Richard, (Worcester, MA)
Richard, try this. Realizing that some petroleum products may be harmful to EPDM rubber roofing if it becomes saturated, carefully moisten a clean, soft, cotton cloth with regular mineral spirits and lightly rub the pine sap from the roof. Do not pour the spirits directly onto the roof, but use a clean portion of the cloth each time. Eventually you should be able to remove all of the pine pitch. Though not always 100% necessary, apply an EPDM protectant to the affected area after removing the pine sap. And don't park under that pine tree any more!
Thanks for visiting the RV Doctor Website, the official home of author and technical educator, Gary Bunzer, featuring select questions from his popular column, The RV Doctor.