Deck pressure washing cost calculator

How much should pressure washing a deck cost?

Most US homeowners pay between $0.50 and $1.50 per square foot to pressure wash a residential deck in 2026 — the highest per-sqft rate of any common exterior surface, because wood requires slow, controlled technique to avoid raising the grain. A typical 200–500 sqft deck lands in the $100–$750 range for a standard cleaning. The calculator below applies your exact sqft, intensity, and ZIP code's regional cost-of-living band so the number you see is realistic for where you live — not a national average.

What changes a deck pressure washing quote

Deck material — and why wood costs more per sqft than concrete

Wood decks (pine, cedar, ipe, redwood) need slow, controlled technique because high PSI raises the grain and damages the surface — that's why deck rates are 3–5× the per-sqft rate of a concrete driveway. Composite decks (Trex, TimberTech) tolerate higher PSI and clean faster, but the surface is still more delicate than concrete. Painted decks need the most caution: aggressive wash strips the paint. For old paint scheduled for repaint, that's a feature; for paint you want to keep, it's a disaster.

Pressure washing vs soft-wash for decks

Sound, structurally healthy deck wood tolerates standard pressure washing at moderate PSI (1,500–2,000) with a 25° or 40° tip. Older boards with visible weathering, splintering, or soft spots should be soft-washed (low PSI plus a mild bleach + percarbonate solution) to avoid further damage. Pick Soft wash in the calculator if your boards are 10+ years old or showing surface checking.

The stain-prep job (most common reason to wash a deck)

Most professional deck washes are done as prep for staining or sealing — stain doesn't bond to dirty wood, and a fresh stain over old grime peels within a year. Plan to wash, let the wood dry 48–72 hours (3+ days in humid climates), then sand any raised grain before staining. The wash + stain combination is typically billed as two separate trades; the calculator above covers only the wash portion.

Algae, mildew, and the north-facing deck problem

Decks on the north side of a house, especially under tree cover, accumulate algae and mildew far faster than south-facing decks. Black or green slick patches indicate organic colonization — these decks need a chemical pre-treatment (sodium percarbonate or dilute hypochlorite) plus a soft-wash to remove the biology. Pick the Heavy intensity in the calculator if you see significant organic discoloration.

Regional cost-of-living impact

Deck washing labor scales with regional cost of living the same as every other surface. A 300 sqft deck at standard intensity costs roughly $285 in Atlanta (0.95× multiplier), $405 in San Francisco (1.35×), and $420 in Manhattan ZIP 100xx (1.40×). The calculator applies your ZIP's USPS-prefix-based regional multiplier automatically.

Frequently asked questions

How much does it cost to pressure wash a deck?: Most US homeowners pay between $0.50 and $1.50 per square foot for residential deck pressure washing in 2026 — the highest per-sqft rate of any common exterior surface. A typical 200–500 sqft deck lands in the $100–$750 range. Heavy organic discoloration or stain-prep work pushes the price toward the high end.
Why does deck pressure washing cost more per sqft than driveway pressure washing?: Wood requires slow, controlled technique to avoid raising the grain — that's the main driver. A skilled operator works at lower PSI with wider tips and overlapping passes, which takes more time per sqft than the surface cleaner attachment used on concrete.
Should I pressure wash my composite (Trex) deck?: Yes, but at moderate PSI (1,500–2,000) with a fan tip. Composite is more durable than wood but still scratches under aggressive direct spray. Trex's official guidance is to use soap and water with a soft brush, but pressure washing at moderate PSI is widely practiced and safe with the right technique.
Will pressure washing damage my deck?: Aggressive pressure washing can fuzz wood grain, etch composite, and strip paint. The risks are managed by an operator who matches PSI and tip to the surface (40° fan tip is standard for wood) and keeps the nozzle 6–12 inches from the boards. DIY damage is most common when consumer users get too close with a narrow tip.
How often should I pressure wash my deck?: Annually for wood decks, especially before re-staining. Composite decks can stretch to every 2–3 years. North-facing decks under tree cover may need 2× per year (spring and fall) to keep algae and mildew in check.
Do I need to seal or stain after pressure washing?: For wood decks: yes, within 30–60 days. Pressure washing opens the wood's pores, and unsealed wood absorbs water that drives premature rot. The cleaning + staining sequence is the most common deck maintenance pattern. Composite and painted decks don't need sealing.
Is this a quote I can hold an operator to?: No — it's an estimate based on industry benchmarks for the wash portion only. It doesn't include stain prep beyond cleaning, board repair, railing/spindle complexity, or chemistry premiums for heavy mildew. Use it to know what's reasonable per square foot; confirm the full quote with the contractor before booking.