Cleaning · low pressure, done properly
Soft Washing Perth. Clear it, don't blast it.
Perth's roofs, render and limestone go black and green with moss, algae and lichen. High pressure blasting strips the top off and damages the surface, and the growth is back within months. Soft washing works differently: low pressure, far gentler than pressure blasting, plus a biodegradable biocide that kills the moss, algae and lichen right through, so the growth dies back and the surface stays clearer for longer. We clean it to the standard our sealing demands. Then we protect it.
Why it matters in Perth
Perth grows the stuff you're trying to clean.
Coastal humidity, hard bore water and a cool wet winter make Perth a breeding ground for organic growth, and it hits the exact surfaces that can't take a blasting. This is where softwash earns its place, and where the wrong method does real damage.
Limestone everywhere
Limestone and liquid limestone walls, pillars and pool surrounds are all over Perth, porous and soft, so they go black and green and pressure pits them. See why pavers go green.
Shaded, slow-dry roofs
Black lichen, orange algae and moss take hold worst on south-facing and tree-shaded roof sections under jarrah and tuart that dry slowly after rain.
Hard water & salt
Hard bore and reticulation water plus coastal salt drive staining and deposits. See how bore water ruins stone and coastal salt.
The winter bloom
Growth accelerates through Perth's wet winter. The best time to clean is heading into spring, once the winter bloom has taken hold.
Soft wash vs pressure cleaning
Two methods. One wrecks the surface.
This is the whole argument. High pressure and soft washing are different methods with different results, and on a delicate surface the difference is the surface itself.
High pressure blasting
Water fired at 2,000 to 4,000 PSI or more. It strips only what's sitting on top, so the growth rooted into the surface returns within months. Along the way it forces water up under roof-tile laps and into the ceiling cavity, pits terracotta and cement tiles, strips Colorbond and paint coatings, and erodes soft render and limestone. It also sprays living spores around, which reseeds nearby surfaces.
Soft washing
The right tool for delicate surfaces. Low pressure, far gentler than pressure blasting, paired with a biodegradable biocide that kills the moss, algae and lichen. No water driven under tiles, no stripped coatings, no chewed-up render or limestone. Because the growth is killed and not just skimmed off the top, the surface stays clearer for longer.
The method
How a proper soft wash works.
No mystery, and no vague promises. Naming exactly how it works, on a roof and on render, is how you tell a real soft wash from a pressure cleaner bolting the word on.
A clean is honest work: it clears today's growth. It is not a seal, and it does not protect the surface. That is the next step, and we keep the two separate on purpose.
- Protect. We pre-wet and cover the surrounding plants, lawn and landscaping so the treatment stays where it belongs.
- Apply at low pressure. A biodegradable biocide solution goes on across the surface at low pressure, at a dilution matched to what we're cleaning. The solution does the work, not force.
- It kills the growth. The biocide kills the moss, algae, lichen and mould right through, not just the top layer.
- It keeps working. The biocide stays active on the surface and reactivates every time it re-wets with rain or dew, so it keeps killing regrowth for months.
- The growth weathers off. As it dies, the growth loosens and washes away with the rain. On render and walls we can rinse gently at low pressure the same day. On a roof there is no blasting and no climbing about, the weather does the clearing over the following weeks and months.
What it's for
Soft wash the delicate surfaces. Surface-clean the hard ones.
Soft washing is for delicate surfaces. Sound hard flatwork is a different job, cleaned with a controlled wide surface cleaner rather than a soft wash, and that surface cleaner has no place on a roof, render or limestone. Here's where each one fits, so you can tell which you actually need.
Soft wash these
- Roof tiles, terracotta and cement
- Colorbond and metal roofs
- Render, stucco and cement sheet
- Painted weatherboard and cladding
- Fibre cement and eaves
- Solar panels
- Limestone, liquid limestone and sandstone
- Brick, and exterior gutters
A surface cleaner belongs here
- Concrete driveways and paths
- Some pavers, with care
- Hard, non-delicate flatwork
On these, a controlled wide surface cleaner is the right tool on sound concrete and pavers. On anything porous, painted or coated, it does damage you can't undo, which is why we reach for soft washing instead.
Honest expectations
What soft washing can't do.
Soft washing kills organic growth. Moss, algae, lichen and mould. Some marks look like growth but aren't, and no wash will shift them. Knowing the difference is a genuine specialist edge, and it's why some soft washes never work: the problem was misdiagnosed.
Not vanadium green
Green that won't budge is often vanadium, a mineral coming out of the clay in the brick or stone, not algae. No wash clears it. Read the green stain that isn't algae.
Not efflorescence
A white bloom on limestone or render is usually efflorescence, salt carried out of the material, not growth. Different problem. See why limestone goes white.
Not rust, oil or graffiti
Rust, oil stains and graffiti are not organic growth, so soft washing won't remove them. We'll tell you that up front rather than take the job and disappoint you.
Safe around the home
Careful with your garden, your roof and your pets.
- Plants covered. We pre-rinse and cover the surrounding plants, lawn and landscaping before we start, and rinse down after.
- Controlled application. A biodegradable solution at a working dilution, targeted at the growth, not poured neat over the garden.
- No water intrusion. Low pressure means no water forced up under roof-tile laps and into the ceiling cavity.
- Pets back to normal. Keep pets off the treated area until it's dried and rinsed, and you're done.
How long it lasts
Clearer for longer, honestly.
A soft wash stays clean far longer than a high pressure clean, months of clear surface rather than a season or two, because the growth is killed off rather than skimmed off the top, and the biocide stays active for months, reactivating whenever it re-wets to knock back new growth.
We won't tell you it's permanent. Growth returns over time, faster under heavy tree cover, coastal exposure and shade. What we can do is keep it clearer for longer, set you up with sensible scheduled upkeep, and then protect the surface so it holds off far longer again.
Now protect it
A clean is temporary. Protection is the moat.
Every soft washer in Perth cleans the surface, and in time the growth returns, so you rebook. We close the loop. Once the surface is clean and prepped, a bare surface will simply re-stain, so that's the moment to protect it. Our surface coating makes it harder for growth to grip, sheds water, and stays cleaner dramatically longer, so you're off the rebooking treadmill. Soft washing is step one. Protecting it is the step a pressure cleaner can't offer. Our sealing work is registered under a 10-year guarantee, which covers the seal, not the clean.
Straight answers
Soft washing, answered.
What is soft washing, and how is it different from pressure washing?
Pressure washing, or high pressure blasting, fires water at 2,000 to 4,000 PSI or more to physically strip whatever is sitting on the surface. Soft washing works the opposite way. We apply a biodegradable biocide solution at low pressure, far gentler than pressure blasting, and it kills the moss, algae, lichen and mould right through rather than skimming it off the top. On render and walls we can rinse it down gently the same day. On a roof we never climb up or blast it off, so the growth dies back and weathers away with the rain over the following weeks and months. Because the growth is killed and not just skimmed off, the surface stays clearer for far longer.
Is soft washing safe for my roof, render and painted walls?
Yes, that is the whole point of the method. Soft washing uses low pressure, so there is no blasting to lift roof tiles, drive water under the laps, strip paint or erode soft render. We pre-wet and protect the surrounding area, then apply a biodegradable biocide that kills the growth. On render and painted walls we rinse it down gently once it has worked. On a roof we never climb onto it or pressure blast it, we spray the biocide from ladders at the gutter line and the growth dies back and weathers off with the rain over the following months. It is the safe choice for exactly the surfaces that high pressure damages.
Is soft washing safe for a Colorbond or metal roof?
Yes. Colorbond and other metal roofs carry a factory paint and coating layer that high pressure can strip or dull. Soft washing uses no abrasion at all, we spray a biodegradable biocide that kills the lichen and algae, and it weathers off over the following months, so the coating is left intact. It is the correct method for the metal roofs that are now common across Perth.
Will pressure blasting damage my roof, and why does the growth come back so fast afterwards?
High pressure can force water up under tile laps and into the roof cavity, pit terracotta and cement tiles, and strip the coating off Colorbond. It also only removes what is sitting on top, so the organic growth that is rooted into the surface returns within months. Soft washing kills the growth right through and does not drive water where it should not go, which is why the result holds far longer.
How often should I soft wash my roof or house in Perth?
Most Perth homes do well with a soft wash every couple of years, sooner if the roof or walls are heavily shaded, under tree cover, or close to the coast where growth takes hold faster. We would rather set you up with sensible scheduled upkeep than have you blast it hard every year.
How long do the results last before moss, algae and lichen return?
A soft wash stays clean far longer than a high pressure clean, months of clear surface rather than a season or two, because the growth is killed off rather than skimmed off the top, and the biocide stays active for months, reactivating whenever it re-wets to knock back new growth. It is honest to say the growth will return over time, faster under heavy shade, tree cover and coastal exposure. We do not claim it is permanent. What we can do is keep it clearer for longer, and then seal the surface so it holds off far longer again.
Is the treatment safe for my plants, lawn and pets?
We pre-rinse and cover the surrounding plants and landscaping before we start, control where the solution goes, and rinse down afterwards. The solution is biodegradable and applied at a working dilution, not poured neat over your garden. Keep pets off the treated area until it has dried and been rinsed, and everything is back to normal.
What do you use, and is it biodegradable?
We use a biodegradable biocide solution matched to the surface, applied at a controlled dilution and targeted at the growth it kills. We are happy to talk you through what goes on your specific surface when we quote. What we do not do is rely on brute pressure that damages the surface to get a result.
Can soft washing clear black streaks, orange algae, green lichen and moss from tiles?
Yes. Black streaks, orange and red algae, green lichen and moss are all organic growth, and that is exactly what soft washing kills. On a roof the growth is not blasted off, it dies back and weathers away naturally with the rain, so the surface keeps lightening over the weeks and months after treatment rather than the same day.
Can soft washing remove rust, oil or graffiti?
No, and we will tell you straight. Soft washing is for organic growth: moss, algae, lichen and mould. It does not remove rust, oil stains or graffiti, which are different problems that need different treatment. Setting that expectation up front is fairer than promising a result the method cannot deliver.
Why won't the green come off my limestone or brick even after cleaning?
That green is often not algae at all. It can be vanadium, a mineral leaching out of the clay in some bricks, pavers and stone, and it will not respond to any wash because there is no organic growth to clear. Diagnosing algae versus a mineral stain correctly is why some soft washes never work. We check first, and we have written up the vanadium green stain that isn't algae so you can see the difference.
Can you soft wash limestone, liquid limestone, retaining walls and pool surrounds without damaging them?
Yes, and limestone is the Perth surface soft washing is made for. Limestone, liquid limestone, retaining walls, pillars and pool surrounds are porous and soft, so high pressure pits and erodes them. Low pressure plus the right biocide kills the black and green growth without chewing up the surface. Note that a white bloom on limestone is usually efflorescence, a salt problem, not growth, so it is treated differently.
When is the best time of year to clean, before or after Perth's winter rains?
Growth accelerates through and just after Perth's cool, wet winter, so the best time to clean is heading into spring, once the winter bloom has taken hold. Clear it then and the surface goes into the warmer, drier months clean. We are happy to book you in at the right point in the season.
How much does soft washing cost in Perth?
Soft washing is quoted per job, because the price depends on the surface, the area, the access and how heavy the growth is. We do not publish a flat rate that turns out wrong on your property. We measure it, look at the surface, and give you a fixed quote before you book, no surprises. Send your suburb and a photo and we will get you a number.
Should I just DIY it with a bunsprayer and bleach?
A bunsprayer of supermarket bleach is how a lot of surfaces get damaged and a lot of gardens get burnt. Getting the dilution, the dwell time and the rinse right, without stripping paint, streaking render or scorching plants, is the actual skill. If the surface is delicate, or up high on a roof, it is worth having it done properly and safely.
Are you insured?
Yes. Extera is fully insured, and we clean to the standard our sealing work demands. We are a surface specialist, not a generalist bolting a soft wash onto a pressure cleaning round, so the surface is treated the way it should be. Every job is quoted and confirmed before we start.
Get a quote
Clear the growth. Then protect it.
Send your suburb, the surface and the area, with photos of the moss, algae or lichen if you have them. Soft washing is quoted per job. We measure it, confirm it's growth and not a mineral stain, and give you a fixed price before you book.
Soft washing is one of Extera's cleaning services. See all cleaning services →