Combatting Roof Algae and Moss: Tips for a Cleaner Roof

Roof algae and moss might appear to be mere aesthetic issues at first glance, but they can cause substantial problems if not addressed promptly. These uninvited guests can degrade your roofing materials, leading to water leaks and reducing your property’s curb appeal as well as more common problems.

In this blog, SHS Roofing will delve into how to identify these pesky growths and offer various solutions to keep your roof clean and in good condition.

The Problem: Algae and Moss on Your Roof

Algae and moss flourish in damp, shaded areas, and your roof is a perfect breeding ground, especially if it doesn’t receive ample sunlight. Over time, these growths can deteriorate the roofing materials, leading to leaks and reducing the lifespan of your roof.

Moreover, a roof tarnished by algae and moss can be an eyesore, which could significantly reduce your property value should you decide to sell your home.

Identifying Algae and Moss

It’s crucial to know how to distinguish between algae, moss, and other types of roof discolouration. Algae usually appear as dark streaks, while moss has a more raised, fuzzy appearance.

It can be easy to mistake algae and moss for dirt or soot, so keen observation is necessary. When in doubt, it’s wise to consult a professional for an accurate diagnosis.

Prevention Methods

Proper Roof Maintenance

Regular roof maintenance is vital in preventing the growth of algae and moss. This involves cleaning gutters to prevent water pooling and removing any debris like fallen leaves.

These simple steps can significantly reduce the likelihood of algae and moss taking root on your roof.

Choose Algae-Resistant Shingles

Algae-resistant shingles are infused with copper or zinc granules that deter algae growth. They are an excellent option for homes situated in damp climates or shaded areas.

However, these shingles can be more expensive than regular ones, and it’s essential to weigh the pros and cons before making a decision.

Improve Roof Ventilation

A well-ventilated roof can dramatically reduce the chances of algae and moss growth. Good airflow ensures that the roof dries quickly, leaving no room for algae or moss to flourish.

Methods to improve ventilation include adding ridge vents or soffit vents, which help to circulate air effectively.

DIY Cleaning Solutions

Chemical Cleaners

Various chemical solutions on the market can eliminate algae and moss effectively. Zinc or copper-based solutions are generally the most effective.

Always read the manufacturer’s guidelines carefully and ensure you take the necessary safety precautions like wearing gloves and eye protection.

Natural Solutions

For those who prefer a more environmentally friendly approach, a vinegar and water solution can also be effective in combating algae and moss. Mix equal parts of white vinegar and water, and apply it to the affected areas using a sprayer.

Let it sit for several minutes before rinsing it off with a hose.

When to Call a Professional

If you’ve tried multiple methods and still find that the algae and moss are persistent, it’s time to call in the professionals. Another sign that you may need expert assistance is if the algae or moss has led to visible damage such as curled or missing shingles.

When choosing a roofing contractor, ensure they are certified and come with good recommendations.

Safety Precautions

Before you embark on any roof-cleaning exercise, it’s crucial to take necessary safety precautions. Always use a sturdy ladder and ensure it is well-anchored before climbing. Opt for rubber-soled shoes that provide good traction to minimise the risk of slips and falls.

Additionally, it’s advisable to have someone on the ground to act as a spotter and assist in case of any mishaps.


Combatting algae and moss on your roof is not just about enhancing its aesthetic appeal but also about extending the lifespan of your roofing materials. Through regular maintenance, the right choice of materials, and effective cleaning solutions, you can keep your roof in tip-top condition.

Remember, safety comes first, so don’t hesitate to seek professional help when the situation is beyond your capabilities.