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Sample colouring of Douglas Fir/Oregon
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Oregon, Douglas Fir
Pseudotsuga menziesii
A second
variety of Douglas Fir, Pseudotsuga menziesii var. glauca is
commonly called Rocky Mountain Douglas Fir or Blue Douglas Fir.
Douglas Fir is a softwood widley available
throughout Australia.
The source of the timber is primarily North America with additional
supplies being plantation grown in New Zealand.
Heartwood colour
ranges from a yellowish to pale reddish yellow (slow growing) to orange red
or reddish brown (fast growing), the colour varying greatly in different
samples. Sapwood is distinctly paler varying in width from about 50mm in
mature trees to 75mm in fast growing plantations. Growth rings are very
prominent because of the considerable difference in density between earlywood and latewood; this also leads to a course unevan surface texture.
The timber is easy to
work, although due to the difference in hardness between earlywood and latewood some care is required in planeing and dressing, differential glueing
can occur and end spliting may result when
nailing.
Douglas Fir is available
in a large range of sizes and lengths, commonly up to 7.2m and often
longer. It has been regularly used as construction timber in Australia
for over 100 years as well as high grade joinery such as windows, doors, mouldings, staircase components and exposed beams.
Timber Properties
Density(average)
650kg/m3 green
530kg/m3 dry
DurabilityClass 4
Strength
Group
S5 green
SD5 dry
Hardness
Rating(average)
2.3kN green
3.2kN dry

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