The Douglas Fir is an evergreen tree that is native to the Western North America, including Canada, the United States and Mexico. Douglar Firs are not “true” firs, despite their common name, and have gone through many different scientific classifications until, ultimately, they were given their own genus name of Pseudotsuga menziesii. Other common names for Douglas Fir are numerous, but include alpine hemlock, black fir, douglas pine, douglas spruce, gray douglas, green douglas, hallarin, Montana fir and Oregon pine among others.
There are two different species that occur in North American; the Coastal Douglas Fir, which extends from central British Columbia to northern California, and the Rocky Mountain Douglas Fir, which is found further inland in states such as Montana, Idaho, Utah, and Wyoming and their surrounding areas. Several varieties of Douglas Fir have been successfully introduced in more temperate zones, where they have become popular as decorative Christmas trees. Douglas Firs thrive in habitats with moist soil that has pH levels of 5-6, and that receive a lot of sunlight.
Douglas Firs generally grow to heights between 40 and 60 feet into an upright conical shape, with the base growth reaching widths of 15-25 feet. In the Pacific Northwest, where this tree is native, Douglas Firs of over 200 feet in height are common. The hardiness of these trees also vary depending on where they are grown. Douglas Firs in this region have to withstand sometimes extreme environmental conditions, and, for this reason, even after being harvested they make some of the most hardy logs and lumber on the market. For this reason, Coastal and Rocky Mountain Douglas Fir have become the industry standard for log timbers used for timber framing. (To see a detailed chart of Douglas Fir specifications such as Janka hardness rating, impact strength and stiffness, see www.mcilvain.com/softwoods/douglas-fir/)
Douglas Fir lumber has a distinct orange cast, due to the creamy yellow color of earlywood and the reddish brown hue of more mature lumber. The difference of hardness between these two types of wood can cause problems as the lumber is being machined if the tools are not kept sharp. Dulled blades can create splintering and “tear out” when used on the relatively soft wood of Douglas Fir. The grain of the wood tends to be very straight with numerous knots, which gives it its rustic character. Aside from the construction industry, Douglas Fir has become popular as an exterior siding, flooring and paneling choice because of its unique aesthetic qualities. Many people believe that Douglas Fir is the ideal species for building a Log Cabin style home.
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