Can an inspection tell what my roof is made of?

The first clues come from shape and scale. Plain tiles are small and flat, often with a slight curve, laid in many overlapping courses so the roof looks finely lined. Interlocking tiles are far larger, with ribs and side grooves that lock one into the next, which gives the roof broad, bold lines. Pantiles show an S-shaped wave. Natural slate is thin, flat and crisp-edged, usually in grey, blue or green tones.

Colour tells part of the story. Clay carries its colour through the body of the tile, in warm reds and oranges. Concrete tiles are often coloured on the surface and fade or weather to a chalkier tone over time. A tile's texture, the way moss grows on it, and the way light catches the edges help a trained eye narrow the options before anyone reaches a ladder.

A closer look settles most questions. On a broken tile or in the loft, the edge shows whether the material is fired clay with a uniform body, a cement mix with a sandy grain, or stone split in layers. Plain tiles carry small nibs on the back that hook over battens. Slates show nail or hook holes near the top edge, and the way they are fixed says a good deal about the roof's age.

The loft adds more. The batten spacing, the underlay or lack of one, and the weight on the rafters point to the covering above. A roofer may photograph the underside of a loose tile, check how many fixings hold each one, and take a sample if there is still doubt. A photograph sent by phone often identifies the family, but a visit is needed to be sure of the detail. Weight is a clue as well: a roof that sags slightly between supports may be carrying a heavier covering than its timbers were designed for, which matters when anyone proposes a swap.

Pitch limits differ by product. Marley gives minimum pitches of 30 to 40 degrees for its clay plain tiles, depending on the type, and 35 degrees for concrete plain tiles, while its interlocking concrete range runs from 12.5 to 25 degrees. For natural slate, Cupa Pizarras reads BS 5534 as setting a minimum of 20 degrees, and says hook fixings have no place on a slope under 25 degrees. The maker's own data sheet has the last word on any given product, since a covering laid below its minimum pitch will let rain in sooner or later.

Lifespan varies as well. CORC says slate can last 100+ years if well maintained. Marley cites Building Research Establishment work for a minimum of 60 years from clay tiles, and expects concrete to reach around 60 too, though it makes clear this is no promise. Our pages on minimum roof tile pitch and tiled roof lifespan give the detail. Repair cost follows the covering too, because Checkatrade's June 2026 table prices each material separately per square metre. Those figures leave VAT out, so check whether any quote includes it.

Arun District Council's conservation area guidance helps with some local roofs. It describes the Steyne and Waterloo Square as stucco terraces whose chimneys matter on the skyline, and wants original slate or clay put back in place of modern substitutes. For Aldwick Road it observes that many slate roofs now wear concrete interlocking tiles instead. Craigweil in Aldwick is described as having plain clay tiled roofs, and Felpham village mentions orange and red clay tile.

None of that tells you what your own roof is made of, and a single street can hold a mix. The only reliable identification is done on your actual roof, with the tiles in hand. If your house is in a conservation area, knowing the tile family also feeds into consent questions, which our pages on changing tiles in a conservation area and matching old roof tiles explain.

Some coverings cannot be named from a distance. Artificial slates, fibre cement sheets and old composite products can look very like the natural kind, and a repair guess based on appearance is where mismatches begin. Weathering changes colour, and moss hides texture. We would rather climb in the loft, handle a spare tile, and tell you we need a sample than put a name on a roof and be wrong.

Age matters for safety as well. HSE's advice for anything put up or refurbished before 2000 is to proceed as if asbestos is in it, and cement sheeting and some boards fall into that picture. If a covering looks like sheet, or you are unsure, leave it untouched and see whether an inspection can find asbestos on a roof. Our roof inspections and surveys hub shows how a visit is arranged, and the answer on how old your roof is pairs well with this one.