Roof cleaning in Kalamunda, Mundaring and the Hills
Updated October 2026
If your roof has gone dark, patchy or green, it is not just dirt. Moss, lichen and algae hold moisture against the tiles, break down what is left of the coating and slowly shorten the life of the roof. A proper clean restores the look of the house in a day and, more to the point, stops that growth doing damage underneath.
We are a referral service, not a cleaning company. Tell us about the roof and we connect you with one of the experienced, insured local roofers we work with, who will quote the job free.
What professional roof cleaning involves
- A walk-over inspection first, because pressure cleaning a roof with cracked tiles or failed pointing pushes water straight into the ceiling
- Clearing the valleys and gutters of bark, leaf and nuts before any water goes on the roof, so the debris does not simply dam up and back under the tiles
- High-pressure cleaning with roof-specific equipment, worked from the ridge down so water sheds the way the roof is designed to
- Treatment for moss and lichen so the growth dies at the root rather than returning in a season
- Gutters and downpipes cleared again of the sludge the clean washes down
Metal roofs are cleaned at lower pressure with the right chemicals, because high pressure can damage older coatings on Colorbond and galvanised steel.
Why Hills roofs grow moss and lichen
Canopy and shade. These are jarrah and marri suburbs, kept that way by council policy as much as by nature, so the southern and south-eastern pitches of most roofs get little direct sun and stay damp long after a winter front has passed. Add a constant drop of bark, leaf and marri nuts holding that damp against the tile, and a sixty-year-old concrete tile that lost its original surface decades ago is a sponge for growth. It shows up worst in the heavily treed streets around Lesmurdie, Glen Forrest and Parkerville.
Where the wash water goes
Worth raising at quote stage, because the Hills are not a plain suburb in this respect. Several of the orchard localities, including Bickley, Piesse Brook, Pickering Brook and Carmel, along with Kalamunda itself, sit in the Middle Helena Catchment Area, and the City of Kalamunda records that the majority of the Darling Range areas in its district are gazetted public water supply catchments. The Water Corporation monitors development within them. Separately, most properties outside the Kalamunda and Mundaring town centres run their own on-site effluent disposal system, so the tank, the leach drains and the disposal area are all on your block.
None of that stops a roof being cleaned. It does mean a sensible roofer will ask where the water will run and where the tank and drains are before they start, and that is a fair question to put to anyone quoting.
What roof cleaning costs
Guide pricing only, from Australian cost guides rather than Perth rates. A pressure-clean-only visit on an average single-storey home typically runs $400 to $900, with larger, steeper or two-storey roofs sitting higher, often up to around $1,500. Moss treatment, clearing heavy debris and minor repairs add to that. If you are cleaning the roof as step one of repainting or restoring it, get the whole package quoted at once, because it is cheaper than booking each trade separately. The numbers are in our roof restoration cost guide.
A warning about cleaning old roofs
Cleaning strips everything off the tile, including whatever remained of the original coating. A badly weathered roof can look blotchy after a clean, which is why roofers often recommend cleaning as preparation for roof painting rather than as a stand-alone cosmetic fix on an old roof. A good local roofer will tell you honestly which situation yours is before you spend the money.
Safety and licensing
A wet tile roof is one of the most dangerous places a person can stand, and on a sloping block the drop off the low side is worse than it looks. The roofers we work with use harnesses and edge protection and carry insurance for working at heights, which is exactly why this is not a job for a homeowner with a ladder and a pressure washer.
WA has no roofing-specific licence class, and that is not the same thing as roof work being unregulated. What matters is how your job is classified, and Building and Energy's own guidance on builder work notes that builder work can include re-roofing.
The regulator is Building and Energy. Builder work is building work that needs a building permit and is valued at $20,000 or more, or $50,000 or more for a Class 10a building, meaning a shed, carport or private garage, and it must be carried out by a registered building contractor or an approved owner-builder. Work that needs no building permit can be carried out by anyone whatever it costs. So there are two questions to ask rather than one. Ask your local government, which is the permit authority, whether your job needs a building permit. Then ask the contractor what registration they hold and check it with Building and Energy before you sign anything. Insurance and an itemised written quote are worth checking too, but they are not a substitute for that. A clean on its own sits well under those figures. On roof coating we will not give you an answer either way. Whether Building and Energy treats roof coating as painting work under WA's painter registration is not settled, so saying a registration is required and saying one is not would both be invented. Ask the contractor in writing what registration they hold for the coating part of your job and check whatever they give you with Building and Energy.
Related services: roof painting, roof repointing and gutters and downpipes.
Frequently asked questions
How often should a Hills roof be cleaned?
Most roofs up here benefit from a clean every 3 to 5 years. Houses under heavy canopy need it more often, because shade and constant debris speed up regrowth.
Will pressure cleaning damage my tiles?
Not when it is done with the right equipment and technique on a sound roof. The risk comes from cleaning over cracked tiles or failed pointing, which is why a proper inspection comes first.
Does roof cleaning get rid of lichen permanently?
Cleaning removes it, and a biocide treatment slows it coming back, but nothing stops regrowth forever on a bare, porous tile under a tree canopy. Sealing or coating the roof after cleaning is what keeps lichen away long term.
Can I clean the roof myself?
We would not recommend it. Wet tiles are treacherous, domestic pressure washers drive water under tiles, and a fall from a single-storey roof is life-changing. The quote for a professional clean is small against that risk.