Parking Lot Pressure Washing
In South Portland, OR

Commercial Parking Lot Pressure Washing

A commercial lot collects whatever the property throws at it. Tire rubber at the entries, cart tracks near the doors, spills in front of the tenant spaces, and drips under the loading area. Pressure washing takes that off the pavement so the lot reads as maintained instead of tired. We clean lots, sidewalks and walkways, entry aprons, dumpster pads, and parking structures for retail centers, office parks, medical buildings, schools, and industrial properties across Clackamas, Multnomah, and Washington counties — Tigard, Tualatin, Lake Oswego, West Linn, Beaverton, and Milwaukie included, and the rest of the south metro besides.

Every job runs the same five steps:

1. Survey — we walk the lot with you, identify what is on the pavement, and note the drains, the slope, and anything that needs protecting.
2. Pre-treat organic growth — moss and algae get a pre-treatment and time to work before any water hits them.
3. Wash — commercial equipment sized to the surface, with the pressure set for the pavement, not cranked to maximum.
4. Rinse and contain — washwater is contained and handled responsibly, not chased into the nearest open drain.
5. Inspect — a second walk-through, so you sign off on the clean lot instead of on a promise.

Moss, Algae, and Organic Growth on Pacific Northwest Lots

This is the part a national cleaning franchise never gets right here. Moss on asphalt is not a housekeeping problem; it is a climate outcome, and the climate is measurable. In the 1991–2020 climate normals published by NOAA’s National Centers for Environmental Information for Portland International Airport, roughly 89 percent of the year’s 36.9 inches of rain falls between October and May. November and December alone bring 11.22 inches. July and August together bring 1.05.

Eight months of that, landing on pavement that sits in the shade of a building line or a stand of firs, is exactly the condition moss and algae want. It shows up first along curb lines and against the north face of a structure, where the pavement never fully dries, then spreads into the stalls.

Two things follow. The growth is slick when wet, which is a traction problem in the months when your lot is busiest and darkest. And it holds moisture against the asphalt long after the rain stops. Pulling it off is a deep clean, not a rinse — the root mat has to be broken down before washing, or it comes back within the season. Shaded lots in this metro generally need it on a schedule, not once.

Oil, Gum, and Stain Removal

Different soils come off different ways, and blasting everything with the same wand is how you end up with a striped-looking lot and untouched stains. We match the method to what is on the pavement:

• Moss, algae, and organic film — pre-treatment with dwell time, then washing.
• Oil and grease at stalls and the loading area — degreaser applied and agitated first, so the wash lifts the soil instead of spreading it.
• Gum at entries and walkways — targeted spot treatment, piece by piece.
• Tire rubber and traffic film across drive lanes — surface-cleaner passes at consistent overlap for an even result.
• General grime on concrete walkways and structure decks — cleaning pass with pressure dialed to the substrate.

Concrete and asphalt do not take pressure the same way, so the settings change when we move from the walkway to the drive lane. Old oil that has soaked in may lighten rather than disappear. We will tell you which stains those are before we start, not after.

Washing Before Restriping

Paint bonds to pavement, not to what is sitting on top of it. Stripe over moss, dust, or an oil film and the line lifts early — usually in patches, which looks worse than a faded line did. Washing first is cheap insurance on the striping that follows.

If we are restriping your lot, we wash the areas that need it as part of sequencing the work: clean, let the pavement dry, then lay the lines. It also gives you an honest look at the surface. A clean lot shows its cracks, its low spots, and its worn markings clearly, which makes the striping plan a real plan. Call for a free estimate and we will scope what your pavement needs.