Zep House & Siding Pressure Washer Concentrate, 1 Gallon is a powerful cleaning solution designed to remove dirt, stains, algae, mold, and mildew from roofs and siding. This concentrate is specially formulated for use in pressure washers and can produce up to 20 gallons of cleaner, making it both effective and economical. It works well on a variety of surfaces including hard coat stucco, brick, wood, vinyl, and aluminum siding. To prevent staining, it is important not to let the product dry on the surface before rinsing. For results on vertical surfaces, apply the solution from the bottom up and rinse from the top down to avoid streaking. test the cleaner on an inconspicuous area first to ensure compatibility, and protect plants by saturating them with water before and after cleaning. Follow the dilution instructions on the bottle and use the appropriate pressure washer nozzles for application and rinsing. After cleaning, allow the surface to dry completely and consider applying a water sealer to protect wood surfaces. Model Number: ZUVWS128