Those black streaks running down roofs all over Northern Kentucky aren’t dirt. They’re algae, and the time to deal with them is before winter sets in, not after. Here’s why we tell homeowners in Walton, Florence, and across Greater Cincinnati to put roof cleaning on the fall list.
What the black streaks actually are
The streaks are a type of algae that feeds on the limestone filler inside asphalt shingles. It spreads a little more every humid summer, and our Ohio Valley humidity is exactly what it loves. Left alone, it shortens the life of your shingles, and it holds moisture against your roof going into freezing weather.
Why moisture on your roof matters in winter
Everything in winter roof trouble comes back to moisture and freezing. Algae and moss hold water against the shingles. When that water freezes, it expands, and it slowly works shingles loose and opens up small gaps. A clean roof dries faster and gives winter less to work with.
Never pressure wash a roof
This one matters. High pressure tears the protective granules right off asphalt shingles and can void your roof warranty. The correct method is soft washing: low pressure and a detergent that kills the algae at the root. The streaks fade and the roof stays intact. That’s the only method we use on shingle roofs.
The gutter connection
While you’re thinking about the roof, look at your gutters. Clogged gutters cause ice dams at the roof edge in winter, and ice dams push water up under your shingles. Roof cleaning and gutter cleaning in the same fall visit is the combination that actually protects your roof through winter.
When to schedule it
Soft washing works best before sustained freezing weather, so October and November are the sweet spot in our area. If you can see streaks or moss from the street, this is the year to handle it.
Want an honest opinion on whether your roof needs it? Send us a photo or call Liberty Power Wash at 859-493-2664. You can also read more about our roof cleaning service. Free estimates, and the price we quote is the price you pay.