Wisdom breeds experience in this field, with older varieties holding a definite advantage. Douglas-fir is grown to a much older age than other timber-it´s typically grown between 40 and 50 years before being harvested. The result is substantially higher stiffness and stability. In general it can be stated that for any given region in New Zealand Douglas-fir timber is typically 2 units of GPa stiffer than radiata pine.

Builders know that stiff timber reduces deflection and movement under loading. That´s why they prefer Douglas-fir for beams and joists. The table below demonstrates the true advantages in stiffness for Douglas-fir.

Douglas Fir Stiffness