If you’ve stood on your driveway after a St. Petersburg summer and watched the concrete go from gray to a streaky green-black, you already know the job needs doing. Pressure washing is the fastest way to strip off the grime, algae, and oil a Gulf Coast climate bakes into the surface, and a careful homeowner can do it in a single afternoon. The steps below cover the PSI that’s safe for concrete, the sweeping technique that avoids zebra stripes, and the one local rule most online guides skip.
Why St. Pete driveways get so dirty
Florida’s climate is hard on hardscapes. UF/IFAS puts it plainly: “Florida is warm and humid,” and in that environment “algae and mildew may thrive” on exterior surfaces.[1] That’s why a St. Petersburg driveway picks up a green film of algae and mildew faster than one in a drier climate, and why a gentle spray of plain water alone won’t lift it. You need pressure, and usually a little chemistry, to get the surface actually clean.
Before you fire up the washer, one local detail matters more than the PSI. Pinellas County code prohibits pollutants from entering surface waters, the drainage system, or roads leading to storm drains.[2] Pollutants that a driveway wash can send down the curb include oil or other automotive fluids, sediment, and the detergent you apply.[2] We’ll come back to keeping the wash legal, but remember this: only rain goes down the drain.
Step 1: Clear and pre-wet the concrete
Start by sweeping or blowing loose stone, dirt, leaves, and debris off the driveway, and move cars, bikes, potted plants, and patio furniture well clear of the work area. If you’re using detergent, cover nearby plants first: the guidance is to use plastic sheets or drop cloths “to protect delicate foliage from harsh spraying or exposure to chemicals or detergents.”[3]
Once the surface is clear, wet the whole driveway down with a garden hose. A damp slab holds the cleaning solution instead of flashing it dry on contact. While you’re at it, note which end of the drive sits highest, since you’ll always work from the high point toward the street so the rinse water runs off ahead of you instead of pooling back over the concrete you just cleaned.
Step 2: Pretreat oil stains before washing
Fresh oil and grease don’t just rinse off under pressure; they need to be broken down first. Spray a concrete-safe degreaser or driveway cleaner directly on the stains and let it sit for ten to fifteen minutes before you touch them with the washer.[4] For stubborn spots, work the product in with a stiff-bristled brush or push broom rather than reaching for a stronger nozzle.
Soap isn’t optional here, by the way. Cleaning solution isn’t always required, but if your concrete has oil stains or heavy grime, it’s worth the extra step: a driveway cleaner loosens dirt, mold, and grime so the pressure washer can actually carry it away.[5] Plain water at high pressure removes the surface layer but leaves the film that re-stains in a few weeks.
Step 3: Set the right PSI for concrete
The single most common mistake on a first driveway wash is too much pressure in one spot, which etches and pits concrete. The equipment side of the industry is blunt about it: using too much PSI can damage the surface you’re cleaning.[6] The right number depends on what’s underfoot.
| Surface | Recommended PSI | Notes |
|---|---|---|
| Concrete (standard, cured) | 2,500–3,000 PSI | Greenworks calls for at least 2,500 PSI with 2.5 GPM to cut through oil, dirt, and algae;[4] its concrete guide puts the floor at 3,000 PSI for concrete surfaces[5] |
| Older, stamped, or decorative concrete | start lower, test first | Stamped or decorative surfaces “may not handle high pressure well,” so pressure gets adjusted down for delicate or older areas[5] |
| Asphalt | lower than concrete | Asphalt is softer, so start at the low end and test a corner; it pits faster than a concrete slab[6] |
| Brick / pavers | wide fan tip, masonry-safe cleaner | The recommendation for brick is a 15° nozzle and a masonry-friendly detergent, not a narrow high-pressure jet[3] |
Cleaning power isn’t only about PSI. Flow rate (gallons per minute, or GPM) matters just as much, and a higher GPM gives you a wider cleaning path, which cuts the time you spend on the slab.[3] That’s why a 2,000 PSI machine with strong flow can out-clean a 3,000 PSI unit with weak flow: higher is not always better.[6]
Whatever number you land on, test on a patch you won’t notice before you tackle the whole driveway, adjusting pressure for delicate or older areas instead of running full tilt from the first pass.[5]
Step 4: Wash in even, overlapping passes
- Start at the higher end of the drive and work downhill in the direction the water flows.
- Hold the wand about 12 inches from the surface and work in overlapping passes.[4]
- Sweep the nozzle steadily side to side, overlapping each stroke by several inches.[4] Keep the wand moving the whole time; stopping in one place is what burns lines into concrete.
- Work in sections, especially in direct sun, so the detergent doesn’t dry before you rinse it.[4]
On nozzle choice, a 15-degree yellow tip is a solid all-purpose option for concrete and asphalt.[4] Use a low-pressure soap tip to apply detergent, then switch back to a high-pressure tip for the rinse pass.[3]
Step 5: Use a surface cleaner for big, flat areas
If your driveway is two cars wide, a surface cleaner attachment is the cheapest upgrade for better results. It connects to the wand and gives you wide, even coverage as you walk it over the concrete: no zebra stripes, no streaks, and it’s faster.[4] It’s optional, but it’s the biggest single improvement you can make on a large slab.
Step 6: Rinse, then check your work
Once you’ve applied detergent to the whole surface and let it dwell, switch to the high-pressure nozzle and rinse. Don’t let the cleaning solution dry on the concrete; that reduces its effectiveness and leaves a film you’ll chase for another pass.[5] Use the same overlapping sweep you used to apply the cleaner, then rinse everything off and assess your work, reapplying stain remover on the spots that need a second round.[4]
Step 7: Seal the driveway when it’s dry
Pressure washing opens up the surface of the concrete, which is exactly the moment to protect it. After the surface is completely dry, roll on a concrete sealer to ward off future stains; moisture trapped under sealant causes problems, so don’t rush the dry time.[5] Greenworks recommends waiting 24–48 hours after washing before sealing, and notes you can choose a penetrating sealer for invisible protection or a film-forming sealer for a slight sheen.[4] Sealing is optional, and you can skip it if you’d rather do a light maintenance wash next season, but it’s what makes the difference between a driveway that stays gray for years and one that re-greens in a few months.
How long does it take to pressure wash a driveway?
For a first-timer with a standard two-car concrete drive, budget two to four hours from setup to final rinse. The bigger variables are the size of the slab, how much staining and algae has built up, and whether you pretreat and seal. Dry time before sealing is extra, up to 24–48 hours.[4]
When to hire a pro instead
Pressure washing a driveway is a safe DIY on ordinary concrete, but some situations are worth handing off. If the slab is already cracked, spalling, or heavily etched, high pressure makes it worse (see our guide on whether pressure washing damages concrete). If you’re dealing with set-in oil stains, skip the guesswork and read our oil stain removal guide or call a pro. If you simply don’t want to spend an afternoon on your knees with a wand, what it costs to have a driveway pressure washed is less than most people expect.
Pinellas County rules: only rain down the drain
This is the step the big national guides leave out because they’re writing for every city at once. In Pinellas County, the water you spray off your driveway is regulated, not disposable. County code prohibits pollutants from entering the stormwater system or roads that lead to storm drains, and “pollutants” explicitly includes oil, automotive fluids, sediment, and chemicals.[2]
Practical version for a driveway wash:
- Never spray oil, grease, or fuel stains so they run down the curb; sop them up and pretreat first.
- Use the mildest cleaner that works, and keep heavy detergent off the grass and out of the gutter.
- Sweep clippings and debris into the trash or the lawn, never into the street.
If you’d rather not think about any of this, a local pro already manages the rinse water for you and knows the county rules cold.[2]
Frequently asked questions
How many PSI to pressure wash a driveway?
For standard cured concrete, 2,500–3,000 PSI is the sweet spot, enough to lift oil and algae without etching the slab.[4][5] Older, stamped, or decorative concrete wants less,[5] and brick and pavers call for a wide fan tip with a masonry-safe cleaner rather than a high-pressure jet.[3]
Should you use soap when pressure washing a driveway?
Yes, when there’s oil or heavy grime on the slab. Cleaning solution isn’t always required, but on a stained driveway it’s the step that lets the pressure lift dirt instead of just wetting it.[5]
What do you put on a driveway before pressure washing?
A concrete-safe degreaser or driveway cleaner on the oil and grease stains, left to sit for ten to fifteen minutes and worked in with a stiff brush.[4]
Do you need a surface cleaner to pressure wash a driveway?
No, but it’s the cheapest way to get even, stripe-free coverage on a large slab and cut the job time.[4] A wand alone works; it just requires steadier, more overlapping passes.
Can pressure washing damage a concrete driveway?
Yes, and the risk climbs with pressure and with the age of the slab: stamped or decorative surfaces may not handle high pressure well,[5] and too much PSI damages the surface being cleaned.[6] That’s why you test a hidden spot first and keep the wand moving. The full breakdown is in our guide to whether pressure washing damages concrete.
Should you seal a driveway after pressure washing?
If you want the clean to last, yes: let the concrete dry completely, then roll on a sealer,[5] and aim for the 24–48 hour window after washing.[4]
Get your driveway clean without the headache
A clean driveway is a cheap curb-appeal upgrade in St. Pete, but it’s also easy to get subtly wrong: one too-slow pass leaves a streak you can’t un-see. If you’d rather skip the rental, the nozzle math, and the rinse-water rules, we’ll handle it.
Get a free pressure washing estimate or call (727) 218-4044. We serve St. Petersburg and Pinellas County, and handle driveways, sidewalks, house exteriors, and pool decks.
Before you book, start with how much pressure washing costs in St. Petersburg, pressure washing vs. soft washing, and how often to pressure wash a house. For a deck, see how to pressure wash a wood deck; for no-equipment options, read how to clean concrete without a pressure washer.
Sources
[1] https://ask.ifas.ufl.edu/publication/HE887 — Closing Your Seasonal Home — UF/IFAS Ask IFAS
[2] https://pinellas.gov/stormwater-runoff — Stormwater Runoff — Pinellas County
[3] https://www.echo-usa.com/applications/pressure-washing-house — ECHO: Pressure Washing Your House
[4] https://www.greenworkstools.com/blogs/greenworks-blog/how-to-pressure-wash-a-driveway-greenworks — How to Pressure Wash a Driveway — Greenworks
[5] https://www.greenworkstools.com/blogs/greenworks-blog/how-to-pressure-wash-concrete-a-greenworks-guide — How to Pressure Wash Concrete — Greenworks
[6] https://www.dultmeier.com/what-psi-pressure-washer-do-i-need — Pressure Washers: What PSI Do I Need? — Dultmeier