Japanese master carpenters are repairing centuries-old [1] temples using an ancient woodworking technique that requires no modern nails or metal fasteners.
This preservation method is critical for maintaining the structural integrity of historic sites in a region prone to seismic activity. By avoiding rigid metal components, these buildings can better withstand the natural movements of the earth.
The practitioners, known as miyadaiku, utilize a method called kigumi. This process involves the creation of precisely carved wooden joints that lock together through friction and geometry [1]. This tradition of craftsmanship has been utilized in Japan for more than 1,400 years [1].
Unlike modern construction, which often relies on adhesives and steel, kigumi allows the wood to breathe and shift. This flexibility is essential for surviving earthquakes and the effects of humid weather [1]. Because the joints are interlocking, the structures can be disassembled and repaired piece by piece without destroying the surrounding material.
"Japan does not use modern nails to repair centuries-old temples. Instead, master craftsmen rely on an ancient woodworking technique," an MSN reporter said [2].
The reliance on natural materials also addresses modern environmental concerns. By eschewing industrial fasteners, the process minimizes the introduction of non-biodegradable materials into the historic sites. A reporter for the Times of India said, "This sustainable craft ensures the longevity of historic buildings and reduces construction waste" [1].
The precision required for kigumi means that each piece of timber must be carved to exact specifications. This ensures a tight fit that maintains the building's stability over centuries without the need for external reinforcements.
“Japan does not use modern nails to repair centuries-old temples.”
The continued use of kigumi represents a intersection of traditional cultural preservation and practical engineering. By prioritizing flexible, organic joints over rigid metal fasteners, Japan maintains a sustainable architectural model that is naturally adapted to its specific environmental risks, such as high humidity and frequent earthquakes.
