Working to Optimize Market Competitiveness of 2×4 Pre-Fabricated Assemblies

Canada Wood Japan is currently collaborating with the Japan 2×4 Home Builders Association on a multi-year joint project to enhance the market competitiveness of 2×4 pre-fabricated assemblies. This project is also receiving support from Japan’s Ministry of Land, Infrastructure, Transportation & Tourism (MLIT). As part of this project work, this year we conducted shear wall tests on assembly designs developed by the PFC rationalization technical committee, under the direction of Committeee Chair Dr. Omi, a Professor at Tokyo City University.

The committee has focused on two types of activities. The first is to clarify the challenges about workability of wall panels, floor panels, and roof panels on site. To assess these challenges committee members visited three construction sites and observed workability of carpenters, provided analysis and design recommendations on how panel fabrication could be streamlined and optimized to reduce assembly time and cost. The other activity is to conduct shear wall tests on those redesigned test specimens fabricated to improve the speed of onsite fieldwork. Normally it is standard practice to use lap joints as wall connections, however the redesigned test specimens featured butt joints which are expected to reduce assembly time by 10 to 15%. The tests were successful in that the shear strength of the test specimens was as strong as normal shear walls, and the speed of fabrication was faster than the standard wall panels. Committee work will continue in fiscal 2022.