For tile and shingle roofs in Miami and across South Florida, soft washing — not pressure washing — is the correct way to clean a roof, and you should expect to pay roughly $399 to $900 for a typical single-family home. High pressure is faster and looks cheaper, but on a Florida roof it blasts off protective granules, lifts tiles and voids warranties — which is why nearly every shingle and tile manufacturer specifies a low-pressure soft wash instead.
Here’s exactly how the two methods differ, what roof cleaning actually costs in South Florida, and how to get rid of those black streaks for good.
Should you pressure wash a roof in Florida?
No. A pressure washer puts out 2,000–4,000 PSI — enough to strip the asphalt granules that protect shingles from UV, and enough to crack or shift clay and concrete tile. Once the granules are gone, the roof ages fast and you can be looking at a replacement years early. Most roofing manufacturers will deny a warranty claim if the roof was cleaned with high pressure.
It also doesn’t actually solve the problem. High-pressure water blasts off the visible top layer of algae while the colony stays rooted in the surface — so the black streaks come back in months, not years.
What is soft washing?
Soft washing combines low-pressure water (around 60 PSI — about the force of a garden hose) with a calibrated cleaning solution. The chemistry does the cleaning, not the pressure. It:
- Kills algae, mold and mildew at the root, so it stays gone far longer
- Leaves protective granules and tile finish intact
- Is the method recommended by shingle and tile manufacturers
- Lasts roughly 4–6× as long as a pressure-washed roof
Soft wash vs. pressure washing, side by side
Soft washing (recommended):
- Pressure: ~60 PSI, safe for every roof type
- Kills algae at the root — results last 18 months to 5 years
- Manufacturer-approved; protects your warranty
- Slightly higher upfront, far cheaper over the life of the roof
Pressure washing (avoid on roofs):
- Pressure: 2,000–4,000 PSI
- Removes only the visible layer — streaks return in months
- Strips granules, cracks tile, often voids the warranty
- Cheaper today, expensive when the roof fails early
How much does roof cleaning cost in South Florida?
For a standard single-family home, professional roof soft washing in South Florida typically runs $399 to $900, or about $0.30–$0.75 per square foot. What moves the price:
- Roof size and pitch — more square footage and steeper, harder-to-access roofs cost more
- Material — tile, shingle and metal each take a slightly different chemistry and approach
- Algae severity — a roof that hasn’t been cleaned in years takes more product and time
- Add-on treatment — an optional preventative biocide (from $0.18/sq ft) that extends results to ~5 years
At 4 Pro Wash, every estimate is locked in writing within 24 hours before any work begins — no surprises on the invoice.
Why is my roof covered in black streaks?
Those streaks aren’t dirt — they’re Gloeocapsa magma, a blue-green algae that eats the limestone filler in asphalt shingles and stains clay and concrete tile. Its spores travel on wind and rain and re-seed from neighboring roofs. South Florida’s heat, humidity and salt air make it one of the most aggressive algae climates in the United States, so a roof that’s simply blasted clean will re-streak within 18–24 months. The only way to keep it off long-term is to kill the colony at the root and leave behind a residual treatment.
How often should you clean a roof in South Florida?
- With a standard soft wash: every 18–24 months
- With a 5-year no-algae treatment: every five years — the residual biocide stops spores from re-seeding
What to look for in a roof cleaning company
Roofs are high-stakes and high up. Before you hire, confirm the company:
- Uses soft washing, not high pressure, on the roof
- Is licensed and insured (we carry $2M general liability — important if anyone is working at height on your property)
- Offers a written guarantee on the result
- Will put the price in writing before starting
4 Pro Wash is a licensed, insured, bilingual crew serving Miami-Dade, Broward and Palm Beach. Our roof soft washing service is backed by a 5-year no-algae guarantee, and our optional roof treatment keeps the colony from coming back. Want a number for your roof? It takes about 60 seconds to request a free, same-day quote.
