How to Deal With Roof Stains From Moss and Algae

Moss and algae are never welcome, stressing homeowners as they take away from a property’s curb appeal. This is why it’s not uncommon for roofing companies to be called upon to deal with the issue.  

Moss vs. Algae: What’s the Difference?

Both look unsightly but only one is actually damaging to asphalt shingles: moss. It can cause the shingle leading edges to curl or lift, increasing risks of blow-offs during windy weather. In severe cases, moss buildup can lead to lateral water movement that causes moisture damage in roof decking or may even lead to leaks.

Moss and algae thrive on roof surfaces with moisture or the north-facing sides of roofing systems that don’t get a lot of direct sunlight and dry out longer than south-facing sides. While your biggest concern about them might be cosmetic in nature, it will pay to address them right away.

How to Get Rid of Moss and Algae

A thorough cleaning involving a 50:50 bleach solution will usually do the trick and get rid of mold and algae. Have the solution applied with a sprayer and let sit for 15 to 20 minutes. Rinse completely with some water. Moss will loosen up over time while algae will disappear and wash away with subsequent rains. NEVER use a pressure washer to clean asphalt shingle roofing to prevent granule loss and premature roof failure.

Preventing Moss and Algae Growth

  • Trim tree branches to allow more sunlight to reach your roof and keep debris accumulation to a minimum.
  • Regularly have your roof inspected for buildup and cleaned.
  • Keep gutters clog-free to promote proper drainage of water when it rains.

Should You Do a Replacement Instead?

When you’re dealing with severe moss and algae, and your roof is already old and/or damaged, it may be best to consider a replacement instead. A roof that’s already on its last legs will likely fail more frequently down the line, pushing you to pay for costly repairs. This can add up, making a replacement more practical in the long run.

Wortham Bros Inc. is the roofer to trust for all your roofing requirements. To learn more about what we can do for you, simply give us a call at (972) 960-3135 or fill out our contact form. Request a FREE estimate today! We serve Dallas, McKinney and the surrounding communities.