Rust-Oleum One-Step Roof Prep Cleaner is a concentrated cleaning solution for single-ply roofing membranes, metal, modified bitumen, concrete and existing coatings. It is a low foaming, high efficiency, and easy-to-rinse cleaner and degreaser that is designed to remove dirt, grease, and contaminants from a roof to help prep the roof before priming, repairs and coating. This cleaner is completely solvent free, non-corrosive, bleach free and has a very low odor.