Chapter one
Horsham stone on the old rectory roof
Findon's rectory is roofed in Horsham stone, and a stone roof is mended with its own slabs before anyone else's.
The Victoria County History describes Findon's rectory house as built of flint and brick and roofed in Horsham stone, with a central part said to date from 1584. That makes it a useful guide to what the village's older roofs are up against. Horsham stone-slates are thick, flaggy sandstone slabs, graded by size and laid in diminishing courses, which means the slabs shrink steadily as the roof climbs. The Stone Roofing Association describes two laying systems. The usual one is double lap. The other, single lapping, belongs to Horsham stone alone, with each joint weathered by Welsh slate shadows bedded in mortar. Horsham District Council's appraisal adds that these roofs carry their substantial weight on strong timbers beneath a steep pitch, so on a stone roof we inspect the frame as well as the stone.
At a glance
- The rectory is flint and brick under Horsham stone
- Keep the roof's own stone wherever it can be saved
- Stone-slate supply was reported short in 2019

1.1 Keep what the roof owns
The Association's first choice is always to retain the roof's own stone for as long as it is sound, which also keeps the colour and weathering that new stone takes years to acquire. Slabs stripped from other buildings are a last resort, because buying them feeds the destruction of historic roofs, and where there is no alternative their source should be checked as legitimate. Where the roof is still short, new Horsham slates fill the gap when they can be sourced. Supply has been a real difficulty: a trade report in 2019 reported that roofing slabs were in crisis-level short supply. So the job begins with a careful count of the slabs the roof already owns, sorted by size, and with new battens and nails under every one that goes back.

1.2 Listed or not, ask first
The National Park Authority's guidance separates routine upkeep and small repairs done in place, which need no listed building consent, from works that replace or alter historic fabric and so change a building's character, which do. The Association adds that moving a roof between single and double lap means the roof's loading must be worked out again, and building control approval or a church faculty may follow. Years of patching have often left Horsham roofs part double lap and part single, with slate shadows filling gaps in the stone, so we record what is there before touching it. Our Horsham stone roofing page covers lifting, sorting and relaying.
What people sayA Horsham stone roof can be relaid in whatever lap pattern suits, provided it still looks like stone.
What is trueThe Stone Roofing Association advises retaining or restoring double lap where it can be done, and altering the lap calls for the loading to be reviewed.







