Let’s talk about the different methods of cleaning moss off your roof!

To provide a comprehensive understanding, we will outline the top 10 options available and offer three ratings for each method, helping you evaluate the risks and benefits effectively.

First, the Effectiveness Rating (0-10). This rating measures how well the method addresses the moss problem. A score of 0 indicates that the method is entirely ineffective, while a score of 10 signifies that the method will leave your roof looking brand new.

Second, the Personal Safety Rating (0-10). This rating assesses the potential dangers associated with each method for homeowners. It considers factors such as the likelihood of inhaling harmful chemicals or the risk of falling from the roof. A score of 0 indicates extreme danger and a method that should be avoided at all costs, whereas a score of 10 implies complete safety and risk-free application.

Third, the Environmental Rating (0-10). This rating evaluates the potential harm a method may cause to your home or the environment. A score of 0 suggests a high probability of causing damage to your home or the surrounding environment while a score of 10 means the method is entirely safe.

With these rating systems in mind, let’s delve into the details of each method.

1: Laundry Detergent (Effective: 0.5/10; Safety: 5/10; Environmental: 7/10)

Total Score: 13.5/30

We’re not really sure who started this rumor but we’ve heard it suggested several times over the years and have even seen some homes where the owner has tried it. The idea that powdered laundry detergent can be used to clean moss off roofs likely stems from its detergent properties and widespread household use. In the past, homeowners often relied on readily available household products for various cleaning tasks due to limited access to specialized products. As such, they experimented with what they had on hand, including laundry detergents. As with many home remedies, the suggestion to use powdered laundry detergent likely spread through word of mouth and anecdotal evidence. If a few individuals claimed to have found success with it, they might have shared their method with others, perpetuating the myth. Some people might have even confused the ingredients in laundry detergent with those in specialized moss removal products. Certain moss removers contain similar surfactants or alkaline substances, leading homeowners to believe that laundry detergent would be equally effective. While powdered laundry detergent might kill some moss due to its cleaning properties, it's not designed for this purpose and can be less effective than specialized products. Moreover, using it improperly can harm your roof and surrounding plants, making it a less advisable solution.

Solution 2: Vinegar (Effective: 2/10; Safety: 5/10; Environmental: 4/10)

Total Score: 11/30

White vinegar is another common household item that homeowners claim can effectively remove moss. A solution of equal parts vinegar and water is sprayed on the moss, left to sit for a while, and then rinsed off. This is another example of a product that can seemingly do everything! Clean windows, remove rust, clean your roof…the list goes on. While vinegar may be able to kill some organic growth on your roof, there are far more cost friendly and effective methods on this list. Let’s keep the vinegar in the kitchen and off the roof!

Solution 3: Zinc Strips (Effective: 2/10; Safety: 7/10; Environmental: 3/10)

Total Score: (12/10)

Installing copper or zinc strips along the roof ridge is a method used to prevent moss growth. These strips function by releasing ions when rainwater washes over them, which then inhibit the growth of moss. However, the effectiveness of this method is often over-exaggerated.

There are several factors to consider with this approach. Firstly, the strips are typically only minimally effective for about five years. Beyond this period, their capacity to prevent moss diminishes significantly. Additionally, the installation process involves hammering the strips into your roof, which can create potential points for water intrusion, thereby compromising the roof's integrity.

In practical observations, it’s not uncommon to see moss growing directly on these strips (we’ve seen it ourselves!), which questions their overall efficacy. Given these limitations, relying on copper or zinc strips is not the best long-term solution for moss prevention on your roof.

Solution 4: Baking Soda (Effective: 0/10; Safety: 5/10; Environmental: 10/10)

Total Score: 15/30

We’ve heard some people claim that sprinkling baking soda directly on the moss and leaving it for a few days can dehydrate the moss, causing it to die. Here’s the truth: This simply doesn’t work, Especially in our wet, PNW climate. This myth may have originated from the look of baking soda. It matches the look of common contractor grade moss removal chemicals so homeowners may have just assumed it would work.

Solution 5: Bleach (Effective: 7/10; Safety: 3/10; Environmental: 7/10) Total Score: 17/30

A mixture of bleach and water is a popular home remedy for roof moss, thanks to its active ingredient, sodium hypochlorite, which is also found in many professional roof cleaners. While bleach can effectively kill moss, it must be used at the right concentration and with proper precautions. Household bleach typically contains around 5% sodium hypochlorite, but this potency can drop to about 3% as it sits on the shelf. For effective moss removal, you’d need to apply bleach at full strength, possibly in multiple applications, making it quite costly. Moreover, bleach can damage most consumer-grade chemical sprayers, and using it safely requires full respirators with the correct chemical cartridges and other safety gear. In short, while bleach can work, it's often impractical and expensive for homeowners to use safely and effectively.

Solution 6: Dish Soap (Effective: 0/10: Risk Rating: 4/10; Environmental: 8/10)

Total Score: 12/30

We’ve heard claims that a mixture of liquid dish soap and water can clean roof moss, but after some research, we concluded it simply doesn’t work.

The idea is that spraying the moss with dish soap and letting it sit for 24 hours will break down the moss cells. However, while dish soap is excellent for cleaning dishes and used by many professional window cleaners, it’s ineffective against roof moss.

Dish soap contains surfactants that remove oils, grime and dirt, but the organic matter, like moss, remains attached and unaffected. While dish soap is environmentally friendly and great for cleaning oil off ducks, it doesn’t impact moss.

In short, save the dish soap for your kitchen and consider more effective solutions for roof moss removal!

Solution 7: Moss Out (Effective: 8/10; Safety: 5/10; Environmental: 3/10)

Total Score: 16/30

Another common approach you might hear about is to head over to your local home goods store, grab a jug of “Moss Out,” and sprinkle it on your roof. Moss Out relies on Zinc Sulfate, which is pretty effective at killing moss. But there are some things you need to consider before going down this route. First, Zinc Sulfate can have a significant environmental impact. If it's not managed properly, the runoff from rain can carry the chemical to plants around your house, potentially killing them. And if your drainage system leads to any water bodies like lakes, rivers, or even storm drains, we highly recommend steering clear of this option. The chemicals can cause lasting damage to natural wildlife in the water. Like any method, using Moss Out requires you to be cautious during application to avoid any accidents. So, while it’s an effective moss killer, weighing these environmental and safety concerns is a must.

Solution 8: Pressure Washing (Effective: 10/10; Safety: 1/10; Environmental: 0/10)

Total Score: 11/30

Using high pressure on an Asphalt Shingle Roof is strongly discouraged. Some homeowners, and unfortunately even some contractors, resort to pressure washers to remove moss. While this method might effectively eliminate moss, it WILL cause significant damage to the roof. A single session with a pressure washer can cut the lifespan of an Asphalt Shingle Roof in half and immediately void its warranty. Therefore, this approach is not recommended under any circumstances. When it comes to Concrete or Tile roofs, using a pressure washer can be acceptable, but only under very specific conditions. Roof manufacturers provide precise pressure guidelines that must be adhered to in order to avoid damage. Additionally, the inherent dangers of maneuvering hoses around on a wet roof present significant safety risks, making this method unsuitable for homeowners. It is crucial to follow the manufacturer's instructions and consider the associated hazards before opting for this cleaning technique.

Solution 9: Brushing (Effective: 8/10; Safety: 2/10; Environmental: 6/10)

Total Score: 16/30

Using a stiff brush to manually scrub moss from your roof is a straightforward but labor-intensive approach. This method entails using a scrub brush attached to a pole to gently remove moss without causing damage to the shingles. It's crucial to handle the brush with care, as aggressive scrubbing can harm the roofing materials.

Typically, the objective is to remove approximately 80% of the moss through brushing, followed by a chemical treatment to eliminate any remaining moss. This two-step process ensures that the roof is thoroughly cleaned without excessive mechanical wear.

However, there are significant downsides to this method. The physical effort required can be substantial, and spending extended periods on your roof increases the risk of falls and personal injury. Therefore, while this technique can be effective, it necessitates caution and proper safety measures to mitigate potential hazards.

Solution 10: Hire a Pro (Effective: 10/10; Safety:10/10; Environmental: 10/10)

Total Score: 30/30

If you’ve made it this far and find yourself thinking, “This seems like a lot more to consider than I thought,” you are not alone. Deciding on the right method, executing it effectively, and ensuring safety are significant factors in the process of cleaning your roof. The complexity and risks involved often make it a daunting task for homeowners. Therefore, we recommend avoiding the risks and hiring a professional. A professional will not only ensure the job is done correctly but will also carry it out swiftly and safely. This allows you the peace of mind to relax and enjoy your clean roof from the comfort of the ground. If you suspect your roof may have a problem with moss growth, give us a call at (206) 484-9879. We would be happy to come out and take care of your home.