Pressure washing looks like a simple job and is actually a skilled one. Too much pressure strips paint, etches concrete, shreds wood siding, and drives water into wall cavities where it causes mold and rot. Too little pressure fails to clean. Wrong chemicals kill landscaping, discolor siding, or leave residue that attracts dirt faster than before the cleaning. The wrong surface-cleaning attachment scars driveways. A bad pressure washing job can cost thousands in damage. A good one makes the house look transformed.
This guide is part of the Know Before You Hire series. At Home Services Co, our pressure washing service uses soft-wash techniques where appropriate, proper chemistry, and trained operators — not just high-PSI spray.
Soft wash vs pressure wash. The current professional standard for most residential surfaces is soft wash — low-pressure application (under 500 PSI) with specific cleaning chemistry (sodium hypochlorite solution, surfactants) that kills algae, mold, and mildew at the root. Soft wash lasts longer than high-pressure cleaning because it addresses the biological growth, not just the visible dirt. High-pressure washing (2,000-4,000 PSI) is appropriate for concrete, brick, some hardscape — not for siding, roofing, or painted surfaces. An operator who uses high pressure on everything is one who only knows one tool.
Red flag #1: pressure-washing siding. Vinyl siding can tolerate moderate pressure. Wood siding, fiber cement, stucco, and painted surfaces should never see high-pressure spray — the water drives behind the siding into the wall cavity, causing mold, rot, and paint failure. A contractor who proposes high-pressure washing on these surfaces is a contractor planning to damage your home. Soft-wash only. See hiring a siding contractor for related siding-inspection guidance.
Red flag #2: pressure-washing roofs. Never. Ever. High-pressure water on asphalt shingles strips the granules off, voids the manufacturer warranty, and shortens roof life by years. Roof cleaning is exclusively soft-wash with proper chemistry. A contractor who proposes pressure-washing your roof is someone you never let on your property. See roofer hiring guide.
Red flag #3: no plant protection. Sodium hypochlorite (used in soft wash) and strong detergents can damage or kill plants. A professional wets down all landscaping before starting, covers sensitive plants, and flushes the area with water during and after the job. A careless operator sprays chemicals and lets them drift where they will. Dead hostas by the foundation are the usual evidence of this.
Red flag #4: driveway spotting. Concrete cleaning with a surface cleaner attachment produces consistent results. Cleaning with just a spray wand produces tiger-striping (darker bands where the wand wasn't held consistently). A contractor who cleans driveways with just a spray wand is using inadequate equipment. Demand a surface-cleaner attachment for flat concrete work.
Red flag #5: mystery chemicals. A professional will tell you what chemistry they are using. A shady operator will dodge. Some operators spray muriatic acid on concrete and siding — acid does work on some stains but causes damage on others, and the residue runoff damages landscaping and aquatic life downstream. Ask what chemicals are being used. Legitimate operators answer directly.
Red flag #6: dramatically below market pricing. A full-house soft wash plus driveway, a typical residential job, runs $300-$700 depending on home size. A $99 'special' is either taking 15 minutes and doing effectively nothing, or using high pressure on surfaces that shouldn't see high pressure. See warning signs of a low-ball bid.
Pricing reality. House soft wash (typical 2,000 sq ft single-story): $250-$500. Two-story home soft wash: $400-$800. Driveway pressure washing (500-1,000 sq ft): $150-$350. Sidewalk, patio, or walkway cleaning: $0.20-$0.40 per sq ft. Deck cleaning: $150-$400 (excluding staining, which is separate). Roof soft wash: $400-$900 depending on pitch and size. Fence cleaning: $150-$500. Complete exterior package (house + driveway + walks): $500-$1,200.
When to schedule. Spring is peak season (cleaning winter grime). Late summer through early fall is also common (post-storm debris cleanup, pre-winter prep). Avoid freezing temperatures — water can freeze on surfaces and in equipment. Avoid immediately before expected rain — the rain re-spots the work. Mid-week scheduling often gets better pricing than weekends.
Surfaces and techniques. Vinyl siding: soft wash with low-chlorine solution. Fiber cement: soft wash only. Stucco: soft wash, gentle — stucco absorbs and holds chemicals. Brick: moderate pressure acceptable. Concrete: high pressure with surface cleaner. Wood siding: soft wash only (wood absorbs water). Wood decks: low-to-moderate pressure with appropriate cleaner. Roofing: soft wash exclusively. Composite decking: low pressure per manufacturer spec.
Insurance and operator training. Pressure washers are dangerous equipment. Injury risk is significant (lacerations, falls, ladder issues). Chemical exposure is a health concern for operators and homeowners. Verify insurance. Ask about operator training — legitimate companies train on chemistry, technique, surface-specific approaches.
Plant protection protocol. A professional soft-wash job follows a protocol: wet down all nearby landscaping before starting, cover particularly sensitive plants, apply cleaning chemistry, rinse the area thoroughly during and after the work, and flush the landscape beds with fresh water. Plants that look healthy at job end but wilt three days later are a sign chemistry remained in the soil. Ask about the protocol.
Stained concrete. Some stains on concrete (oil, rust, efflorescence, organic growth) require specific chemistry beyond standard pressure washing. Oil stains benefit from degreasers. Rust stains from oxalic-acid-based removers. Efflorescence from mild acid. Organic growth from hypochlorite. A one-size-fits-all power wash will not remove all of these. Discuss specific stain issues before scheduling.
Paint prep. Pressure washing is a common preparation step before exterior painting — it removes loose paint, dirt, and mildew. The painter and washer should coordinate: the wash should leave surfaces ready to receive paint (fully dry, no residue). Homeowners scheduling both services independently sometimes find the painter has to re-prep because the wash was inadequate. Let your painter recommend (or bundle with) the pressure washer. See hiring a painter.
HOA considerations. Some HOAs require pressure washing as part of exterior maintenance requirements (every 2-3 years on some covenants). Others restrict pressure washing days and times to avoid neighbor disruption. Know your HOA rules before scheduling.
Frequency. Most homes benefit from exterior soft wash every 1-2 years. Heavy tree coverage, heavy pollen, coastal salt spray, or areas with high humidity accelerate biological growth and may warrant annual cleaning. See spring maintenance checklist for timing.
Post-job verification. Walk the perimeter. No missed spots on siding. Driveway evenly cleaned without tiger striping. Plants are not wilting. No overspray on neighbor's cars or property. Chemistry residue is absent. Any issues are addressed before payment.
The summary. Soft wash for most residential surfaces. High pressure for concrete only. Never on roofs, stucco, or wood siding. Verify plant protection. Specify surface-cleaner attachment for driveways. Budget honest market pricing. Schedule 1-2 year intervals. Pair with exterior paint prep when appropriate.
At Home Services Co, our pressure washing service uses soft-wash methods for siding, roofs, and sensitive surfaces, proper chemistry, plant protection, and appropriate equipment for every surface type. Related: hiring a window cleaner, hiring a gutter cleaner, hiring a painter, spring maintenance, pricing, book, or the full series.