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While many homeowners concentrate on maintaining the ground-level features of their homes, a roof cleaner can help keep the roof looking its best. Often, not until black streaks and patches of moss show up do homeowners realize their roof needs some attention. However, with a good roof washing, even the dirtiest roof can be restored.
While hiring one of the best roof cleaning services is always an option, a roof wash can be a pretty simple DIY job for roofs that are easily accessed. To clean your roof, all you need to do is block out some time, arm yourself with one of the best roof cleaners, and get to work. We evaluated several of the best roof cleaners and even hands-on tested them to provide a list of the products best suited to cut through the dirt, grime, and sludge, revealing your roof’s true colors. After testing, we chose the 30 Seconds Ready-to-Use Outdoor Cleaner as our top pick. We liked it for its versatility, large coverage area, and ease of use.
The cleaners on our list are widely available to order online, so you can have your pick delivered right to your door to save on professional roof cleaning costs. Read on to find out what to look for when shopping so you can choose the best roof cleaners for your needs.
| Testing Stats | |
|---|---|
| Products tested | 5 |
| Time spent testing | 14 hours |
| Tests performed | 3 |
| Price range | $24 to $56 |
Best Overall
30 Seconds Ready-to-Use Outdoor Cleaner
Our Ratings: Ease of Application 5/5; Effectiveness 4/5; Portability 5/5; Ease of Cleanup 5/5; Value 4/5
Product Specs
- Ingredient type: Chemical-based, ready to use
- Quantity: 2.6 gallons
- Coverage: Up to 400 square feet
What We Like
- Most effective roof-cleaning product we tested
- Handled containers provide easy portability
- Sprayer attachment makes application simple
- Cleans a wide variety of surfaces
What We Don’t Like
- Bleach smell is fairly strong
For a roof wash that really does the job, 30 Seconds Outdoor Cleaner proved to be the best roof cleaner for a variety of reasons. Effective and easy to apply, this product stood out among our group of tested products.
To start with, it actually does live up to its name. Since there’s no mixing of dilution required, all a user has to do is spray it on the surface they want to clean (we tested it on concrete, brick, shingles, and metal roofing), wait 30 seconds (although we found a full minute is even more effective), and then spray it off with a hose. No power-washing is required.
This roof treatment product is also easy to move around with. When you’re climbing on a roof with even a slight pitch, safety is paramount, so it’s important to have a handled container that’s easy to move around with.
The bleach smell is the only thing we didn’t care for with this product; it’s more than faint, but not overpowering. However, wearing a mask or some nose plugs is a small price to pay to get the full effectiveness of 30 Seconds Outdoor Cleaner.
Get the 30 Seconds roof cleaner at Amazon (2-pack) or Do it Best.
More Roof Cleaners Worth Your Money
- Wet & Forget Moss, Mold and Mildew Stain Remover, available at Amazon, Ace Hardware, or Walmart.
- Mold Armor E-Z House Wash, available at Amazon, Ace Hardware, Lowe’s, or Walmart.
- Spray & Forget Revolutionary Roof Cleaner Concentrate, available at Amazon, The Home Depot, or Walmart.
- Simple Green Industrial Cleaner & Degreaser, available at Amazon, Ace Hardware, Walmart, Do it Best, or ULine.
How We Chose and Tested the Best Roof Cleaners
There are multiple factors to consider when shopping for an appropriate roof cleaner, from the surface of the roof itself to the specific dirt issues that homeowners are faced with. Our list of recommended products covers the wide array of cleaners available for mold, moss, and mildew to provide the best suggestions for each scenario.
To choose which products to test, we scoured the web for customer reviews, researched all products being considered, and looked for products that we felt could stand up to the rigorous testing we had planned. Since heavy-duty solutions often use bleach and other harsh chemicals, which are not always what shoppers are looking for, we made sure to also include a product that’s more environmentally friendly.
Our testing process included a start-to-finish cleaning session with each product. We applied the roof cleaner by following the instructions on each product, then followed the instructions for cleaning. A typical test had us spraying the product on the affected area of roof, allowing it to sit for an amount of time defined on the product’s instructions (sometimes doing a little scrubbing), and then rinsing the product away.
What to Consider When Choosing a Roof Cleaner
This section will outline the most important considerations to keep in mind while you’re shopping for the best roof cleaner for your home. It covers aspects including the different types of roofing materials, how much coverage you’ll get, and how easy the products are to use.
Types of Roof Cleaners
Don’t rush out and set up the ladder quite yet. You first need to educate yourself on the different types of roof cleaners available. They all work a little differently, and some are much harsher on the environment than others. It’s important to do a little research before you choose the best roof cleaner for your needs.
Bleach-Based
For particularly stubborn stains and discolorations, beach-based cleaners might be the way to go. They’re so strong, in fact, that you don’t even need to scrub or rinse down the roof for them to work. Simply apply them to the roof and let them dry. The bleach will eat through the dirt and grime all on its own.
The thing about bleach-based chemicals, though, is that they’re extremely harsh. Breathing in their vapors can cause coughing, lung irritation, and shortness of breath. Any overspray (or runoff when it rains) can wreak havoc on your plants. These cleaners are so strong, in fact, that it’s best to keep your windows closed for a few days to avoid the fumes and odors.
Chemical-Based
Bleach isn’t the only chemical manufacturers use to restore a roof to its former glory. Some formulas feature ammonia, copper sulfate, and trisodium phosphate, all of which can do a great job of removing the stains, molds, and mosses that grow on roofs.
These formulas can be harsh on your plants as well, though usually to a lesser degree than bleach-based cleaners. They rarely require the user to scrub or apply a second application, and in most cases, there’s no need to keep your windows closed after application. Since they usually come in concentrates, they typically need to be mixed with water unless you have a really stubborn stain.
Eco-Friendly
If you’re looking for a safer, less environmentally detrimental approach to cleaning your roof, check out an eco-friendly cleaner. These formulas break up the dirt, algae, and mold on your roof without the inherent dangers of chemical and bleach compounds.
Eco-friendly cleaners are safe for your kids, plants, and the wildlife that might roam through your property. While it’s entirely possible to have some type of allergic reaction to these products, they’re generally safe to use and less irritating.
Since eco-friendly cleaners tend to use oxygen to break down dirt and roof-loving molds and algae, they work best with a bit of agitation. You’ll likely have to scrub most of your stains and discolorations away, so having a long-handled brush will be incredibly helpful.
Pressure Cleaner
If you want to blast your roof clean, you can always set up a pressure washer and get to work. The pump inside your pressure washer boosts the amount of pressure with which the water comes out of the nozzle, knocking dirt and film clear off your roof shingles.
But pressure washers can also blast your roof shingles right off, so take care when you’re doing any kind of roof pressure washing.
To help increase your pressure washer’s effectiveness, there are many products available that can be mixed into the water. If you don’t use a chemical, though, be aware that water alone might not kill any residual moss and algae.
Raw Chlorine
Raw chlorine, also known as sodium hydrochlorite, cleans a roof while also killing mold and mildew spores. This compound is made to sanitize, removing bacteria at the same time it cleans up stains and grime. When diluting, it’s important to ensure that raw chlorine solutions never comprise more than 30 percent of the roof cleaning solution, and it’s important that they’re thoroughly rinsed off after use.
Roof Material
The first thing you’ll want to consider are all the materials that make up your roof to ensure you use the right product.
Less-durable materials like vinyl and rubber membranes found on flat roofs or RVs are particularly susceptible to damage from harsh chemicals. Heavy-duty cleaners can wear down the roofing components faster than if you used an eco-friendly option.
Tougher materials, like asphalt, metal, or slate roofs, can take much stronger chemicals. You’ll be able to use bleach or chemical-based cleaners without worrying about what they’ll do to your roof’s finish.
Dilution and Chemical Composition
The best roof cleaners can be broken down into two options: eco-friendly and chemical. Eco-friendly options don’t contain harmful chemicals, so they’re safe to use on roofs above gardens and plants. The composition of chemical-based products, on the other hand, isn’t always so environmentally conscious.
Chemical-based cleaners often use chemicals such as ammonia, copper sulfate, and trisodium phosphate. They can be harsh, but they’re extremely effective at removing the stains as well as the molds, algae, and mosses that cause them. Simply diluting them to the manufacturer’s recommended mixture does reduce some of the risk, so it’s important to read and follow the directions carefully.
Coverage
Not all roof cleaners can cover the same amount of square footage, so it’s important to understand how much roof a bottle or jug can handle. To do this, you have to know the size of your roof first: Simply multiply each section of your roof’s width by its height. Tally each of those sections. The number you get after you add up all the different planes is your square footage.
Some of the best roof cleaners come in concentrated formulas that you can dilute for maximum coverage. While their bottles might be small, they can often cover thousands of square feet of roof if you dilute them correctly.
User-Friendliness
Cleaning your roof isn’t all that much fun, so the process should be made as painless as possible. Finding a user-friendly product can make all the difference.
A chemical that you can spray on your roof and leave to do its work is by far the easiest way to clean your roof. Other chemicals might require you to scrub the surface, which can be a challenge if you have a high roof.
Also, consider the application. Although spray bottles are easy to use, covering a large area with a spray bottle is difficult, so they’re ideal for smaller roofs. Concentrate bottles that attach to the end of your hose make applying the chemical to larger roofs extremely easy, but you might not be able to reach high peaks from the ground. Whatever product you choose, be sure to select one that you can apply easily to your particular roof.
Effectiveness
Ultimately, how well the product works at removing stains, molds, algae, and discolorations is one of the most important factors to keep in mind. The more effective the product, the fewer coats you’ll have to apply, and the less often you’ll have to apply it.
Less-effective products don’t always kill the root cause of the discoloration, even if the stain disappears. If that root is still present, there’s a good chance that whatever caused the stain will come back. This means you’ll have to apply your product more often to keep up with it.
Harsh chemicals are by far the most effective way to get rid of stains and often require just one application. However, using eco-friendly products might require you to commit to more frequent cleanings or follow-up applications.
FAQs
For those who have additional questions about choosing or using the best roof cleaner, this section contains answers to some of the most frequently asked questions.
Many of the best roof cleaner manufacturers recommend cleaning your roof every 12 to 24 months to ensure your roof stays clean and free from growths. But whenever you notice discoloration, moss, mold, or mildew, it’s a good idea to give your roof a spray.
It depends on the cleaner. Many of the heaviest-duty cleaners will damage vinyl or fabric awnings, while some biodegradable or lighter-duty cleaners will work quite well. However, it’s important to always refer to the product label before use.
Most roof cleaners are available in concentrated forms, and you can mix them to whatever strength you’d like. If you’re planning to use yours at full strength, it’s a good idea to test it on a smaller space first to see how it affects your surface.
There are a few steps you can take to minimize your roof cleaner’s impact on your plants.
1. Cover your plants in tarps or plastic sheeting.
2. Use only as much chemical as necessary.
3. Ensure your gutters aren’t clogged so any chemical-laden rainwater can flow away from the eaves.
4. Water your plants heavily before, during, and after using your cleaner. Diluting the concentration of chemicals is the best way to lessen the risk of damage.
Basic safety items like goggles, a respirator, and gloves are certainly important. You can also wear long sleeves. Using a long-handled brush or roller, or a garden sprayer, can make applying your roof cleaner easier.
Meet the Tester
Mike Larson is a DIY homeowner, restoring a 100-year-old home in Pittsburgh. His approach to testing products is rigorous to help easily identify what products rise to the top. A professional journalist for nearly two decades, Mike has had bylines in the Detroit News, Palm Beach Post, and the Pittsburgh Business Times.
Additional research provided by Tom Scalisi.
