How to Prevent Algae on a Roof

What is Algae? Algae is a black or green thin coating, or the streaking, you see most commonly on asphalt or wood roofs. Algae is airborne and predominantly seen in warmer, more humid environments such as the South Eastern Regions.

Algae is more severe in shaded, damp and cool areas. Algae holds the moisture onto the roof therefore reducing the roof life. On any asphalt or wood shingles this standing water deteriorates the shingles faster.

Algae is mostly a cosmetic concern as you run a greater risk trying to remove it. The scrubbing and power washing reduces the granules on the shingles, therefore reducing the life of your roofing system. If you want to have the algae cleaned check out our article, “How to Clean Algae on Roof” for the best ways to do so.

There a three ways you can resist algae growth;

  1. Algae Resistant Shingles – Manufactures have created a shingle that is made with algaecides and fungicides used to resist algae growth. Ease note that resist does not mean moss-proof. With an algae resistant shingle it will deter the growth of algae for an extended amount of time.
  2. Install Copper or metal strips. Copper and Zinc metal strips help resist algae growth. You will see that around metal flashings on your roofing system there will not be algae growth present. This is because of the resistance to the zinc and copper in the metals.
  3. Regular Maintenance. Make sure that your roof is maintained twice a year. Your roofing membrane is an organic substance. If debris such as leaves and pine needles are left on your roofing system they will hold moisture and your roofing system will start to deteriorate. Without regular maintenance, your roofing system will not perform at its maximum potential.