Cross laminated timber stands out due to its high load bearing capacity and its dual-axis load-bearing performance when required. Dimensioning takes place according to the specifications contained in DIN 1052:2008-12 or DIN V ENV 1995-1-1 in addition to the requirements made by the relevant manufacturer's Building Authority Approval.
Determination of the load-bearing capacity can only take place taking the static system and load configuration into account. The manufacturers offer dimensioning aids for standard systems and load patterns. Please refer to the section entitled "Construction, dimensioning and structural physics" for more information.
Since the strength and stiffness values can differ strongly depending on the cross-sectional structure and the production process used by the relevant manufacturer, the products are not interchangeable without complete reworking of the structural analysis and, if necessary, the building physics verification!
Sound insulation verification and verification of component fire resistant take place using the building authority test certificates provided by the relevant manufacturer.
If the Building Authority Approvals do not contain any specifications to the contrary, the following characteristic values can be used for cross laminated timber with broad layers without systematic natural spacing of individual lamellae for other verifications of moisture, timber and fire protection.
|Thermal conductivity λ
|Water vapour resistance μ
|Theoretical charring rate
||0,9 mm/Minute (für Lagen ohne Schmalseitenverklebung)
0,65 mm/Minute (für Lagen mit Schmalseitenverklebung)
|Reaction to fire class
In European terms, only an analysis classification with glued laminated timber is possible, and this must be clarified with local building authorities:
D-s2,d0 in accordance with a decision from the European Commission of 09.08.2008 (2005/610/EC) for ρ ≥ 380 kg/m3 and a total thickness t ≥ 40mm.
|Natural durability and resistance to chemical attack
||Corresponds to the natural durability and corrosion resistance of the relevant timber type irrespective of the adhesive used. The German "Informationsdienst Holz" “Konstruktive Vollholzprodukte” contains further information about the properties of various timber types.