Oriented Strand Board (OSB)

OSB, or “Oriented Strand Board” is made from thin strands of timber stacked in oriented layers

connected by a synthetic resin. OSB boards are currently the most widespread woodbased

materials for variety of structural applications. OSB is manufactured from quality virgin wood; thin

strands are gently dried, applied with a synthetic resin with a fixed proportion of paraffin emulsion

and bonded under high pressure and temperature. Excellent mechanical properties are achieved

by selecting suitable wood, defined shape of wood strands, and in particular crosswise orientation

stacking of the three individual layers. Dimension, shape and direction orientation of strands in

individual layers make maximum use of the natural wood properties for achieving the best structural

capabilities. The strands on OSB surface layers are oriented in the longitudinal direction and in the

base layer. The strands are oriented across the panel, these two directions of strand orientation in

each layer give the board a higher level of dimensional stability and excellent mechanical efficiency.

At the same time boards show several times higher strength in the longitudinal board (major axis)

than in the crosswise direction (minor axis). Correct panel orientation towards support is important

especially during installation.