Laminated veneer lumber (LVL, KERTOPUU®)

Laminated veneer lumber (LVL, KERTOPUU®)

Laminated veneer lumber (LVL) is a structural wood product made by gluing together lathe-turned veneers.
 
Laminated veneer lumber is used in all new-build and renovation work and for industrial purposes. Examples of use include load-bearing columns and beams, trusses, ring beams and components for the door and window industry. 
 
In Finland, laminated veneer lumber is made by gluing together 3-mm thick spruce veneers, with the grain direction lengthways in the LVL product. Special products can be made with the grain direction of some of the veneers arranged at right angles. Normally the veneers are not sanded or filled, but laminated veneer lumber can be made to order with the surface veneers selected and sanded.
 
Laminated veneer lumber is available in various finishes and also pressure-impregnated to class AB. Laminated veneer lumber is specified according to Finnish Standard SFS-EN 14374.
 
Maximum width of LVL is approx. 2.5 metres. The manufacturing technique enables long components to be made, but transport problems usually limit the length to approx. 25 metres.
 
Minimum width of beams is 27 mm and maximum 75 mm, in 6 mm increments. Standard heights are 200, 225, 260, 300, 360, 400, 450, 500, 600, and 900 mm.
In horizontal construction, typical centres for LVL are from 5 to 12 metres. As well as floor and roof construction, LVL can be used for trimming and supporting beams and for stiffening. In fire, the charring speed is o.6 mm/min.