Kakushi domekata sanmai hozo

Kakushi domekata sanmai hozo is a joinery method used in Japanese post-and-beam construction. When translated, the name refers to "three layered concealed structure". 

It involves cutting, fitting and stacking three layers of wooden components to create a reinforced column or pillar. At the core is a square post or "hozo" with its grain running vertically. Surrounding this are two outer layers cut from a single wood piece, each with its grain oriented horizontally. The layers are precisely cut so their edges interlock while concealing the core hozo. 

This overlapping, counter-grained lamination technique produces hidden internal strength. It allowed pillars to support significant weight loads without bulking in size. Kakushi domekata sanmai hozo was commonly used to construct the sturdy interior beams and columns holding up temple and shrine roofs. Even today, its triple-layer design utilizing opposing wood fibres continues to lend robustness yet elegance to traditional Japanese architecture.