Why Florida stucco grows mildew so quickly
I look first at how the wall dries. Florida humidity, overhanging branches, and shaded side yards can keep a textured exterior damp. Stucco’s recesses collect deposits, and porous areas can absorb moisture. A sheltered wall may need attention before the sunny front elevation.
Green film and dark specks deserve inspection, but not every mark is mildew. Irrigation rust, dirt, and chalking paint need different decisions. I would rather identify a stain than keep increasing chemical strength because the first pass did not remove it.
Check sprinklers and vegetation too. Cleaning removes the current buildup; correcting repeated wetting and improving clearance helps address the conditions behind it.
Know the wall system before choosing a cleaner
Conventional cement stucco, painted stucco, and EIFS can look similar from the driveway. Their construction and finish instructions differ. I ask about the builder, previous coatings, repairs, and leaks before treating an unfamiliar wall.
Dryvit’s cleaning and recoating guidance recommends gentle cleaning for its textured acrylic finishes and warns that aggressive washing can abrade them and affect warranty coverage. That is product-specific guidance, not proof that every builder warranty automatically becomes void. Use the actual wall-system and paint instructions.
A careful soft wash, step by step
- Inspect and document. Photograph cracks, peeling areas, loose finish, and stains around openings. Agree on what cleaning can reasonably improve. Resolve water-entry concerns before adding water.
- Prepare the surroundings. Move furniture and pet bowls. Protect sensitive fixtures, close windows, and plan where runoff will go. Pre-wet nearby landscaping and use temporary shielding where needed; do not leave plants cooking under plastic.
- Test the treatment. Choose a cleaner permitted for the finish. Where sodium hypochlorite is allowed, dilute it according to the applicable instructions. Test an inconspicuous area and inspect the dried result before treating the elevation.
- Apply gently. Work in manageable sections using low-pressure equipment. Follow the cleaner’s application direction and any pre-wetting instructions. Keep spray away from gaps, vents, and electrical components.
- Allow controlled dwell. Let the treatment work for its specified contact time. Watch sun, heat, and wind. Avoid letting cleaner dry on the wall; more concentration is not a substitute for proper contact time.
- Rinse and review. Rinse gently and thoroughly, generally from the top downward. Post-rinse affected landscaping, manage collected wash water, and check the wall after drying. Address remaining stains separately.
Existing cracks: explain the repair sequence
I want a customer to see existing cracks before cleaning starts. A photograph records their condition, but it does not establish their cause. Widening cracks, loose areas, recurring staining, or suspected leakage call for a qualified stucco or building-envelope assessment.
Never aim a jet into a crack to “clean it out.” Simple Green’s stucco guidance advises repairing cracks or openings before washing because water can enter damaged areas. An opening that admits water should not remain exposed just to finish the wash first.
For an approved cosmetic repair, preparation may involve carefully cleaning the affected area, allowing it to dry, then applying a compatible repair material and coating after curing. The repair professional should set that sequence. “Seal everything after cleaning” is not a universal instruction, and ordinary caulk is not the answer to every stucco defect.
Painted stucco needs a compatibility check
A controlled soft wash can clean sound, compatible exterior paint without intentionally stripping it. I would not promise that every painted wall is immune to color change or lifting. Existing peeling, chalking, poor adhesion, and an unknown coating all affect the decision.
Sherwin-Williams’ mildew guidance notes that repainting may be unnecessary when mildew is the only problem. Its cleaning advice does not guarantee that any bleach concentration is safe on any finish. Use the coating’s care instructions and respect curing requirements for fresh paint.
Watch the test area for changes in sheen or color. Stop if the finish releases or the surface changes. A cleaner cannot restore weathered paint to its original condition.
Ladders and two-story walls change the job
My first access question is whether the wall can be treated safely from the ground. Reaching sideways from a ladder while handling a wet hose creates an avoidable problem. Spray drift also makes second-story work harder to control around windows and neighboring property.
A tall wall may need suitable extension equipment or professionally planned access. Do not stand on a slippery roof to reach a patch of mildew. If safe access or chemical control is uncertain, the sensible DIY limit has already been reached.
Plan maintenance around the actual wall
I use every one to two years as a planning window for a fuller stucco wash, with earlier inspection of persistently shaded areas. Follow any more frequent product-care schedule. A light, localized clean may be enough between larger visits.
Safe Touch’s house-washing service starts with choosing an approach for the surface. Discuss repairs, paint condition, and access before agreeing on the scope.