Krud Kutter House Wash is a proprietary formulation which contains a unique additive which removes tough stains from organic material and leaves the surface completely clean. In addition, special surfactants penetrate the surface to safely and easily dissolve the toughest stains from dirt, oil, grease, bird droppings, tree sap, and acid rain. Even removes gray weathering on wood, chalking and oxidation. Safe and effective on most surfaces. Recommended for exterior siding (wood, vinyl, aluminum), roofing of all types (asphalt shingles, fiberglass shingles, cedar, tile), gutters, stucco, brick and cement block, masonry, walkways and walls.