Horsham stone or clay peg tiles?

1Why people think about the swap

The reasons are practical. A heritage body reported in 2019 that new Horsham roofing slabs were running short, and that owners were often fitting clay tiles or stone salvaged from elsewhere in their place. Clay is made, stocked and well understood by roofers across the county.

Cost and time weigh in too. Stone is specialist work, lifted and laid slab by slab, while tiling goes faster and calls for less specialist handling. For an owner whose roof is tired, the appeal is easy to see.

Those reports are dated, and current supply has not been re-checked, so they are a reason to ask suppliers rather than to assume stone cannot be found. Checking the provenance of reclaimed stone slates matters if you do go down the salvage route, and the main Horsham stone roofing page gives the wider picture.

2Consent comes before a change of material

For a listed building the rule is firm. The Planning (Listed Buildings and Conservation Areas) Act 1990 treats unauthorised work that affects a listed building's character as an offence, and the Adur and Worthing guide gives mismatched repair materials as one case where consent is needed. Swapping stone for tile is exactly that.

A like-for-like repair left in place is different. The South Downs National Park Authority treats minor repairs of that kind as outside consent, but says wholesale replacement of historic fabric affecting character does need it.

If the house is unlisted but stands in a conservation area, ask the planning team before you commit. Inside the Park the question goes to a different body, which stone roofs in the South Downs National Park explains.

Skipping the question is a risk to the sale of the house as much as to the roof, because a buyer's solicitor will ask who approved what, and an unapproved change can be awkward and slow to put right once the new tiles are on.

3What lighter tiles mean for the frame

Stone is heavy and clay peg tile is lighter. The Planning Portal says weight checks apply wherever a replacement covering will be significantly heavier or lighter than the one it replaces, which is a prompt to speak to building control, as is any difference in fire performance.

The frame needs thought. A roof framed with strong timbers for stone does not suffer from carrying less, but other parts of the design may assume a heavy covering, for instance how the roof is held down against uplift. A structural engineer or surveyor can say what is needed; sagging stone roof timbers looks at the frame from the other side.

Re-covering can also bring a thermal upgrade if enough of the roof is renovated. We talk through those thresholds and deal with the Building Regulations notification where the work calls for it.

4Character and the look of the village

Horsham slab roofs are central to how some Sussex villages look, but clay is a local tradition too. Horsham District Council's Steyning appraisal notes that older buildings are typically covered in either slab or peg tile, often over hipped roofs. A swap is not out of place in principle.

The difference is in the detail. Stone has a heavy, uneven face that knits together as it weathers, with large slabs low on the slope. Peg tiles give a smaller, more regular texture and a different colour range. Neither is better, but a council may prefer to keep what is there.

Where only part of a roof is stone, a mixed result can look patchy. Think about how the front reads from the lane, and about resale. The more visible the change, the more likely someone will ask about it. If the back slope is hidden but the front faces the street, the council may weigh the two elevations differently, and that is worth raising early in the conversation.

5Choosing between relaying and re-covering

Start with the stone you already own. The Stone Roofing Association ranks reuse of existing slates first, new Horsham slates second for any shortfall, and salvaged slates from other buildings last. Relaying a stone slate roof shows how that route works in practice.

Re-covering in clay makes sense when the stone has failed beyond reuse, when the house is unlisted and the council agrees, or when the frame suits it. We tell you which applies and why, and we steer you to the job that properly cures the cause even when that is not the biggest one.

Survey first: pictures taken on your own roof, the cause traced, and a written quote giving the full cost as one figure. If clay is the answer you will hold the reasoning to show the council, along with the stone sizing in stone slate sizes if you want to keep part of the roof.