Origin
Tile roofs: reference systems, terminology and models

As for the origins of the tiles themselves, the same vagueness prevails, and the history of roof tiles still contains many grey areas. The creation of interlocking tiles –, including the highly curved – and the appearance of slip tiles, is dated with great accuracy. On the other hand, we have little precise information on the origins of the first flat tiles or of canal tiles, even if it is likely that they represent a "natural" evolution of "Roman" tiles.

It's generally accepted that the Chinese were the first people, around 2700 B.C., to produce terracotta tiles - round tiles similar to today's canal tiles. These tiles were probably made in imitation of "natural" roofs, using split bamboos which, like long "gutters", overlapped in the direction of the slope to form "currents" and "covers", thus ensuring the watertightness of buildings.