Clay tiles typically last 60 years or more, keep their colour because it is fired in, and weigh less. Concrete tiles cost less, come in more profiles, and are heavier — which matters if you are changing from one to the other, because the roof structure was designed for the original load. Concrete also fades, as the pigment is in the surface rather than through the body.
- Changing from clay to concrete adds weight the roof structure may not have been designed for.
- Clay keeps its colour; concrete fades, which is why older concrete roofs look patchy.
- Interlocking tiles of either material cost less to lay than plain tiles, because fewer are needed.
- On a period property, the existing tile is usually the right answer for appearance as well as planning.
The basic difference
Clay tiles are formed from clay and fired in a kiln, in the same way as bricks. The colour comes from the clay itself and the firing, so it runs through the whole tile and is effectively permanent.
Concrete tiles are moulded from sand, cement and pigment, then cured. The pigment is concentrated in a surface layer rather than through the body, which is why an old concrete roof so often looks blotchy: the surface has weathered and the grey concrete beneath shows through.
Both are long-lived, both are used across Coventry, and both are perfectly respectable choices. The decision usually turns on budget, weight and appearance rather than on quality.
Side by side
| Clay | Concrete | |
|---|---|---|
| Typical lifespan | 60 years or more; often far longer | 40–60 years |
| Colour over time | Fired in; essentially permanent | Surface pigment; fades and can blotch |
| Weight | Lighter | Heavier — often substantially |
| Cost | Higher | Lower |
| Profiles available | Plain, pantile, interlocking | Very wide range, including clay imitations |
| Moss and algae | Resists better; less porous once weathered | Porous surface holds growth more readily |
| Frost resistance | Very good in a quality tile | Good when new; declines as the surface weathers |
| Period suitability | Usually the correct choice | Can look wrong on older property |
| Breakage handling | More brittle; handle with care | Tougher, less prone to chipping |
Neither is simply better. On a 1930s semi being re-roofed to a budget, concrete interlocking tiles are a sensible choice. On a Victorian terrace with clay plain tiles, clay is usually the right answer on every count except price.
Weight: the one that is structural
This is the consideration that matters most and gets discussed least.
A roof structure is designed for the load it carries. Rafters, purlins, wall plates and the walls themselves were sized for a particular covering. Changing from a lighter covering to a heavier one adds load that nothing in the structure was calculated for.
The classic case is a roof originally laid in natural slate, later re-covered in concrete tiles. Concrete tiles can weigh considerably more per square metre than slate, and the usual signs are a visible sag in the roof line, spreading at the eaves, and cracking in the gable walls. It is a well-recognised problem and it is expensive to put right.
Going the other way — concrete to clay, or tile to slate — reduces the load and is structurally straightforward, though the batten gauge and fixing specification will change.
The practical rule: if the covering you want is heavier than what is there now, the roof structure needs assessing before the order goes in. A competent roofer will raise this; if nobody mentions it when you ask about changing material, ask directly.
Interlocking against plain tiles
This distinction affects cost more than the clay-or-concrete choice does, and the two are often confused.
Plain tiles are small, flat and laid in a double lap, so every point on the roof is covered by at least two tiles. They look excellent, particularly on older property, and they are the traditional covering for much Victorian and Edwardian housing. The cost consequence is substantial: a plain-tiled roof needs roughly three to four times as many tiles per square metre as an interlocking roof, with the labour to match.
Interlocking tiles are larger, with a profiled edge that laps into the neighbouring tile. Far fewer are needed, they go on faster, and they are the standard for most post-war housing.
So a quote for clay interlocking tiles and a quote for clay plain tiles are not comparable, and a quote for concrete plain tiles may well exceed one for clay interlocking. When comparing, check the tile type as well as the material.
Appearance, and why old concrete roofs look tired
Clay weathers in a way most people find attractive. It mellows, it takes lichen, and because the colour is through the body a chipped corner looks like clay rather than like damage. A hundred-year-old clay roof usually looks better than it did new.
Concrete ages less gracefully. The pigmented surface erodes under UV and rain, progressively exposing the grey body beneath, and because that erosion is uneven the roof develops a patchy, washed-out look. Growth takes hold more readily on the roughened surface. Nothing is structurally wrong; it simply looks tired.
Modern concrete tiles are considerably better than those from a few decades ago, with more durable surface treatments, and the difference is less pronounced than it was. But over the life of a roof, clay will keep its appearance and concrete will not.
Which to choose
- Matching an existing roof: match what is there. Mixing materials on one elevation rarely looks right.
- Period property, especially plain-tiled: clay, and in a conservation area it may be required rather than preferred.
- Post-war semi or detached, budget-conscious: concrete interlocking is the sensible default.
- Planning for the long term: clay, on lifespan and appearance, if the budget allows.
- Roof previously slated: get the structure assessed before specifying anything heavier.
- Heavily shaded roof: clay resists growth better, which is worth something over a few decades.
- A roof you want to forget about: clay. It is the lower-maintenance covering over its life.
Planning and matching
Like-for-like re-roofing is normally permitted development and needs no application. Changing the material or the appearance is where it can matter: conservation areas, listed buildings and Article 4 directions all restrict changes to the external appearance, and that can include the roof covering.
There is also the terrace question. On a run of houses with a consistent roof, changing the covering on one changes the look of the whole row. It is worth a thought and, where you share a party line, a conversation with the neighbour.
What re-roofing costs
These are the roofing figures published across this site:
| Job | Typical Coventry guide price | Notes |
|---|---|---|
| Full re-roof (typical semi) | £5,000–£9,000 | Strip, membrane, batten, re-tile |
| Larger / detached re-roof | £9,000–£12,000+ | Scaffolding included |
| Minor roof repair | from £150–£400 | Slipped or broken tiles, usually one day |
| Chimney repointing / flashing | £300–£900 | Access dependent |
Those figures cover the work rather than a specific tile. Clay sits higher than concrete, and plain tiles of either material sit higher again because of the number needed. We price the actual covering at survey.
We check what the structure was designed to carry before recommending anything heavier, and we will tell you when matching the existing tile is the better answer.
Frequently asked questions
Are clay tiles better than concrete?
Clay lasts longer, keeps its colour because it is fired in rather than applied, resists moss better and weighs less. Concrete costs less and comes in a wider range of profiles. Neither is wrong — on a period property clay is usually the right answer, and on a post-war house being re-roofed to a budget, concrete interlocking tiles are entirely sensible.
Can I change from concrete tiles to clay?
Yes, and structurally it is straightforward because clay is lighter, so you are reducing the load. The batten gauge and fixing specification will change to suit the new tile, and the cost is higher than a like-for-like concrete re-roof. Going the other way — adding weight — is the direction that needs the structure checking first.
Why has my concrete roof gone patchy?
The pigment in a concrete tile sits in a surface layer rather than running through the body. UV and rain erode that layer unevenly over the years, exposing the grey concrete beneath. It is cosmetic rather than structural, and it is the main reason an aged concrete roof looks tired while a clay roof of the same age does not.
Do concrete tiles weigh much more than slate?
Generally yes, often considerably, and this is the single most important thing to check before changing covering. Many roofs originally laid in slate were later re-covered in concrete without the structure being assessed, and the signs — a sagging roof line, spreading at the eaves, cracked gables — are well recognised and expensive to correct.
Should I paint or seal my concrete tiles to restore the colour?
We would generally advise against it. Coatings applied to roof tiles tend to peel, can trap moisture in a porous tile and make it more vulnerable to frost, and they complicate any future repair. If appearance is the issue and the roof is otherwise sound, cleaning carefully is reasonable; recoating usually is not.
Can clay and concrete tiles be mixed on one roof?
On the same elevation, no — the profiles, thicknesses and colours will not match and it looks exactly like what it is. On different elevations of a large property it is occasionally done for cost reasons, but it needs thinking about from the street view. Where a repair needs matching tiles, sourcing the correct material is nearly always worth the effort.
Get the covering matched to the structure
We assess what the roof was built to carry, identify the existing tile and tell you honestly whether matching it or changing it is the better decision. Free inspection, fixed written quote.