Roof Cleaning in Herndon, VA

Clearly Amazing cleans asphalt shingle roofs in Herndon, Virginia, with crews working out of our Northern Virginia office in Sterling. Each estimate is free and made at the house,.

Call (703) 723-7770 for a free on-site estimate.

Your roof and Herndon’s Historic District

Herndon’s Historic District has been listed in the National Register since January 11, 1991. Fairfax County’s summary of the listing names transportation, specifically the Washington & Old Dominion Railroad, as the district’s major historic context and architecture as a secondary one.

According to the town’s FAQ, most exterior changes to buildings in the district require a Certificate of Appropriateness approved by the Historic District Review Board before the work begins, and roof replacement is one of the common applications. The town’s historic-district pages are silent on whether routine exterior cleaning needs a certificate. If your house is in the district and you have questions, the town’s staff can answer them.

The median year built across Herndon’s 8,076 housing units is 1983, according to the Census Bureau’s 2024 five-year figures. About 42.7% of units were built before 1980, 41.0% between 1980 and 1999, and 16.3% in 2000 or later, with the 1970s the largest single decade at 31.2%. Those are figures about when houses went up; they say nothing about when any roof on them was last replaced.

What the dark streaks and moss are

The black streaks that run down shingle roofs are commonly caused by Gloeocapsa magma, a cyanobacterium usually referred to as algae. The Asphalt Roofing Manufacturers Association treats algae as discoloration. Moss grows thicker and keeps shingles wet; removing a heavy mat of it helps head off the moisture retention and granule loss tied to heavy moss.

NOAA’s 1991–2020 normals for Dulles airport put yearly precipitation at 43.24 inches, and May is the wettest month there at 4.72 inches.

What your roof can safely take

ARMA’s guidance warns never to pressure wash an asphalt shingle roof. It also recommends that only trained professionals work on roofs, since walking and working up there is dangerous. According to ARMA, the results of cleaning are temporary and the discoloration may recur. GAF, CertainTeed and Owens Corning, three shingle manufacturers, likewise advise against power washing.

What the job involves

Areas we cover in Herndon

We clean roofs throughout the Town of Herndon, Downtown Herndon and the Historic District included, as well as the Fox Mill Estates and McNair Farms areas.

When to schedule in Herndon

Spring and fall are ideal for roof cleaning, with mild days for the crew and time to plan any repairs the inspection turns up. Any other season is fine as well: before a sale, after a new streak appears, or when moss starts to show on a shaded slope. Growth returns over time, so a roof is best kept on a maintenance cycle, every few years depending on shade.

Questions Herndon customers ask