Black Streaks on Your Roof? A Brevard County Roof Cleaning Guide (Melbourne, Rockledge, Viera)
Updated November 13, 2026
Drive through Melbourne, Rockledge or Viera and you will see it on almost every street: roofs with dark lines running down from the ridge, heaviest on the shaded side. Homeowners usually ask three things. What is it? Is it hurting my roof? Can I just pressure wash it off? This guide answers all three, explains how soft wash roof cleaning works on each type of roof, and lists what to ask before you hire anyone to get on your roof.
What are the black streaks on my roof?
They are mostly a roof algae called Gloeocapsa magma, a blue-green algae that spreads in heat, shade and humidity. It is not dirt, soot or a sign of a leak.
On asphalt shingles, the algae feeds on the limestone filler in the shingle. As the colony grows it darkens to shield itself from the sun, and rain carries it downhill, which is why the streaks run in lines from the ridge. On tile roofs it settles into the porous surface of the tile. North-facing slopes and roofs under oak cover stay damp the longest, so they streak first.
You may also see:
- Lichen: crusty gray-green or pale spots, most often on tile and in shaded valleys
- Moss: green growth in damp, shaded spots and along tile edges
- Mildew and dirt: a dull gray film, mostly on the lower roof and around the gutters
Do black streaks damage a roof?
Early on, the streaks are mostly a looks problem, but the growth does not stay put. Algae, lichen and moss hold moisture against the roof surface, and lichen anchors itself into shingles and tile as it spreads.
Streaks also make a well-kept home look neglected, which matters when you are selling or when your HOA sends a notice about roof stains. Check your roof's warranty terms before any cleaning. If the roof is still under warranty, ask the manufacturer or your installer which cleaning methods it allows.
Should you pressure wash a roof?
No. High pressure can strip the granules that protect asphalt shingles, crack or erode tile, and drive water under the roofing. It also leaves the algae's roots behind, so the streaks come back.
Pressure has its place on concrete driveways and pavers. Roofs, stucco, painted siding and screens need a low-pressure soft wash. Our guide to soft washing vs. pressure washing explains which surfaces need which method.
How does soft wash roof cleaning work?
A soft wash cleans the roof with a cleaning solution instead of force. Here is how Jacobs Pressure Cleaning does it on a Brevard roof:
- Look first. We check the roof material, the downspouts and the plants, pool and screens below before anything is mixed.
- Protect the landscaping. On every applicable job, we pre-wet landscaping, control overspray, and rinse afterward.
- Apply the solution. A cleaning solution made for roof algae goes on at low pressure across the stained areas.
- Let it work. The solution needs dwell time to treat algae, lichen and moss at the root.
- Rinse gently. A low-pressure rinse carries the growth off the roof.
- Rinse the plants. Landscaping and walkways below get a final rinse.
You can see this process on a real job in our Viera tile roof project. The full service is on our soft wash roof cleaning page.
Tile, shingle and metal roofs: what is different?
All three get a low-pressure soft wash. What grows on them, and what to avoid, is different.
| Roof type | What usually grows | What to avoid | How it gets cleaned |
|---|---|---|---|
| Asphalt shingle | Black algae streaks, some moss | High pressure, which strips the granules | Soft wash at low pressure |
| Concrete or clay tile | Black algae, lichen and mildew in the porous surface | High pressure and careless footing, which can crack tile | Soft wash at low pressure |
| Metal | Algae film, mildew and dirt, often on shaded panels | High pressure at seams and fasteners | Soft wash at low pressure |
Brevard has all three. Our Viera project was a tile roof on an estate home with heavy black algae streaking.
How long does a clean roof stay clean in Brevard County?
Most roofs remain clean for 3–5 years, depending on tree cover, weather, and humidity. Shade, tree cover and humidity decide where in that range your roof lands.
Big oaks along the river in Rockledge and the older streets of Melbourne keep roofs shaded and damp, and those roofs streak sooner. Trimming branches back from the roof lets it dry faster after rain. Rinsing a roof with water alone does not reset the clock, because the algae survives underneath.
Can I clean my roof myself?
You can, but most homeowners should not. It means working on a sloped roof from a ladder, handling roof cleaning chemicals above your plants and pool, and mixing a solution strong enough to treat algae without harming what is below. Never put a pressure washer on a roof.
If you hire it out, ask four questions first:
- Do you soft wash roofs, or use pressure?
- How will you protect my plants, pool and screen enclosure?
- Are you licensed and insured, and can I see the certificate?
- Will I get a written quote?
Jacobs Pressure Cleaning is fully licensed and insured, and a certificate of insurance is available upon request.
Who does roof cleaning in Brevard County?
Jacobs Pressure Cleaning soft washes tile, shingle and metal roofs across Brevard County from its home base in Rockledge. The company has served Brevard since 2009 and is rated 5.0 stars on Google. Veteran-owned, fully licensed and insured, PWNA certified, a UAMCC member, a Thumbtack Top Pro, and a nine-time Angi Super Service Award winner.
We clean roofs in Rockledge, Melbourne, Viera, Palm Bay, Cocoa, Merritt Island, Suntree and Titusville, plus nearby communities. Read about roof cleaning in Rockledge, our home base. Same-week scheduling is typically available in priority service areas.
How much does roof cleaning cost in Brevard County?
It depends on the roof's size, pitch, material, how much growth is on it and how easy it is to reach. Jacobs Pressure Cleaning gives a written quote based on your actual roof, not a flat number over the phone. Our Brevard County cost guide explains the quote factors that move the number. The online quote tool is available at any time, and a member of our team responds within 24 hours.
Seeing black streaks on your roof? Get an instant quote online or call (321) 610-4270.
