Krud Kutter House and Siding Pressure Washer Concentrate Advanced Formula is a powerful, commercial strength formula for outdoor cleaning tasks. Ideal for roofing, siding, gutters, brick, stucco and other exterior surfaces. This biodegradable and bleach-free cleaner eliminates dirt, mildew stains, grease and other tough soils. Makes up to 20 gallons and covers up to 5,800 square feet per gallon of concentrate.