Japan approves revised rules on manufacture, performance of LVL; standards effective Feb. 10 establish structural LVL category, aim to improve performance, prevent warping and curving
December 27, 2013
– Japan has approved revised rules on the manufacture and performance of LVL, effective Feb. 10, according to a report by the International Tropical Timber Organization (ITTO).
The Ministry of Agriculture, Forestry and Fisheries issued a public notice on Nov. 12 on the revisions to the Japan Agricultural Standard (JAS) rules on LVL, reported ITTO, quoting information from the Japan Lumber Reports, a fortnightly subscription trade journal.
JAS rules are revised every five years, and the revisions to LVL rules include a lower grade of bending performance and a new standard on cave-in performance, ITTO reported. The revisions also establish two types of LVL: Type A for structural application and Type B, which relates to the percentage and orientation of certain veneer layers and increases the percentage from less than 20% to less than 30%.
The revisions will prevent warping and curving, improve precision of manufacture and result in improved performance of panels and wider boards, ITTO reported. They will also bring JAS rules in line with European standards, which provide for the use of LVL stressed skin panels in applications including the roofs of large buildings.
The revision to cave-in performance standards will allow the use of LVL in the foundations of mid-rise buildings and lower frames of 2x4 buildings, the report said.
The primary source of this article is the International Tropical Timber Organization, Yokohama, Japan, in Dec. 15, 2013.