Chapter one
Wealden clay, slate and reed thatch
Bury's roofs have been reed, then hand-made clay, then slate, and a repair has to know which one it is dealing with.
The Bury Neighbourhood Plan's heritage study describes a village whose roofs have changed with the centuries. Reed, originally cut from the river banks, thatched the cottages for hundreds of years and still does. Hand-made tiles from local Wealden clay then took over on some houses, and slate on others. For a roofer that means two neighbouring houses can need quite different handling. A clay roof is judged by its tiles, battens and nails. A slate roof is judged by its fixings and its headlap, the overlap that stops water creeping uphill under each slate. A thatched roof belongs to a thatcher. We read what the house in front of us has, not what its neighbour has.
At a glance
- Reed from the river banks thatched Bury for centuries
- Hand-made Wealden clay tile replaced thatch on some houses
- Slate replaced thatch on others

1.1 Hand-made clay and how it ages
Hand-made tiles are never perfectly flat or uniform, and that unevenness is part of the village's look. It also means machine-made replacements sit differently: they lie flatter, run to a steadier colour and can show up as a patch. When one slope needs attention, we reuse the sound tiles, look for hand-made or reclaimed clay to fill the gaps, and photograph the result against the neighbouring slopes. A low-pitched porch or lean-to deserves a second look, because each clay plain tile has its own minimum pitch, listed in the table below. Clay roofs also carry ridges and hips, and the 2014 revision of BS 5534 expects those tiles to be mechanically fixed as well as bedded. A bedded ridge with proper fixings is a sound repair; a ridge held up by old mortar and nothing else is one we would re-set.

1.2 Slate where the thatch went
Slate fails differently from clay. Slates slip when the nails or hooks holding them corrode, and a roof can look intact from the lane while a quarter of its fixings are failing; the loft shows daylight or damp first. BS 5534, as quoted by Cupa Pizarras, indicates a minimum pitch of 20 degrees for natural slate, and slate hooks are ruled out on any pitch below 25 degrees. Where a house has thatch beside slate or tile, the joins between them, such as a tiled porch, an extension or a chimney, are where we are most often asked to look. Our slate roofing page covers re-slating and repairs in more depth.
Minimum pitches for Bury's coverings
- Clay plain tile, Canterbury
- 40 degrees (Marley)
- Clay plain tile, Ashdowne
- 35 degrees (Marley)
- Clay plain tile, Hawkins
- 30 degrees (Marley)
- Natural slate
- 20 degrees; no hook fixings below 25 degrees (Cupa Pizarras)
- Slate headlap at 20 degrees
- 115 mm for 500 x 300 slates (Cupa Pizarras)
Source: Marley; Cupa Pizarras, citing BS 5534:2014+A2:2018, fetched October 2026





