Abstract: A flashing for a roof top vent pipe includes a frusto-conical shield member to enclose a portion of the vent pipe and a support base with a central longitudinal axis extending lateral longitudinaly thereof for mounting and securing upon the roof top. An annular upper portion of the shield member sealingly engages around the vent pipe. A pair of laterally spaced elongated stiffener beads extend along the under side of the base upon opposite sides of the longitudinal axis in engagement with the rooftop for stiffening and reinforcing the base at its exposed forward edge against upward bending and flexing under wind pressure to exclude water and debris.