Typical Florida installed cost for roof soft wash (algae/stains): $400–$800 — a curated 2026 planning range, not a bid. The most accurate figure for your home comes from a verified local pro (free, below).
Black streaks on a Florida roof are almost always algae thriving in the heat and humidity — it's a cleaning issue handled with a low-pressure soft wash, not usually a sign the roof is failing.
Plan it — not an emergency.
Common causes:
• Algae growth that thrives in Florida's warm, humid climate
• Shade and tree cover keeping the roof damp longer
• Buildup over years without a cleaning
• North-facing or low-slope areas that dry slowly
• A pitch that says the streaks alone mean you need a whole new roof
• Any plan to high-pressure wash the roof to remove them
• Cleaning with water only, so the algae returns fast
• No protection for the plants and landscaping below
• No proof of insurance or a track record — Florida doesn't license this trade, so those are what protect you
Do black streaks mean my roof is bad?
Usually not on their own. The streaks are typically algae feeding on the roof surface, which is cosmetic at first and common across Florida. Be cautious with anyone using the streaks alone to sell you a full roof replacement — a soft wash removes them, and a separate inspection can judge the roof's actual condition.
How are the streaks removed safely?
With a soft wash — low pressure plus a cleaning solution that kills the algae at the root so it doesn't come right back. High-pressure blasting is the wrong approach; it strips shingle granules and can force water under them, doing real damage to remove a mostly cosmetic stain.
Roof soft wash (algae/stains): $400–$800 (typical ~$600)
Low-pressure soft wash — never high-pressure on a roof, which strips granules. Roof size and pitch drive it.
Curated Florida 2026 estimate — installed cost for a typical FL single-family home, not a bid.
Florida does NOT issue a state license for this trade (local licensing was preempted for most non-structural trades). What protects you instead: general-liability insurance, workers’ comp, and a real track record — exactly what our verification checks.
Whether a permit applies depends on scope — when in doubt, ask the county building department before work starts.
Basis: HB 735 (2021) local-license preemption.
Your request goes to a single verified Pressure Washing & Exterior Cleaning pro in your area — you stay anonymous until you tap connect, and we never sell your info.
Dirty Siding · Driveway Pressure Washing Cost · Green Algae On Driveway
Covered: Lee · Pinellas · Sarasota · Charlotte · Hillsborough · Manatee | As of 2026-08-21 | Local numbers appear only when the sample is large enough to protect privacy.