How Often Should You Pressure Wash Your House? (By Surface)

For most homeowners, washing the house exterior once per year is the right baseline. The exception is humid climates — the Southeast, Gulf Coast, Pacific Northwest, and anywhere with heavy tree cover — where algae and mildew grow quickly. In those regions, twice a year (spring and fall) keeps the exterior cleaner and prevents the kind of deep biological staining that requires stronger treatments to remove.

If you're in a dry climate with little tree cover (Arizona, Nevada, parts of Colorado), you can often go 18–24 months between washes without visible buildup. The risk there is dust and oxidation on paint rather than biological growth.

Concrete driveways typically need cleaning once a year. In cold climates, the right time is spring — after the last freeze — to remove winter road salt, sand, and the dark tire marks that accumulate over the season. In warm climates without a winter road treatment season, once a year in spring works well for most properties.

If you park oil-leaking vehicles, have heavy vehicle traffic, or live near a road with significant runoff, every 6–9 months may be more appropriate. Oil stains are far easier to remove when fresh.

Wood and composite decks benefit from annual cleaning, ideally in spring before peak use season. The reason is practical: spring cleaning removes the previous year's algae and mold growth and prepares the surface for any staining, sealing, or refinishing you plan to do. If you seal or stain your deck, the cleaning should always come first.

If your deck goes untreated (no stain or sealer), plan on cleaning at least once a year. Mold and mildew growth accelerates on bare wood and becomes harder to remove the longer it sits.

Roof cleaning frequency depends heavily on how much shade your roof gets. Shaded roofs — especially those under large trees — accumulate algae, moss, and lichen much faster than sunny ones. In the Pacific Northwest and Southeast, roofs under heavy canopy may need soft washing annually. Fully exposed roofs in dry climates can go 3–5 years without visible growth.

A useful rule of thumb: if you can see black streaks or green patches from the ground, you're overdue. Black streaks (Gloeocapsa magma algae) don't just look bad — they accelerate shingle deterioration. Moss and lichen are worse; their root systems physically lift shingle granules over time.

Gutters are the one surface where twice-a-year cleaning is the near-universal recommendation: late spring (after pollen and seed fall) and late fall (after leaves finish dropping). This prevents the clogs and overflow that cause fascia rot, foundation issues, and water intrusion.

If you have heavy deciduous tree cover directly over your roofline, you may need three cleanings — adding a mid-fall pass as leaves start coming down. Guards help but don't eliminate the need for cleaning entirely.

You don't always need a calendar to know it's time. These are the signs that tell you cleaning is overdue: