Yahazu-zumi

What yahazu-zumi is

Yahazu-zumi lays stones or tiles diagonally in opposing directions so that they form a herringbone pattern. The Japanese name comes from the notched end of an arrow, whose shape the pattern resembles.

In stone it depends on sharply angled pieces. The stone wall at the former Ninomiya Residence in Ehime Prefecture, from the late Edo period, is described as the outer wall of a former village headman's house at the centre of the town, chlorite schist of varying sizes set at acute angles in something approaching this pattern, with larger stones and a flat coping on the house side and smaller, more irregular work behind. The entry judges it to show the state of stone craft before the technique was fully formed.

That judgement is the interesting part. The method has a period of formation, and this wall is valued as evidence of the stage before it.

Chlorite schist splits into thin plates, which makes acute angles easy to obtain. The material makes the method possible.

In modern tilework

It is not confined to stone. The former gatehouse of Hitotsubashi University in Tokyo, built in 1931, is described as rendered in mortar with scratch tile laid this way at the base and Shitami-itabari above, with a metal-roofed bay on the side, in a trim half-timbered building under French tiles.

The name of a stone technique has carried over to tiling. Much as Stretcher bond and English bond name brickwork patterns, this one names a pattern that crosses materials.

On site, read the direction of the units. Where the tilt reverses from side to side and a column of chevrons runs up the wall, that is the pattern. Nunozumi and Ranzumi are judged by their horizontal joints; this one is judged by the diagonal.