Opus spicatum

Opus spicatum, literally "spiked work," is a type of masonry construction used in Roman and medieval times.

Its usage was generally decorative and most commonly it served as a pavement, though it was also used as an infill pattern in walls, as in the striking base of the causeway leading up to the gate tower at Tamworth Castle.

The type of construction was constantly employed in Roman, Byzantine and Romanesque work, and in the latter was regarded as a test of very early date.

[1] The herringbone pattern produces opposing shear plane faces, increasing the relative surface area and therefore rendering it a sounder design for mortar and brick.

The herringbone method was used by Filippo Brunelleschi in constructing the dome of the Cathedral of Florence (Santa Maria del Fiore).