Roof cleaningin Pompano Beach, FL.

East of Federal Highway, which is US-1, Pompano's canal and Intracoastal neighborhoods take salt air every day. On a tile roof, salt settles into the texture of the concrete and holds dirt and moisture there, so algae streaks a canal-side slope sooner and the whole roof reads faded and grey. Most houses here are also old enough, with a median build year of 1974, that Citizens asks for a four-point inspection, and the roof is one of the four points.

A soft wash takes the salt film and the growth off together with no pressure, so the inspector photographs tile rather than streaks. It does not change the roof's age, repair anything or pass an inspection by itself, and nobody honest will tell you it does. If Michael sees cracked, slipped or worn tile while he looks, he says so before he quotes.

On the beach side of Pompano, the sea breeze usually builds through the day, and roof solution is applied as a low-pressure spray. In a stiff onshore wind, spray drifts, and on a canal lot that means it can drift toward a neighbor's car, a boat or the water.

So on waterfront roofs the application is planned for calmer conditions, and if the wind is up, the job waits rather than pushing through. The plants under the drip line are soaked with plain water first and rinsed again at the end, and anything parked close to the eaves is moved. Gutters and downspouts are flushed after so nothing sits in them. It is a small change in timing that keeps the solution on the roof where it belongs.

Cresthaven's first houses were two-bedroom bungalows from the late 1950s, and many have since been expanded. An addition often means a second roof section, sometimes a lower slope and sometimes a different covering from the main roof. Low-slope sections hold water longer and grow faster than the pitched roof beside them. Kendall Green, from 1958, has its own quirk: midcentury ranches with asymmetrical sloping roofs, where one long, shallow slope drains slower than a steep one.

Each section gets a mix that suits its covering, with no pressure anywhere. Where a low-slope section shows ponding, soft spots or open seams, Michael points it out before cleaning, because that is a roofer's question first. The main roof and any additions are quoted together, so there is one number for the whole house and one visit.