The Future of Dry Fit Connections // Huiyuan Leland Li

5/11/2014

Moving toward the end of the semester, all of our projects are heading to the final phase. As a representative project for design+make, the Hardesty Renaissance mobile office design for Asian Americans for Equality (AAFE) did a wonderful job from the scheme to completion. In the AAFE project, the drawer for the media center and conference desk is a particular product that inspiried and attracted me a lot. In appearance, the drawers are just as good as other works. It is special for me because the use of the unique wood joint method - dry fit connection. Thanks to the dry fit connection. The parts of drawers are carefully designed and drafted in rhino and cut by the CNC router. It is possible to assemble the boards without any nails or glue.

 

Hardesty Renaissance Drawers

Chinese Bracket

Nowadays, dry fit connection is mostly used in puzzle toys and artworks. Compared to the prevailing wood connection method with nails, dry fit joints are rarely considered in an architectural construction. The reason is because of the high labor cost, and high-end craft requirements. However, as for me, the dry fit connection has a great potential and advantage in construction process, safety, sustainability and aesthetics.

 

Dry fit connection has a much longer history than the nailed wood connection. It dominated the wood construction method for thousands of years until the mass fabrication of metal nails and screws. The dry fit connection is first found in Chinese construction by the end of the Neolithic, and carried forward in ancient eastern architecture. The Chinese bracket connection represents highest level of dry fit wood connection. It is the perfect combination of both structure and aesthetics. Also, bracket connection has an excellent anti-seismic ability. The flexible structural system of bracket is able to withstand severe earthquakes significantly more efficiently than a rigid system.

I believe that dry fit connections are better and more elegant regardless of additional labor expenses and craft. The assembly process can be greatly shortened thanks to the absence of adhesives and nails. Since the dry fit connections create flexible joints without nails or glue, the architectural appearance and construction quality can rely less on the contractors. Besides, nails and screws are sharp and pointy, by working on typical wood connections, the construction workers can often accidentally injure themselves. Also, the hammering process, poisonous adhesive chemicals, and accidental nail gun discharge could cause hazardous effects to builders. In addition, nails and screws can be a hidden danger to users as well as the noise of drilling and hammering. These problems could all be solved through dry fit connections. Furthermore, as the dry fit wood pieces can easy be taken apart and re-assembled, minimal material waste makes this a sustainable method. In the fabrication process of AAFE, part of the sustainability concept is reusing the wood from pallets to make the table top. But the project is also facing a challenge of taking apart the wood pallets. If there are any nails left inside the wood, it may break the blade while it runs through the table saw, potentially causing hazard to people during the fabrication process. "We have to be especially careful to remove the nails from the pallet in order to protect the tools and more importantly protect ourselves," said Max Taylor, group member of the AAFE project team. However, if the dry fit method were applied for assembly of the pallet, there would not be problems caused by the nails. Finally, by showing the logic of the structure, the dry fit joint is minimalist and elegant.

Taking nails out of a wood pallet

Nowadays, along with the invention and mass fabrication of steel nails and fasteners, dry fit wood connections are almost exstinct in current architectural construction. Thanks to the CNC router in the APDesign workshop, the dry fit assembly for our drawers is achievable. With the popularization of CNC and 3D fabrication methods, will the dry fit assembly method be utilized from a small drawer to a piece larger scale architecture? I think there is a great possibility. The computer based fabrication process can address both cost of labor and craft requirements. In recent years, two projects pioneered different approaches of implementing dry fit wood assemblies. The Swiss Pavilion at World Expo 2000 designed by Peter Zumthor is assembled without glue or nails, and only braced with steel cables. Each beam uses gravity to press down on the one below. As a temporary structure, the dry fit assembly can be reused in other constructions. the Tamedia office building designed by Shigeru Ban applies mortise and tenon joints within a wood structure building. The entirely visiblle connections gives a high spatial quality to the working atmosphere. In the future I believe that even more complicated but stronger connection details will be invented to create a safer, more elegant and sustainable construction method.

Drawer and Slide Track

Swiss Pavilion at World Expo 2000

Tamedia Office Building

Written by Huiyuan Leland Li