Integrity Pro Washers Team
Professional pressure washing and soft washing specialists serving San Diego County.
Last updated: 2026-04-30
What We Found Pressure Washing Kensington Driveways
We pressure washed 18 driveways in Kensington between February and April 2026. Most of them shared the same problem: black algae on the north-facing slabs, especially the ones shaded by the mature pepper and jacaranda trees along Marlborough Drive and Adams Avenue. Hot water at 3,000 PSI with a post-treatment kills it. Cold water alone does not.
Last updated: April 2026
Kensington is one of the older neighborhoods in San Diego. A lot of the driveways went in between 1925 and 1940, and that concrete is porous, soft, and full of micro-cracks where algae loves to root. Run a 4,000 PSI turbo nozzle on a slab like that and you'll cut grooves into it.
The North-Facing Problem
Of the 18 driveways we cleaned this spring, 14 had visible black streaking on the north or northwest sections. Kensington's tree canopy holds moisture against the concrete almost year-round. The shade keeps the slab damp, the moisture feeds gloeocapsa magma, and you end up with what most homeowners call "the dirty side."
Pressure alone doesn't fix it. The algae roots into the pores. We pre-treat with sodium hypochlorite at around 1 percent, let it dwell 8 to 12 minutes, then surface-clean at 195 degrees and 3,000 PSI through a 21-inch hood. After the rinse we apply a lower-strength post-treatment to slow the regrowth. Without that step the streaks come back inside 6 months.
How Much Did These Jobs Cost?
Kensington driveways are mostly two-car, 400 to 600 square feet. Pricing this spring ran from $185 to $295 depending on access, slope, and how many gum spots and oil stains needed spot treatment. A few of the larger Marlborough Drive properties with extended driveways, walkways, and front patios came in at $450 to $625 for the full package.
What Surprised Us
Three things stood out across these 18 jobs.
- The 1920s concrete cleaned up better than we expected. Soft, yes, but it took the wash without scarring as long as we held the surface cleaner moving and never used a zero-degree tip.
- Sprinkler overspray from front lawns was responsible for almost every rust streak we removed. Iron in city water plus exposed rebar in the slab equals orange.
- Two driveways had old paint stripper residue that looked like algae but wasn't. We had to switch to an alkaline degreaser to lift it.
Spring Is the Right Window in Kensington
February through May is when we book Kensington heaviest. The winter rains have washed grit into the algae, the slabs dried out, and the homeowners are entertaining again before summer. Wait until July and you're competing with everyone else who finally noticed.
If your home is in Kensington, Talmadge, Normal Heights, or University Heights and the driveway is starting to look like two different colors, it's the algae. Not stained concrete.
The Technique That Actually Works
This is the order of operations we ran on every Kensington driveway this spring:
- Pre-rinse at low pressure to clear loose debris.
- Apply sodium hypochlorite mix at roughly 1 percent strength. Dwell 8 to 12 minutes.
- Surface clean with 195-degree water at 3,000 PSI through a 21-inch hood. Keep the wand moving.
- Detail edges, expansion joints, and corners with a 25-degree tip.
- Rinse the entire slab into the street side, not the lawn.
- Apply post-treatment to slow algae regrowth.
That's it. No magic chemistry. No 5,000 PSI. Just the right pressure, the right water temperature, and the right dwell time.
Want Yours Done?
We work Kensington every week of the year. See our Kensington service page for what we cover, or send a few photos through our contact form for a real quote. If we cleaned your driveway in Kensington, please leave us a Google review and mention the street. That's how the next neighbor finds us.
Related reading: how often you should pressure wash a driveway in San Diego, why North Park driveways grow algae, how pressure washing can damage concrete.