Assembly Line

How roof tiles are made

Interlocking roof tiles can only be made with a press, which is why they arrived with factories in the 1840s.

stations
6
things upstream
2
raw sources
2
step from the ground
1

The short version

Clay roof tiles are made by mixing clay with water, forming the paste by extrusion or in a tile press, drying it, optionally glazing it, and firing it in a kiln.

  1. Dig the clay

    Roof tiles are traditionally made from locally available materials, with clay and slate the oldest choices. The clay is dug from a pit near the tileworks.

    Goes in
    Clay

  2. Temper it with water

    The clay is cleaned, blended and worked with water to make a smooth, plastic paste that holds its shape when squeezed.

    Goes in
    Water

  3. Press or extrude the profile

    Simple S-shaped Spanish tiles and the Scandia tiles of Northern Europe are traditionally formed through an extruder. Interlocking tiles carry a ridge and can only be made with a tile press.

  4. Dry the green tiles

    Shaped tiles are dried until the water has left the clay. Dry clay is brittle, so the tiles are handled carefully until they are fired.

  5. Brush on a glaze

    Some tiles are given a glaze, a glassy coating that fuses in the kiln. Glazed tiles were standardized in China during the Song dynasty, and Chinese architecture is known for colored gloss glazes on roofs.

  6. Fire in a kiln

    A kiln firing fuses the clay particles into a hard, weatherproof ceramic. Fired clay tile also resists fire, and medieval towns encouraged it as a way to stop fires from spreading.

End of the lineRoof tile

Worth repeating

  • Fired roof tiles have been found at the House of the Tiles in Lerna, Greece.
  • Near Corinth, between 700 and 650 BC, fired tiles began replacing thatch on two temples, and within fifty years they were found at many sites around the Eastern Mediterranean.
  • In Indonesia, approximately 90% of houses on Java use clay roof tile.

Back to the ground

Follow every input upstream and roof tile starts as these 2 raw sources.

ClayWater

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Gold ring 8 stations · 12 raw sources Synthetic graphite 6 stations · 2 raw sources Digital thermometer 7 stations · 26 raw sources Manganese ore 5 stations Stained glass 10 stations · 24 raw sources Toilet 7 stations · 5 raw sources

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Sources

Cite this page: "How roof tiles are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/roof-tile

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