NZTS Roof Cleaning

After a decade of experience cleaning roofs, we have seen all sorts of roofs in all sorts of conditions. The approach taken by our team varies according to your desired outcome, our knowledge of spraying and treatment, and a full job specific roof assessment and job safety analysis.

Our advice is based on experience and allows us and our clients to make an informed decision on how to clean your roof.

We will advise you on an appropriate roof cleaning method according to the condition, age and type of roof and the roof coating.

We at NZTS approach each home and roof cleaning job as if we are working on our own home, and provide advice accordingly. Our experience means that we can adapt to the nature of each job and create a solution that gets guaranteed results.

Roof Types

  • Clear light / Polycarbonate
  • Corrugated iron
  • Tile
  • Decromastic
  • Shingle
  • Concrete

How does moss,
mould and lichen affect a roof?

The buildup of moss, mould and lichen on a roof affects roof surfaces in a number of ways. Lichen is by far the worst offender. Apart from being an unsightly and unwanted guest, it also has roots (rhizines) that anchor and etch into the roof, causing irreparable damage.

The lichen disaggregates surface structures and coatings, greatly accelerating oxidation and rust. Lichen also holds moisture against the roof surface like a sponge long after the clean roof has dried after rainfall or condensation, adding to the speed of deterioration.

Other types of mould have their own detrimental effects by creating acidic byproducts that deteriorate roof surfaces and affect the aesthetic and safety of a roof.


Roof cleaning with a moss, mould and lichen treatment is a safe and practical long-term solution for the roofs of New Zealand homes. The treatment bonds to the roof surface / coating, inhibiting further growth, and works to the root of lichen and mould, causing it to degenerate and slowly wash away with the weather over the course of 6 to 18 months. Your roof will stay clean for up to 3 years following treatment depending on the surface and surrounding environment and sun exposure.

- The most cost-effective roof cleaning option
- Keeps your roof clean for up to 3 years
- Safer than cleaning your roof by water blasting
- Cleans moss, mould and lichen on your roof to the root
- Requires far less access to the roof and walking over the roof than water blasting
- Roof clean treatments work over 6 to 18 months and clean moss, mould and lichen to the root


Roof cleaning treatments are applied with minimal spraying pressure and with hoses that are lightweight and fit the purpose so as not to cause friction and damage that commonly occurs when using a heavy rubber water-blasting hose.We apply roof cleaning treatments under dry conditions to ensure that they bond well to the moss, mould and lichen and to the roof surface or coating, therefore achieving a great result every time. We consider the wind, ensuring the treatment is not blown onto surrounding surfaces and plant life.


Soft washing is an effective solution for cleaning softer green mould off a roof but generally it will not clean denser types of mould, such as black and red moulds and lichen. These mould types need a high-pressure clean to blast them away.

- Fast cleaning results
- Can be carried out in any weather
- Gentler than water blasting your roof


Inhibiting growth is the best defence against moss, mould and lichen on a roof. This is easily done by applying our surface bonding treatment, which acts as an antimicrobial barrier that lasts from 1 to 3 years. Small booster roof cleaning treatments should then be applied every 1 to 2 years to help keep costs down and extend the life of the roof surface.

- Bonds to surfaces and inhibits the growth of moss or mould
- Long lasting
- Extends the life of your roof


A pre-paint treatment will generally be applied to a roof after a pressure wash to clean off remaining organic matter that may adversely affect the new roof paint or coating once applied. The treatment should be left overnight to have the best effect and then washed / hosed off with clean water before any paint is applied.

- Cleans away all organic matter before the roof paint or coating is applied
- Quick and easy to apply
- Allows the roof paint / coating to adhere to the roof without organic growth compromising the overall quality


When you need your roof cleaned in a short timeframe, pressure washing is one of the only solutions for most types of roofs and roof coatings. Although it is a fast solution, it comes with an array of potential issues, including the ingress of water into the roof cavity or building itself, the stripping of coatings from the roof, and damage to roof tiles or iron from walking across the roof while cleaning.

- Fast result
- Can be carried out in any weather
- Provides a clean surface before paint or coatings are applied


The NZTS team undergo an intensive training regime, including (1) in-house NZTS spraying and treatment-specific training and (2) outsourced training in heights safety, fall arrest systems, first aid and dangerous goods management.

Our pride in our work and our safety while cleaning roofs is second to none. See our health and safety page.

We take a proactive approach to conserving New Zealand’s environment when treating and cleaning roofs.



With over 10 years of experience, NZTS has seen nearly everything in the business of exterior cleaning. With our state of the art equipment, we take pride in being able to effectively clean any exterior surface.


Auckland house washing guide

After washing thousands of houses around the Auckland area we thought it might be handy to put up a few of the things that we know to help those washing their house themselves or just for those to see how we like to go about our house washing work.



09 392 0212

Get 20% off on Roof Treatment + House Washing service combo. Use coupon Nov20 Get a free quote