The American Wood Council Monday announced that cross-laminated timbers (CLTs) were approved by the International Code Council for inclusion in the heavy timber construction classification of the 2015 International Building Code. The code change will allow U.S. builders to use the emerging wood-product category in non-residential construction. As part of a project to put together a U.S. CLT design manual, the product, covered on each side with one layer of 5/8-inch Type X gypsum, also passed an ASTM E119 fire endurance test by lasting three hours and six minutes. Visit for more information.