Roof Moss, Lichen & Mould Removal

Moss, lichen, algae and mould are common on Melbourne roofs — and they’re more than an eyesore. Growth holds moisture against the roof, works into joints and coatings, and traps debris that holds yet more moisture, all of which contributes to deterioration over time. FreshDuct removes roof moss and lichen by soft washing — killing the growth at the root and lifting it gently — so the roof is cleaned, protected, and stays clean for longer.

What Grows on Melbourne Roofs

Melbourne roofs commonly grow moss, lichen, algae and mould. Moss forms the thick green or brown mats you see on shaded, damp roofs; lichen is the flatter, crusty growth that grips hard to the surface; algae and mould add staining and streaking. All of them thrive where there’s moisture and a surface to grip — which is why porous tile roofs, and roofs shaded by trees or in damp positions, grow the most. Whatever the mix, the effect is the same: a roof that looks tired and, more importantly, holds moisture where it shouldn’t.

Why It Damages the Roof

The damage from moss and lichen comes mainly from moisture and intrusion. Growth holds water against the roof surface long after rain, keeping the tiles or coating damp; its roots and structures work into the gaps between tiles and into the protective coating; and the mats trap leaves and debris that hold even more moisture. Over time this retained moisture and root intrusion contribute to surface breakdown, and heavy growth can affect how cleanly water sheds off the roof. Removing it protects the roof from this slow, ongoing damage.

How We Remove It

We remove moss, lichen, algae and mould by soft washing: an appropriate treatment is applied to kill the growth at the root, left to dwell so it works thoroughly, then gently rinsed at low pressure. Killing the growth rather than just blasting off the visible layer means the roof stays cleaner for longer, and treated growth often continues to wash away with rain afterwards. It’s also far safer for the roof than high-pressure removal, which can crack tiles and strip coatings. See our soft washing guide.

Keeping It From Coming Back

Some regrowth over time is natural, but you can slow it. Because soft washing kills growth at the root, the roof stays clean longer than after a simple pressure blast. Keeping the roof and gutters clear of leaves and debris removes the moisture and footholds growth relies on; trimming back overhanging branches lets in light and air; and on suitable roofs a protective coating after cleaning further discourages growth. How quickly moss returns depends largely on the roof’s shade, aspect and condition. See our coating and gutter guides.

When to Act

It’s worth acting when growth becomes noticeable rather than waiting until the roof is thickly matted — the longer heavy moss and lichen sit, the more moisture they hold and the more they work into the surface. If you can see green or crusty growth across the roof, streaking, or moss filling the tile gaps, it’s time to clean. Catching it earlier means an easier clean and less accumulated effect on the roof. An inspection will tell you where your roof stands.

Getting a Quote

Moss and lichen removal is part of roof cleaning, quoted per job after an inspection — roof size, pitch, access and how heavy the growth is all matter. We inspect, recommend the right work, and provide a clear quote. Call 0431 918 137 or request a quote. See our cost & quoting guide.

Frequently Asked Questions