Roof Cleaning in Naples, FL

The dark streaks are a living film, mostly algae, and the roofing industry names the organism. The Asphalt Roofing Manufacturers Association (ARMA) writes that Gloeocapsa magma “is probably the most prevalent of several algae species that contribute to discoloration.”

ARMA describes what you see: “Natural pigments produced by these algae may cause white or light-colored roofs to gradually turn dark brown or black. Discoloration may appear uniform or as streaks.” The same bulletin says where it is worst: “Algae discoloration of roofs is most widespread in the Gulf States and along the Northwest and Eastern Seaboards.” Naples is on the Gulf.

GAF's technical advisory bulletin on blue-green algae staining explains the mechanics. Blue-green algae “requires moisture and proper temperatures to grow,” dew is “the primary moisture source,” the spores travel by air from one roof to the next, and the dark color is “a protective sheath” the organism makes against ultraviolet light. GAF adds that blue-green algae “generally grows on the northern exposures of the roof since this exposure generally receives less sunlight.”

On tile, the growth sits on a film of dust

The Tile Roofing Industry Alliance (TRI Alliance) makes a point that matters in barrel-tile neighborhoods: “Mildew, algae and moss do not grow directly on tile but on the accumulation of dust and other organic materials that settle on tile. With enough cycles of heat, moisture and light, spores start to grow.” That film is what a cleaning takes off.

Algae, moss or tree droppings

ARMA separates them: “The algae discolorations should not be confused with moss or tree droppings, which typically produce only localized discoloration.”

A soft wash cleans with chemistry and time instead of force. SoftWash Systems defines it this way: “Unlike traditional pressure washing, which uses high-pressure water to blast away dirt and grime, soft washing uses a low-pressure spray and specialized cleaning solutions.” Those solutions “target organic stains, like mold, mildew, and algae, breaking them down”.

That is the method 239 Exteriors uses: a safe soft-wash cleaning that removes algae, mold and stains without damaging your roof.

What the roofing makers say about pressure

• Asphalt shingle. ARMA is absolute: “Never use a pressure washer to clean an asphalt shingle roof”, and it names the consequence in the same sentence: granule loss, and very likely premature failure of the roof system. Even friction is a problem: “Avoid scrubbing the surface, as this friction may loosen and remove granules.”
• Metal. The Metal Roofing Alliance's cleaning guide says “NEVER use a power washer,” and rules out “steel wool, wire brushes, scouring powders, paint removers or thinners.”
• Concrete tile. Eagle Roofing Products, a concrete roof tile manufacturer, writes that a cleaning should “use only water with the water pressure never exceeding 1200 pounds per square inch (psi),” with a cleaner added only when the roof calls for it and then “only in the most diluted solution possible.”

Shingle loses the granules that protect it, the Metal Roofing Alliance's guide forbids a power washer outright, and tile can be etched by the wrong chemistry: Eagle warns that some cleaning products “can affect the PH of the tile or even etch the surface.” The pressure numbers belong to the surfaces they were written for. Eagle's 1200 psi is a ceiling for concrete tile, not a target, and it does not transfer to shingle or metal.

Dwell, rinse, and no brushes

For asphalt shingle, ARMA's own procedure is a solution of “liquid household bleach (sodium hypochlorite) and water,” left on the roof “for at least 15 minutes but no more than 20 minutes,” then rinsed “by gently spraying the surface with water.” No power washer, and no “brush or broom.” ARMA also cautions that mixing directions “may vary among shingle manufacturers,” so a bleach ratio is the shingle maker's call rather than a universal number. Tile and metal follow their own makers' instructions; the shingle recipe does not carry over.

Barrel tile, asphalt shingle and metal each come with cleaning instructions written by the people who make them, and the instructions differ. This is what they say.

Put the roof type in the project details when you ask for an estimate.

NOAA's 1991 to 2020 climate normals for Naples Municipal Airport put every month's average temperature at 65.3 F or higher, and 32.67 of the year's 49.55 inches of normal rainfall falls from June through September.

GAF names dew as the algae's main water source, and June through September carries two thirds of the year's rain. TRI Alliance lists the local variables that push growth on tile: “location of the structure, the direction the roof is oriented to the sun and the quantity of trees, canals and lakes in the area.”

Hurricane season is the other calendar. The National Hurricane Center's season “runs from June 1 to November 30,” with the peak on September 10 and “most activity occurring between mid-August and mid-October.” November through February each carry under 1.7 inches of normal rain.

Two points recur in what the makers and associations quoted on this page publish: a wet roof is dangerous to walk on, and damage from roof traffic, or not following a maker's instructions, can put a warranty at risk.

Eagle's owner information: “Walking on or putting pressure on tiles can potentially cause damage. Our recommendation is to stay off your roof.” On cleaning specifically, Eagle's 2019 cleaning article: “Walking on a roof can be difficult and dangerous and introducing water only heightens these concerns.” ARMA warns that the solution and the rinse “will make the roof slippery and potentially hazardous to walk on during treatment,” and that “because it is dangerous to walk, climb, or work on a roof, ARMA recommends that only trained professionals engage in such activity.” TRI Alliance strongly recommends that only trained professionals who carry insurance walk a tile roof, and that proper fall protection is used.

The benchmark the trade works to is OSHA's construction fall-protection rule: anyone on a walking or working surface “with an unprotected side or edge which is 6 feet (1.8 m) or more above a lower level shall be protected from falling by the use of guardrail systems, safety net systems, or personal fall arrest systems” (29 CFR 1926.501(b)(1)).

Warranty

Eagle's Florida warranty document excludes “damage to the tile caused by roof traffic or other trades” and failure to comply with the recommendations set forth under its “Owner Information” section, which says to stay off the roof; the 1200 psi ceiling is in Eagle's separate cleaning article, not in the warranty. TRI Alliance adds a sequencing rule: “If your roof is still under warranty from the original installation, contact that contractor for all inspections or repairs so that your original contractor's warranty is not voided.” No maker quoted here says cleaning preserves a warranty. What they tie to a warranty includes damage from roof traffic and whether the maker's own instructions were followed.

Four sets of rules come up on a Naples roof job: the local water rule, the insurance statute, the association's covenants, and the state's contractor licensing law. Each is quoted here so you can check it yourself.

Water use: allowed any day under the county rule, with the right equipment

Collier County's Ordinance 2015-27 sets the standing Phase I water restrictions for the county, and the county's own summary of it reads: “Other outdoor water uses, including car, truck, and boat washing, and the washing of exterior home surfaces and roofs, shall be allowed anytime with the use of Low Volume Pressure Cleaning Equipment, Low Volume Mobile Washing Equipment and/or water hose equipped with an automatic self-canceling or automatic shutoff nozzle. In all cases, the water used must drain to a pervious surface or to a water recycling/reuse system.” A roof wash is not tied to the odd-and-even irrigation days. For a paver driveway, the paver cleaning and sealing page takes it from there. The county's summary does not say how far the rule reaches inside a city, and it is not the rule for an Estero or Bonita Springs address, so for a given address the city or the water utility can say which rule is in force.

During a declared water shortage a second rulebook applies. The South Florida Water Management District's Chapter 40E-21 restricts “outside pressure cleaning” to “only low volume pressure cleaning” in the text for every phase, seven days a week in Phases I and II and on fewer days in Phases III and IV. Those restrictions apply only after the district declares a phase, and the district's order declaring a phase can modify them, so the days in force are the order's. The district posts the current status on its landscape irrigation page.

Insurance: the 15-year rule

For an insurance question, the statute is the place to look, not a cleaner. Florida Statutes 627.7011(5) says an insurer “may not refuse to issue or refuse to renew a homeowner's policy insuring a residential structure with a roof that is less than 15 years old solely because of the age of the roof,” and that for a roof at least 15 years old the insurer “must allow a homeowner to have a roof inspection performed by an authorized inspector at the homeowner's expense before requiring the replacement of the roof of a residential structure as a condition of issuing or renewing a homeowner's insurance policy.” If that inspection shows “5 years or more of useful life remaining,” age alone cannot be the reason for a refusal. A cleaning changes how a roof looks. It does not change its age, and under the statute the useful life remaining is what an authorized inspector's inspection indicates. Whether a clean roof satisfies a particular carrier's letter is a question for that carrier.

Your association

Florida Statutes 720.3035(1)(a) limits an association's authority over “the external appearance of any structure” to what is “specifically stated or reasonably inferred” in “the declaration of covenants or other published guidelines and standards authorized by the declaration of covenants,” and requires that those standards be applied “reasonably and equitably” to all parcel owners. Florida law does not itself require anyone to clean a roof; the covenant does, if it does. In a condominium, Florida Statutes 718.113(1) reads: “Maintenance of the common elements is the responsibility of the association, except for any maintenance responsibility for limited common elements assigned to the unit owner by the declaration.” Whether a roof is a common element, and who orders its cleaning, is the declaration's to say.

Licensing: what Florida does and does not license

Florida's contractor licensing statute, Chapter 489, has no category for roof cleaning, pressure washing or window cleaning. The seventeen categories in section 489.105(3) run from general contractor through roofing contractor to the pool, plumbing and solar trades. Section 489.117(4)(a) goes further and names “pressure washing” among the job scopes for which a local government “may not require a person to obtain a license,” while a local government may continue to offer a license for several listed scopes, among them “rooftop painting, coating, and cleaning above three stories in height,” “if the local government imposed such a licensing requirement before January 1, 2021.” The Collier County Tax Collector states that any business operating anywhere in the county, inside the Naples city limits included, must have a county business tax receipt, and that there are a few exceptions. The licensing line that matters on a roof is the coating clause quoted above: under 489.105(3)(e), coating represented “to protect, repair, waterproof, stop leaks, or extend the life of the roof” is within a roofing contractor's scope.