Roof treatment costs in New Zealand vary depending on your roof size and complexity. On average, prices range from $99 for smaller roofs (50–80 sqm) to $299+ for larger, more complex roofs.

Roof treatment helps protect your roof from moss, lichen, and algae, extending its life and improving water flow.

As a professional exterior cleaning company, we’ve seen how a well-maintained roof can enhance property value and prevent costly repairs.

In this guide, we’ll break down roof treatment costs and what affects pricing.

What Is Roof Treatment?

Roof treatment is a protective service designed to kill and prevent the growth of moss, lichen, and algae on your roof. It involves applying a chemical solution that works slowly over time, breaking down the organic growth and stopping it from returning.

This treatment is especially effective in New Zealand’s humid climate, where moss and lichen thrive. Unlike pressure washing, which can damage roofing materials, roof treatment is a gentler process that preserves your roof’s condition and extends its lifespan. Over time, it helps maintain your roof’s appearance, prevents water damage, and keeps gutters clear.

Roof Treatment Cost in New Zealand (Pricing Chart)

The cost of roof treatment in New Zealand varies depending on the size of your roof and its complexity.

Here’s a breakdown of typical pricing based on property size:

Property Size (sqm)	Roof Treatment Cost
50–80 sqm	$99
81–120 sqm	$149
121–180 sqm	$199
181–220 sqm	$219
221–290 sqm	$249
291–350 sqm	$259
351–450 sqm	$275
451–550 sqm	$285
550+ sqm	$299+ (depends on roof complexity)

How Roof Treatment Pricing Works

Roof treatment costs are mainly based on two factors:

1. Property Size (sqm): The larger the roof, the more chemicals and time are required for treatment.
2. Roof Complexity / Height: Higher, steeper, or difficult-to-access roofs increase the cost due to safety gear, extra labour, and potential for challenging roof conditions.

For homes with double-storey roofs or difficult roof access, a surcharge of $1.50 per extra sqm for double-storey roofs and $1.75 per extra sqm for very complex roofs is typically added.

What Affects Roof Treatment Pricing?

Several factors influence the cost of roof treatment, which is why prices can vary significantly.

Here’s a breakdown of the key elements that impact pricing:

1. Property Size (sqm)

The larger the roof, the more treatment is required. Larger roofs need more chemical solution and take longer to treat. For example, a 300 sqm roof will cost more to treat than a 100 sqm roof due to the increased amount of work involved.

2. Roof Complexity

• Height: A higher roof, such as on a two-storey or multi-level property, requires extra equipment and safety measures, leading to higher costs.
• Steepness: Steeper roofs are more challenging to access and clean, which may increase the price due to the added labour and safety gear needed.
• Access: Difficult-to-reach roofs (e.g., narrow or obstructed access) take longer and often require special equipment, resulting in a surcharge.

3. Roof Condition

If your roof has significant moss, lichen, or algae buildup, it will need a more thorough treatment. This could involve multiple applications or longer dwell times for the chemicals to work, increasing the cost.

4. Additional Services

Roof treatment is often bundled with other services, such as house washing or gutter cleaning. These packages can provide the best value since labour and equipment are shared across multiple tasks.

5. Surcharges for Special Conditions

• Double-storey homes: A typical surcharge of $1.50 per extra sqm applies for double-storey roofs, as these are harder to access.
• Very difficult roofs: If your roof has upper and lower levels or is steep, it may incur an additional $1.75 per extra sqm due to the increased complexity and safety measures.

What’s Included in a Roof Treatment?

A professional roof treatment involves more than just applying a chemical solution. Here’s what’s typically included in the service:

1. Chemical Application

The primary step in roof treatment is the application of a special moss and lichen-killing solution. This slow-acting chemical breaks down moss, algae, and other organic growth on your roof. The treatment is designed to work over several months, continuing to prevent regrowth.

2. Roof Inspection

Before applying the treatment, a professional will typically inspect your roof for any visible damage, like loose tiles, cracks, or blockages in the gutters. This ensures that the treatment is applied safely and does not exacerbate any existing issues.

3. Debris Removal

While not always included in basic roof treatment, debris removal may be offered as an extra. This involves clearing leaves, branches, and other debris from the roof’s surface, making it easier for the treatment to penetrate and work effectively.

4. Application of Preventative Coating (Optional)

Some companies offer an additional treatment after applying the chemical solution—such as a protective coating. This coating helps prolong the effectiveness of the roof treatment and adds an extra layer of protection to your roof against future growth.

5. Post-Treatment Advice

Once the treatment is complete, you’ll typically receive advice on maintaining your roof. For example, if you collect rainwater, it’s recommended that you disconnect your tank from the gutter line before the treatment. After treatment, wait for at least six rainfall events to pass before resuming rainwater collection.

How Long Before the Roof Looks Clean?

Roof treatment works gradually, so the results won’t be immediate. While the chemicals used in the treatment begin to break down moss, lichen, and algae almost immediately, it can take several weeks to see visible changes.

1. Immediate Effects

Right after treatment, you may notice that the moss and lichen begin to discolor and die off, but your roof might still look a little dirty. The treatment solution works slowly, and the appearance improves as it continues to break down the growths.

2. Rainwater Helps the Process

One of the key factors in the effectiveness of roof treatment is rain. Over the next few weeks, rain will wash away the dead moss and algae, revealing a cleaner roof surface. You’ll start to notice a cleaner look after one to two rainfall events.

3. Full Results

While your roof will appear cleaner shortly after treatment, the full results can take 6 to 12 months as the treatment continues to prevent regrowth. The roof will become noticeably cleaner, and the moss and lichen will not return quickly, thanks to the long-lasting effects of the chemical solution.

How Long Does Roof Treatment Last?

The effects of a roof treatment can last anywhere from 6 to 12 months, depending on several factors such as climate, roof material, and environmental conditions.

Here’s what you need to know about the longevity of roof treatments:

1. Typical Duration

Most roof treatments will continue to work for 6 to 12 months after application. During this time, the moss, algae, and lichen growth are actively killed and prevented from regrowing.

This helps protect your roof from damage caused by these organisms, which can trap moisture and lead to rotting or decay.

2. Environmental Factors

• Climate: Areas with heavy rainfall or high humidity may experience faster regrowth, requiring more frequent treatments.
• Roof Exposure: Roofs that are shaded by trees or have poor ventilation may need more frequent treatment due to higher moisture retention, which promotes the growth of moss and algae.
• Surrounding Vegetation: Homes with overhanging trees or lots of greenery are more prone to moss and algae build-up, potentially shortening the time between treatments.

3. Maintenance After Treatment

To maintain the effectiveness of your roof treatment, regular maintenance is important. If moss and algae begin to regrow, cleaning or reapplying the treatment every 1 to 2 years can help maintain a clean, protected roof.

Roof Treatment vs. Roof Replacement: Which Is More Cost-Effective?

When it comes to maintaining your roof, homeowners often face the decision between investing in roof treatment or a full roof replacement. While both have their benefits, roof treatment is usually the more cost-effective option for most homes. Here’s why:

1. Cost Comparison

• Roof Treatment: Typically ranges from $99 to $299+ depending on the roof size and complexity. Roof treatment is affordable and requires minimal disruption. It involves applying a chemical solution to kill and prevent moss, lichen, and algae growth, extending your roof’s life without the need for a full replacement.
• Roof Replacement: Roof replacement is a significant expense, often costing thousands of dollars. It involves removing the old roof and installing a new one, which can take several days and comes with high labour, material, and disposal fees.

2. Longevity

• Roof Treatment: Lasts between 6 to 12 months, but regular treatments every 1-2 years can help keep your roof in top condition for a longer period.
• Roof Replacement: A new roof can last 20 to 30 years, depending on the material. However, replacing your roof comes with higher upfront costs and significant maintenance expenses over time.

3. When to Choose Roof Treatment

If your roof is in relatively good condition but has minor moss or algae buildup, roof treatment is a great option. It helps protect the roof, improves its appearance, and prevents further damage, all for a fraction of the cost of a new roof.

4. When to Choose Roof Replacement

If your roof is severely damaged, leaking, or nearing the end of its life expectancy, a full replacement may be necessary. Roof replacement is a more permanent solution, but it is far more expensive than treatment.

5. Maintenance Savings

Regular roof treatment can prevent major damage over time, saving you money on future repairs or the need for a full roof replacement. It’s a simple, preventative measure that adds long-term value and protection to your home.

Roof Treatment Packages and Best Value Options

Roof treatments can often be bundled with other exterior cleaning services to offer more value and convenience. Combining services such as house washing and gutter cleaning with roof treatment can reduce overall labour costs and improve the appearance and functionality of your home.

Here’s how package deals typically work:

1. House Wash + Roof Treatment

• Starting from $345 + GST
• What’s Included: This package combines a full house wash with roof treatment. While the roof is treated to remove moss, algae, and lichen, the house’s exterior is cleaned, ensuring your entire property looks refreshed.
• Best For: Homeowners looking to improve curb appeal before selling or simply maintaining a well-kept property.

2. House Wash + Roof Treatment + Gutter Clean

• Starting from $590 + GST
• What’s Included: This comprehensive package covers house washing, roof treatment, and gutter cleaning. The gutters are cleared of debris to ensure water flows freely, preventing water damage or blockages.
• Best For: Homeowners looking for complete exterior maintenance, including essential services like roof cleaning and gutter upkeep to protect their home from water damage.

3. Why Bundling is More Cost-Effective

• Labour Savings: By booking multiple services together, the cost of labour is shared across the tasks, reducing the overall price for each service.
• Convenience: Instead of scheduling different services on separate days, package deals provide a one-stop solution that saves time and effort.
• Increased Value: These packages ensure that every area of your exterior is covered, which not only increases the property’s value but also ensures consistent long-term maintenance.

When Is the Best Time for Roof Treatment?

Choosing the right time for roof treatment can make a significant difference in the effectiveness of the treatment and the overall appearance of your roof. Here are the best times to schedule roof treatment:

1. Spring and Early Summer

The ideal time for roof treatment is during spring or early summer, when the weather is dry, and there is less chance of heavy rain. This allows the chemical solution to be absorbed effectively and reduces the risk of washing away the treatment before it has time to work.

Additionally, these seasons are less likely to have the extreme weather conditions that could interfere with the treatment process.

2. After Heavy Rain or Storms

If your roof has experienced heavy rain, storms, or significant moss and algae buildup, it’s a good idea to schedule treatment soon after these events. The treatment can help prevent further growth and water damage while improving the roof’s overall performance.

3. Before Selling Your Home

If you’re planning to sell your home, scheduling roof treatment a few months before listing is a great idea. A clean, well-maintained roof is one of the first things buyers will notice, which can positively impact the sale price. A treated roof also suggests that the home has been well-maintained, giving buyers confidence in its condition.

4. Regular Maintenance

For roofs that don’t have major issues but need regular upkeep, it’s best to schedule roof treatment every 1 to 2 years. This will help maintain your roof’s condition, prevent moss and algae buildup, and avoid costly repairs in the future.

5. Avoid Wet or Icy Conditions

While roof treatment works best in dry conditions, it’s important to avoid scheduling it during wet, icy, or extremely cold weather.

These conditions can affect the treatment’s effectiveness, and working on a wet roof can be dangerous. Always ensure that conditions are suitable for safe and effective application.

How to Choose a Roof Treatment Service

Choosing the right roof treatment service ensures your roof is properly cared for and protected. Here’s what to look for when selecting a provider:

1. Experience and Expertise

Choose a company with experience in roof treatment and exterior cleaning. Sun SoftWash has years of experience treating roofs across New Zealand, ensuring effective results without damaging your roof.

2. Safety Standards

Roof treatments often require working at height. Make sure the service provider follows safety protocols and uses appropriate gear. At Sun SoftWash, we prioritize safety by using proper equipment and trained technicians for all jobs.

3. Transparent Pricing

A reputable company will provide clear, upfront pricing with no hidden fees. At Sun SoftWash, we offer transparent pricing and will give you an accurate quote based on your property size and roof complexity.

4. Quality Products

Ensure the company uses high-quality, eco-friendly products. At Sun SoftWash, we use safe, biodegradable chemicals that are effective in killing moss and algae while being gentle on your roof and the environment.

5. Customer Reviews

Check customer reviews or testimonials to gauge the company’s reliability. Sun SoftWash has numerous satisfied customers across Auckland, Hamilton, and Tauranga, reflecting our commitment to excellent service.

Conclusion

Roof treatment is an affordable and effective way to protect your roof from moss, algae, and lichen, extending its lifespan and enhancing your home’s curb appeal.

Whether you need treatment for a small roof or a more complex multi-level property, the right service can save you from costly repairs down the line.

At Sun SoftWash, we offer professional roof treatment services with transparent pricing and eco-friendly solutions. Don’t wait for moss and algae to damage your roof—contact us today for a free quote and keep your roof in top condition.