Jacksonville, FL ยท Inspection & Protection
Roof cleaning and algae removal in Jacksonville
Updated September 2026
Those black streaks running down a Jacksonville roof are algae, not dirt, and a pressure washer is the wrong tool for them. We soft wash shingle and tile roofs with low pressure and the right solution, then help slow the streaks from coming back.
- Calls answered 24/7
- Low-pressure soft wash
- Shingle and tile roofs
Roof cleaning in Jacksonville, FL means soft washing: applying a cleaning solution at low pressure to kill the algae that causes black streaks, then rinsing gently, rather than pressure washing, which strips shingle granules and can crack tile. It suits shingle and tile roofs, protects plants below with pre-wetting and rinsing, and is often paired with a roof inspection.
Algae, not dirt
Why Jacksonville roofs streak
The dark streaks on many Florida roofs are colonies of airborne algae, commonly identified as Gloeocapsa magma, that settle on the roof, feed on the limestone filler in shingles, and spread down the slope with each rain. They grow fastest on shaded, humid slopes and hold moisture against the roof surface.
The streaks are mostly cosmetic at first, but they hide the roof's real condition and, on heavily grown roofs, keep shaded slopes damp. Cleaning removes them; it does not fix worn or damaged shingles, which is why we look at the roof while we clean it.
Roof Cleaning & Algae Removal
Soft wash shingle cleaning
Soft washing applies a cleaning solution at low pressure, lets it work on the algae, and rinses gently. It kills the growth rather than blasting at it, so the granules that protect the shingles stay where they belong. Plants and lawn below are wetted before and rinsed after, and gutters are flushed so runoff does not sit in them.
The streaks fade over the following days as the dead algae washes off in the rain, rather than vanishing the moment the crew leaves.
Typical market range for soft wash roof cleaning, 1,500 to 2,000 sq ft roof, Jacksonville: $375 to $1,200 (source). A planning figure, not a quote.
Roof Cleaning & Algae Removal
Tile roof cleaning
Concrete and clay tile hold algae and mildew in their texture and in the channels between tiles. They are cleaned the same way, with low pressure and a solution suited to tile, because high pressure can crack tiles, erode the surface of concrete tile and drive water under the tiles into the underlayment. Crews walk tile carefully and replace any tile that was already cracked.
Painted concrete tile needs a gentler solution than bare tile, so we check the finish first.
Roof Cleaning & Algae Removal
Algae prevention strips
After cleaning, zinc or copper strips installed along the ridge release small amounts of metal with every rain, which discourages algae from returning on the slopes below. They work best on the upper part of the roof and less well far down long slopes. Many newer shingles also carry algae-resistant granules that do the same job from within the shingle.
Trimming the branches that shade the roof helps as much as any strip, since algae favors the damp, shaded slopes that dry last.
Roofing in Jacksonville
Shade, humidity and Jacksonville roofs
Algae grows where roofs stay damp, and in Jacksonville that usually means shade. Researchers mapping the city's urban tree canopy put average coverage at about 42 percent, so many roofs have slopes that sit under branches for much of the day and dry slowly after rain. Those shaded slopes are where streaks appear first and return fastest, and where cleaning and trimming make the biggest difference to how the roof looks and ages.
Step by step
How a roof cleaning runs
- 1
Look at the roof first
Condition checked so cleaning does not hide damage.
- 2
Protect the grounds
Plants and lawn pre-wetted; gutters checked.
- 3
Apply at low pressure
Cleaning solution applied to the shingle or tile.
- 4
Let it work
Dwell time for the solution to kill the growth.
- 5
Rinse gently
Roof, plants and gutters rinsed.
- 6
Prevention and photos
Optional ridge strips; before and after photos.
Cost factors
What decides the cost of roof cleaning
Roof size and pitch
Larger and steeper roofs take more solution and more time.
Roof type
Tile takes more care to walk and clean than shingle.
How heavy the growth is
Thick, long-established growth may need a second application.
Prevention strips
Zinc or copper strips along the ridge are an added item.
The range above is a published Jacksonville figure for soft wash roof cleaning, not our quote.
Your options
Soft wash or pressure wash?
| Soft wash | Pressure wash | |
|---|---|---|
| How it works | Solution at low pressure kills the algae | High-pressure water blasts the surface |
| Shingles | Granules stay on | Granules stripped, shingle life shortened |
| Tile | Surface and underlayment protected | Can crack tile and force water under it |
| Results | Streaks fade as the dead algae rinses off | Looks clean at first, regrows sooner |
Asphalt shingle makers generally advise against pressure washing, and damage from it may not be covered by a shingle warranty.
Do it yourself?
Cleaning the roof yourself?
| Task | Homeowner | Roofer |
|---|---|---|
| Spotting algae streaks | Yes, from the ground | Not needed |
| Rinsing gutters and downspouts | Yes, from a ladder on a single story | Two-story edges |
| Pressure washing the roof | No; it damages shingles and tile | Soft wash instead |
| Walking a wet, treated roof | No; it is slippery | Crews with fall protection |
A wet roof coated in cleaning solution is one of the most slippery surfaces a homeowner can stand on. Keep roof cleaning jobs on the ground.
Questions we hear
Roof cleaning questions
Airborne algae, commonly Gloeocapsa magma, that feeds on the limestone filler in shingles and spreads down the slope with rain.
Soft washing at low pressure does not. Pressure washing does, by stripping the protective granules.
It depends on shade and exposure. Heavily shaded roofs streak again sooner than roofs in full sun.
Plants are wetted before and rinsed after to dilute any runoff.
Yes. Cleaning can hide or reveal damage, so we note and photograph anything we see. See roof inspection.
Related work
Other inspection and protection work
Roof Inspection
Covers annual roof checkup, pre-purchase roof inspection, post-storm inspection.
Read the detailsRoof Certification for Insurance
Covers roofs 15 years and older, remaining useful life letters, condition repairs before certification.
Read the detailsRoof Maintenance
Covers pre-hurricane season tune-up, valley and debris clearing, sealant and fastener renewal.
Learn moreGet the streaks off without hurting the roof
Call any hour. We soft wash shingle and tile roofs across Jacksonville and answer 24/7.
