You’ll need to think about many things as a homeowner, from mowing your lawn and landscaping to cleaning your driveway and roof shingles. Ensuring you have a clean roof can increase your curb appeal and keep prevent costly roof repairs

Keeping your roof shingles clean means limiting the amount of mildew that can cause damage. While most people prefer to hire a professional to handle the job, you can clean your roof shingles with little research. 

If you’re learning how to clean roof shingles on your own, here’s everything you need to know to do the best cleaning job possible for this home improvement project. 

What You’ll Be Cleaning Off Your Roof

If you haven’t done roof cleaning before, you might be wondering what you’re supposed to be cleaning off and why you’re cleaning roof shingles. Most people see black stains or algae growth on their roofs. Both options don’t look good and can pose issues for your home later. So here are the two main things you’ll be cleaning off your roof. 

Gloeocapsa Magma (Black Streaks)

Gloeocapsa Magma is that weird black streak you see on your roof shingles or black algae. It’s very common on asphalt shingles and lives on the limestone in your roof. 

It’s a spore-based alga, where the algae spore it and feed on the limestone, degrading it over time. So, cleaning algae is essential. If you don’t clean it soon, the black color will move all over the roof, altering the appearance. 


how to clean roof shingles pressure washing

moss growth isn’t nearly as common as the other algae stains we mentioned, but it’s worth noting. It’s prevalent, especially in an asphalt shingle roof and a cedar shake roof. This blue-green algae latches on and spreads quickly. It can easily get out of hand and move up your shingles, allowing water to seep under them and cause roof leaks. Plus, it’s a fire hazard

Identify The Best Cleaning Method For Your Roof

Depending on what you’re cleaning off of your roof, you’ll use different cleaning methods. The method used to clean your roof shingles can vary depending on your roof type. Soft washing is the industry standard, but some choose the pressure wash method.  

Pressure Washing

When you pressure wash something, it uses a lower concentration of your cleaning solution and can be pretty hot or warm. While some people choose to use this method, you really should only use a pressure washer on your roof’s surface if it’s made of the following materials: 

  • Concrete
  • Brick
  • Aggregate

Soft Washing

More often than not, you’ll want to soft wash your shingles by using a low-pressure but higher concentration of cleaning products. This cleaning method is ideal for:

  • Asphalt shingle roofs
  • Wood decking
  • Painted wood
  • Cedar shake
  • Metal buildings

How To Clean Your Roof Step-By-Step

You’re more than likely going to soft wash your roof. Here’s everything you need to go, including gathering the appropriate materials to make this part of your home look as good as new. 

1. Gather Your Supplies

You’ll need a few things to clean your roof correctly. Some items you might have lying around already, while others you might have to go to the store for. You don’t want to use just soap, but you won’t need a lot of harsh chemicals either. What you’ll need for a roof cleaning include: 

  • One gallon of hot water
  • One cup of liquid chlorine bleach 
  • One cup of powdered laundry detergent
  • A garden sprayer
  • A ladder tall enough for you to reach your entire roof 
  • A broom or scrubber 

Make sure you use laundry-strength chlorine bleach solution compared to regular bleach. Using this product helps inhibit algae growth.

2. Take Proper Safety Precautions

Cleaning a roof can be dangerous. You’ll want a safety rope to tie yourself to the roof if it’s slanted, thick gloves to prevent chemicals from getting on you, and possibly safety goggles depending on your preference. Also, we highly suggest wearing slip-resistant shoes with solid traction to avoid falling. 

3. Remove All Debris

If you see that you have sticks, leaves, and other debris on your roof, you’ll want to remove all of these before you start cleaning, including the surface and the gutters. Cleaning your roof without removing the debris won’t get it in good shape. You can pick everything up by hand or use a leaf blower.

how to clean roof shingles man spraying front of house

4. Combine Your Ingredients

Now you’ll need to combine all the ingredients into the garden sprayer. First, you’ll mix the hot water, liquid bleach, and powdered laundry detergent into the bucket of the low-pressure sprayer. You might need to stir it with a spoon, but you’ll want to wait to start cleaning until all the detergent granules are dissolved. 

5. Being Spray Your Roof in Sections

You’ll want to work in sections when roof cleaning to ensure that you clean it thoroughly and that you don’t slip and hurt yourself. 

The best thing you can do to properly clean asphalt shingles is work in sections by spraying an area of three feet by ten feet or smaller, depending on what you’re comfortable with. It’s best to start from the bottom row and work your way up to avoid slipping. 

6. Let the Solution Sit

After each section, you’ll want to let the cleaning solution sit on your asphalt roof or another type of room for about 15 minutes. When those 15 minutes are up, the roof should still be wet, and you’ll want to take your broom or scrubber and begin scrubbing that area of the roof. 

7. Repeat

You’ll want to repeat the spraying, waiting, and scrubbing steps until you complete your entire roof. As you move from section to section, be careful not to slip on any wet spots lingering on your shingles. 

8. Rinse

Once you’ve cleaned your whole roof with the solution and scrubbed it well, you’ll want to take a garden hose or bucket of water and rinse off the top, which helps remove any leftover bleach from your roof shingles and ensures that they don’t turn different colors from prolonged exposure. 

Final Thoughts

If you are learning how to clean roof shingles, you’ll find that regularly cleaning them will keep your home looking as good as possible. It will also prevent roof algae and other factors from damaging your roof shingles over time. 

The best way to clean algae stains or other elements off your roof is to use a combination of hot water, detergent, and bleach. Then, apply the mixture to your roof, scrub it off, and rinse. Following these steps should get you a beautiful-looking roof in no time.