The density of most plywood is in the 25–50 lbs/ft3 range, with the density of most OSB being between 30–50 lb/ft3. ... Lightness in Weight. Panel Thickness (inches)Approximate Weight (psf) 7/16(OSB only)1.4 15/321.41.5 1/21.51.7 19/321.82.0 11 more rows