Best Time of Year to Remove Moss From Roof

Irvin Cramer

By Irvin Cramer

Last Updated on July, 2024

Have you ever looked up at your roof and noticed the green or black patches? Are you struggling to tackle this mossy mess on your roof?

If YES, you’re not alone, and at the right place. Moss might seem harmless, but it can wreak havoc on your roof if left unremoved. Many homeowners have to spend a lot to repair the damages caused by them. 

Now, don’t panic!

In this article, I’ll explain the perfect timing for removing moss and give you some simple tips for maintaining your roof to prevent moss regrowth. 

After reading this article, you’ll be able to maintain your roof in tip-top shape.

If you’re ready, let’s start. 

Quick Summary

  • The best time of year to remove moss from a roof is summer for manual removal and spring for chemical treatments.
  • It is important to prioritize safety while removing moss from a roof, as accidents such as falling or slipping can occur.
  • In addition to regularly removing moss, preventative measures such as proper ventilation and installing zinc or copper strips can help prevent future moss growth on a roof.

What’s the Best Time of Year to Remove Moss From Roof?

a professional cleaning moss from roof

Summer is the ideal time to remove moss manually, while spring is the best to remove moss by applying chemical treatments as it is the moss-growing season.

Let’s discuss the reasons behind seasonal moss removal. 

During summer, moss enters the dormant state, which means it stops growing. Additionally, due to the heat, moss becomes dry, brittle, and less attached to roof shingles. Hence, it’s easier to scrape it off the roof. 

Moss grows actively in the spring. When you apply chemical treatments they interact directly with the growing cells, causing maximum damage and death. Furthermore, as there’s no rain, the chemicals won’t wash off. 

Attention: Moss thrives on damp surfaces and becomes frozen during the winter. Therefore, it’s difficult to remove them in the winter season. Moss removal in the winter is not recommended.

Methods of Roof Moss Removal

There are different methods for removing moss from your roof. Let’s look into them in detail.

Manual Removal

Manual moss removal is a straightforward method. You brush off the moss manually with a broom or a similar tool. 

All you need is a broom, a sturdy ladder, and protective gear. 

Start from the top and sweep towards the bottom. Don’t apply too much pressure, as it can remove the protective granules found on the roof and damage shingles. 

It’s better to wait for the summer months if you want to remove roof moss manually. During summer, moss dries up and it is easy to sweep it off. 

During winter, moss attaches to the roof surface tightly, and the roof will be slippery. You’ll have to exert extra physical labour to remove them. So, it’s better not to remove moss manually in wet weather. 

Pressure Washing

a professional pressure washing the moss from roof

Pressure washing is an efficient method of roof moss removal. This method can quickly remove large areas of moss. You spray water at high speed using a pressure washer to dislodge moss from the roof surface. 

Ensure you spray the water at a downward angle so that water will flow down easily from the roof.  Avoid power washing with too much water pressure as it can cause irreparable damage to the roof, such as:

  • Loosen the waterproof flashing, leading to leaks in the roof. 
  • Create deep crevices on the roof tiles, allowing algae to grow.
  • Change the colour of the roofing material.

Chemical Treatments

Chemical treatment is designed to kill moss from its roots, making it the best method for roof moss removal. Many different types of chemicals are available for this. You can attach some at the end of a garden hose and spray from the ground level by applying enough water pressure. 

There are certain chemicals that you have to mix and apply on the roof. However, you must remove the moss manually or with a light pressure wash after it’s dead. While applying chemicals, remember to follow the instructions carefully to achieve the best results.

Safety Precautions While Removing Moss From the Roof

Are you planning to remove moss from your roof by yourself? If so, don’t take this task lightly. You could be at risk of accidents such as falling or slipping. Hence, you must prioritise safety. 

Below are some safety precautions to follow:

  • Avoid roof moss removal in wet and windy weather, as the roof surface becomes slippery. 
  • Use a sturdy ladder and place it properly on your roof. 
  • Wear footwear with non-slip soles to prevent slips and falls. 
  • Wear safety gear, including gloves and protective eyeglasses. Gloves protect the hands from scratches and cuts when you manually remove moss, and eyewear prevents loose debris from getting into your eyes.
  • Use the right tools and ensure you correctly use them to avoid accidents.
  • Have a friend or a family member with you rather than doing it alone.
  • Always be on the alert. Step carefully so you don’t fall off the roof. 

Pro tip: Hiring a professional roofing contractor is recommended rather than removing moss yourself. 

Why? First, professional roofers are experienced in moss removal. Hence, they know how to maintain your roof’s integrity, preserve the original colour, and prevent any other damages while removing moss from the affected area. Second, you can ensure your safety.

How Long Does Moss Removal Last?

a person removing the moss from a roof

Moss removal can last for a few months to a few years. It depends on several factors. Let’s look at them:

  • Climate: Moss grows fast in moist areas. Hence, if you’re living in an area with frequent rainfall, you’ll experience rapid moss growth on your roof. 
  • Roof moss removal method: Moss remover chemicals combined with preventive measures give you long-lasting results, especially when it’s done professionally.
  • Location of your house: Moss needs sunlight but prefers shady areas. So, if overhanging branches shade your roof, you will see rapid moss growth.
  • Roofing materials and roof slant: Some roofing materials make it easier for leaves, twigs, and other debris to deposit rather than wash off. Organic matter speeds up the growth of moss. 

If your roof is slightly slanted, there’s more chance of forming standing pools of water due to rain. Water/moisture spreads moss quickly. 

Tips to Prevent Moss Growth on the Roof

Removing moss is not enough to maintain a moss-free roof. You must take preventive measures to stop or slow down future moss growth. It can make all the difference. 

Below are some maintenance tips:

  • Regular cleaning: Keep your roof clean and dry. Remove any debris, leaves, and twigs from the roof’s surface. 
  • Proper ventilation: Ventilate your roof properly to allow moisture to escape and not accumulate on the roof. 
  • Maintain clean gutters: Clean your gutters so the water can flow freely from roof to the ground without accumulating. 
  • Cut down overhanging branches: Trim down branches that overhang your roof. This removes shade, which is important for moss growth. 
  • Install copper or zinc strips: Installing zinc or copper strips is a long-term solution to remove moss from your roof. Zinc provides 5-8 years of moss protection, and copper a few years more than that. 

How do zinc and copper strips remove moss from your roof?

When rains start falling, zinc strips release zinc particles that can kill moss effectively. Copper strips release copper sulphate. It’s a natural herbicide and can kill the moss on your roof. 

What Happens if You Don’t Remove Moss From Your Roof?

a picture of a house roof filled with uncleaned moss

Moss grows in damp, shady areas. A small patch of moss on your roof is not a problem. However, if moss spreads onto a large area, it can cause several issues. 

I’ll list out some of them:

  • Moss absorbs moisture like a sponge, keeping your roof wet all the time. If moisture gets underneath the tiles, they’ll degrade.
  • Moss provides a living habitat and a breeding ground for certain insects and pests. These insects can scatter moss spores and cause them to spread quickly. Additionally, pests can invade your home.
  • Excessive moss can block and damage the drainage points. 
  • Moss appears as a thick green or black layer on the roof. It reduces your home’s structural integrity and aesthetics, making it less appealing to buyers when selling. 
  • Moss creates a slippery surface on your roof, making it difficult and dangerous for you to walk on when you need to carry out roof repairs. 

In summary, excessive moss on your roof can cause severe damage and costly repairs if left unremoved. Hence, don’t think moss treatments are a waste of your money. Removing them on time and regular maintenance of roofs can save you a lot in the long run. 

Are You Ready to Tackle the Moss Damage on Your Roof Effectively?

Moss appears as green/black patches on your roof. If left unremoved, they can cause water damage, roof disintegration, pest invasions, and many other problems. Hence, you must remove moss from your roof as soon as you see it. 

Summer is the best month for the manual moss removal process, and spring is perfect for killing moss with chemicals.  Maintain your roof regularly and follow other preventive tips to prevent/slow down moss regrowth. 

It’s better to hire a professional moss removal service than doing it yourself. It ensures your safety and avoids damages to the roof caused due to incorrect moss removal methods. 


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