REF · MATERIAL GUIDE · PITCHED ROOFS
Welsh slate vs concrete tile — when each one wins
Two perfectly valid roofing materials with completely different economics. Sean Brown’s honest take on when concrete is the right call, when slate is, and when you actually need to think about clay or stone instead.
The 30-second answer
Welsh slate: 75–100 year lifespan. £42–£68/m² fitted. £1.60 per m² per year. The right call for a forever home, a heritage property, or a conservation area — and it’s the cheapest per-year roof you can fit on a UK domestic.
Concrete tile — what it is
A press-moulded concrete tile with an interlocking edge profile. Modern versions (Marley Eternit Modern, Redland Cambrian, Sandtoft Standard Pattern) are BS 5534 compliant, frost-tested, and dimensionally stable. Lifespan 30–40 years typically; some Marley Eternit ranges carry 50-year warranties.
Where it works
- Post-war housing stock (1950s onward) where the roof structure is designed for the weight
- Properties NOT in conservation areas (concrete tile would jar visually on a Victorian terrace)
- Modest budgets that need the best £-per-year ratio in the short-to-medium term
Where it doesn’t
- Pre-1900 stock (looks wrong)
- Conservation areas (often refused at planning)
- Heritage homes where you’ll sell into a slate-preferring market
Welsh slate — what it is
Natural slate, riven by hand (or now: hydraulic press, but riven texture preserved). The “Welsh” classification specifically refers to slate quarried in Snowdonia / North Wales — Penrhyn and Cwt-y-Bugail are the two main 2026 sources. Independent BBA tests give a 100-year service life.
Where it works
- Pre-1940s housing stock that originally had slate (concrete tile would devalue the property visually)
- Conservation-area homes — often the ONLY material planning will accept
- Forever homes — where the 100-year lifespan means it might be the last roof the property ever needs
- Properties where kerb appeal matters at sale time
Where it doesn’t
- Roof structures designed for concrete tile may need bracing for the slate’s slightly different load pattern (rare, but check at survey)
- Properties where you’ll only stay 5–7 years and the buyer market is indifferent to material
£-per-year-of-life — the numbers
| Material | Fitted £/m² | Lifespan | £/m²/year |
|---|---|---|---|
| Felt flat roof | £45–£75 | 10–12 yr | £6.10 |
| EPDM flat roof | £60–£90 | 20+ yr | £3.20 |
| Concrete tile | £18–£32 | 30–40 yr | £2.50 |
| Clay pantile | £28–£42 | 50–80 yr | £1.90 |
| Welsh slate | £42–£68 | 75–100 yr | £1.60 |
| Stone slate | £85–£140 | 100+ yr | £1.10 |
The order matters. Cheaper now usually means more expensive per year of life.
What about clay pantile?
The forgotten middle option. Sandtoft Goxhill and Dreadnought are the two manufacturers we use. 50–80 year lifespan, £28–£42/m², £1.90 per m² per year. The natural choice for a Victorian Nottinghamshire terrace and often the cheapest “right answer” in conservation areas.
What about manufactured / fibre-cement slate?
Cembrit, Marley Eternit Birkdale — these are fibre-cement composite “slates”. Look-alikes that cost £30–£45/m², 50-year warranty. We fit them when planning insists on slate but the budget won’t stretch to natural. Honest, durable, but not the same material.
Common questions
Will my structural roof carry slate?
Welsh slate weighs ~25 kg/m², concrete tile ~45 kg/m². Slate is LIGHTER than concrete tile, so if the existing structure carries concrete tile, slate is almost always fine. The reverse isn’t always true. Confirmed on survey.
Does slate need maintenance?
Hardly any. A 10-year visual inspection for slipped slates or moss build-up is standard. Compared to concrete tile (which can frost-shatter and need patching), slate is the lower-maintenance material.
What’s the warranty?
Penrhyn Welsh slate: 100-year service-life warranty (BBA-certified). Marley Eternit concrete tile: 50-year manufacturer warranty. Our labour: 10-year written guarantee on either.
