How Does Summer Sunlight Impact Algae Growth on Roofs?

Summer in Worcester County brings more than sunshine and BBQs—it also creates the perfect storm for black streaks, algae, and moss to thrive on your roof. If you’ve noticed dark patches forming on your shingles, you’re not alone. The combination of heat, humidity, and long daylight hours gives algae and moss the ideal conditions to multiply fast. But what does this mean for your home’s health?

What Are Those Black Streaks on My Roof?

Those dark, streaky stains aren’t just dirt—they’re often a type of blue-green algae known as Gloeocapsa magma. While they might seem like a cosmetic issue at first, they can lead to serious roof degradation over time.

• Feeds on limestone filler in shingles

• Holds moisture, weakening roofing materials

• Reduces energy efficiency by absorbing more heat

Worried about those stains? Learn more about our roof cleaning services that gently remove algae without damaging your shingles.

The Difference Between Algae, Moss, and Lichen

It’s not all the same gunk on your roof. Here’s how to tell them apart:

• Algae (Black Streaks): Thin, dark, streaky patches. Feeds on shingles. Spreads fast.

• Moss (Green Tufts): Grows in damp, shaded areas. Holds moisture. Can lift shingles.

• Lichen (Crusty Growth): Combo of algae and fungi. Very difficult to remove without damaging the roof.

Each requires a different cleaning approach—one more reason to trust the pros at Kings of Pressure.

Dangers of Ignoring Roof Algae and Moss

You might be tempted to let nature run its course, but that’s a costly gamble. Here’s what can happen:

• Shingle Deterioration: Moisture breaks down shingle material, shortening your roof’s lifespan.

• Leaks and Rot: Moss lifts shingles, letting water seep into the underlayment.

• Reduced Home Value: Black streaks and moss growth are major eyesores for potential buyers.

• Higher Cooling Bills: Algae-darkened roofs absorb more heat, increasing interior temps.

Routine maintenance helps prevent these issues before they take root. Call (774) 402-4670 to schedule a roof inspection or cleaning.

Tips for Preventing Algae Growth on Your Roof This Summer

1. Trim Overhanging Branches: More sunlight = less moisture retention.

2. Clean Gutters Regularly: Clogged gutters overflow and feed roof algae.

3. Install Copper/Zinc Strips: Natural algaecides that help inhibit growth.

4. Schedule Annual Soft Washing: A gentle, effective method to eliminate algae without voiding shingle warranties.

Need help getting started? Our roof experts are here to walk you through a maintenance plan tailored for your home.