Low density oriented strand boards

A method of producing a strand board having an average density of between 450 and 550 Km/m by providing a first set of strands having a moisture content of between 25 and 45% based on the dry weight of said strands and a second set of strand having a moisture content of between 5 and 7% based on the dry weight of said strands and forming a lay-up having a core layer formed of strands from the second set of strands sandwiched between a pair of surfaces layers each formed from strands of the first set. The lay-up is then pressed between heated platens into a consolidated panel having an average density of between 450 and 550 Km/m by closing the platens to the thickness of said consolidated panel in less than 30 seconds and raising temperature the said core layer to 100° C. in less than 35 seconds without increasing the core gas pressure above 0.17 MPa.