The majority of Maidstone's housing stock falls into one of two categories: pre-1950s properties with original clay tiles or Welsh slate, and post-war properties (1950s through to the 1990s) with concrete interlocking tiles. When it comes to replacement, the question of clay vs concrete is one we discuss at virtually every survey across the area.
The Basics: How They Differ
| Property | Clay Tiles | Concrete Tiles |
|---|---|---|
| Material | Fired natural clay | Cement, sand, aggregate |
| Weight | Heavier per tile | Slightly lighter per m² |
| Lifespan | 60–100+ years | 30–50 years |
| Colour stability | Excellent — fired-in colour | Fades over 15–25 years |
| Cost per m² (supply) | £18–£35 | £8–£18 |
| Conservation area use | Acceptable / required | Generally not acceptable |
| Moss resistance | Higher (denser surface) | Lower (more porous surface) |
Why Clay Tiles Last Longer
Clay tiles are fired at very high temperatures, which produces a dense, low-porosity tile that is inherently resistant to moisture absorption and frost damage. A good clay tile from a reputable manufacturer has an essentially unlimited service life providing it's correctly fixed and the nails don't fail first. Many original Edwardian clay plain tile roofs across Maidstone and Bearsted are still perfectly serviceable after 100+ years.
Concrete tiles are made from cement, sand and aggregate with a surface coating. The coating fades and weathers over 15–25 years, and the concrete body absorbs more moisture than clay. Freeze-thaw cycles in Kent winters cause progressive delamination — the surface aggregate separates from the tile body. This is the failure mode we see on virtually all the 1960s and 70s concrete tile estates across Penenden Heath, Park Wood, Larkfield and Coxheath.
The Cost Difference
Clay tiles typically cost 30–60% more per square metre in materials than concrete interlocking tiles. On a standard 3-bed semi in Maidstone with a 70 square metre roof, this translates to roughly a £1,500–£2,500 difference in total project cost. Over a 50-year period, however, you would expect to re-tile a concrete roof at least once more than a clay roof — making clay potentially more cost-effective over the long term on a property you intend to keep.
When Concrete Tiles Are the Right Choice
Concrete interlocking tiles remain a perfectly valid roofing material and are the appropriate choice in a number of situations. On post-war properties where the original specification was concrete tiles and there's no conservation area requirement, concrete tiles are a cost-effective and proven material. Modern concrete tiles are significantly better than their 1960s predecessors — thicker, with better surface finishes and longer warranty periods. If you're replacing a roof on a 1970s semi in Larkfield or Penenden Heath and budget is a consideration, quality modern concrete tiles with a breathable felt underlay will give 35–50 years of reliable service.
When Clay Tiles Are Required or Strongly Preferable
For any property in Maidstone's conservation areas, clay plain tiles are required where the original specification was clay. Substituting concrete in these areas is a planning breach. For Victorian and Edwardian properties outside conservation areas, clay tiles are strongly preferable — they match the aesthetic of the property, perform better in the damp Kent climate, and will significantly outlast concrete alternatives. If you're spending money on a full re-roof on a period property, spending an extra 30% on clay rather than concrete is almost always the right long-term decision.
What About Modern Clay Interlocking Tiles?
Modern clay interlocking tiles — as opposed to traditional clay plain tiles — offer many of the durability and colour stability benefits of clay in a format compatible with the standard batten spacing of post-war roofs. They're a good option for replacing concrete tile roofs on interwar and post-war properties where you want the longevity of clay without the higher cost of plain tiles. We use them regularly on Bearsted and West Malling semis from the 1930s–60s.
For advice on the right specification for your Maidstone property, call 0162 229 6232 for a free survey. Our roof replacement page has more detail on the full re-roofing process.