Penn Ohio Roofing
Roof Cleaning
Safely remove moss, algae, and streaks.

Those dark streaks and green patches on your roof aren’t just cosmetic — they’re living organisms that eat away at the protective granules on your shingles. Our soft-wash roof cleaning safely removes moss, algae, and streaks without damaging the shingles or voiding your warranty. Regular cleaning extends the lifespan of your roof and keeps your home looking great from the curb.
As an Owens Corning Preferred Contractor, we deliver premium installations backed by industry-leading warranties. Every project is handled by our in-house crews — no subcontractors — and finished with a thorough clean-up so your property looks better than when we arrived.
What Is Roof Cleaning?
Roof cleaning is the removal of the black algae streaking, moss, lichen, and debris that build up on shingles. On Sharon homes the black streaks are almost always Gloeocapsa magma, an airborne algae that feeds on the limestone filler in asphalt shingles. It is cosmetic at first and destructive later — moss and lichen hold moisture against the shingle and shorten the life of the roof.
How Roof Cleaning Is Done Correctly
- 1Soft washing: a low-pressure application of a cleaning solution that kills the organism, followed by a gentle rinse. Pressure never exceeds what a garden hose delivers.
- 2The solution is left to dwell so it kills the algae at the root rather than just bleaching the surface.
- 3Plantings, siding, and walkways are pre-wet and rinsed so nothing downstream is damaged.
- 4Valleys and gutters are cleared of debris in the same visit, since that is where moisture sits longest.
Safe Cleaning Practice
- Soft wash only — it is the method ARMA and the shingle manufacturers accept.
- Clean before moss establishes a root structure, not after it has lifted the shingle edges.
- Address the shade and drainage that let it grow: trim overhanging limbs, clear the gutters.
- Consider zinc or copper strips at the ridge to slow regrowth.
Methods to Avoid
- Pressure washing an asphalt roof. It blasts off the granules that are the shingle's UV protection and will void the manufacturer warranty.
- Scraping or wire-brushing moss off. It takes the granules with it.
- Undiluted bleach with no plant protection.
- Walking a wet, algae-covered roof — it is as slick as ice.
Warning Signs on a Sharon, PA Home
- Black streaks running down the slope, usually worst on north-facing planes.
- Green moss cushions along the shingle butts or in the valleys.
- Crusty gray-green lichen spots that will not rinse off.
- Granules collecting in the gutters.
- Debris packed in the valleys holding moisture.
What Drives the Cost of Roof Cleaning in Sharon
- •Roof square footage and pitch.
- •How heavy the growth is and whether it is algae, moss, or lichen.
- •Access and landscaping protection required.
- •Whether gutter cleaning and minor repairs are bundled in.
