Moss, lichen, algae and dirt hold moisture against roof tiles, block water flow and speed up wear. Royce Roofing cleans terracotta and concrete tiled roofs with industrial pressure equipment running at 4,000+ psi, matched to the condition of your tiles, and clears gutters with industrial vacuum equipment.
At a glance
- Industrial pressure cleaning at 4,000+ psi, matched to tile condition
- Terracotta and concrete tiled roofs, ridge capping, valleys and gutters
- We inspect before we clean, and replace cracked tiles from our own yards
- The first step of every restoration and painting job
- Free quote
What we clean
Tiled roof surface
Terracotta and concrete tiles, stripped of moss, lichen, algae and built-up dirt.
Ridge capping and valleys
Where debris and growth collect and hold water against the roof.
Gutters
Cleared of moss, leaves and tile grit with industrial vacuum equipment, without washing it down the downpipes.
Why moss and lichen grow on roofs
Monier, one of Australia’s biggest tile makers, explains that moss and lichen spores settle where moisture and dirt build up. On Melbourne roofs that means south-facing planes, areas shaded by trees, valleys full of leaves and the lower courses where water slows down. Once established, growth holds water against the tile surface, roots into it, and traps more dirt, so it spreads.
- South-facing and shaded roof planes stay damp longer
- Overhanging trees drop leaves and seeds into valleys and gutters
- Older concrete tiles with worn coatings are more porous and hold moisture
- Blocked valleys and gutters keep the lower roof wet
Sources: Monier: Roof cleaning and maintenance.
Why get your roof cleaned
Protect the tiles
Removing moss and lichen stops them holding water against the tiles, which slows wear on porous concrete.
Keep water flowing
Growth in valleys and gutters backs water up under the tiles. A clean roof drains as designed.
Spot problems early
On a clean roof, cracked tiles, failed pointing and rusted valleys are easy to see. We point them out.
Prepare for painting
Coatings will not bond to a dirty or mossy surface. Proper cleaning is what makes a roof coating last.
Get your roof cleaned properly
Free quote, and we will point out anything else that needs attention.
Pressure cleaning done right
Pressure is a tool, not the goal. Some tile makers, Monier among them, advise against pressure washers on roofs, because the wrong pressure, nozzle or angle can etch a weak tile, crack brittle ones, or drive water up under the tile laps. That is why our approach starts with the roof, not the machine.
- Inspect firstWe check tile condition, pointing and valleys before cleaning, and tell you about anything already broken.
- Match the method to the tileSound tiles get a full industrial clean. Fragile, weathered or glazed tiles are cleaned with more care, or we tell you if cleaning is not the right answer.
- Replace what we findAny cracked tiles exposed by the clean are replaced from our own yards.
- Clear valleys and guttersDebris washed from the roof is vacuumed out of gutters rather than left to block downpipes.
Sources: Monier: Roof cleaning and maintenance.
If you have a rainwater tank
National enHealth guidance on rainwater tanks says the tank inlet should be easy to detach so the tank can be bypassed when needed, that cleaning agents that could harm water quality should not be used, and that run-off from newly painted roofs should not be collected. Tell us about your tank when you book, so it can be disconnected before cleaning starts and reconnected once the roof has been rinsed clean.
Sources: enHealth: Guidance on the use of rainwater tanks; Victorian Department of Health: Rainwater.
How often should a roof be cleaned?
| What | How often | Source |
|---|---|---|
| Roof and gutters on homes collecting rainwater | Twice a year, or more in leafy or dusty areas | enHealth |
| Valleys | At least once a year, more often near trees | Monier |
| Professional roof inspection | About every five years | Monier |
| Full roof clean | When moss, lichen or dirt build-up is visible, or before any coating | Royce Roofing |
Sources: enHealth: Guidance on the use of rainwater tanks; Monier: Roof cleaning and maintenance.
Clean, restore or paint?
If the tiles and pointing are sound, a clean may be all the roof needs. If it is faded or the pointing is failing, it usually makes sense to clean and then restore or recoat in the same job, because the roof is already prepared.
| Roof condition | Usually needs |
|---|---|
| Sound tiles, some moss and dirt | Pressure clean |
| Faded concrete tiles, sound pointing | Clean and roof painting |
| Cracked tiles, failing pointing, faded surface | Full roof restoration |
Our restorations use a 4-coat system: one primer coat, two full-colour base coats and one protectant coat. Monier notes that painting does not improve a tile’s waterproofing, so we only recommend a coating where it serves the roof, not as a substitute for repairs.
Read more: roof cleaning vs restoration and our guide to pressure washing roofs.
What affects the cost of roof cleaning
| Factor | Why it matters |
|---|---|
| Roof size | More area takes longer to clean. |
| Height and pitch | Double-storey and steep roofs need more safety set-up. |
| Amount of growth | Heavy moss and lichen take more passes than light dirt. |
| Tile condition | Weathered tiles need slower, more careful cleaning, and cracked tiles may need replacing. |
| Gutters and valleys | How much debris needs vacuuming out. |
| Access | Where the crew can set up equipment and run water. |
Safety on every job
WorkSafe Victoria’s compliance code for housing construction puts edge protection such as guard railing ahead of harnesses and ladders when controlling the risk of falls from a roof. Our crews set up our own temporary safety rail, ladder guards and, where there are old skylights, safety nets before anyone works on the roof. Every crew member holds a working at heights qualification.
Sources: WorkSafe Victoria: Prevention of falls in housing construction.
Common questions
Can pressure cleaning damage roof tiles?
Done badly, yes. The wrong pressure or angle can etch weak tiles, crack brittle ones, or force water under the laps. That is why we inspect the roof first and match the method to the tiles. Sound terracotta and concrete tiles clean up well; badly deteriorated tiles need a different plan.
Is it better to soft wash or pressure clean a tiled roof?
It depends on the tiles. Sound concrete and terracotta tiles respond well to industrial pressure cleaning, which strips moss, lichen and dirt. For fragile or glazed tiles a gentler approach is safer. We inspect first and recommend the method that suits your roof.
Do I need to be home while you clean the roof?
Not necessarily. As long as we have safe access to the roof and an outdoor tap, our team can complete the work while you are out. We let you know when the job is finished and whether we spotted anything on the roof that needs attention.
What about my rainwater tank?
Tell us when you book. National rainwater guidance says the tank inlet should be bypassed when needed and run-off from newly painted roofs should not be collected. Disconnect the tank inlet before cleaning starts, and reconnect it once the roof has been rinsed clean.
How often should I clean my roof?
Clean it when moss, lichen or dirt build-up is visible, and always before a coating. Valleys should be cleared at least once a year, and more often under trees. If you collect rainwater, national guidance recommends cleaning roofs and gutters twice a year.
Is pressure cleaning part of a roof restoration?
Yes. Every restoration and roof painting job starts with a full clean, because coatings and new pointing will not bond properly to a dirty or mossy surface. If you are planning a restoration, the clean is already included in the job.
Do you clean gutters as well?
Yes. We clear moss, leaves and tile grit from gutters using industrial vacuum equipment, which avoids washing debris down the downpipes or across your yard. We also check gutters for damage and tell you if any sections need repair.
Can you clean terracotta roof tiles?
Yes. Terracotta cleans well because its colour is fired through the clay, so a proper clean brings back the original colour. Older terracotta can be brittle, so we inspect first and replace any cracked tiles from our yards with matched terracotta.
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