Black Stains on Your Asphalt Roof?

You are working on your lawn, you have cleaned all of your windows and doors, then you look up to your roof and see black stains appearing to “run” down your roof. What is that?  It is blue – green algae that grow in climates with warm and humid summers. That definitely describes a Georgia summer!

The most important information that you need to know is that this algae does no damage to the roofing, it just makes your roof look dirty and may hurt curb appeal. You might notice that this algae is absent below metal flashing around your chimney or vents. Cooper and zinc coating on the metal are toxic to this particular type of algae. When it rains, some of the coating gets washed down the roof, essentially “coating” the area of roof from algae. Roofing manufacturers are working to create algae resistant shingles, and you can request them but they may add more cost to your overall roof budget.

So what can a homeowner do to remove these stains during the spring and summer months?  At Bell Roofing, we suggest keeping your roof, gutters, and valleys free of leaf debris that will help keep the roof from staining and the algae forming quickly. We need to point out that we do not encourage the use of a pressure washer on the roof to do this. Pressure washers can damage shingles on the roof, and with use you may end up having to replace your roof. You can use a pressure washer on a gutter, but still be very careful.

One of the first steps in cleaning out your gutter is getting rid of the so called “goop”. This would be leaves and debris that have compacted in the gutter over the months. After removing the debris it is time to bring out the pressure washer. You have to be very careful at what angle you use the pressure washer on the gutters. If your gutters are older, it might be better to use a nozzle spay on a hose to clean them out. Pressure washers can damage older gutters. Please use a secure ladder, non–slip shoes, and have someone out spotting you as you work.

If you have more questions about how to keep your gutters clean, we would love to help you! We recommend having a professional come out and clean you gutters, and we want to be that professional!  Contact us to have Bell Roofing come out to look at your gutters, and provide you with a free estimate! Here’s to a healthy roof!