Roof treatment · Perth
Roof Moss, Lichen and Algae Treatment that keeps working.
A long-acting biocide treatment for your roof that kills the moss, lichen, mould and algae, then keeps working to slow it coming back. We soft wash it on at low pressure from ladders at the eaves, never blasting the roof and never walking it. It stays active on the roof for up to 24 months, reactivates every time it re-wets with rain or dew, and clears the roof over the following months as the dead growth weathers off. If you want the green gone first, that is our roof cleaning service, and this is how you keep it clearer for longer. The same treatment also treats render, walls and paths, free after any hardstand clean.
Why it matters in Perth
Why Perth roofs green up and stay that way.
Perth's wet, humid winters and warm summers are ideal for organic growth. Moss and lichen grip the shaded, damp southern face of a roof, black algae streaks down the tiles, and the same growth spreads onto render, walls and paths. Blasting only strips the top layer and leaves the roots and spores behind, so it grows straight back. A treatment kills the growth where it grips and keeps working long after the day.
Moss & lichen
Grips the damp, shaded southern face of a roof and holds moisture against the tile, where it does the most harm.
Algae & black streaks
The dark streaks running down a roof or across render are algae, spread by Perth's humid winters and tree cover.
Mould & mildew
Settles on shaded render, walls and eaves near trees and the coast, where the air stays damp.
Growth that returns
Blast it off and the roots stay behind, so it regrows fast. A treatment works at the source and keeps working.
How the treatment works
It kills the growth, then keeps working.
This is what sets a treatment apart from a one-off clean. We apply the biocide, it kills the moss, lichen, mould, mildew and algae on the roof, and then it stays active up on the surface and keeps working over the months that follow. The dead growth weathers off on its own. Nothing is blasted, scraped or pressure cleaned.
It kills the growth
The biocide kills the moss, lichen, mould, mildew and algae it lands on, down where it grips the roof rather than just taking the top layer off.
It stays active up to 24 months
It keeps working on the surface long after the day, and it reactivates every time it re-wets with rain or dew, so it keeps killing new growth as it tries to take hold.
The growth weathers off
No blasting needed. As the growth dies it washes off naturally with the rain over the following months, so there is nothing to strip or pressure off the roof.
The mechanism
What the treatment does, step by step.
A treatment is a slower, kinder way to clear a roof than a blast, and it holds for far longer. Here is exactly how it plays out from the day we apply it.
- Kills the growth. The biocide kills the moss, lichen, mould, mildew and algae it lands on.
- Stays active up to 24 months. It keeps working on the surface long after we leave, not just on the day.
- Reactivates when it re-wets. Rain and dew wake it back up so it keeps killing new growth.
- Works over 3 to 12 months. The result appears progressively, not the same day we apply it.
- The growth weathers off. As it dies it washes away naturally with the rain, with no blasting.
- No pressure damage. Nothing is stripped, scraped or blasted, so the roof stays intact.
How we treat a roof
A roof treated, never blasted.
A roof is exactly where a treatment beats a blast. We soft wash a dilution of the biocide onto the roof at low pressure from ladders at the gutter line. We do not climb onto the roof and we do not pressure-blast it, because unless it is a full restoration, blasting a roof creates leak pathways and damages tiles, pointing and bedding. The treatment kills the moss and lichen and it weathers off over the following months. Need the growth cleared first? That is our roof cleaning service.
Soft washed from the eaves
We spray the treatment on at low pressure from ladders set at the gutter line, so it reaches the roof without anyone walking it.
Never blasted or climbed
We do not pressure-blast the roof and we do not climb onto it. That is safer for the roof and the crew, and it is a deliberate choice.
Why blasting a roof is worse
High pressure blows out pointing and bedding, chips tiles and forces water under the flashings, which is how a clean becomes a leak.
Also treats
The same treatment on your render, walls and paths.
The roof is where this treatment earns its keep, but the same biocide clears any surface that greens up. We apply it to render, walls, paths, driveways and other hardstand, and it works on the same organic growth wherever it grips. It goes on free as the finishing step after any hardstand clean, and on its own it is quoted per job.
- Render and walls. Shaded, mouldy or streaked render, walls, eaves and fascia, treated standalone.
- Paths and paving. Slippery, green paths and paving, treated on their own or free after a clean.
- Driveways and hardstand. Applied free as the finishing step after a driveway or patio clean.
Results, honestly
What a treatment will and will not do.
On-brand honesty, because it saves everyone a bad day. A treatment clears a roof and holds it for far longer than a blast, but it works over time, not on the day, and it is not a guarantee against Perth's weather.
- It works over months, not the day. Results appear progressively over 3 to 12 months as the growth dies and weathers off.
- It is not a same-day clean. You will not see a before-and-after on the day, because the rain does the clearing.
- Some marks can stay. Where lichen has sat for years it can etch the surface, and that mark can remain after the growth is gone.
- It is not permanent. Nothing keeps a Perth roof green-free forever. The treatment kills what is there and slows the return.
- The treatment is not guaranteed. Our 10-year guarantee covers the sealing service only. The clean and the treatment are not guaranteed.
What it costs
Free with a clean, or quoted per job.
There is no published treatment rate, because roofs and surfaces vary too much for a flat number. Here is how it is priced, so you know what to expect before we ever quote it.
Free after a hardstand clean
When the treatment follows a driveway, path or patio clean, it is included free as the finishing step. There is nothing extra to pay for it.
Standalone, quoted per job
On its own, a roof or surface treatment is priced on the surface, its size and access, and how much growth is on it. We confirm a fixed price before you book.
The quote is free
We assess the roof or surface and the growth and confirm a fixed, no-obligation price first, so there are no surprises on the day.
Now protect it
We clean it, we treat it. Then we protect it.
A treated roof eventually re-grows, because Perth's weather never stops feeding the growth. The way to keep it clearer for much longer is to protect it. Once the growth is killed and the roof is clean, we can seal it with a breathable, colourless mineral coating that helps the surface shed water, so moss, lichen and algae find it harder to grip. Unlike an acrylic roof repaint that traps moisture in the tile, this one lets the surface breathe. The treatment clears what is there, and the protect step is our sealing service, registered under a 10-year guarantee. No pure cleaner offers clean, treat and protect as one system.
Perth and the South West
Roof treatment across Perth.
We treat residential, commercial and strata roofs across the Perth metro and into the South West, and the same treatment clears render, walls and paths: Joondalup, Wanneroo, Butler, Ellenbrook, Fremantle, Canning Vale, Kalamunda, Rockingham, Baldivis and Mandurah, and everywhere between. Fully insured, and a JUMBOGUARD Certified Applicator. Send your suburb and we will confirm.
The questions we get
Roof treatment in Perth, answered.
What is a roof treatment, and how does it work?
It is a long-acting biocide we apply to a roof that carries moss, lichen, mould, mildew or algae. The biocide kills the growth, then stays active on the roof for up to 24 months. It reactivates every time it re-wets with rain or dew and keeps working, so the growth dies back over the following months and weathers off naturally with the rain. There is no blasting and no same-day strip. The treatment does the work over time, which is why the roof stays clearer for longer.
What growth does the treatment kill?
It kills moss, lichen, mould, mildew and algae, the organic growth that turns roofs green and black and streaks render, walls and paths. It works on the growth where it grips rather than just taking the top layer off, which is why the surface stays clearer for longer than a quick blast.
How long does the treatment stay active on the surface?
Up to 24 months. Unlike a rinse that is gone the moment it dries, the biocide keeps working on the surface, and it reactivates every time it re-wets with rain or dew. That long active life is what keeps killing new growth as it tries to take hold.
How long before the moss, lichen or algae clears?
Roughly 3 to 12 months. This is a treatment, not a same-day clean. The growth dies off and then weathers away with the rain over the following months, so the result appears progressively rather than on the day we apply it. Heavier growth on a shaded, damp surface takes longer to clear than a light film.
Do you blast or scrape the growth off after treating?
No. The dead growth weathers off naturally with the rain, so there is no blasting, scraping or pressure cleaning needed. On a roof that matters, because high-pressure blasting is what creates leak pathways and damages tiles, pointing and bedding. Letting the treatment do the work keeps the surface intact.
Is the treatment really free?
When it follows a hardstand clean, yes. After we clean a driveway, path or patio we apply the biocide as a free post-treatment to slow the growth coming back. As a standalone treatment on its own, for render, walls, paths or a roof, it is quoted per job.
What surfaces can you treat with the biocide?
Render, walls, paths, driveways and other hardstand, and roofs. It suits the surfaces where organic growth takes hold, and it is applied to suit each one. On roofs it is the main method, soft washed on at low pressure. On hardstand it goes on free after a clean, and on render and walls it is available as a standalone treatment.
Can you treat my roof for moss and lichen without blasting it?
Yes, and that is exactly how we do it. We soft wash a dilution of the treatment onto the roof at low pressure from ladders at the gutter line. We do not climb onto the roof and we do not pressure-blast it. The treatment kills the moss and lichen and it weathers off over the following months, so the roof is never blasted.
Will the growth come back, or is the treatment permanent?
Nothing keeps a Perth surface green-free forever, and we will not tell you otherwise. Perth's damp winters feed moss, lichen and algae, so the growth will eventually return. What the treatment does is kill what is there and slow the return, and its long active life keeps working for up to 24 months. To keep a roof or hardstand clearer for much longer, the next step is to protect it with our sealing service.
How much does a standalone surface treatment cost in Perth?
A standalone treatment is quoted per job, because surfaces vary too much for a flat rate. The price depends on the surface, its size and access, and how much growth is on it. We assess it and confirm a fixed price before you book, and the quote is free. When the treatment follows a hardstand clean, it is included free.
Is the biocide treatment guaranteed?
No. Our 10-year guarantee covers the sealing service only. The clean and the biocide treatment are not guaranteed, because organic growth depends on the weather, shade and how exposed the surface is, which are outside our control. We are upfront about that. The guaranteed step is protecting the surface with our sealing coating once it is clean.
Why do moss, lichen and algae keep coming back in Perth?
Perth's wet, humid winters and warm summers are ideal for organic growth, worst on shaded, damp and southern-facing surfaces and near the coast. Blasting only strips the top and leaves roots and spores behind, so it grows back fast. The treatment kills the growth and stays active for up to 24 months to slow the return, and sealing the surface afterwards keeps it clearer for longer again.
Should I seal the surface after treating it?
It is the best way to keep it clearer for longer. Once the growth is killed and the surface is clean, we can protect it with a breathable mineral sealing coating that helps the surface shed water, so moss, lichen and algae find it harder to grip. That protect step is our sealing service and is registered under a 10-year guarantee. Treating clears what is there, sealing slows what comes next.
Get a quote
Treat your roof for moss, lichen and algae.
Send your suburb, the surface and rough size, with photos of the growth if you have them. The treatment kills the moss, lichen, mould, mildew and algae, then keeps working as the dead growth weathers off over the following months. Free after a hardstand clean, or quoted per job standalone. Then, if you want it to stay clearer for longer, we can protect it.