How forming affects the unit
Pressing and extrusion are ways to shape workable clay before drying and firing. A mold or die helps produce the intended profile, while additional operations can create holes, nibs, trims or surface features. Historic products may show variation that is part of their character. Modern products also have defined tolerances; identical nominal dimensions do not mean two products have the same installed fit.
Compare the finished product
A manufacturing method does not by itself tell you whether a tile suits a cold climate, a steep roof, or a particular exposure. Compare documented performance and the maker’s instructions for the actual tile. Check how the unit bears on the supporting system, how adjacent tiles overlap, and which accessories complete the roof. Avoid choosing an attachment detail solely because another tile was formed the same way.
Use samples before committing
For a replacement or extension, have a tile specialist compare an actual candidate with an existing unit and the installed layout. Document differences in curvature, thickness, edges and bearing points. A small approved mockup can expose fit problems before a large order is placed. Keep the approved sample with the written product schedule, so later substitutions are evaluated against an identifiable reference.
Further reading & technical sources
Consult the current product documentation and local requirements for your project. These introductions are not installation specifications.
More tile roofing guides
- How clay roof tiles are made
- Terracotta, ceramic and clay: what the names mean
- Why roof tile is not floor or wall tile
Tile Roofing USA editorial guide · Published October 28, 2026.