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Professional Roof Treatments in Hamilton & Waikato
Moss, lichen, and mould on your roof aren't just cosmetic problems. Left untreated they lift roofing materials, block gutters, and shorten the lifespan of your roof significantly. Hamilton's damp winters and shaded sections make roofs particularly vulnerable. We treat your roof properly using low-pressure methods that remove the growth without causing damage in the process.
28+ Reviews from Hamilton Homeowners
Everything That's Included in a Professional Roof Treatment in Hamilton
Why Moss and Lichen Are More Damaging Than They Look
Moss and lichen anchor themselves to roofing material using root-like structures that physically break down the surface over time. On concrete tiles this degrades the protective coating. On iron roofing it accelerates rust underneath the growth. Lichen in particular is extremely difficult to remove once established because it bonds directly to the surface, which is why treating it early with the right product makes a significant difference to both the cost and the result.
Why We Don't Use High Pressure on Roofs
High-pressure washing on a roof strips protective granules from concrete tiles, breaks the seals on iron roofing, and can crack or dislodge tiles entirely. It also removes the visible growth without killing the organism underneath, meaning it grows back faster. Our low-pressure treatment applies a professional biocide solution that penetrates and kills moss, lichen, and mould at the root. The dead growth then breaks down and washes away naturally with rain over the following weeks.
What Roof Types We Treat and How
We treat all common roof types found across Hamilton and Waikato including corrugated iron, long-run steel, concrete tiles, and clay tiles. Each material requires a different approach. Solution strength, dwell time, and rinse pressure all vary depending on the roof type and severity of the growth. We assess your roof before starting and adjust accordingly so the treatment is effective without putting your roofing materials at risk.
Hamilton's Local Roof Treatment Specialists
MJ Exterior Cleaning is run by Max and Josiah, two Hamilton locals who carry out every roof treatment themselves. No subcontractors, no crews you've never met. You deal directly with us from the initial quote through to the finished job.
We carry out roof treatments across Hamilton suburbs including Rototuna, Flagstaff, Hillcrest, Chartwell, Dinsdale, and Frankton, as well as properties throughout the Waikato region. Hamilton's climate creates ideal conditions for moss and lichen to establish quickly, particularly on roof sections that retain moisture longer. A roof that hasn't been treated in three or more years will typically show significant growth that is actively degrading the surface underneath. Catching it at the right stage means the treatment is more effective and the roofing material is still in good condition underneath. Our biocide treatments are long-lasting and continue working after we leave, killing spores and slowing regrowth for significantly longer than a pressure wash would achieve. With 17 five-star Google reviews from Hamilton homeowners, we've built our reputation on thorough work and honest advice. If you're unsure whether your roof needs a treatment or a full clean, we'll take a look and tell you exactly what it needs.