Picture two tiled roofs on the same Mount Martha street. One owner has just had theirs painted. The other has been told theirs “never needs it”. From the footpath the roofs look much the same, so who is right? Quite often, both are. It depends on the tile. The terracotta vs concrete roof tiles question decides how your roof ages, what maintenance it actually needs, and what you should pay for when a quote lands in your inbox.
Here is how we explain the difference to people on the Peninsula, whether they are looking after an existing tiled roof or choosing tiles for a new one.
Two tiles that look alike from the street and behave very differently
Terracotta tiles are made from clay that is shaped and fired in a kiln, much like a brick or a flowerpot. The colour is either in the clay itself or in a glaze baked onto the surface. Either way, it does not wash off.
Concrete tiles are a mix of cement, sand and pigment, pressed into shape and cured. They usually leave the factory with a surface coating that gives them their colour and smooth finish. That coating is the part that wears.
That single difference explains most of what follows. A terracotta tile mostly stays the tile it was on day one. A concrete tile slowly loses its outer skin, and once that skin is gone the cement and sand underneath are left to face the weather on their own.
How to tell which tiles are on your roof
You do not need to climb up to work this out, and we would rather you didn’t. A few checks from the ground or the roof space usually settle it:
- Look at the back of a tile in the roof space. If you can see the underside of a tile near the manhole, terracotta shows a clay colour (often orange or reddish) right through. Concrete is grey on the back regardless of the colour on top.
- Check a spare or broken tile. Many homes have a few leftovers behind the shed. Snap edge orange or buff means clay. Grey and gritty means concrete.
- Look in the gutters. Fine sandy grit collecting in the gutters is a common sign of concrete tiles shedding their surface.
- Look at the edges. Concrete tiles tend to be thicker with a blunter leading edge. Terracotta is usually thinner and crisper.
If it is still unclear, a roofer can tell in seconds. It is one of the first things we note on any inspection, because it changes the advice.
How each one ages in Peninsula weather
Our roofs deal with salt air from both bays, plenty of winter rain, and shaded south faces that rarely dry out properly. Tiles of either kind cope with salt far better than bare metal, because there is nothing to rust. The differences show up in how the tile surface holds up.
Concrete: the coating goes first
On older concrete roofs we usually find a faded, chalky surface that comes off on your hand. Under that, the tile turns rough and porous. Rough, damp surfaces are exactly where lichen and moss take hold, and once they do they keep the tile wet for longer. The tile itself often stays sound for a long time. It just looks tired and holds more water than it used to.
Terracotta: the tile lasts, the details around it don’t
Terracotta keeps its colour and shape well. What fails on these roofs is usually everything else: the mortar bedding under the ridge caps cracks and falls out, individual tiles crack when someone walks on them, and valleys fill with leaf litter. Terracotta is more brittle than concrete underfoot, which is why we see so many cracked tiles near TV antennas and solar panels where other trades have been working.
Both roofs grow lichen on the shaded side. On concrete it is worth dealing with sooner because the tile surface is already softer.
Why the tile type changes what a restoration should include
This is where homeowners most often get caught out. A tile roof restoration is not one fixed package. What a sensible one includes depends heavily on which tile you have.
For a weathered concrete roof, a coating system usually makes sense. Once the factory finish has gone, cleaning the tiles and applying a proper sealer and membrane coating restores a surface that sheds water and resists growth. Skipping the coating on a badly worn concrete roof is often false economy.
For terracotta, painting is mostly cosmetic. Unglazed terracotta that has simply faded can be painted if you want a fresh colour, but it is rarely needed to keep the roof sound. Glazed terracotta is a poor candidate for paint in the first place, because coatings struggle to grip that glassy surface. On most terracotta roofs the money is better spent on cleaning, replacing cracked tiles and rebedding and repointing the ridges.
So if you have terracotta and a quote leads with a full paint job, ask why. And if you have tired concrete and a quote skips the coating, ask the same question. Our tile roof restoration work starts with identifying the tile and its real condition for exactly this reason.
Replacing a few broken tiles is harder than it sounds
Matching tiles is a genuine headache on older roofs, for both types. Tile profiles change, manufacturers retire colours, and a brand new tile rarely matches one that has weathered for decades.
With terracotta we can often source a close match from salvaged stock, and because the colour is in the clay, a good secondhand tile blends in well. With concrete, a replacement tile in the right profile is usually easier to find, but the colour almost never matches a weathered roof. That is one reason people with patched concrete roofs end up coating the whole thing.
If you have spare tiles from the original build, keep them. They are worth more than they look.
Choosing tiles for a new roof or an extension
If you are building, extending or replacing, the choice comes down to a few practical points.
Upfront cost. Concrete is generally the cheaper tile to buy. Terracotta costs more, and the gap varies with the profile and finish you choose.
Long term upkeep. Terracotta’s colour does not depend on a coating, so you are less likely to face a recoat down the track. Concrete will eventually need its surface looked after.
Weight. Concrete tiles are heavier. On a new build the frame is designed for it. On an extension or an older house, or if you are switching from a lighter roof, the frame needs checking before anyone commits to heavy tiles.
Matching what is already there. On an extension, matching the existing roof often matters more than which tile is better in theory. A mismatched roofline is very noticeable on a Peninsula street.
Whichever tile you choose, what goes underneath counts as much as the tile. Tiles are not a fully waterproof skin on their own; wind can drive rain up under them, which is why we recommend installing a sarking membrane under the tiles on new tile roofs. If you are still weighing up tile against metal altogether, our comparison of Colorbond and tile roofs covers that decision.
Common questions about terracotta and concrete tiles
Which is better, terracotta or concrete roof tiles?
Neither wins outright. Terracotta holds its colour and needs less surface maintenance, while concrete is cheaper to buy and tougher underfoot. For a long term home where you want minimal upkeep, terracotta usually suits. If the budget is tight or you are matching an existing concrete roof, concrete is the sensible choice.
How can I tell what roof tiles I have?
Check the underside of a tile from the roof space or look at a spare tile. Clay shows orange or buff right through, while concrete is grey on the back and gritty at a broken edge. Sandy grit building up in your gutters also points to concrete.
Is it okay to walk on a clay tile roof?
We would advise against it. Terracotta is brittle and cracks easily under a misplaced foot, and a cracked tile can leak for months before anyone notices. Roofers know where to step and how to spread their weight, and they are working with proper fall protection.
Do terracotta roof tiles need painting?
Usually not. The colour sits in the clay or the glaze, so terracotta does not rely on paint for protection. Painting it is a cosmetic choice, and glazed tiles are best left unpainted because coatings struggle to bond to them.
What goes under concrete roof tiles?
Tiles of either type sit on timber or steel battens fixed to the roof frame. On most modern roofs there is also a sarking membrane under the battens, which catches wind driven rain and dust that gets past the tiles and directs it into the gutters.
What are the downsides of terracotta roof tiles?
They cost more to buy, they crack more easily if walked on, and finding an exact match for an older profile can take some hunting. The ridge capping mortar on older terracotta roofs also needs attention over time, as it does on concrete roofs.
Not sure what your roof needs?
If you are looking at a tiled roof and wondering whether it needs a coating, a few new tiles or just a good clean and repoint, the first step is knowing which tile you have and what condition it is really in. Get in touch about a roof restoration on the Peninsula and we will give you a straight answer based on what is actually up there.
