Pressure washing in Bellingham, WA

What a house wash costs in Bellingham

A full house wash in Bellingham runs $385 to $825. The starting rate is $0.30 per square foot, and most homes take half a day to a full day.

That covers siding, trim, soffits, the outside faces of the gutters, and the entry. Roofs, driveways, patios, and fences get priced separately, because they are different surfaces at different pressures carrying different risks.

What pushes a wash toward the top of the band:

• How much is growing on it. A house washed every other year is a fast job. A house in Columbia sitting under a mature fir that has not been touched in eight years has real green and black growth packed into the lap shadow lines, and that needs dwell time and often a second application.
• Access. Two stories, a steep lot in South Hill, or a wall reachable only over a deck rail changes the setup and the time.
• Substrate. Cedar and painted wood get low pressure and more hand work. Vinyl and fiber cement move faster.
• Add ons. Roof, driveway, walkway, fence, and deck each add area, and each one has its own safe working pressure.

Ask for the price broken out by surface rather than by the hour.

A number with no surface list attached is a number you cannot compare against anyone else's. Current scope and timing are on the pressure washing page.

Pressure washing price bands in Bellingham, WA

Access and how much growth is on the shaded side move the number more than house size does, and roof, driveway, and fence are separate surfaces with separate pricing.

What is actually growing on your house

Bellingham averages about 36 inches of rain a year and it arrives across a long cool season. November averages 5.4 inches, December 4.9, January 4.8. August, the driest month here, averages 1.3.

Eight months of damp is a growing season for anything that lives on siding.

What actually comes off a Bellingham house, roughly in order of how much of it there is:

• Algae. The green film that shows first on north and east walls and under eaves. It holds moisture against the paint film, and it is what most people are looking at when they say the house looks dirty.
• Mildew. Black speckling, heaviest in shade and behind shrubs. It is a living organism with roots into the coating, which is why rinsing it off does not end it.
• Moss. Real moss along north facing roof edges, in gutter lines, on the north walls of houses under a fir canopy, and in the gaps of decks and walkways.
• Chalk. Powdery pigment on paint that has weathered past its service life. Rub a wall with your palm. If your hand comes back colored, that coating is chalking, and the chalk has to come off before new paint will bond to anything.
• Salt film. On the windward walls of homes in Edgemoor and Fairhaven that face Bellingham Bay.
• Pollen and road grime. Seasonal, and the easiest thing on this list to remove.

The gap between removing what you can see and killing what is there is the whole argument for using a detergent instead of raw pressure. Algae and mildew that get blasted off but never killed are back on the same wall by the following March.

Pressure, soft washing, and the PSI that ruins things

Most residential house washing should not be high pressure at all. Soft washing runs at roughly 500 to 1,000 psi and leans on the cleaning solution, usually sodium hypochlorite in the 2.5 to 6 percent range with a surfactant, to kill growth while the water carries it away. It uses about a third of the water that blasting does.

Safe working pressures by surface, worth knowing before you rent anything:

• Wood and cedar siding. Around 800 psi at the very top, and lower is better. Past that you carve the soft spring wood out of the board and leave permanent striping.
• Vinyl siding. Roughly 1,000 psi maximum, always angled downward. Pressure driven up under a lap course pushes water behind the siding, and then you have mold inside the wall instead of algae outside it.
• Fiber cement. Soft wash. The board itself takes pressure, but the caulk joints and the factory finish do not.
• Asphalt shingle roofs. 500 to 800 psi at the absolute top, and realistically it should be a chemical soft wash with almost no pressure at all. High pressure strips the mineral granules off the shingle and voids most manufacturer warranties.
• Unsealed concrete. The one surface that genuinely takes 3,000 to 4,000 psi, which is why driveways get cleaned with a rotary surface cleaner rather than a wand.

The tip matters as much as the number on the machine. A 0 degree pencil tip at 1,500 psi does more damage than a 40 degree fan at 3,000. If a bidder talks about psi without mentioning tips, dwell time, solution strength, and rinse distance, what they are describing is a rented machine.

Distance is the other control nobody mentions. Pressure at the tip and pressure at the wall are different numbers, and backing the wand off from six inches to eighteen cuts what actually lands on the siding by a large margin. That is why an experienced hand can clean cedar with the same machine that would wreck it in someone else's grip.

Hot water is worth asking about on greasy surfaces like a garage apron or a restaurant back door. On siding it adds very little, because the growth comes off through chemistry and dwell time rather than heat.

Where the wash water is allowed to go

Almost nobody asks about this, and in Bellingham there is an actual rule attached to it.

Bellingham Municipal Code chapter 15.42 prohibits the discharge of anything other than rain into the storm drain system, and pressure wash wastewater is named directly. The city's direction is that wash water goes to the sanitary sewer, or soaks into a planted area as long as it does not saturate the ground and run off.

There is a second layer on older buildings. PCBs were used in some paints from roughly 1950 to 1979, and the city's guidance is that wastewater from buildings suspected of carrying PCB paint cannot enter a storm drain at all and may have to be handled as hazardous waste. That is more of a commercial and institutional issue than a bungalow issue, but it is real on older structures.

On a residential wash it comes down to four things:

1. The nearest storm inlet gets blocked or bermed before water starts moving.
2. Rinse water is directed onto lawn or beds where the ground can absorb it.
3. Detergents get chosen for what happens after the rinse. Bellingham Painting Co. uses eco-safe detergents for exactly that reason.
4. Plants are pre-wetted before any solution goes on and rinsed again afterward, which dilutes whatever lands on them.

If your lot drains toward a street inlet, ask how that gets handled before the crew starts. On a Lake Whatcom property in Silver Beach or Sudden Valley, ask twice. That lake is the drinking water supply for Bellingham, and the runoff rules around it exist for a reason.

Pre-1978 houses and washing old paint

Seventeen percent of Bellingham's housing units were built in 1939 or earlier, and 42.8 percent before 1980. On plenty of those houses the paint under the current coat contains lead.

Washing on its own is usually not a lead disturbance in the regulatory sense, because you are taking off dirt and growth rather than paint. It crosses the line the moment the pressure starts removing paint. The EPA Renovation, Repair and Painting rule applies to contractors working on pre-1978 housing once the job disturbs more than 20 square feet of exterior paint, and it requires the firm to hold EPA Lead-Safe certification. Bellingham Painting Co. is an EPA Lead-Safe certified firm.

What that changes at your house:

• Where paint is loose or failing, pressure comes down and the work shifts to detergent and hand tools instead of trying to blast the wall clean.
• The ground under the work area gets covered so chips can be collected rather than washed into the soil around the foundation.
• Chips get picked up when the crew packs up rather than raked into the beds.

If you have a 1920s house in the Lettered Streets with paint curling off the south wall, the honest answer is that washing is the wrong first move. That wall needs scraping and priming, and the wash belongs inside a repaint rather than sold to you as a standalone service.

Anyone offering to pressure wash the peeling paint off an old house is offering to spread lead dust around your yard, and it is worth knowing that before you say yes to the low bid.

Washing before a repaint and the 48 hour rule

Every exterior repaint starts with a wash, and that wash has two jobs. It removes growth so the mildewcide in the new coating is not fighting a live colony from day one, and it removes chalk so the paint has something solid to grip.

Then the house has to dry.

Wood siding wants 48 hours of dry weather between washing and the first coat, and longer on a north wall or under a deep overhang. Fiber cement and vinyl come back faster because they do not absorb water the same way. The way to settle the question is a moisture meter on the siding rather than a look and a guess.

Dew makes this harder than the forecast suggests. Bellingham nights in July and August average about 54 degrees F, and by September a clear night drops the surface below the dew point and puts water back on siding that was dry at six in the evening. A crew that schedules a wash for Thursday and a first coat for Friday morning in September has not left enough room.

Coating a surface that is still wet under the film causes blistering and adhesion failure, and it tends to show up in the first wet season, which here starts in October. That is why a pre-paint wash appears as its own line on a bid instead of getting folded into day one of painting.

If you are booking an exterior repaint, the wash normally sits inside that contract. As a standalone service in the years between paint jobs, it is what keeps growth from getting a foothold in the first place.

How a half day to a full day runs

Most Bellingham houses are a half day. A large two story with the roof, driveway, and fence added becomes a full day.

Setup. Windows and doors checked closed, exterior outlets and light fixtures covered, the storm inlet protected, and every plant within reach soaked with plain water first so it cannot take up solution.

Apply. Solution goes on from the bottom up, which stops it running down dry siding and streaking. It sits for whatever dwell time the product calls for, usually a few minutes, and gets kept wet the entire time rather than allowed to dry on the wall.

Rinse. Top down, at whatever pressure the surface tolerates, with water directed away from the storm drain. Under the eaves and behind the downspouts is where growth hides, so those get worked deliberately instead of passed over.

Detail and check. Entry door, porch ceiling, light fixtures, and a walk around with you. Plants take a second rinse before anyone packs up.

What a working crew does that a rented machine cannot is keep solution off hot dry surfaces and work one wall at a time so nothing dries partway through. The wand also stops a foot further back on cedar than it does on vinyl, and that judgement is most of the skill in this trade.

Half a day sounds quick. Most of it is setup and dwell time, and the rinsing itself is the fastest part of the job.

What goes wrong and what the fix costs

Water driven behind the siding. This is the expensive one. Pressure aimed upward under a lap course pushes water into the wall cavity, where it feeds mold in the sheathing and the insulation. You will not see it for a year. The repair is opening the wall.

Furring and striping on cedar. Too much pressure, held too close, on soft wood. It is permanent. The only correction is sanding the boards, and across a whole elevation that is a real bill.

Granule loss on the roof. High pressure on asphalt shingles strips the mineral surface that protects the asphalt underneath, shortens the roof's remaining life, and voids most warranties. Roofs get soft washed or they get left alone.

Etched or lap marked concrete. A wand instead of a rotary surface cleaner leaves visible stripes across a driveway. Cosmetic only, and permanent.

Dead plants. Solution landing on plants that were never pre-wetted or rinsed. Rhododendrons and ferns, which sit in half the yards in this town, are among the more sensitive things you can splash.

Growth back inside six months. Pressure applied with no cleaner that kills the organism. The wall looked good in July and is green again by March.

There is also the quiet one that nobody bills for. Washing a house that already has failing paint pulls more of it loose, and now you are looking at a repaint you were planning to defer two more years. That is worth a conversation before the wash rather than after, because on a house that far along the smart order is scrape, prime, paint, and the wash becomes the first step of that job instead of a separate one.

Set against a $385 to $825 wash, every one of those repairs costs more than the job itself did. That is the practical case for hiring the wash out rather than renting a machine with one tip and finding out which of these you get.

Renting a machine, and how often to do this

A consumer pressure washer from a rental counter or a hardware store is a legitimate tool for concrete and patio furniture. It is a poor tool for siding, mostly because of what does not come in the box. You get a set of tips, no chemical injector worth using, and no way to soft wash, which leaves the only variable you control being how hard you hit the wall.

If you are going to do it anyway:

1. Use the widest fan tip you have, usually 40 degrees, and stay at least 18 inches off wood siding.
2. Buy a house wash detergent carrying a mildewcide rather than using dish soap. Killing the growth is the entire point.
3. Apply bottom up, rinse top down, and keep the wall wet the whole time.
4. Wet the plants before and after, and never aim upward under a lap course.
5. Stay off the roof entirely.

How often: most Bellingham houses want a wash every 1 to 2 years, and the shaded north side more often than the sunny side. A house under a fir canopy in Silver Beach or on a north slope in Columbia is an annual job. An open lot out toward Ferndale or Lynden can stretch to three years.

Washing on that cadence is the cheapest maintenance available on a painted exterior, because algae that never gets a foothold never holds water against the paint film. It is also the difference between a repaint reaching the far end of its service life instead of the near end. If you are having a deck stained this summer, get the house and the deck washed in the same visit.