Buyers Guide: Finding the Best Roof Cleaner for Your Home

Your home’s roof is the first line of defense against the elements. Just like anything else, your roof will age and get dirty over time. Roof cleaning products make it easy to restore the original beauty of your roof without having to shell out several thousand dollars to replace it.

But, with so many different products on the market, it can be difficult to decide on a good match for your needs. Today, we’ll cover everything you need to know about these products to help you select the best roof cleaner for your house.

These five products represent the best roof cleaner options on the market. Depending on the type of roof you have and how dirty it is, you’re likely to find one of these products is a perfect match for your home.

1. Spray & Forget Roof Cleaner

One of the most popular choices for a roof cleaner is Spray & Forget. This concentrated cleaner can tackle roofs up to 2,000 square feet.

Spray & Forget is free of harmful chemicals such as bleach, lye, acid, heavy metals, or phosphates. It’s non-corrosive, non-caustic, and non-acidic.

The ingredients are safe and eco-friendly, and this product can be used on any outdoor material, including vinyl siding and outdoor furniture, so you’ll be able to use any extra concentrate you have to take care of other exterior cleaning projects you have.

Using Spray & Forget couldn’t be easier. It’s available in multiple configurations so you can pick the one that’s easiest for you. The value size is most popular, and all you’ll need to do is add the concentrate to a sprayer, fill it with water, and get to work. There’s also a sprayer bottle available that connects directly to your hose, eliminating the need for a sprayer.

Once you’ve sprayed the solution onto your roof, your work is done. No rinsing, washing, or additional work is required. Once sprayed, the concentrate gets to work removing dirt, grime, algae, mold, mildew, moss, and lichens from your roof. It penetrates roofing materials to eliminate pesky root systems and leaves you with a pristine roof that looks like it was just installed.

What We Like

  • Available in multiple configurations
  • Doesn’t contain harsh chemicals
  • Requires no rinsing or washing

What Could Be Better

  • Doesn’t work as quickly as chemical products

2. Wash Safe Industries Roof Wash

Roof Wash from Wash Safe Industries is one of the most popular eco-friendly roof cleaners on the market, and it’s favored by many roofing professionals.

Unlike most products, which come in the form of a concentrated liquid, Roof Wash comes in a powder. To use it, you’ll add a half cup of Roof Wash concentrate to a gallon of hot water and stir for several minutes to activate the solution. One three pound jar of Roof Wash can clean up to 3,000 square feet, making it one of the more economical options on the market.

Once mixed, you should allow about 15 minutes for the solution to activate, at which point it can be added to a garden sprayer for application on the roof. Roof Wash tackles stains from regular wear, as well as black algae, moss, mold, mildew, and lichen.

Roof Wash only has a six hour half life before it begins to biodegrade, which makes it one of the safest products on the market, which is ideal if you have pets, children, or expensive landscaping features you’d rather not ruin with harmful chemicals.

The makers of Roof Wash recommend following up with a low-speed pressure washer after applying the roof cleaner. While this step isn’t necessary, it greatly accelerates the process, allowing you to enjoy your newly clean roof sooner than if you allowed nature to finish the job for you.

What We Like

  • Economical
  • Chemical free
  • Easy to mix and apply

What Could Be Better

  • Heavily dirty roofs may require a second application

3. Wet and Forget Moss, Mold, Mildew, and Algae Cleaner

This all-purpose exterior cleaner is one of the safest options on the market, and it’s ideal for homeowners who are looking to clean other exterior surfaces in addition to your deck.

Wet and Forget is recommended for virtually any outdoor surface. Beyond roofs, it also cleans aluminum, clay, brick, asphalt, composite, artificial turf, fabric, marble, metal, PVC and virtually any other surface you can think of.

This bleach-free, phosphate-free, and non-acidic cleaner calls for no additional scrubbing, rinsing, or power washing, so it’s perfect for homeowners looking for the easiest possible solution to beautifying their home’s exterior.

Wet and Forget capably cleans moss, algae, lichen, mold, and mildew, which makes it perfectly suited for roof cleaning. The active ingredients get to work eradicating the root of the stain, and mother nature does the rest.

This cleaner is also one of the cheapest options on the market, but it still costs about the same when all is said and done. While each bottle of Wet and Forget may be cheaper, it produces only six gallons of spray, which is roughly half what you’ll get from other concentrates.

What We Like

  • Works on all outdoor surfaces
  • Non-acidic – won’t degrade roof shingles
  • One step application process

What Could Be Better

  • Makes about ½ as much spray as the competition

4. MMR Pro Mold Killer and Mold/Mildew Stain Remover

If you’re looking to take a scorched earth approach to ensure that your roof is completely clean when the job is done, RMR-86 might be a good option for you.

RMR-86 quickly and effectively tackles both interior and exterior stains and restores the original beauty to many different surfaces. Unlike the options we’ve covered above, this is a bleach-based cleaner, so you’ll want to exercise caution when using it.

Compared to the alternatives, RMR-86 works considerably faster than more eco-friendly options. While a low-speed pressure washer or a scrub brush can help accelerate the cleaning process, this cleaner will eradicate staining on your roof without any additional effort on your part.

Each gallon of concentrate only treats 200-400 square feet, which is considerably less than the coverage you’ll get from the other cleaners we’ve covered. Keep that in mind before getting started, since using RMR-86 will be more expensive than any of the alternatives.

Since this spray works so quickly, it’s ideal for projects that need to be completed immediately. If you’re hosting the Fourth of July bash this year and you waited until July 3rd to clean the roof, this is exactly the kind of cleaner you need.

What We Like

  • Fast results
  • One step application

What We Don’t Like

  • Contains bleach
  • Poor coverage – can get expensive

5. Green Off Mold, Mildew, Algae & Moss Remover

Rounding out our top five list is Green Off, another concentrated spray cleaner that’s a popular option for use on all sorts of roofing.

Green Off is an all-purpose outdoor cleaner that’s as well suited to roofs as it is PVC fencing, aluminum or vinyl siding, play equipment, driveways, stone, outdoor furniture, and virtually anything else.

One gallon of concentrate produces three gallons of spray, which is about half as much as some competitors offer for about the same money, which makes Green Off a bit more expensive than other options.

All you’ll need to do is spray the Green Off onto your roof and let nature do the rest. The manufacturer recommends spraying on an overcast day, so minimal evaporation occurs and suggests against spraying when rain is in the forecast.

For tougher stains, an additional application a few weeks after the first is recommended. A low-pressure power washer or a quick scrub down can help accelerate the process.

What We Like

  • One step process
  • Chemical free

What Could Be Better

  • Not concentrated enough

What to Know Before You Buy

While roof cleaning products are a fairly straight forward concept, there are a few things you should know about the different options on the market before you decide on the best roof cleaner.

Types of Roof Cleaners

When it comes to roof cleaners, you’ll find several different options on the market. Depending on your needs, one of these should be ideal for you.

Low-Pressure Green Cleaners

These days, eco-friendly cleaning products are beginning to dominate the roof cleaner market. These products are perfect for most homeowners, as they’re able to restore the original beauty of your roof without the use of harmful chemicals or bleach.

These cleaners provide a complete solution to roof cleaning, and they can easily remediate algae, lichens, and moss from your roof.

These cleaners are applied with low pressure, and rarely require anything more than some gentle scrubbing to clean your roof. Most cleaners use oxygenation to accelerate the cleaning process, and despite the fact they don’t have any harsh chemicals, they still provide an impressive level of clean for your roof.

Eco-friendly cleaning solutions are usually compatible with any type of roof, and they allow you to complete the job without the need to protect plants, grass, and vegetation in the area. Green cleaning products are also ideal for homes with pets or small children.

If there’s one downside to eco-friendly products, it’s that they tend to be more expensive than products which use harsh chemicals to clean your roof, since those chemicals are typically much less expensive than the green alternatives found in eco-friendly cleaners.

Bleach Based Cleaners

Bleach-based cleaners are usually made from a concentrated solution of sodium hypochlorite

(chlorine bleach). Some high-powered cleaners will also use trisodium phosphate (TSP), as well.

These cleaners are much harsher than the eco-friendly options we discussed above. With a bleach-based cleaner, you simply spray the roof with the cleaning solution and wait for it to dry. Once dry, the cleaner may be reapplied. This process is repeated until the roof is acceptably clean.

The harsh chemicals in these cleaners can kill organic organisms like algae, moss, and lichens instantly. It’s common for remnants of these organisms to remain on your roof after cleaning. Usually, they’ll fall off on their own after it rains in your area a time or two.

While these cleaners are easy to apply and more cost-effective than eco-friendly options, they present some dangers you’ll want to be aware of before committing to one.

There’s a harsh smell associated with bleach-based cleaners, and they also present serious risks to your lawn and landscaping, since bleach and phosphates can kill plants, shrubs, and grass that they come in contact with.

If you have small children or pets, they should be kept away from the area while the roof is being cleaned. If possible, try to keep pets and children away from the immediate area for 48-72 hours.

Other Chemical Cleaners

Beyond bleach, there’s also some other chemical based options that are used for roof cleaning. Chemicals like copper sulfate or trisodium phosphate are also popular alternatives to bleach that are used in roof cleaning products.

For galvanized roofs, a chemical emulsifier is a popular roof cleaner. These products usually use ammonia, and they do a good job of removing grease, grime, and other compounds from metal roofing.

While these cleaners may not be quite as caustic as bleach, they do suffer from the same drawbacks as bleach-based cleaners, and they can pose a serious threat to your vegetation and landscaping in the immediate area of your roof.

With certain types of chemicals, they can also degrade the shingles of your roof, which can shorten the lifespan of your roof, forcing you to replace it long before you would have to otherwise.

High-Pressure Cleaners

These types of cleaners are designed to be used with a pressure washer to remove stains from your roof. Sometimes, only water is used, although a chemical solution can also be added to accelerate the cleaning process.

Using a pressure washer to clean your roof isn’t advised. These cleaners rely on high pressure to get the job done, but that can also be very damaging to the roof, especially if you have shingles.

Not only can they damage your roof, but they’re also not as effective as green or bleach-based products since they don’t do anything to address the root systems of organisms like moss or lichens.

While it may work at first, you’ll quickly notice that algae, moss, and lichens are back on your roof in just a few months.

I like breaking out the power washer just as much as the next guy, but when it comes to your roof, it’s best to avoid using it altogether.


Q: I don’t have children or pets, should I still avoid chemical cleaners?

While green cleaners have usurped chemical options as the preferred way to clean your roof, chemical cleaners are still fast and effective. If you take care when applying these chemicals, you shouldn’t run into any problems.

Consider covering trees and grass in the immediate area with drop cloths, or renting a runoff recovery system to prevent chemicals from leaching into your lawn and landscaping.

Q: How much does roof cleaning cost?

Cleaning your roof is something you’ll probably be able to tackle yourself. But, if you’d prefer to go the professional route, there’s plenty of professionals who specialize in roof cleaning.

Depending on the type of roof you have, it’s size, and the condition, a roof cleaning typically costs around $500, but you can expect to pay more if you have a large or difficult to clean roof.

Of course, if you go the DIY route, cleaning your roof will be considerably cheaper. The average roof is around 3,000 square feet, and depending on the product you use and how heavily concentrated it is, you’re likely to only need three bottles of roof cleaning concentrate at the absolute most.

With an average cost of about $40 per one-gallon bottle, the whole project should cost you somewhere between $40-120 and a few hours of your time.

Q: Do I need any special equipment to clean my roof?

Cleaning the roof doesn’t require anything in the way of specialized equipment, but there are a few tools you’ll want to have at the ready before getting started. For one, you’ll need a hose long enough to comfortably reach your roof. You’ll also want to have a large scrub brush for stubborn areas that need extra attention as you clean.

Final Verdict

Each of the five roof cleaners we covered above should make a fine choice to help you restore the original look of your roof. However, there’s one product that rises above the other alternatives to achieve the title of best roof cleaner.

Wash Safe Roof Wash is our favorite product, as it delivers in virtually every category. The heavily concentrated powder covers a massive 3,000 square feet, so you’ll be able to get more bang for your buck with this product compared to the competitors.

It’s effective and easy to use, and beyond DIYers, it’s also a popular choice with many roof cleaning professionals as well. Also, since it’s an oxygen-based cleaner with an incredibly short half-life, it can be used without any concern for your lawn, landscaping, pets, or children, as it’s completely safe for them.

Like every eco-friendly cleaner, you’ll want to use a low-speed pressure washer after the cleaner has been applied to accelerate the process. If you’re looking for more immediate results in one step, you may want to check out a bleach-based cleaner, like RMR-86. What roof cleaner will you use? Tell us in the comments.

About Brandon Potters

Hi, I’m Brandon and I can’t express how excited I am that you chose The Saw Guy as your resource for project ideas, tool reviews, and all-around guide to the world of DIY. I spent years in the construction industry refining my knowledge of various trades and even spent a few years working at a major hardware store. ​If there is anyone who can help you make a well-informed, unbiased, budget-conscious decision, it’s me and my team.

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