Some embodiments relate to a roofing membrane. The roofing membrane comprises a scrim. The scrim has a top surface and a bottom surface. The roofing membrane comprises a cap layer on the top surface of the scrim. The cap layer comprises a first non-styrenic polypropylene polymer, a first polypropylene impact copolymer, and a first olefin block copolymer. The roofing membrane comprises a core layer on the bottom surface of the scrim. The core layer comprises a second non-styrenic polypropylene polymer, a second polypropylene impact copolymer, and a second olefin block copolymer. The roofing membrane is configured to prevent migration of at least one oil from a layer to the roofing membrane. Some embodiments relate to a roofing structure comprising the roofing membrane, a method for installing the roofing membrane, and the like.