Chapter one
Ageing clay tiles on flint and brick
Clay tile is the covering the council's appraisal names for Earnley, and old clay needs reading tile by tile before it is judged.
Earnley's conservation area appraisal calls flint and red brick, with clay tiles for the roofs, the most prevalent materials in the area, and it describes the church as a simple composition of flint pebbles with stone quoins. A clay roof ages gradually. Tiles do not fail all at once, and a great many old ones are still sound. What goes first is usually the edge: the nib, the small lug that hooks over the batten, snaps, or the face of the tile flakes in frost, or the nail through it has rusted away. A tile in that state sits on the roof by habit, and the next gale takes it.
At a glance
- Marley reports a 60-year minimum life for roof tiles
- Old peg-tile roofs are judged on inspection
- Minimum pitch varies by tile pattern

1.1 How long clay lasts
Marley reports that the Building Research Establishment worked out a minimum life expectancy of 60 years for roof tiles, though such figures are only an expectation. On historic peg-tile roofs, says the Building Conservation Directory, that same 60 years is no reliable yardstick. So in practice the decision comes from inspection. We tap tiles, lift a few to look at nibs and nails, and check the battens beneath. Where a roof is sound in the main, a repair that replaces broken tiles with matching ones makes more sense than stripping it. Good tiles lifted from a slope can be set aside and put back on the same roof, with new ones matched for size and colour used only to fill the gaps, so the roof keeps its weathered look.

1.2 Pitch, fixing and the heritage question
Every tile pattern has its own minimum pitch. Marley lists its clay plain tiles at 30 to 40 degrees depending on the pattern, and its pantile from 15, so a replacement must suit the slope it is going on. Wienerberger's guidance is that a single-lap tile be held by one mechanical fixing at the least, and the older rule for tiles along the roof perimeter was two. A2:2018, the 2018 amendment to BS 5534, adds a caveat for historic roofs, where the recommendations may be inappropriate; Marley's advice is to consult the planning authority and conservation experts first. For an Earnley house inside the conservation area, that means a call to Chichester District Council before an old roof is re-fixed to modern rules. If you want a record of the roof as it stands, our photographs give you one. Our pitched roofing page sets out what a full re-tile involves.
Facts for judging a clay tile roof
- Minimum life for roof tiles
- 60 years, an expectation only (Marley)
- Old peg-tile roofs
- 60 years is not a reliable guide (Building Conservation Directory)
- Clay plain tile minimum pitch
- 30 to 40 degrees by pattern (Marley)
- Single-lap tiles
- One or more mechanical fixings per tile (Wienerberger)
- Code of practice
- BS 5534:2014+A2:2018
Source: Marley; Building Conservation Directory; Wienerberger; BSI, fetched October 2026





