The roof must be clean, dry and free of any oil, grease, dirt or loosely adhered coating. Surface should be cleaned with Roof Protect to ensure proper adhesion. It was field tested to be compatible with RvRoofMagic and provides a very deep cleaning vs standard cleaners. Roof Protect emulsifies contaminates and provides improved surface preparation by effectively removing oil, grease, mildew, dirt, and other soils from your roofing membrane. It also has a built in mildewcide to kill any living mold spores on your roof prior to application of RvRoofMagic. You can also use Roof Protect annually to further protect your roof.