofing on a roof having two sections joined by a valley. For this configuration, a curved, flexible connector is used which is formed of a rubber pipe.