TL;DR
- Most San Diego deck cleanings run $150 to $500. Small composite decks land low. Large wood decks with marine-layer mildew land high.
- Per square foot, expect $0.35 to $0.75 for cleaning only, higher than the national $0.30 to $0.70 because coastal mildew needs real chemistry.
- Wood decks need soft washing, not high pressure. High PSI splinters and furs the boards.
- Clean plus stain or seal is a separate, bigger scope: roughly $1.50 to $4.00 per square foot.
Deck and patio cleaning in San Diego costs $150 to $500 for most homes. A small composite or trex deck with light dust sits near the bottom. A big wood deck with green mildew on the north-facing boards sits near the top. Per square foot, cleaning-only work runs about $0.35 to $0.75 here. That’s a touch above national averages because our marine layer grows mildew that a plain water rinse won’t touch. Here’s exactly what moves the number, with real San Diego specifics.
The core pricing grid
We price decks and patios by surface type, square footage, and how much organic growth has set in. Rough ranges for cleaning only:
- Small deck or patio, under 200 sq ft, light dust: $150 to $225
- Standard backyard deck, 200 to 400 sq ft, some mildew: $225 to $350
- Large deck, 400 to 700 sq ft, moderate growth: $325 to $475
- Oversized or wrap-around, 700+ sq ft: quoted per site visit
- Concrete or paver patio, priced separately: $0.30 to $0.90 per sq ft by surface
National sources like HomeGuide and Angi put deck cleaning around $0.30 to $0.70 per square foot, with totals near $100 to $350. Those numbers assume a quick rinse of a clean deck. In San Diego, north-facing and shaded decks carry mildew that needs detergent and dwell time, so real-world totals run a little higher and earn their keep.
What actually drives the price
1. Surface material
This is the biggest factor, bigger than size for most decks.
- Composite or PVC (Trex, TimberTech): Easiest case. Soft wash with detergent, low-pressure rinse. Baseline pricing.
- Pressure-treated or cedar wood: Needs soft washing and careful chemistry. High pressure furs the grain and raises splinters. Baseline plus 10 to 20 percent.
- Hardwood (ipe, mahogany): Slow, gentle work to protect the finish. Baseline plus 15 to 25 percent.
- Concrete or paver patio: Different method entirely, priced by the foot. Pavers include re-sanding.
If you’re unsure which method your deck needs, our guide on pressure washing vs power washing vs soft washing breaks down which surfaces take which approach.
2. Square footage
Measure the deck floor, length times width. A typical backyard deck runs 200 to 400 square feet. Add a wrap-around or a second level and you’re over 600 fast.
Per-square-foot cleaning rates:
- $0.35 to $0.50/sq ft for composite with light soil
- $0.50 to $0.65/sq ft for wood needing soft wash and mildew treatment
- $0.30 to $0.60/sq ft for concrete patio with a surface cleaner
- $0.60 to $0.90/sq ft for paver patio, includes re-sanding
3. Mildew and algae load
This is the San Diego variable. Our marine layer keeps coastal and shaded decks damp most mornings. North-facing boards, decks under tree canopy, and anything in Encinitas, Cardiff, La Jolla, or Point Loma grow black and green mildew that a rinse alone won’t kill.
- Light surface dust: included in base price
- Moderate mildew on shaded sections: plus $40 to $80 for pre-treat and dwell
- Heavy green and black growth (north-facing coastal): plus $80 to $150
- Embedded mildew in old, gray wood: quoted per site, may need brightener
Kill the mildew at the root and it stays gone for a year or more. Just rinse the surface and it’s back in six weeks.
4. Hard water and mineral staining
Inland San Diego water is hard. Sprinkler overspray and pool splash leave white mineral haze on decks and patios, especially in East County. Removing it takes acid-based chemistry, not pressure.
- Light mineral haze: plus $30 to $60
- Heavy efflorescence on concrete or pavers: plus $60 to $120
5. Access
A ground-level deck off a wide gate is the fast case. A second-story deck, a hillside lot, or a yard you reach only through the house all add setup time. In hillside neighborhoods like Mount Helix, Rancho Peñasquitos, and parts of La Jolla, this is real.
- Side-gate access only: plus $20
- Second-story or elevated deck: plus $40 to $90
- Hose carry over 100 feet or stair access: quoted per site
Cleaning only vs. clean plus stain or seal
These are two different jobs, and the gap matters for budgeting.
Cleaning only restores the look, removes mildew and grime, and runs $150 to $500 as above. Good for composite, or wood you want to keep raw.
Clean plus stain or seal is a multi-day scope. Clean, let the wood dry 48 hours, then sand if needed, then apply stain or sealer. National pricing runs $1.50 to $4.00 per square foot all in. We handle the cleaning and prep side. If your deck is due for refinishing, our walkthrough on how to prep a deck for staining covers the wash, dry time, and what a stainer needs from us.
Regional pricing across San Diego County
We run jobs from Oceanside to San Ysidro. Base pricing is steady countywide, but microclimate changes the mildew adder.
- Coastal (Oceanside, Carlsbad, Encinitas, Del Mar, La Jolla): Heaviest marine-layer mildew on north-facing and shaded boards. Budget toward the upper mildew adders.
- North County inland (San Marcos, Escondido, Poway): Dust and sprinkler overspray dominate. Mid-range, watch for hard-water haze.
- Central SD (Clairemont, North Park, Kensington, Normal Heights): Mixed. Older homes often have decades-old wood decks that need brightener.
- East County (El Cajon, La Mesa, Santee, Alpine): Hot, dry, hard water. Lower mildew, higher mineral staining.
- South Bay (Chula Vista, National City, Imperial Beach): Salt air plus older surfaces. Careful work on aging wood.
Why the cheapest quote usually costs more
A sub-$100 deck quote is almost always a high-pressure wand job with no chemistry. On wood, that does real damage:
- Furred, splintered grain that snags bare feet
- Mildew back within six weeks because nothing killed it at the root
- Gouged board edges where a tight nozzle dug in
- Border plants burned because nobody pre-wetted the landscaping
- Dirty runoff straight into the storm drain
That last one matters here. San Diego’s stormwater rules treat wash water with detergent or debris as pollution that can’t enter the storm drain untreated. We capture or divert runoff so it doesn’t reach the gutter. Our full breakdown is in stormwater compliance for San Diego pressure washing. A cheap operator who hoses everything into the street is leaving you exposed and the neighborhood dirtier.
A note on HOA rules
Many San Diego HOAs require deck and patio maintenance on a schedule, and some restrict when and how you can do exterior work. Coastal and planned communities in Carlsbad, Del Mar, and Rancho Santa Fe often spell out approved methods. Check your CC&Rs before you book. Soft washing satisfies most HOA standards because it’s gentle and contained.
How to get an accurate quote without a site visit
For most decks, we can give a firm quote from photos:
- A wide shot of the whole deck or patio
- A close-up of the dirtiest or most mildewed area, usually the north-facing or shaded section
- Approximate square footage, length times width
- The surface material, wood, composite, concrete, or pavers
- Whether you want cleaning only or clean plus prep for staining
Expect a written quote back within a business day. Decks over 700 square feet, elevated structures, or anything decorative get a free in-person estimate first. Every quote is upfront and itemized, no surprise add-ons after we arrive.
Frequently asked questions
How much does it cost to clean a deck in San Diego?
Most residential deck and patio cleanings run $150 to $500. Small composite decks land near the bottom, large wood decks with heavy coastal mildew near the top. Per square foot, plan on $0.35 to $0.75 for cleaning only.
Should my wood deck be pressure washed or soft washed?
Soft washed. High pressure splinters and furs wood grain. Soft washing uses detergent and a low-pressure rinse to lift mildew and dirt without damaging the boards. We soft wash all wood decks by default.
Why is San Diego deck cleaning a bit more than national averages?
The marine layer. North-facing and shaded decks here grow black and green mildew that a plain rinse won’t kill. Real removal needs detergent, dwell time, and sometimes a wood brightener, which adds a little over a quick national-average rinse.
Does deck cleaning include staining or sealing?
No, those are separate. Cleaning restores the look and removes mildew. Staining or sealing is a multi-day scope that runs about $1.50 to $4.00 per square foot all in, because the wood has to dry 48 hours after cleaning first.
How often should I clean my deck in San Diego?
Once a year for most decks. Coastal and heavily shaded decks that grow mildew fast may need it twice a year. Composite in full sun can sometimes stretch to 18 months.
Will the cleaning harm my plants or run into the storm drain?
No. We pre-wet and rinse surrounding landscaping, and we capture or divert wash water so detergent and debris don’t enter the storm drain, in line with San Diego stormwater rules.
Ready for a real number
Send a few photos and we’ll send back a written, itemized quote, usually within a business day. Most decks book and finish inside a week. See what’s included on our deck and patio cleaning page, or call (858) 925-5546 to talk it through. Upfront pricing, soft-wash done right, all of San Diego County.