How to Pressure Wash Your House Exterior Safely

Pressure washing your house exterior requires the right equipment, proper technique, and safety precautions to clean effectively without damaging siding or windows.

1. Pick Your Power Level. Use a pressure washer rated between 1,500-2,500 PSI for most home exteriors. Electric models work well for single-story homes, while gas-powered units handle larger jobs better. Start with the lowest pressure setting and work up as needed. Different siding materials require different approaches: vinyl and aluminum can handle moderate pressure, while wood siding needs gentler treatment.
2. Protect What Matters Most. Close all windows and doors securely. Cover electrical outlets, light fixtures, and air conditioning units with plastic sheeting and tape. Move outdoor furniture, plants, and decorative items away from the house. Sweep or rinse loose debris from the area you'll be washing. Check for any loose siding, trim, or caulking that high pressure water could damage further.
3. Treat Stubborn Stains First. For heavily soiled surfaces or mildew problems, apply a cleaning solution before pressure washing. Mix a mild detergent with water according to manufacturer instructions, or use a bleach solution (1 part bleach to 10 parts water) for mold and mildew. Apply the solution with a garden sprayer or the detergent attachment on your pressure washer. Let it sit for 10-15 minutes but don't allow it to dry completely.
4. Work Top Down Methodically. Begin at the highest point of your house and work downward. Hold the spray wand 12-18 inches from the surface and use smooth, overlapping strokes. Keep the nozzle moving to avoid concentrating pressure in one spot, which can damage siding or force water behind it. Work in manageable sections, completing each area before moving to the next.
5. Angle Down, Never Up. Spray at a slight downward angle to prevent water from getting behind siding or trim. For horizontal siding, spray along the length of each board rather than directly at the seams. Avoid spraying upward under siding edges. When cleaning around windows, use lower pressure and be extra careful not to force water around window seals.
6. Rinse, Inspect, Dry Completely. After washing each section, rinse thoroughly with clean water to remove all cleaning solution and loosened dirt. Work from top to bottom again during rinsing. Inspect your work as you go, paying attention to areas that might need additional cleaning or lower pressure. Allow the house to air dry completely before removing protective coverings.