Ijuk Thatch

Ijuk is the black, wiry fibre that grows around the leaf bases of the sugar palm (Arenga pinnata). In Indonesia it is used as a thatching material and as binding cord, and it gives the traditional roofs of the Minangkabau, Karo Batak and Balinese temples their distinctive dark colour.

Uses in roofing

• Thatch: bundles of fibre are laid in overlapping courses on battens. Ijuk thatch covers the curved gonjong roofs of the Minangkabau rumah gadang in West Sumatra, where it is laid to follow the upswept gables.
• Binding: in Karo Batak houses of North Sumatra, ijuk fibres both bind the roof structure, without nails or screws, and thatch the roof.
• Temple roofs: in Bali, thatched roofs of black ijuk are paired with gold-coloured pinnacles on shrines and pavilions. Balinese builders also thatch with coconut or rumbia (sago palm) leaves, and use sirap, hardwood shingles.

Properties

Its dark colour and coarse texture distinguish it from straw-coloured grass (alang-alang) and leaf thatch.

Status

Karo Batak roofs bound and thatched with ijuk can rise up to about 15 m (49 ft), showing that the material can cover very large, complex roof forms. The fibre is also used on Balinese pavilions (bale), which are thatched structures with or without walls, similar to the Javanese pendopo.

Ijuk remains in use on heritage houses and temples.

Sources and gaps

Figures on how many roofs still use ijuk: published information is limited.