Kayabuki

Kayabuki (茅葺) is the Japanese term for roofs thatched with grasses (kaya), most often miscanthus (susuki) or reed. For most of Japanese history it was the ordinary roof of rural houses, and it survives today on preserved farmhouses, in heritage villages and on some of the country's most sacred shrines.

Materials and form

Thatch was made mainly from miscanthus; where it was hard to obtain, builders used wooden shingles instead. Farmhouses (nōka) were most often hipped (yosemune), with a thick thatch sloping on all four sides, while more elaborate houses combined thatched and shingled sections in irimoya (hip-and-gable) form. Steep pitches shed rain and snow. Along the ridge, crossed timbers (umanori) or bundles of reed finished the thatch and could indicate a family's standing in the village.

Regional forms

• Gasshō-zukuri - the very steep "praying hands" roofs of Shirakawa-go and Gokayama, an enlarged form of the sasu rafter structure. Their large attics were used for rearing silkworms. The villages were inscribed as a UNESCO World Heritage site in 1995.
• Shrine thatch - the main halls of Ise Grand Shrine are roofed with thatched reed in the ancient shinmei-zukuri style and are rebuilt every 20 years; the 62nd rebuilding was completed in 2013, and the first is recorded in 692.

History

Prehistoric pit dwellings in Japan were roofed with grass, and thatch remained the common rural roof through the Edo period, when distinctive farmhouse types matured. In towns, thatch gave way to clay tile for fire protection, and in the 20th century most thatched houses were re-roofed or replaced.

Heritage and maintenance

Thatch needs regular renewal and community labour. In 2020 UNESCO inscribed Japan's traditional skills for the conservation of wooden architecture, which include both thatching and the harvesting of plants for thatch, as intangible cultural heritage.

See also

Similar grass-thatch traditions in the region include Korean choga (rice-straw thatch).