A roof valley inset provides a flexible material with angularly extending arms. Dividers may be useful to direct water toward respective arms in a base pan and the arms may taper, such as to a point away from the other arm. Dividers may be provided as permanently connected to the base pan or detachably connected for ease in shipping. The dividers may also have cantileveredly connected legs which extend above a portion of the arms to assist in covering shingles, when installed.