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Category: TERRACOTTA MOSS ROOF CLEANING
18/06/2026
Why Do Terracotta Roofs Get So Much Lichen, Moss And Black Mould?
Learn Why Terracotta Roof Tiles Attract Lichen, Moss And Dark Organic Staining — And Why Regular Roof Treatment Helps Keep Them Cleaner For Longer.
Terracotta roofs are a beautiful and long-lasting roofing choice, especially on older homes and character properties. Their warm clay colour gives a home a classic look, but over time many terracotta roofs start to develop patches of lichen, moss, algae and dark staining. So why does this happen? The simple answer is that terracotta tiles create the right conditions for organic growth. When moisture, shade, airborne dirt and weathered roof surfaces come together, lichen and moss can quickly take hold. Terracotta Tiles Are Porous Terracotta tiles are made from fired clay, which means they naturally have a porous surface. Even when the roof looks dry from the ground, the tile can still hold moisture in tiny surface pores. This moisture gives moss, algae and lichen a place to survive and spread. Once the roof stays damp for long enough, spores can settle on the surface and begin to grow. Older Tiles Become Rougher Over Time When terracotta tiles are new, they usually have a harder, smoother outer surface. But after years of exposure to sun, rain, wind, frost, pollution and general weathering, that surface can become rougher. A rough tile gives lichen and moss something to grip onto. This is why older terracotta roofs often have more visible growth than newer roofs. Lichen in particular can be very stubborn because it does not simply sit on top of the tile. It attaches itself tightly to the surface, which is why it can be difficult to remove without the right treatment process. Shade Makes the Problem Worse Organic growth is usually worse on parts of the roof that do not get much direct sunlight. Common problem areas include: -Roof sections shaded by trees -South-facing sides of the roof -Areas behind chimneys -Valleys and low-drainage areas -Sections around solar panels, dormers and roof features When the roof does not get enough sun, it dries slowly after rain, dew or fog. The longer the tiles stay damp, the better the conditions become for moss, lichen and algae. Trees and Debris Add Nutrients Moss, lichen and algae do not need much to survive. Dust, pollen, leaves, bark, bird droppings and general airborne dirt can all provide enough nutrients for growth. Homes near trees, gardens, parks, farms or damp environments often see faster roof growth because more organic material lands on the tiles. Once leaves and debris collect in valleys, gutters or tile overlaps, they can hold even more moisture against the roof. What People Call “Black Mould” Is Often Algae or Organic Staining Many homeowners refer to dark roof staining as black mould. In many cases, it may not be household mould in the usual sense. The black marks on a roof are often caused by algae, cyanobacteria, mildew-like growth, pollution, soot, or dead organic matter. These stains are most common where moisture sits on the tile surface or where rainwater carries dirt and nutrients across the roof. Whatever the exact cause, black staining is usually a sign that the roof surface is staying damp and collecting organic material. Moss and Lichen Can Spread Once They Start One of the main problems with moss and lichen is that they can make the roof even more suitable for future growth. Moss holds water like a sponge. Lichen creates a rough surface. Algae and staining can trap moisture films across the tile face. This means that once organic growth has started, it can gradually spread unless the roof is treated. Why Regular Roof Treatment Matters Terracotta roof growth is not just a cosmetic issue. Heavy moss and lichen can hold moisture against the tiles, block gutters, slow drainage and make the roof look older than it really is.
22/01/2026
🧱 Before & After – Terracotta Tile Moss Treatment 🧱
Wow! Look At The Difference!
These aerial photos show a clear comparison between moss-treated and non-treated terracotta tile roofs. 🔸 Treated roof (Right/ brighter tiles): ✔ Moss, mould & lichen killed at the root ✔ Natural terracotta colour restored ✔ Ongoing clean as rainfall slowly washes away dead growth ✔ No high-pressure cleaning required 🔸 Untreated roof (Left / darker tiles): ❌ Heavy moss and lichen build-up ❌ Trapped moisture and increased tile deterioration ❌ Reduced roof lifespan over time Our treatment is water-based, biodegradable, non-corrosive and pH neutral, making it ideal for terracotta tiles where pressure cleaning can cause damage or water ingress. 📸 These results speak for themselves — a safer, long-term solution that lets the roof clean itself naturally over time. If you’re noticing moss or dark staining on your roof, request a free quote: https://mossrooftreatment.com.au/quote-your-roof Or give us a call on 1300 007 411 and speak to one of our team!
24/10/2022
Nubrick Terracotta Tile Moss Treatment Results
Mercy Place Rice Village Retirement Village
Wow! Look at the results of the moss treatment at these orange terracotta tiled units. Roughly 12 months after the application the lichen and mould is all gone and it looking great! No pressure cleaning was involved!
15/07/2021
Heavy Moss & Lichen Coverage On Terracotta Tiles
Terracotta Tiled Roof Newcomb
This roof required a lot of maintenance, roof repairs, repointing, valley work, replace broken tiles and more. One of the main factors that can contribute to the deterioration of terracotta tiles is thick moss & lichen growth. It causes leaks, tiles to break and restricts water flow. By Moss Treating the Terracotta Tiles before conducting other roof works, you are preventing further growth and making it easier for tradesmen to walk and work on. Pressure Cleaning old terracotta tiles like these ones, is NOT recommended as water will enter the roof and cause ceiling stains and other damage. Once moss is dead from treatment product, it will begin to break down and wash away overtime, give these heavy covered roofs roughly 12-18 months for all of the moss to be gone. Some roof can take a little longer in more extreme cause of thick moss growth (40+ years). Here are some before and after shots, plus images from the tradesmen on the day of application.
22/05/2021
Red Glazed Terracotta Tiled Roof With Lichen Growth
Moss Roof Treatment On Glazed Terracotta Tiles
Glazed Terracotta tiles are one of the trickiest tiles to work on, due to being very slippery when wet. Trying to pressure clean them is dangerous and not worth the risk. By using Moss Roof Treatment we avoid walking on the roof as the product is applied by tradesmen from ladders which is safer and avoids accidently breaking tiles. The product will not affect the glaze on the tiles and just kill the lichen and spores. Here is a great example of a glazed tile roof we have moss treated.
07/02/2021
Terracotta Before And After
Results Of Moss Roof Treatment
The Terracotta tiled roof was treated in October 2019 and the latest Ariel image shows some fantastic results! A difficult roof surface that wasn't suited to other cleaning methods, the gentle application of moss roof treatment not only kills the surface moss but also the spores to prevent future growth. Ideal for all terracotta roof tile types and colours, the product will kill the moss within 3 weeks, then it further breaks down & washes away overtime with the assistance of the wind and rain. We generally allow 12-18 months for this process (weather dependent).
07/11/2020
Thick Moss Growth On Brown Terracotta Tiles
Best Way To Get Rid Of Moss On Terracotta Tiles
This Terracotta Tiled Roof in Ballarat East was covered in green lichen & moss. It was causing leaks and needed to be removed to identify where the water was entering. We applied Moss Roof Treatment to the surface to kill the moss and spores to prevent any further growth. Then let the wind and rain break it down and wash it away. The roof now looks fantastic, and the customer was able to get the leaks fixed 1 month after the application as the moss had started to shift and disappear.
17/01/2020
Thick Moss On Terracotta Roof.
No Pressure Cleaning Required.
Roof cleaning, roof wash or high pressure cleaning can damage the roof surface. Our Roof Moss Removal Treatment is gentle on surfaces, without causing unnecessary roof works. We service Geelong, Ballarat, Warrnambool, Melbourne and surrounding areas. For clean roof tiles or slate tiles contact us.
25/10/2019
Really Thick Moss.
Thick Terracotta Moss On Roof. Ballarat East
Terracotta Moss Treatment We apply our product Moss Roof Treatment to Terracotta roof surfaces to kill, moss, mould & lichen. The product will kill the moss within 3 weeks, then it break down & wash away overtime with the assistance of the wind and rain. We generally allow 12-18 months for this process (weather dependent). Roof Clean Roof cleaning, roof wash or high pressure cleaning can damage the roof surface. Our Roof Moss Removal Treatment is gentle on surfaces, without causing unnecessary roof works
01/02/2019
Moss & Lichen Coverage On Terracotta Tiles
Terracotta Tiled Roof Anakie
This roof required a lot of maintenance, roof repairs, repointing, valley work, replace broken tiles and more. One of the main factors that can contribute to the deterioration of terracotta tiles is thick moss & lichen growth. It causes leaks, tiles to break and restricts water flow. By Moss Treating the Terracotta Tiles before conducting other roof works, you are preventing further growth and making it easier for tradesmen to walk and work on. Pressure Cleaning old terracotta tiles like these ones, is NOT recommended as water will enter the roof and cause ceiling stains and other damage. Once moss is dead from treatment product, it will begin to break down and wash away overtime, give these heavy covered roofs roughly 12-18 months for all of the moss to be gone. Some roof can take a little longer in more extreme cause of thick moss growth (40+ years). Here are some before and after shots, plus images from the tradesmen on the day of application.
26/04/2016
Moss Roof Treatment After Roof Repairs
Roof Repairs Before Or After Moss Roof Treatment.
After cleaning ridge caps rebedding where needed and replacing valley iron with a full flexi point to all ridges caps it was ready to apply a full coat of moss roof treatment to kill all spores of mould and lichen.
