How a Roman Roof fits together

Sketch of a Roman roof: t (tegula), i (imbrex), a (antefix)

Roman tile is usually orange-red in colour with a characteristic grey core. The Roman roof tiles or “tegula” had upturned edges called “flanges”. There were curved tiles or “imbrex” which fitted over the flanges.  The “antefix” tiles were roughly triangular tiles, often decorated, for fixing to the ends of the roof ribs at the level of the eaves. 

A flue tile used in a hypocaust