The Problem
Coral Gables patios sit under heavy tree canopy in neighborhoods like the Historic District and Old Cutler Road corridor, which means shade, leaf litter, and moisture linger on concrete and cement surfaces longer than in open, sun-exposed yards. That combination produces dark algae streaks, green mildew patches, and tannin staining from oak and ficus leaves that regular rinsing doesn't remove.
The Diagnosis
Algae & mildew
Green or black patches in shaded, damp areas — the most common issue we see on Coral Gables patios.
Tannin staining
Brown or rust-colored blotches from leaves and mulch that standard degreasers won't lift.
Efflorescence
A white, chalky residue on cement patios, caused by mineral deposits rising through the surface — common on older, unsealed cement.
Oil & rust stains
From furniture legs, grills, and planters left in one spot too long.
The Solution
Once we know what we're treating, we select the method. Algae and mildew removal uses pressure calibrated to avoid etching soft or aged cement. Tannin and rust stains need a targeted pre-treatment before pressure washing. Efflorescence requires a different chemical approach entirely, since scrubbing or pressure can spread the mineral residue rather than remove it.
Booking Process
Book and describe the staining you're seeing.
On-site diagnosis of staining type and surface condition.
Full patio cleaning with method matched to the diagnosis.
Final inspection together.
What Coral Gables, Florida Customers Say About Hank Robotics
"Outstanding service from start to finish. The team did an excellent job cleaning our high rise building and the results were impressive. They were professional, efficient, and very cost effective. I highly recommend them for high quality exterior cleaning!"
"Hanu and his team are absolutely amazing! You don't need to search any further. They get it done fast and they get it done with excellence."
"Super impressed with Hank Robotics' drone cleaning. Clean results, smart tech, and genuinely cool people to work with. Highly recommend."
Frequently Asked Questions
Why does my patio keep growing algae even after cleaning?
Shaded, damp areas under tree canopy regrow algae faster. A regular cleaning schedule keeps it from building back up.
What's the white residue on my cement patio?
That's usually efflorescence, which needs a specific cleaning approach rather than standard pressure washing.
Can tannin stains from leaves be fully removed?
Most tannin staining lifts with the right pre-treatment before pressure washing, though very old, set-in stains may lighten rather than disappear completely.
