Stucco is a durable exterior finish, but its textured surface collects dirt, dust, pollen, mildew, and algae over time. In Austin, where humidity spikes during summer and fall, green or black staining on north-facing stucco walls is especially common. Regular cleaning keeps your stucco looking good and helps you spot early signs of damage before they become expensive repairs.
Can You Pressure Wash Stucco?
Yes, but with caution. Pressure washing is the most effective way to clean stucco, but too much pressure will damage the finish, blast out mortar, and force water into the wall cavity.
**Safe pressure settings:** - Stay at or below **1,500 PSI** - Use a **25-degree or 40-degree nozzle** — never a zero-degree (red) tip - Maintain **18 to 24 inches** between the nozzle and the stucco surface - Spray at a **downward angle** to prevent driving water up behind the stucco
Step-by-Step Cleaning Process
**1. Inspect and repair first.** Before any water touches the wall, check for cracks, chips, or loose stucco. Water forced into damaged areas can cause serious problems behind the wall. Patch any cracks with masonry caulk and let it cure for at least a week before cleaning. If you are not sure whether cracks are a concern, get them assessed first.
**2. Pre-rinse the wall.** Start with a gentle rinse to remove loose dirt and debris. Work from top to bottom.
**3. Apply a cleaning solution.** Use a mild, masonry-safe detergent. For mildew and algae, a solution of one part white vinegar to five parts water works well. For heavier biological growth, a masonry-specific cleaner or diluted oxygen bleach (sodium percarbonate) is effective. Avoid chlorine bleach — it can discolor stucco and harm nearby plants.
Apply the solution with a pump sprayer or low-pressure nozzle and let it sit for 10 to 15 minutes without drying.
**4. Wash the wall.** Using 1,500 PSI or less, wash from top to bottom in overlapping passes. Keep a consistent distance and angle. Do not hover over one spot.
**5. Rinse thoroughly.** A final rinse removes all cleaning solution residue.
**6. Let it dry completely.** Allow 24 to 48 hours of drying before painting or applying any sealant. Stucco is porous and absorbs water deeply — it takes longer to dry than you might expect.
Cleaning Without a Pressure Washer
If you do not have a pressure washer, you can clean stucco with a garden hose, a stiff-bristled brush (not wire — use nylon or natural fiber), and a masonry cleaner. This method takes more effort but is gentler on the stucco and appropriate for older or more delicate finishes.
Scrub in circular motions, working in small sections from bottom to top to prevent streaking. Rinse from top to bottom.
How Often to Clean Stucco
In Austin, plan on cleaning your stucco exterior once or twice a year. Spring is a good time to remove winter grime and pollen buildup. A second cleaning in early fall addresses mildew growth from the humid summer months. Regular cleaning is a key part of stucco maintenance that extends the life of your finish.
When to Call a Professional
Hire a professional cleaning service if your home is taller than one story, if you have extensive mildew or algae coverage, or if the stucco has existing damage that makes pressure washing risky. Professional soft-washing services use lower pressure with specialized cleaning solutions that are effective and safe for stucco.
If cleaning reveals damage you did not notice before — cracks, soft spots, or staining from behind the wall — contact a stucco repair contractor before continuing. Cleaning can also be a good time to evaluate whether it is time to paint your stucco.
Questions About Your Stucco?
Star Stucco of Austin helps homeowners across Travis County maintain and repair stucco exteriors. If cleaning has revealed damage or you need professional stucco repair, contact us for a free assessment or call (512) 706-9699.
Frequently Asked Questions
Can you pressure wash stucco?
Yes, but keep the pressure at 1,500 PSI or below and use a 25-degree or wider nozzle. Maintain 18 to 24 inches of distance and spray at a downward angle. Too much pressure damages stucco and forces water behind the wall.
What is the best cleaner for stucco walls?
A mild masonry-safe detergent works for general cleaning. For mildew and algae, use one part white vinegar to five parts water or a diluted oxygen bleach solution. Avoid chlorine bleach, which can discolor stucco.
How often should you clean stucco?
Clean your stucco exterior once or twice a year. In Austin, spring cleaning removes pollen and winter grime, and a fall cleaning addresses mildew from the humid summer months.