Hemudu Stilt Houses

The Hemudu culture flourished in the lower Yangtze region of eastern China from about 5500 to 3300 BCE. Its type site, near Yuyao in Zhejiang province and about 22 km (14 mi) northwest of Ningbo, was discovered in 1973. Related sites include Tianluoshan, also in Yuyao, and sites on the Zhoushan islands. In the wet, low-lying landscape of the Yangtze delta, the Hemudu people lived in long houses raised on stilts.

Raised houses

The houses stood on timber piles above damp ground, with communal longhouses common at Hemudu sites; they have been compared to the longhouses of present-day Borneo. Raising the floor would have kept people and stores above damp ground and seasonal water.

Timber joinery

The waterlogged soil preserved hundreds of worked timber components. Many carry sunmao joints, the Chinese term for mortise-and-tenon joinery, in which a projecting tenon fits a cut socket. They are described as the earliest known use of this joinery in Chinese timber-frame building. Mortise-and-tenon joinery later became the basis of the traditional Chinese timber frame.

Roofs

No Hemudu roof survives intact. Reconstructions show pitched roofs on the raised timber frames, but the covering material and pitch are inferred rather than preserved.

End of settlement

Two major floods changed the course of the nearby Yaojiang River and salinised the soil, forcing residents to abandon their settlements.

Significance for roofing history

Hemudu shows that by about 7,000 years ago builders in China were joining timbers with shaped joints rather than only lashing them. Jointed frames are stiffer and can carry heavier roof coverings, which is a precondition for the tiled roofs that later developed in the region.