Stucco gives homes a timeless and elegant look. Its textured surface adds character and helps with insulation. But like any exterior finish, it collects dust, algae, and mildew over time. Cleaning it with a power washer can restore its beauty, but it must be done carefully. If you use too much pressure or the wrong technique, you can easily damage the stucco surface. Here’s how you can power wash stucco the right way without harming the finish.

Understand Your Stucco Type

Before you begin, identify what kind of stucco your home has.

• Traditional stucco is cement-based and more durable.
• Synthetic stucco (EIFS) has a softer finish and a layer of insulation underneath, making it more delicate.

Knowing your type helps you choose the right pressure and cleaning method. If you’re unsure, test a small section first.

Inspect and Repair Before Washing

Walk around your home and look for cracks, chips, or loose patches. Power washing can push water deep into damaged areas, leading to moisture problems later. Seal small cracks with caulk and repair larger ones before you start. Let the repairs dry fully.

Choose the Right Equipment

For stucco, you need a power washer with adjustable pressure settings. Avoid heavy-duty machines designed for concrete or brick. A pressure range between 1,200 and 1,500 PSI is generally safe for most stucco surfaces.

Use a wide spray nozzle, preferably a 25- or 40-degree tip. This spreads the water evenly and prevents it from hitting the wall too hard. A narrower nozzle can dig into the stucco and cause pitting or erosion.

Prepare the Surface

Start by wetting the area with a garden hose. This step prevents the cleaning detergent from soaking too deep into the porous surface. Cover nearby plants, windows, and outdoor lights with plastic sheeting to protect them from the detergent and high pressure.

Use the Right Cleaning Solution

Choose a mild detergent made for stucco or exterior cleaning. Avoid harsh chemicals like bleach or acidic cleaners. Mix the detergent with water as directed on the label. You can use a soap dispenser attachment on your power washer to apply it evenly.

Let the detergent sit for 5 to 10 minutes, but don’t let it dry. If it starts to dry, lightly mist it with water.

Power Wash the Right Way

Keep the nozzle at least 18 inches away from the stucco surface. Work in small sections, moving from bottom to top when applying detergent and top to bottom when rinsing. This prevents streaking.

Use gentle, sweeping motions. Never hold the spray in one spot for too long. Pay special attention to corners and edges where dirt tends to build up, but use lower pressure in those areas.

If you notice dirt that doesn’t lift easily, stop and use a soft-bristled brush to scrub it gently before rinsing again.

Rinse Thoroughly

Rinse the stucco thoroughly to remove all detergent and dirt. Work from the top down so the dirty water doesn’t run over cleaned sections. Be patient with this step; leftover soap can cause streaks or leave a film on the surface.

Allow Proper Drying

After cleaning, let the stucco dry naturally for at least 24 hours. Avoid painting or sealing until it’s completely dry. Moisture trapped underneath paint or sealant can cause bubbling or cracking later.

Common Mistakes to Avoid

• Using too much pressure
• Holding the nozzle too close
• Ignoring cracks or damage before cleaning
• Using harsh cleaners that strip the surface
• Skipping the rinse step

When to Call a Professional

If your stucco has heavy mold, deep stains, or delicate detailing, it’s safer to hire a professional. Experts know how to adjust the pressure, choose the right detergents, and prevent water from seeping behind the finish.

Conclusion

Power washing stucco is not about force, it’s about technique. By using moderate pressure, the right tools, and gentle cleaners, you can make your stucco look fresh again without damaging the finish. If you clean it once or twice a year, your home will maintain its charm and curb appeal for years to come.