垂木

The rafters attached to the underside of the roof, consisting of multiple wooden beams.
The arrangement of rafters can vary: densely spaced ones are called繁垂木 (prosperous rafters), slightly less dense ones are半繁垂木 (half-prosperous rafters), sparsely spaced ones are疎垂木 (sparse rafters), and pairs of rafters spaced apart are吹寄垂木 (grouped rafters).
Additionally, in the case of two layers of rafters, the upper layer is called飛燕垂木 (flying swallow rafters), and the lower layer is地垂木 (ground rafters).
The rafters can be attached perpendicularly to the eaves as平行垂木 (parallel rafters), or arranged in a radial pattern for寄棟 roofs, called扇垂木 (fan rafters).
Rafters made from logs are called丸垂木 (round rafters), while those made from squared timber are角垂木 (square rafters).