Most Florida homeowners know that the dark black and gray streaks spreading across their roof are algae. What most don't know is that allowing that algae to remain untreated can void their shingle manufacturer warranty — and that using the wrong cleaning method to remove it can void it just as effectively.

If you have an asphalt shingle roof in Volusia, Flagler, or St. Johns County, understanding the relationship between roof algae, warranty coverage, and proper cleaning methods could save you tens of thousands of dollars.

What Your Shingle Warranty Actually Says About Algae

Major shingle manufacturers — GAF, Owens Corning, CertainTeed, and others — include specific language in their warranties about algae growth and cleaning. The key provisions most homeowners miss:

Algae-resistant shingles have conditional coverage. Many premium shingles are marketed as "algae-resistant" and carry warranty coverage for algae discoloration. But this coverage is conditional — it typically requires that the homeowner maintain the roof properly and address algae growth within a specified timeframe. Allowing algae to spread unchecked for years can be used to deny warranty claims.

Improper cleaning voids coverage. Shingle warranties explicitly prohibit high-pressure washing. The Asphalt Roofing Manufacturers Association (ARMA) — the industry body that sets standards for shingle manufacturers — specifically states that pressure washing asphalt shingles is not an approved cleaning method. A warranty claim filed after pressure washing damage will be denied.

Granule loss from any cause affects coverage. Shingle warranties cover manufacturing defects, not damage caused by improper maintenance. If an inspector determines that granule loss was caused by pressure washing rather than a manufacturing defect, the claim is denied — even if the underlying issue (such as premature granule loss) might otherwise have been covered.

How Roof Algae Damages Shingles Beyond Aesthetics

The dark streaking on your roof isn't just cosmetic. Gloeocapsa magma — the cyanobacteria responsible for the discoloration — actively damages your shingles in several ways:

Granule loss acceleration — algae growth loosens the granules embedded in asphalt shingles. As the algae spreads and the colony grows, it physically dislodges granules, accelerating the wear that shingles are designed to resist over 20–30 years.

UV protection degradation — shingle granules provide UV protection for the asphalt layer beneath them. As algae loosens granules and reduces granule density, the asphalt is exposed to more UV radiation, accelerating oxidation and brittleness.

Moisture retention — algae growth holds moisture against the shingle surface, creating conditions for mold and mildew growth in the shingle mat itself. This moisture cycling accelerates the freeze-thaw damage that affects shingles even in Florida's mild winters.

Spread to decking — in advanced cases, algae and mold growth can penetrate through damaged shingles to the roof deck, causing wood rot and structural damage that is far more expensive to repair than the roof cleaning that would have prevented it.

The Only Approved Cleaning Method: Soft Washing

ARMA's published guidelines for cleaning asphalt shingle roofs specify a single approved method: low-pressure application of a cleaning solution containing sodium hypochlorite (bleach), followed by a gentle rinse. This is what the industry calls soft washing.

The guidelines specifically state that pressure washing is not recommended because it can damage shingles by removing granules. Any cleaning method that uses high pressure on asphalt shingles is outside manufacturer guidelines — and any damage resulting from that cleaning is not covered by warranty.

When you hire a professional roof cleaning company, ask specifically whether they use soft washing or pressure washing. A company that pressure washes asphalt shingles is not following manufacturer guidelines, regardless of what they tell you about their equipment or technique.

How Often Should Florida Roofs Be Soft Washed?

In Volusia, Flagler, and St. Johns counties, most asphalt shingle roofs benefit from professional soft washing every 2–3 years. Factors that increase cleaning frequency include:

• Heavy tree coverage — shaded roofs develop algae faster
• Proximity to water — homes near the ocean, rivers, or retention ponds have higher humidity exposure
• North-facing roof sections — these stay moist longer and develop algae faster than south-facing sections
• Previous algae growth — once algae establishes on a roof, it tends to return faster after cleaning

Roof Washing Across Our Service Area

We provide professional soft wash roof cleaning throughout:

Volusia County — Daytona Beach, Port Orange, Ormond Beach, New Smyrna Beach, Edgewater, Holly Hill, South Daytona, Deltona, DeLand, Orange City

Flagler County — Palm Coast, Flagler Beach, Bunnell, Beverly Beach, Marineland

St. Johns County — St. Augustine, Ponte Vedra Beach, Nocatee, St. Johns, Fruit Cove, Julington Creek, Palm Valley, World Golf Village, Palencia

Protect Your Roof and Your Warranty

Don't let algae growth void your shingle warranty or shorten the life of your roof. A professional soft wash cleaning is one of the most cost-effective maintenance investments a Florida homeowner can make.

Call (386) 564-6700 or request a free quote online. We're licensed, insured, and follow ARMA-approved soft washing guidelines on every roof cleaning job. We've been protecting Florida roofs since 2010.