Can power washing damage vinyl siding? Yes. Extruded residential vinyl siding can easily warp, crack, or puncture when exposed to pressure exceeding 1,500 PSI. To prevent permanent structural damage, water-wrap mold intrusion, or voiding your manufacturerβs warranty, you must restrict washing to a maximum limit of 1,200 PSI, maintain a 12-to-18-inch distance, and use a wide-angle 40-degree white fan tip combined with a specialized, low-pressure chemical surfactant. (Use our dynamic siding age and temperature calculator below to find your property’s exact shatter threshold).