Should a roof be cleaned before hurricane season?

Two kinds of document bear on this question, and they were written by different bodies for different reasons.

The first is the storm calendar. The National Hurricane Center states that the Atlantic hurricane season runs from June 1 to November 30, that its peak is September 10 with most activity between mid-August and mid-October, and that tropical cyclone activity sometimes occurs before and after those dates. The dates and the Naples rainfall beside them are set out on the storm calendar for Naples.

The second is the growth. ARMA writes that algae growth occurs “to varying degrees” in all regions of the U.S. and southern Canada, “especially those subjected to warm, humid conditions,” and TRI Alliance, writing about tile, says: “With enough cycles of heat, moisture and light, spores start to grow.” NOAA's Naples Municipal Airport normals for 1991 to 2020 show the rain arriving with the season: 2.76 inches in May, then 7.41 in June, 7.77 in July, 8.89 in August and 8.60 in September.

Put the two side by side and they overlap in the same warm, wet months. What neither set of documents does is join them. Nothing read from ARMA, TRI Alliance, Eagle Roofing Products or GAF ties a roof cleaning to the hurricane season, and none of them says a cleaning changes how a roof meets a storm.

A cleaning removes growth and staining from a roof surface. The documents give three separate reasons not to treat it as more than that ahead of a storm.

The statute draws the first line. Florida Statutes 489.105(3)(e) counts coating as roofing contractor work, “except when coating is not represented to protect, repair, waterproof, stop leaks, or extend the life of the roof.” The statute speaks of coating, not cleaning, and none of those five things is what a cleaning does. Where a cleaning ends and a roofing contractor begins is laid out on where a soft wash cleaning stops.

TRI Alliance draws the second. It states that, while research continues, there is no known manufacturing procedure or coating applied on the job site with a long-term preventive effect on the growth, so no coating put on before the season is known to hold the growth off through the wet months. Eagle Roofing Products' Florida limited warranty text, as archived, supplies the third: it excludes damage to the tile or structure caused by hurricanes and other acts of nature, whatever state the surface was in. Whether a clean roof lasts longer in general is its own question, answered on whether roof cleaning helps a roof last longer.

With the storm reasoning set aside, what is left is the ordinary one: does the roof show enough growth that its owner wants it gone.

Eagle Roofing Products' 2024 spring article names a sign rather than a date, significant discoloration on the roof, so the trigger is the discoloration, whatever the calendar says. A roof that shows streaks in April shows them for the same reasons it would in October.

NOAA's Naples normals put the months just before the season among the drier ones. Whether the dry stretch is the right time of year overall is answered on the right time of year for roof cleaning in Naples.

ARMA's prevention bulletin for asphalt roofing adds a homeowner maintenance line that sits beside any cleaning: trimming tree branches back lets more sunlight reach the roof and minimizes debris, which makes the roof less inviting to moss and algae. For limbs and leaves already on a tile roof, Eagle tells owners to use a rake, a long stick or another tool rather than walking the tiles.

The questions a storm really raises about a roof, whether a tile is loose, cracked or ready to lift, are not cleaning questions.

Eagle's owner information sends inspection and repair work to the original roofing contractor, or to another qualified licensed roofing contractor when the original one is unavailable. Whether a tile is ready for wind is an inspection question of that kind, and a separate call from any cleaning. What happens to a roof cleaning once a storm has actually passed, and the claim steps Florida's Department of Financial Services lists, is answered on whether a roof can be cleaned after a hurricane.

The same months raise a glass question too, answered on cleaning windows before hurricane shutters go up. Glass matters to the roof job itself as well. Bleach and other sodium hypochlorite solutions appear among the materials the National Glass Association's FB01-00 paper says may harm laminated glass. Impact windows are built with laminated glass, so where a roof above them is washed, keeping the solution off that glass is one of the job's technical requirements.