Pressure Washing FAQ: Costs, PSI, Timing, and What Homeowners Get Wrong
How much does pressure washing cost?
Most residential jobs fall into predictable ranges. Nationally, expect roughly:
- Full house wash (siding): $220–$450 for a typical 1,500–2,500 sq ft home; two-story homes run 20–30% more
- Driveway: $100–$260 depending on length and staining
- Deck or patio: $120–$250
- Roof (soft wash only): $300–$700
- Fence: $150–$300 for an average backyard run
Per-square-foot pricing usually lands between $0.10 and $0.50. Heavy oil stains, gum, rust, or years of neglect push you toward the top of the range because they require pre-treatment and extra passes.
What's the difference between pressure washing and soft washing?
This is the question that matters most for protecting your home. Pressure washing uses high-pressure water — typically 2,000–3,500 PSI — and is right for concrete, brick pavers, and stone. Soft washing uses low pressure (under 500 PSI, about the force of a garden hose) combined with a detergent solution that kills mold, algae, and mildew at the root.
As a rule of thumb:
- Concrete driveways and sidewalks: 3,000+ PSI is fine
- Vinyl siding: soft wash, or no more than 1,300–1,600 PSI at a safe distance
- Wood decks: 500–1,200 PSI with a wide fan tip
- Asphalt shingle roofs: soft wash only — ever. High pressure strips granules and voids many roof warranties
If a company quotes you a "pressure wash" for your roof or painted siding, ask follow-up questions. The right answer is almost always soft washing.
How often should I have my house washed?
For most homes, once a year keeps siding, walkways, and driveways in good shape. Bump that to every 6–9 months if you have heavy tree cover, live in a humid climate where algae thrives, or are near a busy road that deposits grime. North-facing walls and shaded areas grow mold fastest, so check those first.
Two timing tips: wash before any repainting or staining project (paint adheres poorly to dirty or chalky surfaces), and schedule roof or siding cleaning at the first sign of black streaks — those are Gloeocapsa magma algae, and they spread.
Can pressure washing damage my home?
Yes — and this is where most DIY jobs go wrong. The common failure points:
- Water forced behind siding, causing hidden moisture and mold inside walls
- Etched wood from holding a narrow tip too close (you'll see fuzzy, raised grain)
- Blown-out window seals and torn screens
- Stripped paint — a problem on pre-1978 homes, where disturbed paint may contain lead
- Sprayed mortar joints on older brick, which can loosen and crumble
The fix is simple: match the PSI and nozzle to the surface, keep the wand 12–18 inches away, spray at a downward angle on siding, and never point high pressure at windows, vents, light fixtures, or electrical outlets.
Is it cheaper to DIY?
Sometimes — for flat concrete. A rental machine runs $40–$100 per day, plus detergent, and a driveway takes most beginners 2–4 hours. But consumer-grade machines top out around 2,000–2,800 PSI with low water flow (GPM), so jobs take longer and results are often streaky. For two-story siding, roofs, or anything requiring ladders and chemicals, the math (and the risk) usually favors a pro, who carries commercial equipment at 4+ GPM and insurance if something goes wrong.
How do I prepare for a pressure washing visit?
A 15-minute prep makes the job faster and protects your stuff:
- Close all windows and doors tightly; note any known leaky seals
- Move vehicles, grills, planters, and patio furniture away from work areas
- Shut off exterior outlets or point them out to the crew
- Water your landscaping beforehand — pre-soaked plants absorb less detergent overspray
- Make an outdoor water spigot accessible and confirm it works
- Keep pets and kids inside during the wash
Does regular washing actually protect my home's value?
It does more than look good. Algae and mildew hold moisture against siding and shingles, shortening their lifespan, and grime buildup accelerates paint failure. Real estate agents consistently rank exterior cleaning among the cheapest curb-appeal improvements — a few hundred dollars that helps a home show thousands of dollars better. Annual washing is maintenance, not cosmetics.
The bottom line
Know your surface, respect the PSI, and stay on a once-a-year schedule. If your job involves a second story, a roof, delicate siding, or stains that haven't budged, it's worth getting a quote from a local pressure washing pro — most offer free estimates, and an experienced crew can usually finish in a morning what would eat your whole weekend.