What terracotta is, glazed and unglazed
Monier, one of the big Australian tile makers, describes terracotta as kiln-fired clay with a vitreous (glass-like) coating that shrugs off moisture, UV and airborne pollution. Glazed tiles have a shiny fired finish; unglazed tiles are the matt, earthy red on so many older homes.
Monier says moss and lichen take hold more readily on terracotta than on concrete, unglazed especially, though the growth is only on the surface. It also says its tiles are salt safe and won't corrode, which counts for a lot near the beach. We have no link with Monier or Bristile; we just quote what they publish.
How long does a terracotta roof last?
By Monier's account, a century or more of service from terracotta isn't unusual. A NSW Government heritage schedule takes a more cautious line: 40 years for a terracotta roof covering, with a look every 7 years. Either way, the tiles tend to outlive the mortar, valley irons and battens around them.
Monier gives a 30 year product warranty on tiles bought from 1 July 2026 and installed to its guides. Bristile lists up to 100 years on selected terracotta. That covers the tile, not the roofer's workmanship, so ask about both.
Terracotta, concrete tile or steel?
| Terracotta | Concrete tile | Steel sheeting | |
|---|---|---|---|
| Colour over time | Fired into the clay, so it doesn't fade (Monier) | A surface coat that weathers to a softer matt look (Monier) | Factory-baked paint; painting over it voids BlueScope's warranty |
| Weight, one example each | Monier Marseille: 47.25 kg per square metre | Monier Elabana: 49.5 kg per square metre | Corrugated Colorbond at 0.42 mm: 4.35 kg per square metre |
| Lowest pitch | 15 degrees with sarking for Marseille, 12 for some profiles | 15 degrees for most Monier concrete profiles | 5 degrees for corrugated, 1 degree for some concealed-fix profiles |
| Moss and lichen | Grows more readily, unglazed especially | Grows less than on terracotta | Rain washes the open roof clean (BlueScope) |
What upkeep does terracotta need?
Most of the work is along the top. Bedding is the mortar that holds the ridge and hip caps down, and pointing is the finishing layer that seals it. Monier lists cracked bedding as a common cause of leaks and says repairs should use modern flexible pointing.
Keep valleys, gutters and downpipes clear at least once a year, twice under trees, and have the roof inspected every five to seven years, as Monier suggests. Don't let anyone pressure wash the tiles, which Monier warns can damage them, and don't paint them: once unglazed terracotta is painted, it needs recoating from then on.
What to ask a roofer about a terracotta roof
- Are my tiles glazed or unglazed, and how will you clean them?
- Where will replacement tiles come from, and how closely will they match?
- Will the ridges be repointed with a flexible compound?
- Will you follow the tile maker's installation guide, so the warranty holds?
- Are my gutters galvanised? BlueScope warns they can corrode early under glazed terracotta and suggests Colorbond or Zincalume steel gutters.
What you can do, and what's for a roofer
You can
- Check ridges and tiles from the ground with binoculars after storms
- Clear gutters from a ladder if you're comfortable
- Trim branches that drop leaves into the valleys
Leave to a roofer
- Walking on the tiles, which crack under a boot
- Replacing tiles and rebedding ridges
- Cleaning off moss without a pressure washer
If it were our roof
If the tiles are sound, we'd leave them alone and put the money into the ridges, the valleys and any broken tiles. We wouldn't paint terracotta: it's the one roof whose colour looks after itself. For a new roof, terracotta earns its higher price mainly on a home you'll keep for decades, with a frame built to carry tiles.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.