April 11, 2025

How to Clean Moss Off Your Roof

Green moss on your roof — not just an aesthetic problem. It’s a risk to the entire structure. If it’s not removed in time, you may need major repairs sooner than you think. Here’s why moss is dangerous for roofing, how to remove it, and who you can trust with this procedure.

On which roofs does moss grow?

Any homeowner can face a situation where their roof begins to grow moss. However, it most commonly occurs on porous roofing materials, like asphalt shingles or wooden shakes. The favorable conditions for moss growth are high humidity and shade.

Moss is least likely to appear on metal roofs. Their smooth surface dries quickly after rain and doesn’t become a comfortable environment for fungal growth.

Moss requires moisture to grow, so it often starts to grow on the north side of the roof and in areas shaded by trees. Flat or low-pitched roofs are also at risk because moisture drains more slowly. As a result, moisture stays on the roof longer, and moss has more time to grow.

How to tell if there is moss on your roof

Moss is easy to spot. Simply look at the roof from the north side or in particularly shaded areas. If there are fluffy green clumps in the cracks or gaps between shingles, it’s moss. Areas where water accumulates create ideal conditions for moss growth, allowing spores to settle. It’s best to start removing the vegetation as soon as you notice the first patches.
Moss harms both the aesthetics of the house and the functionality of the roof.

How moss harms your roof

Moss is a non-vascular plant that thrives in a damp, shaded environment. In a forest, it looks natural and indicates healthy ecology, but on a roof, it becomes a destructive environmental factor. It retains moisture, which gradually damages roofing materials.

Destroys roofing materials: Moss retains and accumulates moisture, which harms roofing materials. It accelerates wood rot and can lead to leaks. The high humidity also creates the perfect conditions for mold, which is harmful to human health.
Attracts pests: This environment attracts rodents and insects, which further compromise the integrity of the roof. Over time, these problems accumulate, leading to large-scale damage, and the roof may require major repairs or, in the worst case, replacement.
A moss-covered roof is unsafe and can become a breeding ground for harmful mold, which poses a risk to your health.

Affects the aesthetics of the roof

Moss-covered shingles look old and neglected. The appearance of the house deteriorates, making it look abandoned or worn-out. It’s perfect for a horror movie scene, but not for living.
A clean roof enhances the home’s aesthetic appeal, which in turn raises its market value. It creates a well-maintained look.

Clogs the gutter system

Gutters become clogged over time with leaves, branches, and debris, and when you add moss, water can no longer flow freely off the roof. It pools at the edges and causes further moss growth.
It’s important to regularly clean gutters to prevent moss from spreading and to maintain the roof’s good condition. Proper drainage ensures that the plant won’t take root.

Lifts shingles

Over time, the plant begins to grow under the shingles, lifting them up. This allows water to seep into the attic space, damaging the supporting structures, interiors, furniture, and appliances.

It’s useful to know: Small patches of moss don’t cause major problems. However, as time goes on, they spread across the entire roof, compromising the shingles’ seal and destroying roofing materials. That’s why moss should be removed as soon as it’s spotted. If the damage is serious, the shingles may need to be removed as well.

Professional roofers can help determine what kind of intervention is needed for your roof.

Tools required for cleaning

If you plan to carry out the work yourself, gather the necessary tools:

Backpack or pump sprayer (for weeds)
Caulking gun
Climbing boots, along with a harness, rope, and carabiner
Extension ladder
Broom with a long handle
Multi-tool with a smooth attachment
Tin snips
Tool belt
Trash bag

Work at height requires special safety measures, and you will need to carry all the tools with you to avoid descending the roof every time you need something.

Materials needed for moss removal

Along with the tools, you will need some materials:

Moss killer in liquid or granular form
Zinc roofing strips
Caulking tubes
Water

Next, we will explain how to use these tools and materials.

Safety is a must

Working on the roof is not easy. You need to protect yourself from the possibility of falling. For this purpose, use climbing gear, safety ropes, and harnesses. If you’re using these for the first time, study the instructions and practice in a safe place. Make sure the anchor bracket fits your roof type.
Choose shoes with non-slip soles. Move carefully across the roof to avoid damaging roofing materials. This is especially important for metal shingles: even small stones or sand can scratch the surface.
It’s advisable to have a partner for the work. They will hold the ladder, hand you tools, and can call for help in an emergency.

Step-by-step instructions for moss removal

Moss can be removed from the roof year-round. It grows actively in spring and autumn, so don’t miss the moment. However, during summer, it goes dormant and becomes brittle, making it easier to remove.
It’s best to perform the work on a cloudy day. This way, the moss remover will not evaporate too quickly. But also make sure no rain or thunderstorms are expected.

Step 1: Prepare the work area

Set up the ladder and secure it with a ladder lock. It’s best to place it on a firm surface, such as a driveway or paved area, to ensure the ladder doesn’t move while you are on it.
Wear protective goggles, a respirator, and rubber gloves to shield yourself from the chemicals you will use.
Cover the lawn and plants near the roof with plastic film. This will prevent moss spores, runoff water, and chemicals from damaging the vegetation. Some recommend spraying the area with a dishwashing solution after treating the roof to help with moss spores. Choose natural solutions to avoid harming the environment.

Step 2: Spray water on the moss

Moss is easier to remove if it is hydrated and becomes loose. To do this, climb onto the roof with a hose and spray water under low pressure. Work from the top down to avoid lifting the shingles.
Tip: Do not use high-pressure washers, especially on asphalt shingles. The pressure can dislodge protective granules, loosen the shingles, and force water into the seams between the elements.

Step 3: Remove the moss

Once the moss is wet, it can be removed with a soft-bristle brush or a damp cloth. Some people prefer using a construction spatula.
Start from the upper part of the roof, working your way down. If the top is difficult to reach, use a long-handled brush or attach the spatula to the brush to work from a distance.
If you notice the top layer of asphalt shingles starting to peel off, stop the process. The next step will help remove the moss.

Step 4: Apply a moss removal solution

If the moss has deeply embedded into the shingles, a chemical solution will be necessary. It can be either liquid or granular. If using granular, dissolve the granules in the specified amount of water (as per the instructions).
A sprayer or pump sprayer is the best tool for applying the solution. This way, the solution will soak into the moss without excess dripping off the roof. Allow the solution to sit for a while—no less than 15 minutes. In some cases, you may need to wait for a full 24 hours (check the instructions).

Step 5: Lift the shingles

Carefully cut the material between the bottom of the ridge shingles and the top surface of the next layer. Lift the ridge elements to access the space underneath.
Do this around the entire perimeter.

Step 6: Install zinc strips

You will need a roll of galvanized roofing tape, a caulking gun, and metal scissors.
Cut a strip of the tape about 60-90 cm in length. Stick it under the shingles you trimmed in the previous step. Then, use the caulking gun to secure the shingles on top of the galvanized tape. At least half of the tape should be exposed on the outside.
Repeat this process around the entire perimeter of the roof, making sure all roofing elements are adhered with the tape.

Tip: When the zinc strip comes into contact with water, it releases ions that prevent the growth of moss. You can buy zinc strips at any hardware store.

Step 7: Wait for the moss to fall off

The next few weeks will show if your efforts were successful. If everything was done correctly, the moss will start to brown and fall off by itself. If the moss hasn’t changed after two weeks, apply more moss remover.
If the moss is dry but not falling off, use a soft-bristle brush to remove it manually.

Methods you should not use

A small amount of moss can be removed on your own. However, if it covers a significant portion of the roof or if the slopes are too steep, it is better to leave the work to professionals.
There are many incorrect methods for removing moss. They can be effective but also create additional risks, such as damaging shingles or the roof itself.
We do not recommend using the following methods:

Washing off the moss. Many people simply try to wash the moss off the shingles. However, this can damage the protective layer of the roofing material, including metal roofs. The plant clings tightly to the surface where it has taken root.
Pressure washing. This technique is powerful enough to remove moss, but it also destroys the adhesive that holds the shingles in place, and may lift shingles. Pressure washing can also harm asphalt coatings, changing their color and lowering their performance. High-pressure washing can lead to leaks.
Aggressive chemicals. High concentrations of bleach or other chemicals can damage shingles, leading to leaks. These harsh substances can also contaminate the yard, soil, and groundwater.
Another reason to avoid these methods is that they may void the roof’s warranty. This happens because the homeowner is improperly using the roof covering. If you want to remove moss yourself but are unsure if you can do it safely, consult with professional roofers.

Frequently Asked Questions

Moss removal is a common task for homeowners in Cape Cod. Therefore, we receive a variety of questions.

Can I remove moss myself, or should I hire a professional?

If the moss is minimal, you can do the work yourself. However, for large-scale tasks, it’s better to hire a professional. Additional risk factors include steep roofs. Working at height is always dangerous. You will need special equipment, and it’s better to have a partner. Therefore, in most cases, the risks are not justified, and it’s safer to hire qualified roofers.

What natural remedies can I use to prevent moss from growing on my roof?

A mixture of white vinegar and water has proven effective. If you mix equal parts of these substances in a sprayer or garden sprayer and add a few drops of dishwashing liquid, it will help prevent moss growth. Regularly treating the roof — every few months — is recommended.
Other preventive methods include trimming hanging branches. A common cause of moss growth is the shade cast by trees. Removing this shade reduces the risk of moss growth.

Does regular cleaning of gutters help prevent moss growth on the roof?

Yes. Moss often starts growing in blockages that form inside the gutters. Additionally, when the drainage system is working efficiently, water doesn’t stagnate on the roof’s surface, making conditions less favorable for moss growth.

Are there eco-friendly products for killing moss on the roof?

Yes, there are eco-friendly solutions available. These are typically made from biodegradable soap, apple cider vinegar, or other types of vinegar.

What should I do if the moss problem persists even after applying chemicals?

If you’ve treated the roof with special chemicals but the moss hasn’t disappeared, we recommend consulting professional roofers. They will conduct a thorough roof inspection, use the most effective treatment methods, and provide advice on future maintenance. This will help not only remove the moss but also prevent it from returning.

How do moss strips work, and are they effective?

Moss strips are made of zinc or copper. They work by releasing particles (ions) during rain, which negatively affect the moss spores. As water flows over these strips, it carries the particles that prevent moss growth.
This solution is considered effective and provides long-term protection for your roof against moss.

Dmitry Labkovich

Since 2002, I have dedicated my career to construction, starting as a cleanup worker and laborer. Despite tough conditions, I quickly mastered roofing and siding, and within six months, I was handling complex tasks. Later, I became a subcontractor, growing the business with a partner and expanding our team.

In 2011, I founded Roofing and Siding of Cape Cod and Boston. At the same time, I continued working with major firms, building a reputation through high-quality work and excellent service. In 2010, I joined the Coast Guard Reserve, which helped me develop leadership skills. Before my deployment in 2018, I built a reliable team that ensured steady company growth.

Today, Roofing and Siding of Cape Cod and Boston is a team of 30+ professionals, all OSHA-certified. We continue to expand while maintaining top-quality standards and exceptional customer service.

**Experience & Expertise**

- 20+ years in the roofing and siding industry
- Hands-on experience from laborer to business owner
- Managing a team of 30+ professionals
- Business development and client relations

**Education & Certification**

- Practical training in roofing and siding techniques
- OSHA safety certification
- Coast Guard Reserve service experience
- Ongoing professional development in construction

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