How much does roof cleaning cost?
What you are paying to remove
The black streaks on many Georgia roofs are a blue-green algae that feeds on the limestone filler in shingles and thrives in humid, shaded conditions, often on north-facing slopes. Moss and lichen show up on heavily shaded roofs, especially in the mountain counties and under big trees. Algae is cosmetic at first; moss holds moisture and can lift shingle edges.
Price drivers
- Roof area. More squares, more solution and time.
- Pitch and height. Steep and two-story roofs require more safety setup.
- Severity. Light streaks clean in one pass; thick moss needs dwell time and sometimes a second visit.
- Access and landscaping. Protecting plants, covering beds and rinsing them adds labor.
- Gutters. Some cleaners include gutter clearing afterward; ask.
Method matters more than price
The safe approach is a low-pressure application of a diluted cleaning solution, typically bleach-based with a surfactant, allowed to work and then rinsed or left to weather off, following the shingle manufacturer's guidance. High-pressure washing blasts away granules, the shingle's UV protection, and shortens roof life. Ask any cleaner what pressure and solution they use and how they protect plants and gutters.
Keeping it clean longer
- Zinc or copper strips near the ridge release metal ions with each rain that slow regrowth.
- Trimming trees to let in sun and air.
- Choosing algae-resistant shingles at the next replacement.
Read black streaks and algae on roofs and moss and lichen on roofs. Robust Roofing explains what to avoid in its algae streaks guide.