根ね継つぎ

noun

underpinning; splicing a rotting post

Architectural term for repairing or reinforcing the base of a wooden post or pillar, often by splicing a new piece onto the rotted bottom.

• 古ふるい寺じ院いんの柱はしらに根ね継つぎを施ほどこして、腐くさった部ぶ分ぶんを補ほ強きょうした。

  They performed underpinning on the pillars of the old temple, reinforcing the rotted sections.