Sample colouring of Douglas Fir/Oregon
Sample colouring of Douglas Fir/Oregon

 

 

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.

Jim Tardif, standing near a big Douglas Fir in the Umatilla National Forest, Oregon USA.Photograph courtesy of Dave Powell USDA Forest Service.         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

                                                                                    Typical Douglas Fir regrowth in North America