IMBREX, in architecture, one of the raised, covering tiles, placed over the joints between the flat or pan tiles in an ancient Greek or Roman roof. The pan tiles were laid with the joints in each course, or row, exactly in line with the joints above and below, so that the imbrex tiles formed continuous ridges. In the simpler types, the imbrex was approximately semi-circular, but in more monumental examples, especially where the roof tiles were in marble, the imbrex had straight sides and an angular top. At the lower end of each row of imbrex tiles was an ante-fix (q.v.) or decorative terminal.