"All framing lumber shall be Douglas Fir-Larch", is a standard note on all engineered plans from PMHI. The reason is simple. When architects and engineers look for the best in structural lumber, their first choice is Douglas Fir. It is dimensionally stable and universally recognized for its superior strength-to-weight ratio.  The species also enjoys a documented superior performance against strong forces resulting from natural phenomena such as winds, storms and earthquakes.

Even the leading supplier of wood framing construction connectors, Simpson Strong-Tie, acknowledges the superior load carrying capacity of Douglas Fir. It has its own column of higher load values, when compared to other lumber species, for the same connector or hanger!

Douglas Fir is truly the ideal structural and general purpose wood for framing lumber in residential, light commercial, multistory and industrial construction.

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The Douglas Fir/Western Larch species combination has the highest modulus of elasticity of all the North American softwood species. This is the ratio of the amount a piece of lumber will deflect in proportion to an applied load; it is a reflection of the species' high degree of stiffness, an important consideration in the design of floor and roof systems.

In strength properties, Douglas Fir/Western Larch has the highest ratings of any western softwood for extreme fiber stress in bending (Fb); for tension parallel-to-grain (Ft); for horizontal sheer (Fv); for compression perpendicular-to-grain (Fc); and for compression parallel-to-grain (Fc//).
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These physical working properties, and excellent dimensional stability, are the primary  reasons Douglas Fir is the standard against which all other framing lumber is judged. It is also tight knotted and close-grained, adding the bonus of beauty to its structural capabilities.

Only those builders looking to "cut corners" use the lesser grades of framing lumber, such as Hem Fir and Canadian SPF. Look for yourself the next time you walk through a home under construction....look for the words "Doug Fir" in the lumber grade stamps. If other species of lumber are listed, it is an inferior product and simply not as strong as Douglas Fir. Which do you want in your new home?