flow volumes will not cause harm because water flowing down a surface will tend to adhere to that surface the water flowing down the surface of the shingle system of the present invention will tend to follow the slanting lower edges of the shingle elements in the direction of the slanted edges so as to provide a way to control the flow of water on the surface of a roof application_number US 79144901 A description fig1 shows an invention roof shingle 10 as can be better seen in left side view of fig2 and lower edge end view of fig3 roof shingle 10 generally includes a base shingle 14 that forms a head lap section 4 at its upper end and forms the base for a butt lap section 6 at its lower end butt lap section 6 further includes a first shingle 8 a 1 layered on top of base shingle 14 and a second shingle 8 a 2 layered on top of first shingle 8 a 1 as can be seen in fig1 first shingle 8 a 1 includes a saw tooth pattern of slanted lower edges 9 in a similar fashion second shingle 8 a 2 includes a saw tooth pattern of slanted lower edges 16 that are aligned and parallel to edges 9 the flow of water 23 across invention shingle 10 is illustrated in fig4 as can be seen in fig4 water flow.