Valley flow controller

A method for controlling flow from a roof valley of a roof into adjoining gutters on edges of the roof valley, the method comprising:

• providing a flow controller having
• a base with a distal end, a proximal end and longitudinal sides connecting the distal end and proximal end, the base having a plane base portion bounded by the distal end with a substantially plane shape, wherein the distal end is disposed so that with the flow controller installed to the roof, or adjoining gutters on edges of the roof valley, the distal end is located toward the roof, and the proximal end is located away from the roof, and toward a front edge of the adjoining gutters, wherein the proximal end has a form that describes an included angle, edges of the included angle being generally aligned with the adjoining gutters, and wherein the proximal end has a demi-bullnose shape between the plane base portion and edges of the included angle, and a cleft that extends through the demi-bullnose shape from the plane base portion to an apex of the included angle, forming a flow channel with opposite channel walls that separate and respectively intersect sections of the demi-bullnose shape aligned with edges of the included angle
• effecting controlling flow from the roof valley over each of the plane base portion, the demi-bullnose shape and flow channel and collecting into the adjoining gutters.