Removes dirt, grease, oil, and mildew stains. Contains "SPOREX" additive which removes tough stains from mildew, mold, algae, fungus and moss. For exterior siding, roofing of all types, gutters, stucco, brick and cement block, masonry, walkways and walls. Covers up to 2,000 sq. ft. Water-Based. Bio-degradable. Non-flammable. Non-toxic. Non-abrasive.