How to Remove Moss and Algae From Your Roof

It happens. You come home, walk up the driveway, and suddenly a discolored green patch stands out to you from afar.


Before you break out the hose and power wash your rooftop, there are a few things you need to know about cleaning away moss and algae from your roof. Properly treating moss and algae so that you aren’t left with stains or chipped tiles doesn’t have to be a complicated process, and there are some easy solutions you can mix to combat nature’s paint job.

Here’s the information you need to clean up any affected areas.

Why Do Moss and Algae Grow on the Roof?

Moss and algae grow on the roof in shaded areas where the sun is absent. Additionally, if the shaded area is cooler and frequently exposed to damp weather conditions, the likelihood of moss and algae thriving is much higher.

If you want to prevent future growth, the best thing to do is remove any shaded areas from your roof (if at all possible). You can primarily do this by trimming the trees around your house. You can also clear away debris from your gutters or shingles. This will greatly reduce the amount of water trapped near your roof and will reduce the possibility of unwarranted growth.

What to Clean With

You might need a little more than water to wash away the green patches. Here’s a small list of supplies and some DIY solutions you can create before tackling the issue.

  • Dawn Ultra: 8 oz. for every 2 gallons of water
  • (Dawn Alternative) White Distilled Vinegar: 1 cup for 1 gallon of water
  • (Dawn Alternative) Chlorine bleach: 1 cup for 1 gallon of water
  • Ladder: so you can either get up to the roof or see the roof better as you wash it
  • Hose: for rinsing down any cleanser solutions you’ve implemented
  • Spray bottle: for applying cleanser solutions
  • Brush: for scrubbing away. You can choose any brush that won’t damage your shingles

How to Clean Your Roof

Power washing your house immediately with the hose can damage your roof unless you take the precautions to do it properly. If you aren’t sure, consult with a pressure washing service. 

Here are the steps you need to take to clean away the moss and algae:

1. GENTLY Spray the Roof with Water

A light coating of water over all the affected areas will help the moss and algae absorb anything you plan to apply to your roof.

2. Apply your Choice of Cleanser

You can use the spray bottle and generously coat your DIY solution on the moss and algae. After you finish applying your cleanser, leave it alone for about thirty to forty-five minutes to allow it to sink in.

3. Scrub the Roof

Take the brush and start cleaning away!

4. Lightly Spray Again

For the final step, you’ll want to spray down your rooftop again. This can help you check for any remaining moss or algae. If any affected areas remain, repeat the process from step 2.


The best way to prevent moss or algae is to make sure the sun can shine on all areas of your roof. If they do grow, moss and algae can easily be cleaned from your roof using a few simple steps and a DIY cleanser made from ingredients around the house.