The paper presents the study of the effect of multiple cyclic humidification on the compressive strength across the grain edgewise of laminated veneer lumber (LVL), long-term sustained in conditions with high humidity. A significant decrease in its strength properties during cyclic humidification (up to 18% in three cycles) has been proved. The dynamics of crack growth due to the influence of the humidity factor is given.

Keywords: laminated veneer lumber, timber structures, strength, cyclic dampening, drying cracks, hygrostalness