There are more than a hundred softwood species in North America. To simplify the supply and use of structural softwood lumber, species in major lumber producing areas having similar strength characteristics are combined. Having a smaller number of combinations makes it easier for a building inspector to ensure that products having the design strengths specified by the building designer are installed. Because non-structural products are graded solely on the basis of appearance quality, non-structural products are usually sold as individual species (for example, eastern white pine, Western Red Cedar, Douglas fir).
The four species groups of Canadian lumber and their characteristics are shown below.
The Spruce-Pine-Fir species group makes up by far the largest proportion of dimension lumber since the species in this group grow throughout most of Canada. The other major species groups for dimension lumber are Douglas Fir-Larch (N)and Hem-Fir (N). Northern Species include the other commercial species for Canadian lumber.