1 An early term for long boards used on roofs. Records dating from the 8th century first used the terms itaya 板屋 (board roof), and itabukiya 板葺屋 (board-covered roof). The size of the boards and the direction they were laid is not clearly known. However, the pent roofs *hisashi 廂, at Hōryūji 法隆寺 (late 7th century) Nara, planks were laid at right angles to the wall. Then the roof boards were set over the spaces between planks. Rainwater run-off was controlled in such a way that only a very minimal amount of seepage under the upper boards occurred. The method is called *yamatobuki 大和葺.
Ise Jingū Naikū Sotonomiumaya 伊勢神宮内宮外御厩 (Mie)
2 The shingles, 60-70 cm long × 15 cm wide × 0.6-0.75 cm thick, used on vernacular houses, found especially in Nagano Prefecture. The shingles are split along the annual rings and are cured for up to one year. These shingles are joined along their sides by a type of edge joint called *hagi 矧. The exposed part of the shingles is about 30 cm long. Usually made of chestnut wood.