MPW 2: Redesigned Midply Wall System Recognized in Japanese Building Code

Known as MPW 2, this redesigned MIDPLYTM wall system 2.0 is gaining recognition and can be integrated within Japanese code-compliant construction as the result of voluntary evaluation work conducted by Canada Wood Japan. Unlike the previous voluntary evaluation, this time we managed the technical process in-house to save money and accumulate knowledge that will come in handy in promoting MPW2. Previously,  technical testing work was conducted to determine the performance of the new MIDPLYTM layup.

What’s different with MPW2 versus the original MIDPLYTM (MPW)?

The development of MPW2 was initiated by Canada Wood Japan to address the limitations of the regular Midply configuration. MPW2 consists of one ply of OSB located at the centreline of the wall with a new framing layout of one side of nominal 2×4 studs and 4×4 hemlock studs on the other. This new framing arrangement offers the same lateral resistance as regular Midply while it also significantly enhances the vertical and out-of-plane load resistance. Increased wall cavity depth enables thicker insulation and accommodates electrical and plumbing services better. While regular MPW’s shear strength factor is 5.6, MPW 2’s is 10, 1.8 times stronger. As a result, MPW2 broadens the application of its use to exterior shearwalls and offers improved performance.

Efforts are underway to partner with Japanese builders and developers to adopt this new high-performance MPW2 assembly in Japan’s non-residential sector.