How soft washing cleans a roof — low pressure and the right treatment to kill moss and lichen at the root, without the damage high-pressure blasting causes.
8 min read FreshDuct Melbourne Melbourne, Victoria
Soft washing is the roof-cleaning method we favour — and for good reason. Instead of blasting a roof with high-pressure water that can crack tiles and strip coatings, soft washing uses low pressure and an appropriate treatment to kill and lift moss, lichen, algae and grime, then a gentle rinse. It cleans effectively, protects the roof, and keeps it cleaner for longer because it kills growth at the root. Here’s how it works and why it’s the better choice.
Low PressureNo cracking, stripping or water ingress
Kills GrowthTreats moss & lichen at the root
Lasts LongerStays cleaner than a pressure blast
Soft washing works in three steps: a treatment is applied to the roof, left to dwell so it kills moss, lichen and mould at the root, then gently rinsed — lifting growth without high-pressure damage. Treated growth often continues to wash off with rain afterwards.
What Soft Washing Is
Soft washing is a low-pressure cleaning method that lets the right treatment do the work rather than relying on force. A treatment is applied to the roof to break down and kill dirt, moss, lichen, algae and mould; it is left to dwell so it works thoroughly; then the roof is gently rinsed at low pressure. The result is a clean roof achieved without the high-pressure water that can damage tiles, coatings and the structure beneath. It is the standard approach for cleaning roofs properly.
How Soft Washing Works
The process is straightforward and effective: apply the treatment, let it dwell, then rinse gently. Applying the treatment coats the roof and its growth; the dwell time lets it kill moss, lichen, algae and mould at the root; and the low-pressure rinse lifts away the loosened material without harming the roof. Because the growth is killed rather than just knocked off the surface, the roof stays cleaner for longer and continues to improve as treated growth washes off with rain. It is method over muscle.
Soft Wash vs High Pressure
High-pressure blasting physically forces contaminants off a surface. On hard surfaces like driveways and paths that is appropriate, but on a roof it is risky — the force can crack and chip tiles, strip the protective coating that guards the surface, and drive water up under the tiles. Soft washing achieves a clean roof without any of that, because it relies on treatment and low pressure rather than force. We use soft washing on roofs and reserve pressure washing for suitable hard surfaces. See our pressure washing guide.
Why It’s Better for Roofs
Soft washing is better for roofs on every count that matters: it cleans without cracking tiles or stripping coatings; it doesn’t force water under the roof; it kills moss and lichen at the root so results last longer; and it suits both tile and metal roofs. In short, it delivers a genuinely clean roof while protecting the very thing you’re cleaning — which high-pressure blasting cannot reliably claim. For a roof you want to keep in good condition, soft washing is the sensible choice.
What to Expect After
You’ll see a clear improvement straight after cleaning, and continued improvement over the following weeks. Because the treatment kills growth at the root, treated moss and lichen often keep breaking down and washing away with rain after we leave — so the roof can look progressively better. This gradual continued clearing is normal and a sign the treatment is working. The roof is also left protected, not damaged, ready to stay cleaner for longer.
Getting a Quote
Soft-wash roof cleaning is quoted per job after an inspection, with the treatment and approach matched to your roof. We inspect, recommend the right work, and provide a clear quote. Call 0431 918 137 or request a quote and inspection.
Frequently Asked Questions
What is soft washing?
Soft washing is a low-pressure roof and exterior cleaning method that relies on an appropriate treatment to do the work, rather than brute force. Instead of blasting the surface with high-pressure water, a treatment is applied to break down and kill dirt, moss, lichen, algae and mould, left to dwell, then gently rinsed at low pressure. It cleans effectively while avoiding the damage high pressure can cause to roofs — which is why it is the preferred method for most roof cleaning.
How is soft washing different from pressure washing?
The key difference is pressure and approach. Pressure washing uses high-pressure water to physically blast contaminants off a surface, which works on hard surfaces like driveways but can crack tiles, strip coatings and force water under a roof. Soft washing uses low pressure and a treatment that kills and loosens growth so it can be gently rinsed away — cleaning the roof without the mechanical force that damages it. We use soft washing on roofs and pressure washing on suitable hard surfaces. See our pressure washing guide.
Does soft washing kill moss and lichen?
Yes — that is one of its main advantages. The treatment used in soft washing kills moss, lichen, algae and mould at the root, not just on the surface. Because it kills the growth rather than just blasting off the top layer, the roof stays cleaner for longer, and treated growth often continues to wash away with rain over the following weeks. This is more effective and longer-lasting than simply removing the visible growth with pressure. See our moss & lichen guide.
Will I see results straight away?
You’ll see immediate improvement, and continued improvement afterwards. The roof looks much better straight after cleaning, and because the treatment kills the growth at the root, treated moss and lichen often keep breaking down and washing off with rain over the following weeks — so the roof can continue to improve after we leave. This gradual continued clearing is normal and expected with soft washing, and part of why it is effective.
Is soft washing safe for all roof types?
Soft washing is suitable for the great majority of roofs — tile (concrete and terracotta) and metal/Colorbond — precisely because it avoids the high pressure that damages them. It cleans without cracking tiles, stripping coatings or forcing water under the roof. The exact treatment and approach are matched to the roof type and condition, which we assess on inspection. For any roof, soft washing is the gentler, safer choice over high-pressure blasting.
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