Roof Washing in Summerville, SC

What those black streaks actually are

The dark stripes running down Lowcountry roofs are Gloeocapsa magma — a cyanobacteria that feeds on the crushed limestone inside asphalt shingles. It spreads downslope with rainwater (hence the streaks), holds moisture against the roof, and shortens shingle life while making a 10-year-old roof look 25. Around Summerville it's not a maybe; give any shingle roof here enough shade and humidity and the streaks arrive on schedule. Moss and lichen — the fuzzy stage — do even more direct damage by prying up shingle edges.

Why roofs are never pressure washed

A pressure washer takes the algae off a shingle roof along with the granules that are the roof — instant years of artificial aging, and a warranty-voiding move per every shingle manufacturer. The correct method is the industry-standard soft wash: a sodium-hypochlorite-based mix applied at low pressure, allowed to kill the growth, then rinsed with the roof's own gravity doing most of the work. Streaks typically vanish same-day; heavier moss browns and sloughs off over a few weeks of weather. Gutters get flushed, landscaping below gets pre-soaked, covered where needed, and rinsed after. The same low-pressure logic governs every surface that can't be sanded or repainted back to normal — the two-methods explainer lists which ones.

Pricing

A cleaned roof in this climate stays streak-free roughly 2–4 years, longer than any other surface covered on this site, because the treatment kills the colony rather than shaving its surface. The siding underneath runs a shorter clock, closer to every one or two years, so a single roof job usually outlasts two rounds of soft washing the siding. Why one roof lands at the low end of those bands and another near the top is set out in the roof cleaning cost breakdown.

The two moments people call

The HOA letter — roof streaks are the most-cited exterior violation in Summerville's newer communities, and the letters come with deadlines. And the listing — a streaked roof reads as "needs a new roof" to buyers scrolling photos, even when it has 15 years left. A $500 clean regularly protects a five-figure negotiation. Either way, send photos of your roof or call (843) 994-2432.

What to send when asking about a roof

A roof can usually be priced from the ground. Useful photos show each slope that carries streaks, the steepest pitch on the house, and anything that makes access harder, such as a second story above a flower bed, a screened porch under the eaves or a gutter run packed with debris. Mention the shingle type if you know it, and say whether any section is metal, since metal and asphalt are not treated in exactly the same way. If the streaks have thickened into raised green or gray patches, say that too; that growth takes longer to loosen after treatment. Siding, roofs and driveways each come due on their own timetable, and the wash schedule for siding, roofs and concrete puts the three side by side.

One honest disclaimer

Cleaning makes a roof look and function its age instead of older — it doesn't repair one. Curled, cracked, or bald shingles are a roofer conversation, and a good washing company will say so plainly from the ladder before you spend cleaning money on a roof that needs replacing.