
Commercial & strata · exterior clean and protect
Commercial cleaning & building maintenance in Perth.
We are Perth's sealing specialists, and we clean to the standard sealing demands. For strata and commercial buildings that means the exterior: limestone and render walls, facades, glass and roofs soft washed, concrete and car parks cleaned with a controlled surface-cleaner pass, then protected so they stay clearer for longer. We clean it. Then we protect it.
Why it matters in Perth
What Perth does to a building's exterior.
Perth is hard on the outside of a building in ways that reward the right method and punish the wrong one. Soft, porous surfaces, a wet winter that feeds growth, and mineral-heavy bore water all leave marks. Blast them with pressure and you make them worse. Here is what we are actually treating.
Soft, porous limestone
Perth limestone and cement render drink up water and are easily damaged. Blast them with high pressure and you pit and open the surface, which is also why they can go white and flaky. We never pressure-blast them.
Winter mould, algae & lichen
On shaded, damp walls and paths, organic growth flares through Perth's cool, wet winters and darkens renders, brick and paving. It needs a biocide that kills it at the source, not just blasting the film off the top.
Bore & reticulation staining
Iron and calcium in bore water bake orange and brown stains onto render, limestone, paths and glass. It needs a stain treatment, then protection so it does not simply return.
Coastal salt
Near the coast, salt crusts and works into porous stone and paver joints. Coastal stone stays sounder when it is cleaned and then protected against salt taking hold.
Red dust & UV chalking
Summer dust and hard UV dull rendered facades and leave a chalky film on exposed walls, so buildings look tired well before they are due for repainting.
Roof moss & lichen
Tiled roofs on the shaded side grow moss and lichen that hold moisture against the tiles. We treat them with a biocide soft washed from the eaves that kills the growth, and it weathers off over the following months. We never climb onto or pressure-blast a roof.
How we do it
The chemistry does the work, not the pressure.
There are two ways to clean a building's exterior. High-pressure blasting drives water and spores into and under the surface, strips soft renders and limestone, and only removes the film on top so growth returns quickly. Soft washing does the opposite: a low-pressure application of a biodegradable biocide that kills the mould, algae and lichen so it clears at the source, not just the film on top. We lead with soft washing, and use a controlled surface-cleaner pass on the hardstand that can take it.
Soft washing, our default
A biodegradable biocide applied at low pressure and left to work. It kills mould, algae and lichen at the source and is safe on soft, porous surfaces, so the result stays clearer for longer.
Surface cleaner, hardstand only
For concrete, exposed aggregate paths and car parks we run a wide flat surface cleaner evenly across the slab. A controlled, even pass, not blasting, matched to the surface and never a blunt handheld lance.
Never on soft surfaces
We do not blast limestone or render. High pressure pits and erodes them, opens the pores so they soil faster, and pushes water where it should not go. Soft washing is the right tool there.
- The treatment does the work, not brute pressure, so soft surfaces are cleaned without being damaged.
- Growth is killed at the source, not just blasted off the top, so the surface stays clearer for longer and we schedule upkeep rather than promise permanence.
- Bore and mineral staining is treated, with a purpose-formulated stain remover, not scrubbed harder into a soft surface.
- We identify before we treat. What looks like green on stone is not always algae, so we confirm whether it is growth or a mineral stain first, because they need different treatments.
Built for strata & facility managers
A program, not a reactive one-off.
Organic growth peaks over the cooler, wetter months, so the smart move is a scheduled program built around Perth's seasons: clear and re-protect heading into the drier months, rather than reacting once the walls have gone black. We define a scope of works, split it into periodic tasks, and speak to the jobs you actually have.
Strata managers & councils of owners
Scheduled common-property cleaning, billed and reported to the council, sized to the levy budget so there are no surprises at the AGM.
Facility & building managers
Periodic exterior programs for office, retail and mixed-use assets, run to documented method statements and reported after every visit.
Owners & committees
Apartment complexes, aged-care and body-corporate property, cleaned and protected to hold the building's presentation and its capital value.
- Public liability insurance, with a certificate of currency available on request.
- Documented SWMS and JSA for every job, provided to your manager or committee before we start.
- Police-cleared operators on site, working to a defined scope.
- Access capability for facades, high walls and architectural glass, within what we can do safely.
- Before and after photo reports after each visit, ready to drop into a committee pack or AGM report.
- Fixed, scoped pricing agreed before work starts, with no lock-in contract and no surprise invoices.
We work across the Perth metro, from coastal Cottesloe, Scarborough and Hillarys to Subiaco, Nedlands, Joondalup, Canning Vale and the eastern suburbs. This page is part of Extera's exterior cleaning services.
The Extera play
We clean it. Then we protect it.
A bare surface re-stains. Cleaning gets it back, but the moment it is clean it starts drawing in salt, minerals and grime again. So while it is clean and prepped, we protect it: MineralProtect on porous surfaces like limestone, render, concrete and brick, GlassProtect on glass facades, balustrades and balcony glass. A protected surface resists re-soiling and re-staining, which means fewer re-cleans and a lower whole-of-life cost. The protection is a sealing service, applied to a JUMBOGUARD standard and registered under a 10-year guarantee. No generic cleaner offers that.

Now protect it
Clean, then seal the surface.
Cleaning prepares the surface. Sealing is what keeps it clearer for longer. Once we have cleaned a surface, this is how we protect it.
Questions
Commercial & strata cleaning, answered.
How much does commercial or strata cleaning cost in Perth?
Cleaning is quoted per job, not sold at a flat rate. Exterior surface cleaning depends on the surface, the access and how far the staining has gone, so instead of a fixed hourly figure we assess the property on site and give you a fixed, scoped price before any work starts. You see exactly what is included and what it costs, in keeping with the transparent pricing we are known for on the sealing side.
How often should a strata or commercial building be cleaned on the outside?
It depends on aspect, shade and how close you are to the coast, but most Perth buildings do well with a scheduled exterior soft wash once or twice a year. Organic growth like mould, algae and lichen flares over the cooler, wetter months from roughly May to September, so the ideal window is to clear it and re-protect heading into the drier, warmer months. A periodic program keeps it clearer for longer and spreads the cost predictably across the year.
Who is responsible for cleaning common property in a WA strata?
Under the Strata Titles Act the strata company, through its council of owners, is responsible for maintaining common property, and it funds that work through owner levies. In practice the strata manager or building manager arranges the cleaning on the council's behalf. We can bill and report directly to whoever holds that role.
Can you take over from our current cleaning contractor, and is there a lock-in contract?
Yes. We can pick up an exterior cleaning scope from an existing contractor, and we do not tie you into a lock-in contract. You can run us as scheduled periodic visits or as a one-off, and adjust the scope at any review. We would rather earn the next visit than lock you in.
Do you work directly with strata managers and body corporate committees?
Yes. We work with strata managers, councils of owners, body corporate committees and facility managers at every step, from the site assessment and scoped quote through to invoicing and reporting. We speak to the jobs you actually have: predictable levy and facility budgeting, committee and AGM reporting, and protecting the building's capital value.
Are your operators police-cleared, and what insurance do you carry?
Yes. Our operators are police-cleared, and we carry public liability insurance with a certificate of currency available on request. Every job is run to a documented safe work method statement and JSA, and we can provide those to your manager or committee before we start.
Will you provide before and after photo reports for committee and AGM meetings?
Yes. Every scheduled visit is documented with before and after photos and a short written summary you can drop straight into a committee pack or AGM report. It gives owners clear evidence that the levy is being spent well and the asset is being looked after.
Is high-pressure cleaning safe for Perth limestone and render?
No, and this is where a lot of damage gets done. Perth limestone and cement render are soft and porous, so blasting them with high pressure pits the surface, erodes the finish and opens the pores, which makes them soil and stain faster afterwards. We soft wash these surfaces instead, using a low-pressure application of a biodegradable treatment so the chemistry does the work, not the force.
How do you clear black mould, algae and lichen from walls and paving?
We soft wash. A biodegradable biocide is applied at low pressure and left to work, so it kills the growth at the source rather than just blasting the film off the top and leaving the rest to return quickly. Because the biocide does the work we do not need damaging pressure on soft surfaces, and the result stays clearer for longer. Growth is natural over time, so we schedule periodic upkeep to stay ahead of it. What looks like green on stone is not always algae either, sometimes it is a mineral stain that needs a different treatment, so we identify it first.
How do you remove orange bore-water stains, and will they come back?
Orange and brown staining from bore and reticulation water is iron and calcium carried out of the ground and baked onto render, limestone, paths and glass by the sun. We treat it with a purpose-formulated stain remover, then, because a bare surface simply re-stains, we can protect the surface so the minerals cannot key into it as easily and it stays clearer for longer. It is not permanent, the reticulation keeps depositing minerals, so pairing the treatment with protection and sensible sprinkler settings is what breaks the re-stain cycle.
Can you clean and protect the surface so it stays cleaner for longer?
Yes, and this is our edge. After we clean, we can apply MineralProtect to porous surfaces such as limestone, render, concrete and brick, or GlassProtect to glass facades, balustrades and balcony glass. A protected surface sheds water, resists re-soiling and re-staining and is easier to clean next time, which means fewer re-cleans and a lower whole-of-life cost. The protection is a sealing service, applied to a JUMBOGUARD standard and registered under a 10-year guarantee. Cleaning on its own does not protect or repel, it prepares the surface so protection can do that job.
Do you clean roofs and clear roof moss?
On suitable roofs, yes, but it is a treatment rather than a same-day strip. We do not climb onto the roof or pressure-blast it, because blasting a roof creates leak pathways and damages tiles and pointing. Instead we soft wash from ladders set at the eaves, spraying a biocide at low pressure that kills the moss, lichen and algae. It stays active on the surface for up to 24 months, works over roughly three to twelve months, and reactivates each time it re-wets with rain or dew. As the growth dies it weathers and washes off with the rain, so the roof clears progressively over the following months rather than on the day. We assess access and pitch first and only take on what we can do safely, and we do not offer roof restoration or repointing. Roof growth returns over time, so this suits a scheduled program.
Get a quote
Get it cleaned. Then keep it that way.
Request a site assessment and a scoped quote. Tell us the property type, the surfaces involved, how many buildings or levels, and whether it is on bore or scheme water, with photos if you have them. We assess on site and confirm a fixed, scoped price before any work starts, then, if you want, protect the surface while it is clean so it stays that way for longer.

