How to Clean a Roof: A Guide to Commercial Roof Cleaning

Your commercial roof plays a vital role in protecting your property, ensuring energy efficiency, and maintaining curb appeal. Over time, however, dirt, moss, algae, and debris can accumulate, compromising its performance and appearance. Knowing how to properly clean a roof is essential for extending its lifespan and preventing costly repairs.

In this guide, we’ll cover the steps for effective commercial roof cleaning, the tools and methods to use, and why hiring professionals can make all the difference.

Why is Commercial Roof Cleaning Important?

Regular roof cleaning isn’t just about aesthetics—it’s also about functionality and safety. Here’s why commercial roof cleaning is critical:

• Prevents Damage: Moss and algae can trap moisture, leading to leaks and structural issues.
• Extends Roof Lifespan: Routine cleaning reduces wear and tear, prolonging the life of your roof.
• Improves Energy Efficiency: A clean roof reflects more sunlight, helping to regulate indoor temperatures and lower energy costs.
• Enhances Curb Appeal: A spotless roof boosts the overall appearance of your commercial property.

Steps to Clean a Commercial Roof

1. Inspect the Roof

Before starting, conduct a thorough inspection to identify areas that need attention. Look for:

• Moss, algae, or lichen growth.
• Stains or discoloration.
• Blocked gutters and drainage systems.
• Cracks, leaks, or damaged areas.

Addressing these issues during cleaning can prevent further damage and ensure a more effective clean.

2. Clear Loose Debris

Remove leaves, branches, and dirt from the roof using a soft-bristle broom or blower. Clearing debris ensures the cleaning process is more thorough and prevents blockages in gutters or downspouts.

3. Choose the Right Cleaning Method

The method you use depends on your roof’s material and the type of dirt or stains present. Here are the most common cleaning techniques:

Pressure Washing

• Best For: Concrete, asphalt shingles, or metal roofs.
• How It Works: High-pressure water jets remove dirt, moss, and algae effectively.
• Caution: Use a moderate pressure setting to avoid damaging the roof surface or dislodging shingles.

Soft Washing

• Best For: Delicate or older roofs, including slate or clay tiles.
• How It Works: A low-pressure spray combined with cleaning solutions gently removes grime and organic growth.

Chemical Cleaning

• Best For: Removing tough stains, moss, and algae.
• How It Works: Apply a biocide or specialised roof cleaner, let it sit for the recommended time, and then rinse thoroughly.

Steam Cleaning

• Best For: Sanitising and removing moss and algae without chemicals.
• How It Works: High-temperature steam loosens dirt and kills organic growth, ideal for eco-friendly cleaning.

4. Apply a Biocide Treatment

After cleaning, apply a biocide treatment to prevent moss, algae, and lichen from regrowing. This treatment penetrates the surface, ensuring long-lasting protection and reducing the frequency of cleaning.

5. Clean the Gutters and Downspouts

While cleaning the roof, ensure the gutters and downspouts are free of debris. Blocked drainage systems can lead to water pooling and roof damage.

6. Rinse and Inspect

Rinse the roof thoroughly with water to remove any leftover cleaning solution. Conduct a final inspection to ensure all dirt, stains, and organic growth have been removed and check for any new damage.

Tools Needed for Roof Cleaning

Here’s a list of essential tools and equipment for roof cleaning:

• Soft-bristle broom or blower for debris removal.
• Pressure washer or garden hose with a high-pressure nozzle.
• Biodegradable cleaning solution or biocide treatment.
• Safety gear, including harnesses, gloves, and non-slip footwear.
• Ladders or scaffolding for safe roof access.

Safety Tips for Roof Cleaning

Cleaning a roof can be hazardous, especially for commercial properties with large or high surfaces. Follow these safety tips to minimise risks:

• Use Safety Gear: Wear a harness, helmet, and non-slip shoes to prevent accidents.
• Work in Teams: Never attempt to clean a roof alone. Have a team member assist or monitor from the ground.
• Check the Weather: Avoid cleaning on rainy or windy days, as wet surfaces increase the risk of slips and falls.
• Hire Professionals: For larger or more complex roofs, hiring commercial roof cleaning specialists ensures safety and efficiency.

Why Hire Professional Commercial Roof Cleaning Specialists?

While some property owners may opt for DIY cleaning, hiring professionals offers several advantages:

1. Expertise and Equipment

Professionals have the knowledge and tools to clean a variety of roof types safely and effectively.

2. Long-Lasting Results

Specialists use treatments like biocide to prevent moss and algae regrowth, reducing the need for frequent cleaning.

3. Damage Prevention

Improper cleaning methods can cause damage to your roof. Professionals know the best techniques for each material, ensuring your roof remains in excellent condition.

4. Time and Cost Efficiency

Hiring specialists saves you time and ensures thorough cleaning, preventing costly repairs caused by neglect.

How Often Should You Clean a Commercial Roof?

The frequency of commercial roof cleaning depends on factors such as location, roof type, and weather conditions. As a general rule:

• Urban Areas: Clean every 6–12 months due to higher pollution levels.
• Rural Areas: Clean every 1–2 years, or more often if moss and algae growth are common.
• After Severe Weather: Clean as needed to remove storm debris and prevent damage.

Keep Your Roof Clean and Functional

Regular commercial roof cleaning is essential for maintaining your property’s safety, energy efficiency, and appearance. By following the steps outlined above—or hiring professional roof cleaning specialists—you can ensure your roof remains in top condition for years to come.

Looking for expert commercial roof cleaning services? Contact Exterior Express today for reliable and efficient roof cleaning solutions. Our specialists use advanced techniques and equipment to ensure your roof stays clean and protected. Get your free quote now!