A utility pipe encasement collar for preventing water from weather related sources such as rain and snow from traveling rearwardly along the exterior surface of the utility pipe and into a building structure from which the pipe projects. In a first embodiment the collar includes a weather proof elastomeric sheet material having an opening therethrough sized to inherently huggingly accommodate a utility pipe passed through the opening, and a generally rigid support member extending laterally from the elastomeric sheet material. In a second embodiment the collar includes a first generally rigid weather proof sheet member having an upright generally U-shape opening therethrough and a second generally rigid weather proof sheet member having an inverted generally U-shape opening therethrough. The upright and inverted openings are alignably slidable opposite each other while the utility pipe is disposed within both U-shaped openings to thereby provide a generally perpendicular collar surrounding the pipe as formed by the sheet members.