How often should I clean my roof?
It’s a common question we hear from homeowners across New Zealand, especially after installing a new roof or noticing early signs of moss or mould. The answer depends on a few factors, but one thing is consistent. Roof cleaning is not something we recommend doing yourself.
Modern roofing systems are designed to last, but they also rely on protective coatings that can be damaged easily by the wrong cleaning methods. High-pressure washing and harsh chemicals are still widely used, and both can shorten the life of a roof if applied incorrectly. For that reason alone, professional roof cleaning is the safest option.
Start by checking your roof warranty
If you have a newer roof, particularly Colorsteel or Colorcote, the first step is always to check your warranty documentation. Many roof warranties include specific maintenance and wash frequency requirements. These guidelines are important, because failing to follow them can affect your warranty coverage.
In many cases, the warranty dictates how often a roof should be washed or treated, and what methods are acceptable. This is another reason DIY cleaning can be risky, as the wrong approach can unintentionally void your warranty.
Roof cleaning is about using the right method
Roof cleaning is often thought of as a cosmetic job, but the real purpose is protection. Moss, mould, and lichen hold moisture against the roof surface and slowly break down protective coatings. Once those coatings are compromised, the roof becomes more vulnerable to corrosion and premature ageing.
At Hawksbill, we use a specially formulated product to take care of organic growth without damaging your roof, and the components are plant and pet safe. After an initial Hawksbill Restore™ treatment, the roof becomes clear of organic growth over a period of 12 months. No scrubbing, no chemical stripping.
All Hawksbill treatments provide 24 months of protection. We can guarantee that no moss, mould, or lichen growth will appear during that 24-month protection period. Find out more about our extensive guarantees by speaking with our team today.
How often we recommend roof cleaning
Outside of any warranty requirements, our general recommendation is simple. After your initial Hawksbill Restore™ treatment, your roof should be re-sprayed every 24 months (2 years). This keeps the protective barrier active and prevents organic growth from becoming established in the first place.
This approach works particularly well in New Zealand conditions, where moisture, wind, and nearby vegetation make regrowth likely if roofs are left untreated. Regular re-spraying is far more effective and cost-efficient than allowing growth to return and starting again from scratch.
Why professional treatment makes the difference
As roof cleaning is our only service, we understand roofing materials, coatings, and local conditions in detail. Our products are chlorine bleach free, safe for roof coatings, and gentle on surrounding plants and landscaping. The goal is long-term protection, not short-term visual results.
By putting your roof on a simple two-year treatment cycle, you remove the guesswork and avoid the risks associated with DIY cleaning. Your roof stays protected, warranties remain intact, and maintenance becomes predictable.
If you are unsure how often your roof should be cleaned, or if you want to put a proper maintenance plan in place, Hawksbill can help.
