Removing Stains From Asphalt Shingles

by Karen Bates
(last updated February 21, 2022)


If you have shingles made of asphalt, you may have noticed stains that have developed on your roof. These unsightly black streaks can make your roof look dirty and beat up even if the shingles on your roof aren't very old. Regardless of how recently your roof has been reshingled, these dark stains might make you think about replacing your roof shingles just to make your roof look nice again.

These streaky stains are usually caused by a kind of algae that thrives in humid regions. Roof shingles introduced within the last twenty years are more likely to attract an algae problem, because they are made of different materials that the algae thrive on. This algae loves the materials in your asphalt roof and live and grow on the shingles. The black you see accumulating on the roof over time is dead cells from these algae.

The good news is that you don't have to replace your roof to get it looking new again. Instead, you can clean the roof and take measures to prevent future algae problems. With the right knowledge and materials, you can clean the shingles yourself.

  • Choose a cleaner for your roof. There are different options you can buy that are made specifically for getting algae off your roof. Follow the directions for the product carefully.
  • You can also use an oxygen bleach (not chlorine) powder that you can mix with water. If you try this method to clean your roof, it is best to do it on a cloudy day so that the mixture won't dry too quickly. Mix the bleach with water (about one quart of bleach to one gallon of water) and 3 ounces trisodium phosphate (which can be found in hardware stores) and put in a garden sprayer. Get the roof wet with the mixture, then let sit for about fifteen minutes or so. Use a hose to rinse it off.
  • To stop the algae from returning, try installing some sheet metal that is coated with either zinc or copper below the roof's ridge on both sides. Zinc and copper are toxic to the algae and will help to keep it from coming back.

Always use caution when cleaning your roof yourself. Be sure that the ladder you use to climb up onto the roof is secure and stable. When on the roof, be aware of slippery conditions caused by water. You might want to consider wearing some kind of safely harness to prevent slipping.

Author Bio

Karen Bates

An English student who enjoys writing and art, Karen has had her poetry published in her university's literary journal and has several novels in the works. ...


Wine Set

Have you ever needed to open a bottle of wine only to find that you didn't have a corkscrew or foil cutter? Be prepared ...

Discover More

Using Stencils to Decorate

Are you looking for an easy and inexpensive way to decorate your home? Using stencils on walls or other surfaces in your ...

Discover More

Kids Bedroom Furniture

Picking out kids' furniture can be a fun task. You can go along with a theme or look for furnishings in colors and shades ...

Discover More

Tough Cleaning Jobs Require Brawny! Brawny paper towels provide the versatility you need: the strength for demanding jobs and the softness to clean up your child's messy face. This 24-roll pack of pick-a-size sheets can handle just about every cleaning task in your home. Check out Brawny 24-Pack Giant Paper Towels today!

More Cleaning Tips

Removing Creosote from Asphalt Shingles

Whether it is after a particularly cold winter, or simply a cold snap, there comes a dirty job that needs to be done if ...

Discover More

Cleaning Asphalt Shingles

Most home owners are surprised to learn that the stains they see on their roof are caused by fungus, and do not result ...

Discover More

Removing Stains from Shingles

Shingles on the top of you house can become stained by mildew, moss, and lichen. Molds can spread and damage the roof of ...

Discover More

FREE SERVICE: Get tips like this every week in Cleaning Tips from Tips.Net. Enter your address and click "Subscribe."

View most recent newsletter.


If you would like to add an image to your comment (not an avatar, but an image to help in making the point of your comment), include the characters [{fig}] (all 7 characters, in the sequence shown) in your comment text. You’ll be prompted to upload your image when you submit the comment. Maximum image size is 6Mpixels. Images larger than 600px wide or 1000px tall will be reduced. Up to three images may be included in a comment. All images are subject to review. Commenting privileges may be curtailed if inappropriate images are posted.

What is four minus 4?

2022-02-21 07:06:54

Ray M

Home Depot sells the Master Flow 2.67 in. x 50 ft. Zinc Moss and Mildew Preventer Strip for this purpose.

Newest Tips

FREE SERVICE: Get tips like this every week in Cleaning Tips from Tips.Net. Enter your address and click "Subscribe."

(Your e-mail address is not shared with anyone, ever.)

View the most recent newsletter.