A pressure washer on full blast can permanently damage your concrete driveway

Concrete driveways have an outer layer called the cement paste — a dense, relatively smooth surface that seals the rough aggregate underneath. It's what makes newer concrete resist oil and stains better than old concrete. When a pressure washer is set too high, aimed too close, or fitted with a zero-degree nozzle, that paste layer erodes. The result looks like pitting, fine surface streaks, or exposed gray aggregate — and it's permanent because cement paste cannot be replaced once it's gone.

Ironically, damaged concrete becomes harder to keep clean, not easier. The freshly exposed aggregate is rougher and more porous than the original surface, so oil, mold, and algae now penetrate deeper and bond more readily. A driveway blasted with too much pressure often stains faster every subsequent year — the opposite of what the cleaning was supposed to accomplish.