pressure-washing

How Much Does Pressure Washing Cost in Seattle, WA? 2026 Prices for Moss, Roofs, and Hillside Lots

How much does pressure washing cost in Seattle, WA? 2026 prices for house washing, driveways, and roof moss treatment, plus sales tax and hillside access costs.

How Much Does Pressure Washing Cost in Seattle, WA? 2026 Prices for Moss, Roofs, and Hillside Lots

Washing a standard driveway in Seattle, WA costs about $150 to $350 in 2026, and a full exterior wash on a single-story house runs $300 to $550. Two-story homes move into the $450 to $950 range. Roof cleaning is its own purchase entirely and commonly lands between $450 and $1,200.

Two things make this market behave differently from a sunbelt city. Everything here grows moss, so the job is biological rather than cosmetic, and Washington charges retail sales tax on the labor. A $600 quote in Seattle collects a little over ten percent on top, which is a line most homeowners never see coming.

The third factor is terrain. A crew washing a flat rambler in Shoreline and a crew washing a three-story house cut into a hillside in West Seattle are performing different work at different risk, and the invoices reflect that. Here is how the pricing sorts out.

What Seattle Homeowners Pay by Surface

Flat concrete is the cheapest cleaning available because a surface cleaner attachment covers ground fast and evenly. Vertical surfaces cost more per square foot because they need low pressure, cleaning solution, dwell time, and care around windows, vents, and planting beds. Those two facts explain most of the spread between quotes.

Minimum charges of $175 to $300 are standard across the metro, which means a small patio booked alone costs about the same as a small patio booked with a walkway. Companies quote by the visit, not by the minute. Grouping surfaces into a single appointment is the most reliable way to lower the per-item cost.

Typical Seattle ranges this year look like this:

• Driveway, patio, or walkway: $150 to $350, roughly $0.20 to $0.40 per square foot
• House wash by soft wash, one story: $300 to $550
• House wash by soft wash, two story: $450 to $950
• Composition roof cleaning and moss treatment: $450 to $1,200
• Cedar deck or fence: $175 to $600
• Gutter face brightening: $100 to $250 for an average home

Concrete, Pavers, and the Green Film Between Them

Seattle concrete does not get dirty so much as it gets colonized. Algae and moss take hold on shaded north-side walkways and in the joints between pavers, and by February a flat surface can be genuinely slick. Cleaning that is a safety purchase before it is an appearance purchase.

Pavers carry an extra step. Cleaning blasts polymeric sand out of the joints, so a proper job includes resanding at $0.50 to $1.50 per square foot, and skipping it invites the pavers to shift over the next wet season. Ask whether resanding is included or quoted separately, because plenty of low bids leave it out.

Siding, Gutters, and the Trim Nobody Looks At

Most Seattle houses wear painted wood, fiber cement, or vinyl, and all three call for soft washing rather than high pressure. The solution kills the algae film and the rinse carries it off, which is why the results last longer than a pressure-only cleaning that leaves spores behind. High pressure on lap siding forces water behind the boards and creates a problem you will not find until it rots.

Gutter faces need a separate product. The black vertical streaking on aluminum is oxidation bonded to the finish, and a house wash rinse does not touch it. Brightening adds $100 to $250 and is worth bundling with the wash rather than booking later.

Roof Cleaning Is Not Pressure Washing

Moss on a Seattle composition roof is the most expensive maintenance failure in this climate. It grows thickest on north-facing slopes shaded by Douglas fir and cedar, holds water against the shingle surface, and lifts the edges until rain runs underneath instead of over the top. A roof rated for thirty years can lose five to ten of them to moss alone.

The correct treatment is low pressure with a moss-killing solution, followed by time. The moss dies, dries out, and sheds over the following weeks with wind and rain doing most of the removal work. Expect $450 to $1,200 for an average home, more for steep pitches and complex rooflines.

Anyone proposing to pressure wash an asphalt shingle roof should be removed from your list without further discussion. High pressure strips the mineral granules that protect the shingle from ultraviolet light, and it voids nearly every manufacturer warranty in writing. The damage is permanent and invisible from the ground for about two years.

Zinc or copper strips installed at the ridge cost $200 to $600 and slow regrowth for several seasons by releasing trace metal ions every time it rains. Pairing a treatment with strips is cheaper than repeating the treatment every eighteen months. Cedar shake roofs need a different chemistry and a gentler hand, so confirm the company has done them before.

Sales Tax Lands on the Labor in Washington

Exterior cleaning is a retail service in this state, which means the whole invoice is taxable rather than just the materials. In Seattle the combined rate sits a little above ten percent, so a $700 house wash bills closer to $775 once tax is added. Nearby cities in King County run a few tenths of a point in either direction.

That detail matters when comparing quotes, because companies present it inconsistently. Some quote tax-inclusive and some quote the labor and add tax at the bottom of the invoice, and a homeowner comparing the two thinks one bid is six percent cheaper. Ask every bidder whether their number includes tax.

Anyone who has priced this work in Portland notices the gap immediately, since Oregon collects no sales tax at all. On a single house wash it is a rounding error. On a full exterior package with a roof treatment, gutter brightening, and two decks, it is real money.

Hillside Lots Change the Quote

Queen Anne, Magnolia, West Seattle, and Beacon Hill are full of houses where the street side is one story and the back is three. Reaching that back elevation means ladder work on a slope, extension wands from below, or in some cases a lift, and every one of those options adds labor and risk. A two-story quote on paper can be a four-story reality at the downhill wall.

Access to water and power belongs in the conversation too. Crews need a working exterior spigot with decent flow, and a house where the only hose bib sits on the uphill side means a long run of hose and a slower job. Some companies bring a buffer tank for exactly this reason.

Parking is the quiet Seattle surcharge. A crew that has to shuttle equipment from a block away on a narrow street with no driveway spends thirty minutes doing it twice. Mention your parking situation when you request the quote and the estimate you get back will be closer to the final bill.

Where the Wash Water Ends Up

Seattle storm drains run to creeks, the ship canal, and Puget Sound with no treatment in between. Letting detergent-laden runoff enter a storm drain is a violation for the contractor and a potential problem for the property owner, and Seattle Public Utilities takes it seriously enough that legitimate companies plan for it.

The practical fix is containment and redirection. Crews block the drain, berm the low side, and route the wash water to a landscaped area or capture and dispose of it in the sanitary sewer where the utility allows that. It is not complicated, and the equipment is not expensive.

Ask any bidder how they handle runoff on a driveway job. A company that shrugs at the question is a company operating without the equipment, and the response tells you plenty about the rest of their standards. Reputable operators answer it in one sentence.

Timing, Frequency, and Who to Hire

The dependable dry window here runs from roughly July into September, and good crews book several weeks out during it. Roof and moss work is different, though. Treatments applied in early fall have the wet season to do the removal work for you, which is why many companies push moss service from September into November.

Once a year covers most Seattle homes for the house wash, with flatwork sometimes stretching to eighteen months. Properties under heavy conifer cover, homes on the water where salt air accelerates buildup, and north-facing walls that never see direct sun all need it more often. Waiting three years does not save money; it turns a wash into a heavier and pricier restoration job.

Insurance is the hiring question that matters most. Exterior cleaning by itself is not a licensed specialty trade in Washington, so ask for a current certificate of general liability sent from the agent rather than a forwarded PDF. Any company that also does repairs, gutter replacement, or roof work needs an active contractor registration with Labor and Industries, and the L&I lookup shows the bond, the insurance, and any lawsuits filed.

Two or three written bids on the same list of surfaces is enough to see your market's range. Pulling those from pressure washing companies serving your neighborhood makes the outlier obvious, and our Seattle area home maintenance cost guides cover the gutter, roof, and deck work that usually gets scheduled in the same season.

Frequently Asked Questions

How much does it cost to pressure wash a house in Seattle?

A single-story soft wash runs $300 to $550 in 2026, and a two-story home runs $450 to $950 before sales tax. Add a few hundred dollars for a downhill elevation that needs ladder work or extension equipment.

Can moss be pressure washed off a roof?

No, and attempting it strips the protective granules from asphalt shingles and voids most manufacturer warranties. The correct approach is a low-pressure treatment at $450 to $1,200 that kills the moss and lets weather carry it off over the following weeks.

When is the best time of year to pressure wash in Seattle?

July through September is the reliable window for house and concrete washing because surfaces dry and crews can schedule around the weather. Roof moss treatment works better in early fall, when months of rain follow the application and do the removal.

Do I pay sales tax on pressure washing in Washington?

Yes, cleaning services are taxable retail services here, and the Seattle combined rate runs a little over ten percent. Confirm whether a quote includes it before comparing two bids side by side.

How often should a Seattle home be washed?

Once a year is the standard rhythm for siding, and flat concrete can often stretch to eighteen months. Homes shaded by conifers or sitting on the water accumulate growth faster and benefit from a shorter cycle.