How to Clean Stucco and Pressure-Wash Your South Florida Home Before Listing

Knowing how to clean stucco is one of the cheapest ways to lift a South Florida listing. Our heat, rain and shade feed mildew and algae, and those dark streaks show up in every exterior photo. A careful wash can make a tired house look kept up. But too much pressure can gouge the finish and leave you with a repair bill. This guide is for sellers in Palm Beach County and nearby. It covers a safe cleaning method, pressure limits, roof and paver work, runoff and HOA rules, and what to do when a clean wall shows cracks.

Key takeaways

• Sto Corp. advises a TSP and water mix, with bleach added only when algae or mildew is present, left on for about 15 to 20 minutes.
• For acrylic stucco finishes, Sto says to stay around 200 to 500 psi, keep the nozzle several feet back and never exceed 500 psi.
• Don't let wash water run into storm drains. Check county, city and HOA rules first.
• Cleaning often reveals hairline cracks. Fix them, or at least know about them, before a buyer's inspector does.
• Fixr lists a typical whole-house pressure wash at about $700, with most jobs between $500 and $900.

Why you should know how to clean stucco before listing

Buyers form a view of a home before they open the front door. Online, the first photo is almost always the front of the house. So green or black streaks under the eaves, gray splash marks near the ground and rust stains under the hose bib all hurt that first look.

Also, a clean exterior tells a buyer the owner kept up with maintenance. That matters in South Florida, where buyers and their inspectors look hard at water intrusion. A dirty wall can make them wonder what else was skipped.

Finally, cleaning is cheap compared with painting. If the color is sound and the wall is just dirty, a wash may be all you need.

What grows on Florida stucco

Most of what you see on a stucco wall here is biological. Sto Corp. describes algae as usually green stains and mildew as black stains that look like dirt. Both thrive on the shady, damp sides of a house and under roof overhangs. You will also see dirt splashed up from planting beds, rust from sprinklers that use well water, and dark runs where gutters overflow.

The type of stain matters. Dirt rinses off. Algae and mildew are alive, so they need a cleaner that kills them, or they come back within weeks. Rust needs its own product.

How to clean stucco step by step

The steps below follow Sto Corp.'s maintenance guide for acrylic and acrylic elastomeric finishes. Your stucco may have a different finish or paint, so read any product label and test a small area first.

Check the surface first

Walk the house before you wet anything. Look for cracks, loose patches, gaps around windows and doors, and soft or hollow spots. Water forced into an open crack can make a small problem worse. So mark any trouble spots and keep the spray away from them.

Also close windows, cover outlets and light fixtures, and protect plants. Wet the plants with plain water before and after you clean so any runoff is diluted.

Pick a cleaning solution

Sto's generic mix is 1 to 2 cups of trisodium phosphate (TSP) detergent in 1 gallon of warm water. For algae or mildew, it adds 1/2 to 1 quart of bleach. Sto notes that if there is no algae or mildew, bleach isn't needed. It also warns that without bleach, or without enough time on the wall (about 15 minutes), the growth will come back.

Wear gloves and eye protection, and never mix bleach with ammonia or other cleaners. Also check whether your HOA or city limits certain chemicals outdoors.

Soak, scrub and rinse

Apply the mix by brush or sprayer and let it soak for 15 to 20 minutes. Work from the bottom up so streaks don't form on dry wall below. Then, for heavy spots, scrub lightly with a soft to medium bristle brush. Finally, rinse the whole surface with clean water and let it dry.

Sto's list of things to avoid is short and clear. Don't use solvent cleaners like acetone or gasoline. Don't use steam or high heat. And don't use stiff or wire brushes or heavy scrubbing.

Pressure washing: how to clean stucco without damage

A pressure washer saves time, but it is also the most common way people damage stucco. Sto's guide says to keep the pressure at about 200 to 500 psi and hold the nozzle several feet from the wall. It warns that going over 500 psi can destroy the surface of the finish, and it lists high-pressure washing and sandblasting as things not to do.

So use a wide fan tip, keep the wand moving and spray at an angle, not straight on. Stay well clear of window seals, door frames, light fixtures and any crack. If you rent a machine, check its rating, since many gas units start well above 500 psi.

Soft wash vs. pressure wash

Many local crews offer a soft wash. That means a low-pressure spray of cleaner, a dwell time, then a gentle rinse. It follows the same idea as the Sto method. Fixr puts soft washing at $0.25 to $0.35 per square foot. If you hire out, ask the company how it handles stucco and what pressure it uses.

Roofs, pavers and the rest of the exterior

Once the walls are clean, the roof and driveway can look worse by contrast. Fixr's figures, updated in January 2025, put an average roof wash at $450 to $700 and a driveway at $180 to $240.

Roofs need care. Tile and shingle roofs can crack or lose granules under high pressure, and walking on tile can break it. Most sellers hire this part out. Before you do, check any roof warranty terms. And if your roof is older, our guide on replacing the roof before selling can help you decide what to spend.

Pavers, pool decks and walkways respond well to a wash. However, washing can pull sand from paver joints, so plan to re-sand. Also clean screen enclosures, gutters and the front door. The entry is where buyers wait while the agent opens the lockbox.

Runoff, chemicals and HOA rules

Wash water with bleach, detergent and dirt should not go into a storm drain. In Palm Beach County, many storm drains lead to canals, lakes and the Lake Worth Lagoon. The county code has a stormwater pollution prevention article, and many cities have their own rules. Sto's guide also says to check local rules for disposal of cleaning solution and wastewater.

In practice, block or cover nearby drains, keep runoff on the lawn or planting beds where you can, and use the least chemical that does the job. If you hire a company, ask how it handles runoff.

Next, check your HOA. Many associations set exterior maintenance standards and some may cite owners for mildew on walls or roofs. Others limit work hours or require vendor insurance. Our overview of HOA rules in Florida explains how these documents work. If you plan to repaint after cleaning, most HOAs also require color approval.

When cleaning reveals cracks

A clean wall shows every flaw. Sto notes that stucco is brittle by nature and some cracking is normal. Still, cracks that let water in can cause damage behind the wall.

Sto's guide sorts cracks by width. Hairline cracks are up to about 1/32 of an inch, and it suggests a color-matched elastomeric coating. Moderate cracks are up to about 1/8 of an inch, and those call for mesh and a base coat or a flexible crack filler. It also warns that patched areas rarely match the rest of the wall perfectly, so a full side may need a new finish coat.

Wider cracks, stair-step cracks, bulges or stains that keep coming back can point to a bigger issue. Have a pro look before you list. A pre-listing inspection can also tell you what a buyer's inspector is likely to flag, so you can fix it, price it in or disclose it.

What it costs to hire out

Fixr's January 2025 figures put a typical whole-house pressure wash at about $700, with most jobs from $500 to $900. Per square foot, it lists $0.30 to $0.80. These are national numbers. Local prices vary with house size, number of stories, how dirty the walls are and whether you add the roof, driveway and pool deck.

Get two or three quotes. Ask each company what pressure it uses on stucco, what cleaner it uses, how it protects plants and drains, and whether it carries insurance.

How to clean stucco on a budget: what to do yourself

If you are handy, you can do much of this yourself for the cost of supplies and a rented sprayer. Single-story walls are a good DIY job. Second stories, roofs and anything that needs a tall ladder are better left to a crew.

• Spot-clean the worst streaks with a garden sprayer and a soft brush.
• Rinse with a garden hose instead of a pressure washer where you can.
• Wash the front of the house first, since that is the listing photo.
• Trim plants away from the walls so they dry faster and stay clean longer.
• Fix leaky gutters and aim sprinklers away from the walls.

Then, time the wash for a week or two before listing photos. That leaves time to touch up and keeps the walls fresh for showings.

Frequently asked questions

How do you clean stucco without a pressure washer?

Use a garden sprayer or brush to apply a mild cleaner, let it sit, scrub lightly with a soft brush, and rinse with a garden hose. Sto's guide notes a garden hose works for a full wall and a brush for isolated spots.

Can bleach damage stucco?

Sto's own guide adds bleach to its mix for algae and mildew. Still, bleach can harm plants and some paints, so dilute it, test a small area and rinse well.

How often should you clean stucco in Florida?

There is no set schedule. Shady, damp walls may need a wash every year or so, while sunny walls can go longer. Clean when you see streaks, and always before listing photos.

Should I paint stucco instead of cleaning it?

Only if the paint is faded, chalky or peeling. If the color is sound, a wash is far cheaper. Clean first either way, since paint does not stick well to a dirty wall.

Will buyers notice how clean your stucco is?

Yes, mostly in photos and at the curb. Streaks make a home look neglected, and inspectors take a close look at stucco cracks and stains for signs of water.

Sources

• Sto Corp., Stucco repair and maintenance instructions
• Fixr, Cost to pressure wash a house
• Palm Beach County Code, Chapter 27, Article VII, Stormwater pollution prevention

Getting ready to sell? Book a no-obligation listing consultation and we will walk your home with you, point out the cheap fixes that matter, and skip the ones that don't. Book a listing consultation or check what your home is worth. Buying instead? Talk to a buyer's agent about homes in Boynton Beach, Royal Palm Beach or Port St. Lucie.