If you’ve noticed black streaks creeping across your Portland, ME roof this summer, you’re not alone. Those unsightly marks are likely algae — and summer’s heat, humidity, and long sunny days create the perfect environment for algae, moss, and lichen to thrive. Understanding why this happens can help you protect your home and know when to call Viking Power Wash for expert roof cleaning.
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What Are the Black Streaks on My Roof?
Those black streaks aren’t just dirt! They’re usually:
- Gloeocapsa magma: A type of blue-green algae common on asphalt shingles.
- Moss: Green, velvety patches that hold moisture.
- Lichen: A mix of algae and fungi that attach tightly to roofing materials.
Why do they matter?
- They trap moisture, leading to shingle damage.
- They reduce your roof’s reflective ability, increasing home energy costs.
- They make your home look older and neglected.
Learn more about Viking Power Wash’s roof cleaning services: Roof Cleaning Services
How Summer Sunlight Fuels Algae Growth
Here’s what makes summer the “golden hour” for algae and moss:
– Long daylight hours give algae more time for photosynthesis.
– Warm, humid air speeds up their growth cycles.
– Shade + moisture (especially under trees) create microclimates where algae flourish.
While sunlight seems like it would dry things out, in reality, it often fuels algae activity — especially on the north-facing or shaded sides of roofs.
Why Algae and Moss Are Worse in Summer
Summer conditions accelerate the problem:
- Nighttime condensation: Traps moisture, feeding algae colonies.
- Pollen + dust: Provide extra food sources.
- Storms: Push debris and spores onto your roof.
Unchecked, algae and moss can lift shingles, break down granules, and shorten your roof’s lifespan. Regular professional cleaning helps prevent expensive repairs later on.
Can Algae Damage My Roof?
Yes!
- Algae and moss hold water, promoting rot.
- Lichen can etch into shingle surfaces.
- Heavy growth may lead to leaks or wood rot underneath.
Viking Power Wash uses a soft wash technique — gentle on shingles, tough on contaminants — to safely remove algae and moss.
How to Protect Your Roof This Summer
Here’s what you can do:
- Trim back trees to reduce shaded, damp areas.
- Ensure gutters are clean to improve water runoff.
- Schedule a professional soft wash to remove existing algae and apply preventative treatments.
For DIYers, avoid high-pressure washing — it can damage shingles! Always trust trained pros for delicate roof care.
Stop Summer Roof Damage Before It Starts!
Let Viking Power Wash protect your roof from summer’s algae invasion. Call 207-615-3161 today, visit vikingpowerwash.com, or check out their Google Maps listing.
Keep your home looking sharp, extend your roof’s life, and rest easy knowing Viking’s experts are on your side — fighting algae, moss, and grime all summer long!