Canada Wood Today | The Canada Wood Group

JAS Standard Revisions on Dimension Lumber

Hidehiko Fumoto

By Hidehiko Fumoto

Deputy Director and Manager Technical Services, Canada Wood Japan

February 28, 2013

The technical committee meeting starts in mid-March to revise the JAS (Japanese Agricultural Standard) dimension lumber standard.  This revision is scheduled as one of the routine practice at 5-year interval.  This standard, known as JAS600, was originally established in 1974, referencing mostly the NLGA rules.  With regard to the structural design accommodating dimension lumber, the design stresses assigned for JAS-graded SPF in Japan are identical to those for NLGA.  This means that the statistical mother population of JAS graded SPF dimension lumber should be theoretically equal to that of NLGA.  Therefore, revising JAS grading rule too drastically may lead to losing the basis for mutually recognized in-grade test database for deriving the design stresses for JAS and NLGA dimension lumber.  As for the movement from domestic lumber industry, there appears to be a request that the species group of Japanese Sugi should be recognized as Hem-Tam as opposed to WRC.  The domestic group is also asking for relaxing the rate of growth of Sugi.  Careful monitoring is needed as these requests are all driven politically and not based upon scientific and technical rational. Canada Wood Tokyo will participate in this standards review committee to monitor developments and address issues as necessary.