Roof treatment in New Zealand typically costs from $99 to $299+ for a standard residential property.
The final price depends on your roof size, roof height, access, pitch, and the level of moss, mould, algae, or lichen growth. Larger or more difficult roofs may require more treatment solution, safety equipment, and time.
This guide explains roof treatment prices in NZ, what affects the cost, how treatment compares with roof cleaning, and when you may need more than a standard treatment.
Roof Treatment Prices in New Zealand
[Price table]
Below is a general roof treatment price guide for standard residential properties with normal access conditions.
| 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) |
These prices apply to moss treatment, mould treatment, and algae treatment, the same chemical solution targets all three. You won’t pay separately for each type of growth.
What Is Roof Treatment?
Roof treatment is a maintenance service that applies a specialised solution to control moss, lichen, mould, and algae growth.
Unlike roof washing, treatment does not provide an instant clean result. It works gradually over time. After application, the treatment begins breaking down organic growth, while rainfall helps wash away the dead material over the following weeks and months.
Roof treatment is often a suitable option when the roof is structurally sound but has visible moss, algae, mould, or lichen growth.
What Affects Roof Treatment Cost?
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
A double-storey, steep, multi-level, or difficult-to-access roof may need additional safety equipment and labour.
Typical surcharges may include:
- Double-storey roofs: around $1.50 per extra sqm
- Very complex roofs: around $1.75 per extra sqm
Complex roofs may include steep sections, multiple levels, restricted access, or areas that require additional safety planning.
3. Roof Condition
Heavy moss, deeply rooted lichen, or thick organic buildup can require more time and may need a second treatment application.
Some roofs may also need physical moss removal or roof cleaning before treatment can work effectively.
4. Additional Services
Roof treatment is often booked with other exterior maintenance services, including:
Booking several services together can reduce overall labour and equipment costs.
Moss, Mould, Algae and Lichen Treatment Costs
Moss, mould, algae, and lichen treatment generally follows the same price structure shown in the table above.
The main cost factor is not the specific type of growth. It is the size, access, height, and condition of the roof.
Lichen may take longer to break down because it attaches more deeply to roofing materials. In cases of heavy lichen growth, your technician may recommend additional treatment or physical removal before applying the solution.
Roof Treatment vs Roof Cleaning: Which Do You Need?
Roof treatment and roof cleaning are not the same service.
| Roof Treatment | Roof Cleaning |
| Applies a treatment solution to control organic growth | Physically removes dirt, moss, debris, and growth |
| Works gradually over time | Provides more immediate visual results |
| Often suitable for light to moderate moss, mould, algae, or lichen | May be required for heavy buildup or thick debris |
| Lower-maintenance option for many roofs | May require more labour, equipment, and access work |
Roof treatment is often the better option when the main issue is biological growth and the roof does not need immediate physical cleaning.
Roof cleaning may be more appropriate when there is heavy moss buildup, thick debris, blocked gutters, or a strong need for immediate visual improvement.
A professional inspection can help determine the right approach for your roof.
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.
Many homeowners opt for a recurring roof maintenance schedule rather than booking ad-hoc. A treatment every 12-18 months keeps moss, mould, and algae from re-establishing.
This is often available as part of a maintenance package alongside gutter cleaning and house washing, ask about bundle pricing when you request a quote.
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.
The chemicals used are typically sodium hypochlorite-based or proprietary biocide solutions designed for NZ roof materials, biodegradable and safe for surrounding gardens once dry.
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.
Optional Extra Services
Depending on your roof condition, you may also need:
- Gutter cleaning
- Debris removal
- Roof cleaning
- House washing
- Additional treatment applications
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.
Roof Treatment Packages and Bundle Pricing
Combining exterior maintenance services can offer better value than booking each service separately.
1. House Wash + Roof Treatment
Starting from $345 + GST
This package combines a house wash with roof treatment to improve the overall appearance and maintenance of your property.
2. House Wash + Roof Treatment + Gutter Clean
Starting from $590 + GST
This package includes house washing, roof treatment, and gutter cleaning.
It is a practical option for homeowners who want to maintain several exterior areas in one visit.
When Roof Treatment Is Not Enough
Roof treatment is designed to manage moss, mould, algae, and lichen growth. It does not repair roof damage.
You may need advice from a qualified roofing contractor if your roof has active leaks, cracked or missing tiles, rust or corrosion, loose flashing, or signs of structural damage.
Treating organic growth can improve roof appearance and maintenance, but it cannot fix underlying roofing issues.
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. 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.
Roof Treatment Cost NZ FAQs
How much does roof treatment cost in NZ?
Roof treatment generally costs from $99 to $299+, depending on roof size, access, height, and complexity.
Is roof treatment cheaper than roof cleaning?
In many cases, yes. Roof treatment is often a lower-cost maintenance option because it works gradually without requiring full physical cleaning. However, heavily soiled roofs may need cleaning before treatment.
Does roof treatment remove lichen as well as moss?
Yes. Roof treatment can target moss, mould, algae, and lichen. Lichen may take longer to break down because it attaches more deeply to the roof surface.
How often should I treat my roof?
Many homeowners schedule treatment every 12 to 18 months, depending on rainfall, shade, tree cover, and how quickly moss or algae returns.
Does a double-storey roof cost more to treat?
It can. Double-storey, steep, or difficult-to-access roofs may cost more because they require additional safety equipment, labour, and time.
Can roof treatment fix roof leaks?
No. Roof treatment manages moss, mould, algae, and lichen growth. It does not repair damaged tiles, leaks, corroded roofing, or structural problems.
Do I need roof cleaning or roof treatment?
It depends on the condition of your roof. Treatment is often suitable for biological growth that can break down gradually. Roof cleaning may be needed for heavy moss buildup, debris, or immediate visual results.
Get a Roof Treatment Quote
Roof treatment is a practical way to manage moss, mould, algae, and lichen growth before it becomes a larger maintenance issue.
For an accurate quote, the roof size, access, height, pitch, and level of buildup should be assessed first.
Contact Sun SoftWash for a clear roof treatment quote based on your property and roof condition.
