Wet and Forget has a unique combination of biodegradable selective surfactants for moss, mold and mildew stain removal on any exterior surface. When diluted with water and applied, it immediately penetrates the unsightly stain. Each time it rains, this safe, cleansing combination reactivates to gently lift the moss, mold and mildew stain without damaging the surface. Wet and Forget is an EPA approved one step process that requires no scrubbing or rinsing. It is non-acidic, non-caustic and contains no bleach. Be patient, Wet and Forget's gentle cleaning action takes time depending on how heavy the stain is and results are visible over time. Remember good things take time, and Wet and Forget continues to clean for up to a year. No special equipment is required. Just apply Wet and Forget with a pump-up garden sprayer. After the first application simply reapply Wet and Forget at the first sign of moss, mold and mildew stains returning. Wet and Forget can be used on any outdoor surface. Some examples of these surfaces are: asphalt (blacktop), Astroturf, aluminum siding, awnings, brick pavers, composite decking, concrete, driveways, docks, fiberglass boats, fiberglass shingles, fiberglass hulls/topsides, green houses, gutters, inflatable dinghies, limestone, marble, marinas, natural stone, outdoor furniture, outdoor planters, paint surfaces, patios, patio furniture, plastic houses, recreational vehicles, retaining walls, sails, sandstone, shade sails, sidewalks, stucco, tennis courts, teak decks, textured finishes, tiles, tombstones, umbrellas (outdoor), vinyl siding, wood.