Born as an intelligent evolution of chipboard and an economical alternative to phenolic plywood, OSB makes use of small-diameter or fast-growing timber, valorising forest raw material 100%.
The panel's strength does not come from a confused timber mass, but from the exact geometry of the strands (flat flakes up to 150 mm long). In the two outer layers, the strands are oriented parallel to the long side of the panel, while in the inner core they are arranged perpendicularly. Pressed at high temperature with polyurethane (PMDI) or melamine (MUF) resins, they form a non-deformable board highly resistant to bending and shear.
Standard EN 300 classifies OSB from 1 to 4 according to mechanical strength and tolerated humidity. In construction, almost exclusively OSB/3 (structural for humid environments) is used. Thanks to the presence of moisture-resistant thermosetting glues, the panel physiologically acts as a natural vapour retarder (mu between 150 and 300).
Standards
European and international references applicable.
Physical properties
Usage environment
Construction almost exclusively uses OSB/3 (structural in humid environments). Install panels with open joints (3 mm) on studs to prevent swelling.