Roof Cleaning • Non-Pressure
Those Black Roof Streaks Need Treatment, Not High Pressure
Dark staining on asphalt shingles is commonly associated with algae growth spreading across the roof. Aggressive pressure can dislodge shingle granules and shorten a roof's service life. We use a treatment-based, low-pressure approach designed for roofing materials.
The Approach
What those streaks actually are
The black streaking that shows up on shaded roof planes in the Carolinas is commonly associated with a cyanobacteria, often referred to as Gloeocapsa magma, that colonizes shingles and spreads as airborne spores land and multiply. It holds moisture and discolors the shingle surface. Humidity, shade, and overhanging trees all encourage it.
It's an appearance and moisture problem, not necessarily an emergency, but it doesn't wash off with a garden hose, and it gets worse over time.
Why we never pressure-wash a roof
Asphalt shingles are not designed to withstand concentrated high pressure. Force-washing a roof can loosen granules, the shingle's UV protection, and create uneven wear. Roof cleaning done properly is a chemical treatment process with minimal pressure: the solution is applied, given dwell time to address the growth, and allowed to rinse away with rain or a gentle rinse.
Roof work also means everything below the roofline is in the runoff path. Plant and property protection gets special attention during roof treatments, shrubs, flower beds, and lawn areas are pre-wetted and rinsed throughout the process.
What to expect
A responsible roof cleaning is more process than spectacle:
- Assessment of the roof's condition, access, and the extent of staining
- Protection setup for landscaping and anything in the runoff path
- Application of a shingle-appropriate cleaning treatment at low pressure
- Dwell time so the treatment can address the growth
- Rinse-down of surrounding plantings, and a follow-up check of the work area
Common Questions
Roof Cleaning FAQs
Something else on your mind? Call us or send the estimate form, real answers, no pressure.
Do you use high pressure on roofs?
No. High pressure is the wrong tool for asphalt shingles, it can dislodge the protective granules. We use a low-pressure, treatment-based method designed for roofing materials.
What causes black streaks on roofs?
Dark roof streaks in our region are commonly associated with algae growth (often called Gloeocapsa magma) that colonizes shingles, especially on shaded, humid sides of a roof. It spreads via airborne spores, which is why whole streets often develop it around the same time.
Will cleaning my roof make it last longer?
We don't make service-life promises. What we can say: the treatment addresses living growth that holds moisture against the shingle surface, and it avoids the mechanical damage that pressure washing causes. For specific roof-life questions, a roofer is the right authority.
Is it safe for the plants below my roofline?
Roof cleaning puts everything below the work area in the runoff path, so plant protection is a core part of the process: pre-wetting, covering where needed, and continuous rinsing during application. We explain the setup before starting.
Related services
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