How to Clean and Power Wash Your Concrete Patio

Concrete might seem indestructible, but it acts like a giant sponge. Over time, pores in the slab soak up grease, moss, and dirt, turning a once-bright patio into a dull, gray eyesore. Cleaning it isn't just about aesthetics; it is about stripping away the organic buildup that makes your outdoor space slick and slippery during the rainy months. Done well, a deep clean restores the original texture of the concrete and prepares it for a fresh coat of sealer. Avoid the temptation to use a high-pressure concentrated stream immediately, as this can etch and damage the surface. The goal is to let the chemistry do the heavy lifting before the water clears the debris away.

1. Clear the stage first. Move all furniture, grills, and planters off the patio. Use a stiff-bristled push broom to sweep away loose leaves, dirt, and cobwebs.
2. Let chemistry do the work. Mix a biodegradable concrete cleaner with water in a garden sprayer according to the manufacturer's ratios. Spray an even coat across the entire surface and let it dwell for 10 minutes without letting it dry out.
3. Attack the tough spots. Use a stiff-bristle deck brush to agitate stubborn oil spots or mildew patches. Apply extra cleaner to these specific areas while scrubbing.
4. Test before you blast. Connect your garden hose to the pressure washer and purge any air from the pump by squeezing the trigger before starting the motor. Attach a 25-degree nozzle tip, which provides a safe balance of power and coverage.
5. Keep motion constant and smooth. Hold the wand 12 inches from the surface and move in consistent, sweeping side-to-side motions. Work from the highest point of the patio toward the lowest point where drainage occurs.
6. Rinse and wait it out. Use a low-pressure spray to wash any remaining loosened dirt off the edges of the patio. Allow the concrete to air dry completely for at least 24 hours.