Cross laminated timber (CLT)

Cross laminated timber is a solid plane timber product for load-bearing purposes. It is used as a panel or plate element.

Cross laminated timber (CLT) consists of at least three layers in sawn timber which are normally glued at right angles to one another, whereby individual sawn timber layers can be arranged longitudinally along their narrow sides or at systematic lateral spacing to each other. Cross laminated timber is currently manufactured exclusively from softwood. Individual layers may, however, also be replaced by derived timber products such as OSB and parallel laminated veneer or plaster materials. 
Thanks to their crosswise construction cross laminated timber elements are firstly extremely dimensionally stable, and secondly they can transfer loads both longitudinally and transverse to the main load-bearing direction.
Cross laminated timber components whose laminate layers are glued without systematic lateral spacing are constructed symmetrically in cross-section back. The construction of cross laminated timber components whose laminar layers are glued to one another with systematic lateral spacing is based on the requirements placed on each specific structural component. 
Cross laminated timber is also occasionally sold as thick timber or crossply timber or under a manufacturer-specific name. The English name of cross laminated timber is also occasionally used in German-speaking regions.

Cross laminated timber may be used in utilisation classes 1 and 2, in other words for expected equilibrium moisture contents of up to 20%. This means that utilisation is possible both inside buildings and in the open air under roofs.