Sandwich structures and rib stiffened panels from metal, fiber materials and plastics has been recognized as efficient and material saving solutions for applications requiring lightweight design elements, like ships, trains and aircrafts[1]. In addition to weight reduction, sandwich structures also allow to integrate addition properties for the panel like insulation and wave damping layers. Wood is now widely used in sandwich design for building walls and floors, where insulation properties is most important than weight reduction. However excellent mechanical properties of plywood are suitable for manufacturing of lightweight sandwich panels for heavy duty load applications like floors in passenger transport. Mechanical properties of single plywood layer (veneer) in longitudinal direction are close to GFRP fabric ~ 17 GPa. Changing orientation of layers is possible to create tailored solutions for specific load conditions. Plywood sandwich panels with rib stiffener cores are not widely studied, thus there is potential to create more weight efficient solution than traditional plywood boards. The aim of current research is to find most effective cross section design for plywood sandwich panels with rib stiffened and corrugated core as well as to develop overall methodology for assessing efficiency of sandwich panel, taking stiffness and volume of full plywood board as reference.