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Without algae protection, shingles can manifest black streaks in as little as 3 years.

Copper Granules Reduce Black Streaks

Humidity and sunlight create the perfect environment for algae growth. On a roof, this growth often manifests as black streaks that alter your roof’s color and mar its appearance.


To combat this problem, we utilize copper-coated granules from 3M.

What are those Black Streaks?

Dew on roofs, combined with humidity and sunlight exposure, creates the perfect environment for algae growth which, on a roof, can cause unsightly staining in the form of black streaks.


In very humid environments, these streaks can manifest in as few as 3 years after installation, and they only get worse with time.

Why Not Just Clean the Roof?

Climbing on the roof and attempting to remove black streaks caused by algae growth via pressure washing is dangerous and can damage your roof by dislodging the shingle’s granules, their primary defense against damage and UV aging.

How it Works

Mix of Copper-Coated Granules Impedes Algae Growth

To combat the problem of black streaks, we use 3M™ Copper Granules. These granules, which blend inconspicuously into the shingle’s color, are uniformly distributed on the shingle’s surface, and release copper ions which inhibit algae growth, preventing it from getting started in the first place.


For maximum algae protection, our shingles featuring Scotchgard™ Protector utilize at least a 10% blend of 3M™ Copper Granules.


Malarkey was the first shingle manufacturer to receive the Scotchgard™ Protector designation from 3M.

Key Features

Raw Base Mineral

Dense, non-porous, mineral is the core of the granule, providing strength and long-lasting, weather-resistant durability.

Ceramic Coating

Colored, ceramic coating adds lasting color vibrancy, in an array of colors, and helps defend against hail, scuffing, and UV aging.

UV Coating

UV coating acts as sunscreen to help protect the shingle from premature aging from UV sunlight.

Copper Coating

Copper coating inhibits algae growth.

Scotchgard and Scotchgard Protector, including the 3M logo, are all trademarks of 3M.