Onigawara

What an onigawara is

An onigawara is the ornamental tile set at the end of a roof ridge. It caps the junction where the ridge terminates, helping the roof shed water there, and it closes the outline of the roof.

Any tiled roof may carry one, whether laid with Sangawara-buki or with the older round-and-flat system. The main hall of Saifukuji in Shiga Prefecture, built in 1862, is described as a hall of the Pure Land sect roofed Irimoya-zukuri in formal tiles, with a ridge-end tile bearing an inscription dated 1865.

That single sentence carries two useful points. Tiles of this kind are sometimes inscribed, and the date they carry need not be the date of the building.

At Saifukuji the recorded date of construction is 1862 while the tile is inscribed 1865, a gap of three years.

Dating the roof, not the building

A roof is replaced as its covering wears out, so its date often differs from that of the structure beneath. An inscription on a ridge tile is best read as evidence of when work was done on the roof.

Ridge tablets serve a similar purpose inside a building. They are sometimes designated as Tsuketari alongside the structure, and for a storehouse in Dozo-zukuri they are often what fixes the year of construction. In both cases the question worth asking is which part of the building the date refers to.

On site, look up at both ends of the main ridge and at the foot of the descending ridges. Inscriptions are usually cut on the back or the side of the tile and are rarely legible from the ground, so the record or a survey report is where the date will be found.