A Visit to Keymer: Keeping Heritage Roofing Alive

I was fortunate to be invited to Keymer last week for an exclusive factory tour, offering a fascinating insight into the traditional craft of handmade clay roof tiles.

Keymer’s story stretches back over 400 years to the potteries of Ditchling, Sussex, where skilled craftsmen first began producing these distinctive tiles in the late 1500s. In 2015, the company moved to Ewhurst after being acquired by Wienerberger, a global brick manufacturer. This transition safeguarded Keymer from the increasing pressure of cheap foreign imports, securing the future of high-quality handmade clay tiles for the UK’s historic buildings. Today, Keymer tiles continue to be used on listed properties and prestigious heritage sites alike such as Hampton Court Palace and St. Paul’s Cathedral, ensuring that they retain their authentic appearance while benefiting from modern durability.

The Making of a Keymer Tile

Every Keymer tile starts with locally sourced Weald clay, prized for its rich colour and durability. This clay is quarried in Ewhurst and carefully stacked in 20-metre-high layers, where it is left to settle for a year. When ready for use, the clay is extracted in vertical slices and gradually processed into finer pieces. Sand and other natural additives are then mixed in to control shrinkage and enhance colour before the material is transported to the adjacent brick and tile factory.

At the factory, water is reintroduced to the clay, which is then compressed and extruded through sieves. These shape the raw material into either long, continuous rectangular forms for bricks or flat slabs for tiles, which are then precision-cut into their final shape.

Tile sieves used to extrude clay into tiles

Keymer tiles are finished by hand, using time-honoured techniques. Traditionally, the clay is dusted with sand, then pressed sand-side down into a wooden mould. Skilled craftsmen once slapped the back of each tile to prevent sticking before pressing down on a former to create the distinctive nibs, maker’s mark, and date. This means that every handmade tile bears the imprint of its maker’s palm—a unique signature of craftsmanship. The handmade nature of Keymer tiles ensures that no two are exactly alike, giving roofs an organic, timeworn charm that machine-made tiles struggle to replicate. The firing process naturally creates subtle variations in colour and texture, mimicking the beautiful weathered appearance seen on historic roofs.

Each Keymer tile has the maker's handprint on the back imprinted on the back.

The tiles are then slowly dried before being stacked into kiln cars, each holding around 3,700 tiles. They are fired at an intense 1,050ºC, a process that guarantees strength and weather resistance, ensuring they stand the test of time on heritage rooftops.

Protecting the Future of Handmade Heritage Tiles

Keymer also offers a bespoke heritage service, allowing customers to commission custom-made tiles, bricks, and finials. The company’s extensive archive of historic moulds means that if you’re searching for a particular brick or tile to match an existing building, there’s a good chance Keymer already has the mould—and can produce the exact quantity needed. With a library of moulds dating back centuries, Keymer’s archive allows them to recreate rare or region-specific brick and tile designs that might otherwise be lost to time.

Brick moulds for just about every shape and size you can think of.

In an era where many traditional manufacturers have been forced to close due to an influx of lower-quality imports (which, surprisingly, do not have to meet the same UK quality standards as domestically produced materials), it is reassuring to see companies like Keymer keeping our roofing heritage alive. Conservation officers and heritage architects often require original materials to maintain a building’s listed status. Using inappropriate modern tiles can affect not just aesthetics but also breathability, longevity, and weathering patterns. Keymer’s dedication ensures that listed properties and historic buildings continue to be restored with materials that honour their original character and craftsmanship.

A Commitment to Sustainability

Keymer is also committed to sustainability, ensuring that its traditional methods have minimal environmental impact. Unlike mass-produced tiles that rely heavily on imported materials, Keymer sources all its clay locally, reducing transportation emissions. Fired at high temperatures using energy-efficient kilns, Keymer tiles are built to last for centuries, reducing the need for frequent replacements and landfill waste.

A big thank you to the team at Keymer for an informative and enjoyable day.

#listedproperty #buildingconservation #periodproperty #repairinglistedproperties