Removes tough stains from: dirt, mold, algae, mildew and more. Special surfactants penetrate the surface to safely and easily dissolve the toughest stains. Removes gray weathering on wood, chalking and oxidation. 1 gallon makes 20 gallons,cleans 4,000 sq. ft. Cleans, degreases and restores wood siding, vinyl siding, aluminum siding, asphalt shingles, fiberglass shingles, cedar shingles, tile roofing, gutters, wood fences, wood decks, stucco, brick, cement block, masonry, concrete driveways, walkways, RV's, patio furniture, boats and more. Non-Toxic, Non-Abrasive, Biodegradable. Non-Flammable.