The Truth about the Black Streaks on Your Roof

There are many myths and discussions about the black streaks on your roof. Here are a few explanations about what they are, how to clean them, and some other information to make your roof last 25-30 years.

What are the black streaks on my roof?

Black streaks on the roof are actually a blue-green algae known as Gloeocapsa Magma that is spread by airborne spores. More often than not it starts on the north side of your home. The algae can actually travel to other areas of the roof, and to neighbor’s roofs, due to the spores it produces that are carried by the wind

This algae feeds on the limestone filler that is used in today’s shingles.

The black streaks also allow the moisture to remain on the roof for longer periods of time — which then lead to the growth of moss and lichens.

Roofs that are even just a few years old can show signs of the black streaks.

Are there things I can do to prevent these black streaks?

There are algae resistant shingles on the market today, but even these roofs can — and will — get the algae, it just takes a little longer

Some roofing companies are pushing the installation of Zinc strips as a way to keep the roof clean. Roof Cleaner has cleaned many of roofs that have had these installed. The roof will be free of the black streaks for a couple feet below the strip, but beyond that the roof is covered in the algae.

Does my roof need to be replaced?

There are roofing companies in West Michigan that will tell homeowners that the black streaks on the roof is actually the tar leeching out of the shingles and that the homeowner needs to replace the whole roof — this is completely false. Many homeowners do not know any better, so they replace the roof at a minimum of $5000 — when their roof could have been cleaned for a small fraction of that cost

How can I make my roof last a long time?

Today’s roofs need to be cleaned in order for them to reach their full 25-30 lifespan.

Another good tip is to make sure there are no trees or tree branches hanging over the roof, sunlight is a roof’s best friend.

Give Roof Cleaner a Call to Remove the Black Streaks on Your Roof!

Roof Cleaner has years of experience in removing these stains from area roofs. We have been cleaning roofs in West Michigan since 2008. Give us a call for a FREE roof cleaning consultation. Our phone number is (616) 240-3465. Roof Cleaner services the entire West Michigan area, including the cities of Grand Rapids, Holland, Grand Haven, Muskegon, Spring Lake, Ada, Caledonia, Lowell, Rockford and more.


Black Streaks on Your Roof