How to Pressure-Wash Siding Without Damaging It
Tip selection, distance, and the cleaners that actually work.
Pressure-washing siding is largely a DIY job that can be done safely — but improper technique drives water behind siding, damages caulking, and can void warranties. The right approach is closer to 'soft washing' than aggressive blasting.
The right technique
Use a 25° or 40° tip (white or green) — never a 0° or 15° tip on siding. Keep the wand 18-24" from the surface. Spray at a downward angle to avoid forcing water behind the siding.
Pre-treat with a siding cleaner (oxygen bleach-based products like Wet & Forget) for 10-15 minutes before rinsing. The chemistry does the work; the water just rinses.
What to avoid
Never spray upward at horizontal lap joints — forces water behind the siding. Don't spray around electrical outlets, dryer vents, or window/door seals.
Avoid chlorine bleach if you have nearby landscaping — it kills plants. Most siding manufacturers explicitly warn against high-pressure washing in their warranty terms; check yours before starting.