DOUGLAS FIR
The Douglas fir is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir, Rocky Mountain Douglas-fir and Mexican Douglas fir.
ADANACK NOTES
An ideal softwood for both interior and exterior applications because of it strength and versatility and is available in a wide range of specifications. It is native to western North America and is also known as Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir, Rocky Mountain Douglas-fir and Mexican Douglas fir. It is an incredibly valuable commercial timber, widely used in construction and building purposes.
PROPERTIES
General Description
The heartwood is light reddish Brown in colour, usually quite distinct from the lighter coloured sapwood. The abrupt change in contrast in colour between early-wood and late-wood bands, produce a prominent growth ring figure which is a feature of plain sawn surfaces and of rotary cut veneer. Grain is generally straight, or slightly wavy. Medium to coarse texture, with moderate natural lustre.
Uses
Suitable for cladding, exterior work joinery, gates, fences and garden furniture.
Seasoning
Imported Douglas fir is not a difficult timber to dry on arrival in this country or in Europe , because the moisture content has already been reduced prior to shipment.
Working Properties
The timber has a moderate resistance to cutting edges with machine edges and hand tools and finishes cleanly. It is a very stiff and hard timber which is very resistant to suddenly applied loads. It is much stronger in bending and compression along the grain than other comparable timbers.
Durability
Despite being a softwood Douglas Fir is moderately durable and susceptible to insect attack.
Density
It has a medium density, machines and glues well. The grain is fine. The weight is 34lbs/ft³ (530 kg/m³)and it has a relative density of .51.
Mechanical Properties
Douglas Fir is one of the strongest softwoods making it more immune to abrasive wear & tear than other softwoods. Not suitable for steam bending due to it's resin content.
Coating/Non Coating
Accepts glues, paint and clear finishes. Somewhat difficult to stain especially with oil stains, requires heavy sanding to lessen resistance to stain.
Fixings & Fasteners
Nailing and screwing properties are good, but pre-boring is necessary and there is a strong tendency to split.
