Pseudotsuga menziesii

 

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Family: Pinaceae

 

 

 

 

 

 

 

 

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Douglas-Fir

 

 

 

The genus Pseudotsuga contains about 7 species native to North America [2], and eastern Asia (China to Japan) [5]. The wood of pine can be separated microscopically into the white, red, yellow and the foxtail/pinyon pine groups. Douglas-fir is named for Henry Douglas (1798-1834), a Scottish botanist who traveled in North America. The word Pseudotsuga means ‘false hemlock" , while menziesii is used in recognition of Archibald Menzies (1754-1842), a Scotch physician and naturalist, who discovered Douglas-fir in 1793 on Vancouver Island, British Colombia.

Other Common Names: abete di Douglas, abete odoroso d'America, abeto, acahuite, achahuite, alpine hemlock, black fir, blaue Douglas-tanne, blauwe Douglas, blauwe Douglas spar, blue Douglas-fir, British Columbia Douglas-fir, British Columbia pine, British Columbian pine, cahuite, Canadian Douglas-fir, coast Douglas-fir, Colorado Douglas-fir, Colorado pino real, Colorado real pino, Columbian pine, common Douglas, common Douglas-fir, cork-barked Douglas spruce, Douglaasfenyo, Douglas, Douglas azul, Douglas bleu, Douglas des montagnes, Douglas du Colorado, Douglas glauca, Douglas pine, Douglas spruce, Douglas vert, Douglasfichte, Douglas-fir, Douglas-gran, Douglasia, Douglasia azzurra, Douglasia glauca, Douglasie, Douglaska, Douglaskuusi, Douglasspar, Douglastanne, Duglas, Duglazija, golden rod fir, gray Douglas, green Douglas, groene Douglas, grune Douglas-tanne, guallame, guayame, guayame Colorado, hallarin, hayarin, hayarin Colorado, inland Douglas-fir, interior Douglas-fir, Montana fir, Oregon, Oregon Douglas, Oregon Douglas-fir, Oregon fir, Oregon pine, Oregon spruce, Pacific Coast Douglas-fir, Patton's hemlock, pin de Douglas, pin de i'Oregon, pin d'Oregon, pinabete, pinho de Douglas, pino de corcho, pino de Douglas, pino de Oregon, pino Oregon, pino real, Puget Sound pine, red fir, red pine, red spruce, Rocky Mountain Douglas-fir, Santiam quality fir, sapin de Douglas, spruce, yellow Douglas-fir, yellow fir, yellow national fir.

Distribution: The range of Douglas-fir extends from the Rocky Mountains to the Pacific coast and from Mexico to central British Columbia. The Douglas-fir production comes from the Coast States of Oregon, Washington, and California and from the Rocky Mountain States.

The Tree: Douglas-fir reaches heights of 250 feet (76.20 m), with a diameter of 6 feet (1.83 m), in coastal stands that are between 200 and 800 years old. The largest intact specimen was recorded at 330 feet (100.58 m) near Littlerock Washington.

General Wood Characteristics: The wood of Douglas-fir varies widely in weight and strength. When lumber of high strength is needed for structural uses, selection can be improved by applying the density rule. This rule uses percentage of latewood and rate of growth as they affect density. For equivalent knot sizes, the higher density generally indicates stronger wood. Sapwood of Douglas-fir is narrow in old-growth trees but may be as much as 3 inches (7.62 cm) wide in second-growth trees of commercial size. Fairly young trees of moderate to rapid growth have reddish heartwood and are called red-fir. Very narrow-ringed wood of old trees may be yellowish brown and is known on the market as yellow-fir.

 

Weighta

 

Weight

Location

MCb

SpGrc

lb/ft3

 

Coast

Green(37%)d

0.45

38

 

 

12%

0.48

34

 

 

Ovendry

0.51

NA

 

 

 

 

 

 

Interior West

Green(34%)d

0.46

38

 

 

12%

0.50

31

 

 

Ovendry

0.52

NA

 

 

 

 

 

 

Interior North

Green(30%)d

0.45

35

 

 

12%

0.48

30

 

 

Ovendry

0.50

NA

 

 

 

 

 

 

Interior South

Green(30%)d

0.43

NA

 

 

12%

0.46

32

 

 

 

References: (56, 185) 

Ovendry

NA

NA

 

 

Mechanical Propertiesa?

Property

Green

Dry

 

 

 

Coast

 

 

MOE

1.56 ´ 106 lbf/in2

 

1.95 ´ 106 lbf/in2

 

MOR

7.70 ´ 103 lbf/in2

 

12.4 ´ 103 lbf/in2

 

C| |

3.78´ 103 lbf/in2

 

7.23 ´ 103 lbf/in2

 

C^

0.38 ´ 103 lbf/in2

 

0.80 ´ 103 lbf/in2

 

WML

7.6 in-lbf/in3

 

9.9 in-lbf/in3

 

Hardness

500 lbf

 

710 lbf

 

Shear| |

0.90 ´ 103 lbf/in2

 

1.13 ´ 103 lbf/in2

 

 

 

 

Interior West

 

 

MOE

1.51 ´ 106 lbf/in2

 

1.83 ´ 106 lbf/in2

 

MOR

7.70 ´ 103 lbf/in2

 

12.6 ´ 103 lbf/in2

 

C| |

3.87 ´ 103 lbf/in2

 

7.43 ´ 103 lbf/in2

 

C^

0.42 ´ 103 lbf/in2

 

0.76 ´ 103 lbf/in2

 

WML

7.2 in-lbf/in3

 

10.6 in-lbf/in3

 

Hardness

510 lbf

 

660 lbf

 

Shear| |

0.94 ´ 103 lbf/in2

 

1.29 ´ 103 lbf/in2

 

 

 

 

Interior North

 

 

MOE

1.41 ´ 106 lbf/in2

 

1.79 ´ 106 lbf/in2

 

MOR

7.40 ´ 103 lbf/in2

 

13.1 ´ 103 lbf/in2

 

C| |

3.47 ´ 103 lbf/in2

 

6.90 ´ 103 lbf/in2

 

C^

0.36 ´ 103 lbf/in2

 

0.77 ´ 103 lbf/in2

 

WML

8.1 in-lbf/in3

 

10.5 in-lbf/in3

 

Hardness

420 lbf

 

600 lbf

 

Shear| |

0.95 ´ 103 lbf/in2

 

1.40 ´ 103 lbf/in2

 

 

 

 

 

 

Mechanical Properties, cont’d

Property

Green

Dry

Interior South

 

 

MOE

1.16 ´ 106 lbf/in2

 

1.49 ´ 106 lbf/in2

 

MOR

6.80 ´ 103 lbf/in2

 

11.9 ´ 103 lbf/in2

 

C| |

3.11 ´ 103 lbf/in2

 

6.23 ´ 103 lbf/in2

 

C^

0.34 ´ 103 lbf/in2

 

0.74 ´ 103 lbf/in2

 

WML

8.0 in-lbf/in3

 

9.0 in-lbf/in3

 

Hardness

360 lbf

 

510 lbf

 

Shear| |

0.95 ´ 103 lbf/in2

 

1.51 ´ 103 lbf/in2

 

Reference: (187) (2-inch standard).

 

Drying and shrinkage

 

Percentage of shrinkage

(green to final moisture content)

Type of Shrinkage

0%MCb

0%MCc

0%MCd

Tangential

7.6

6.9

7.5

Radial

4.8

3.8

4.8

Volumetric

12.4

10.7

11.8

Reference (187).

b Coast.

c Interior North.

d Interior West.

Kiln drying schedule

Conventional Temperatures/Moisture Content-Controlled Schedulesa

 

 

 

 

 

 

 

Condition

4/4, 5/4

stock

6/4 stock

8/4

stock

10/4

stock

12/4

stock

British Schedule

4/4 stock

Lower Grades

 

 

 

 

 

 

Coastal

T7-A4

NA

T7-A4b

NA

NA

NA

Inland

T9-A4c

NA

T9-A4c

NA

NA

NA

 

 

 

 

 

 

 

Upper Grades

 

 

 

 

 

 

Coastal

T11-A4

NA

T10-A3

T5-A1

T5-A1

NA

Inland

NA

NA

NA

NA

NA

NA

Reference (28 & 177).

BMaximum wet-bulb depression 25oF, Reference (177).

CMaximum wet-bulb depression 20oF, Reference (177).

 

Conventional Temperatures/Time-Controlled Schedulesa

 

Lower Grades

Upper Grades

Condition

4/4, 5/4 stock

6/4 stock

8/4 stock

4/4, 5/4 stock

6/4 stock

8/4 stock

12/4, 16/4 stock

Standard

291b

291c

291c

294d

294d

294d

288

aReference (28).

 

High Temperaturesa

Condition?

4/4, 5/4 stock

6/4 stock

8/4 stock

Other Products

Standard

400b,c,d,e

400b,e

400b,e/414e

NA

aReferences (28).

 

Working Properties: No information at this time.

Durability: Rated as moderately resistant to decay. (187)

Preservation: No information at this time.

Uses: Douglas-fir is used mostly for building and construction purposes in the form of

lumber, timbers, piles, and plywood. Considerable quantities go into railroad crossties, cooperage stock, mine timbers, poles, and fencing. Douglas-fir lumber is used in the manufacture of various products, including sash, doors, laminated beams, general millwork, railroad-car construction, boxes, pallets, and crates. Small amounts are used for flooring, furniture, ship and boat construction and tanks. Douglas-fir plywood has found ever-increasing usefulness in construction, furniture, cabinets, and many other products.

Toxicity: Can cause dermatitis, septic splinter wounds, or contact eczema. (69, 150 & 207)

 

Additional Reading & References Cited (in parentheses):

28. Boone, R. S.; Kozlik, C. J.; Bois, P. J., and Wengert, E. M. Dry kiln schedules for commercial woods - temperate and tropical. Madison, WI: USDA Forest Service, FPL-GTR-57; 1988.

29. Bormann, B. T. Douglas-Fir an American wood. Washington, DC: USDA Forest Service, FS-235; 1984.

69. Hausen, B. M. Woods injurious to human health. A manual. New York, NY: Walter de Gruyter; 1981.

150. Mitchell, J. and Rook, A. Botanical dermatology: plants and plant products injurious to the skin. Vancouver, BC: Greenglass Ltd.; 1979.

184. Summitt, R. and Sliker, A. CRC handbook of materials science. Vol. 4. Boca Raton, FL: CRC Press, Inc.; 1980.

187. USDA. Wood handbook: wood as an engineering material. Madison, WI: USDA Forest Service, FPL Ag. Handbook No. 72; 1974.

207. Woods, B. and Calnan, C. D. Toxic woods. British Journal of Dermatology. 1976; 95(13):1-97.