Density and species of timber veneer
The density of plywood and LVL is approximately equivalent to the density of the timber species used to manufacture the product. The density of pine plywood is in the range 500 – 650 kg/m3. Eucalypt hardwood plywood density can exceed 900 kg/m3 depending on the timber species used.
Generally, higher density species have higher engineering properties. Species of timber may also be chosen to provide a suitable substrate to achieve a high quality finish.
The veneer grade used in plywood or LVL will affect its structural performance. The use of all A or B grade veneers in structural plywood will increase its engineering properties by one stress grade. However, usually only higher quality face veneer grades are specified for aesthetic reasons, rather than structural performance.
Marine plywood has high grade face and core veneers to not only allow a high quality finish, but to also increase impact resistance and minimise water penetration through any knots in core veneers. Useful qualities in boat building material! (Note: marine plywood is not waterproof – the final external surface finish provides the waterproof coat).
Veneer arrangement and veneer thickness
The veneer arrangement and thickness of individual veneers within plywood and LVL is critical in determining dimensional stability and the structural performance characteristics of strength and stiffness.