Concrete is one of the most forgiving surfaces to pressure wash — and one of the easiest to leave with permanent stripes if you rush it. Whether you're tackling a patio, walkway, or driveway, the key is consistent technique and the right approach for the stains you're dealing with. Here's how the pros do it.
1. Clear and sweep first
Move furniture, planters, and anything loose off the surface. Sweep away leaves and debris. A quick pre-rinse keeps dirt from being blasted into nearby siding and windows.
2. Pre-treat stains
Oil, rust, and organic stains (algae, mildew) usually need a pre-treatment to break down before you wash. Plain high pressure alone often just polishes the stain into the surface. Pre-treating and letting it dwell does most of the real work.
3. Use the right tip and keep it moving
A 25-degree tip is a safe starting point for concrete; a surface cleaner attachment gives the most even result and avoids stripes. Keep the wand moving in steady, overlapping passes and hold a consistent distance from the surface. The most common DIY mistake is pausing or varying distance, which etches visible lines into the concrete that don't come out.
4. Rinse toward the drainage
Work in sections, rinsing dirty water toward the street or drainage so you're not pushing grime back over clean concrete. Finish with a full rinse so no cleaning solution dries on the surface.
When to call a professional
Some jobs are worth handing off. Consider a pro if you're dealing with:
- Heavy oil or grease (gas stations, garages, restaurant patios) that needs hot-water washing.
- Large driveways or commercial lots where even results matter and a surface cleaner is essential.
- Delicate adjacent surfaces — stucco, painted siding, or wood — where overspray can cause damage.
- Stubborn rust, paint, or stains that resist DIY treatment.
If you'd rather skip the rental and the risk, we clean concrete patios, walkways, and driveways throughout San Jose and the Bay Area — including hot-water washing for the stains cold water can't touch. Reach out for a free quote.