Oriented strand board is a versatile, structural wood panel, created to equal or improve upon the characteristics of exterior grade plywood. OSB panels are composed of thousands of rectangular wood strands, oriented in three crisscrossing layers, and bonded with weather-impervious adhesive under high pressure and temperature. OSB engineered panels are dimensionally stable. They resist deflection and delamination while providing racking resistance under wind or seismic stress. The most common application of OSB is in single and multi-family residential construction where it is used as the structural element in walls, roofs and floors. OSB is also used in a variety of other applications such as the vertical component of wood I beams, industrial containers, pre-insulated building panels, crating and site hoardings.
Unlike plywood, OSB can be made from many tree species and from small diameter trees. Plywood can be manufactured only from large diameter trees of a few species. This manufacturing advantage gave birth to a wave of OSB mills whose product has now largely replaced plywood in many markets.
GFP began its development activities in northern Maine in 1979 as strand orientation was being perfected and there was but one rudimentary "OSB" mill in the USA and when the product was of no significance within the plywood market. Today, the market is known as the “structural panel market”, OSB has largely replaced plywood in residential construction and the “American Plywood Association” has become “APA, the Engineered Wood Association”.