Douglas-Fir (Pseudotsuga menziesii)

Douglas-Fir (Pseudotsuga menziesii)

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Common Name(s): Douglas-Fir

Scientific Name: Pseudotsuga menziesii

Distribution: Western North America

Tree Size: 200-250 ft (60-75 m) tall, 5-6 ft (1.5-2 m) trunk diameter

Average Dried Weight: 32 lbs/ft3 (510 kg/m3)

Specific Gravity (Basic, 12% MC): .45, .51

Janka Hardness: 620 lbf (2,760 N)

Modulus of Rupture: 12,500 lbf/in2 (86.2 MPa)

Elastic Modulus: 1,765,000 lbf/in2 (12.17 GPa)

Crushing Strength: 6,950 lbf/in2 (47.9 MPa)

Shrinkage: Radial: 4.5%, Tangential: 7.3%, Volumetric: 11.6%, T/R Ratio: 1.6

Color/Appearance: Can vary in color based upon age and location of tree. Usually a light brown color with a hint of red and/or yellow, with darker growth rings.  In quartersawn pieces, the grain is typically straight and plain. In flatsawn pieces, (typically seen in rotary-sliced veneers), the wood can exhibit wild grain patterns.

Grain/Texture: Grain is generally straight, or slightly wavy. Medium to coarse texture, with moderate natural luster.

Endgrain: Small to medium sized resin canals, infrequent and variable in distribution; solitary or in tangential groups of several; earlywood to latewood transition abrupt, color contrast high; tracheid diameter medium-large.

Rot Resistance: Douglas-Fir heartwood is rated to be moderately durable in regard to decay, but is susceptible to insect attack.

Workability: Typically machines well, but has a moderate blunting effect on cutters. Accepts stains, glues, and finishes well.

Odor: Has a distinct, resinous odor when being worked.

Allergies/Toxicity: Although severe reactions are quite uncommon, Douglas-Fir has been reported to cause skin irritation, nausea, giddiness, runny nose, along with an increased likelihood of splinters getting infected. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.

Pricing/Availability: Should be widely available as construction lumber for a modest price. Old growth or reclaimed boards can be much more expensive.

Sustainability: This wood species is not listed in the CITES Appendices, and is reported by the IUCN as being a species of least concern.

Common Uses: Veneer, plywood, and structural/construction lumber.

Comments: Named after Scottish botanist David Douglas, (though the scientific name is in honor of Archibald Menzies, who first described the tree in the 1790s). Douglas-Fir is technically not a true Fir (Abies genus), but is in its own genus: Pseudotsuga.

The tree itself grows to be very large, and yields a large amount of usable lumber and veneer for plywood. It is an incredibly valuable commercial timber, widely used in construction and building purposes. The wood is very stiff and strong for its weight, and is also among the hardest and heaviest softwoods commercially available in North America.

The mechanical properties listed represent the average values from four regions: coastal, interior west, interior north, and interior south.

Related Species:

None available.

Related Articles:

Scans/Pictures:

Douglas-Fir (Pseudotsuga menziesii)

Douglas-Fir (sanded)

Douglas Fir (sealed)

Douglas-Fir (sealed)

Douglas-Fir (endgrain)

Douglas-Fir (endgrain)

Douglas-Fir (endgrain 10x)

Douglas-Fir (endgrain 10x)

Douglas-fir (quartersawn)

Douglas-fir (quartersawn)

  • Shelley

    I found that after burning this wood we, meaning my two Standard Poodles and me, couldn’t breath very well. I didn’t connect it soon enough to stop the effects of the difficulty to breathing and the couphing, until after a couple of days. I had to take my oldest, Cash, to the Vet and he had to go on medication. Cottonwood almost killed me a few years earlier when I burned it on a reguler basis. I now have found a couple of woods that my dogs and I can not use on a regular basis. I have found that if something changes in our health and you have changed something in your firewood you need to stop and check it out. It CAN kill you!!!!!!!!!!!!

    • Shawn

      How can it kill you? your not supposed to breathe in the smoke… Yes breathing any smoke will kill you….

    • maam2u

      did you make sure it was very dry and well seasoned???? burning anything green or half green is bad for anyone and bad for the chimney (creosote).

  • Himanshu

    Thanks for the information. I have read here http://www.urbandexterous.com/characteristics-of-douglas-fir-wood/ that it offers good struggle to splitting which makes it a good lateral holder of drilled objects. Is it true?

  • pradeep kumar dawda

    Than ks a very good information . it is very use ful in engeneering and construction parts

    thx a lot
    pradeep

  • john

    Good Morning ,does anyone know how much weight can be put on a 1 and a half inch by 2 inch Pc. of doug fir 2 inch tall that is hanging over a metal frame 9 inches,I am wanting to do this for floor framing for my rv trailer 16 inch on center