Basic information : The sapwood is light in color and narrow in width. Heartwood varies from yellow to reddish brown. The colors of early wood and late wood are distinct, and the latter has a deeper, sharper ribbon. This color difference causes the shape of the wood grain to be different when the flat saw is used. The wood material is fine to medium, and the texture is straight and non-permeable. Douglas fir is one of Canada's strongest commercial softwoods. It has high hardness and high abrasion resistance. It is suitable for wear and tear as a factor, such as brackets, bridge components, wooden houses and commercial buildings.

Structural characteristics : Douglas fir is world-famous for its excellent strength-to-weight ratio. Its high specific gravity provides good nail holding and fixing force. It is suitable for wooden frames used in residential buildings, small commercial buildings, multi-storey buildings and industrial buildings. . In the softwood species of North America, Douglas fir not only has a high modulus of elasticity, but also the outermost bending fiber stress, the tensile force, the transverse shear force, the horizontal grain pressure and the grain pressure are also extremely good. Because of the physical properties of Douglas fir, the durability of the heartwood and the outstanding physical stability, many construction companies around the world use Douglas Fir as the standard for judging all framed wood. Douglas fir is known for its structural properties and its appearance is beautiful. Douglas fir is the most commonly used type of wood when design structures require large wooden beams, long spans or specially shaped arches (eg churches, bridges, stadiums, etc.). In the construction of residential buildings, commercial buildings, public buildings, tower buildings and water facilities, the structurally laminated beams made by Douglas Fir are commonly used as horizontal load-bearing frames for roofs, floors and pillars. Glued beams are also a reliable building material in the construction of industrial plants, warehouses, garages, and even architectural structures that require a beautiful appearance.

Appearance grade : Douglas fir has a light rose color and a beautiful straight texture, which darkens after sun exposure. Douglas fir's ductile fibers are not easy to cut or sculpt by hand, but smooth cutting surfaces can be obtained with sharp power tools and machine tools. This wood can be processed into a variety of products in the shape of the grain, the surface is easy to paint, and can maintain a variety of dyeing and varnish. The bark of the tree is thick and deep scaly. The leaves are strip-shaped, about 1.5-3 cm long, the ends are blunt or slightly pointed, the top is dark green, the lower color is lighter, and there are two gray-green stomata bands. The fruit of the tree (cone) is oval-obovate, about 8 cm long, brown and shiny. The scales are rhomboid or nearly rhomboid, and the scales are longer than the scales. The middle lobes are narrow and long, and the lobes on both sides are wider and shorter.

Douglas fir hi-light, like warm and humid climate and well-drained acidic soil, can withstand the drought in winter and spring. The bark is in the shape of a leopard, the heartwood is reddish, the sapwood is light yellow and has a resin. The material is tough, elastic and has a long shelf life. Wood can be divided into coastal and inland types. Douglas fir is a good building and appliance material.

Classification: 1) Non-defective materials (no thrift): Class II and above non-defective materials, Class III non-defective materials and Class 4 non-defective materials. 2) Processing materials (re-processed into non-defective materials): top processing material board, secondary top processing material board, first grade and above processing materials, wood line materials A and B. 3) Architectural use: light frame materials, lightweight structural frame materials, structural shelves and panels.

Main use: Douglas fir has many uses. Citi pine is a widely used structural material, which is favored by engineers and builders. It is especially suitable for structural parts and heavy wood structures. It is also widely used. Wood piles, railway sleepers, sawmills, warehouses and countless other areas that focus on structural performance. As a hard and stable wood, Douglas Fir can be used to build wood frames for light and heavy construction.

Due to its high strength and good gluing properties, Douglas fir is often used to make glulam beams of various structures, including indoor sports fields, swimming pools, churches and supermarkets. Douglas fir has a good appearance and is easy to process. It is suitable for processing into window frames and door frames, mouldings, cabinets and other joinery products. The hardness and strength of Douglas fir also increase durability. Douglas fir has high corrosion resistance and excellent structural properties, so it is also the main wood for the production of industrial tanks, vats and other storage containers. Its stability and ease of processing make it a material for manufacturing industrial parts. Because Douglas fir has a high bearing capacity and a high weight ratio, the main applications in construction engineering are glulam beams and building blocks. The most extensive of these is the use of building wood. The wooden building is called the mouth material. Mainly based on 35*85 specifications. There are also different specifications depending on the geographical location. Among them, Hangzhou is mostly 39*89, and there are also 5*10 specifications. Saw panels are usually processed into outdoor landscape wood panels, which are treated with anti-corrosion treatment and are the preferred material for outdoor wood flooring.

Conservation value: Douglas fir (Yellow cedar) is Canada's largest tree and contains two major species: coastal Douglas fir and inland Douglas fir. The sapwood is light in color and narrow in width. Heartwood varies from yellow to reddish brown. The colors of early wood and late wood are distinct, and the latter has a deeper, sharper ribbon. This color difference causes the shape of the wood grain to be different when the flat saw is used. The wood material is fine to medium, and the texture is straight and non-permeable. Douglas fir is one of Canada's strongest commercial softwoods. It has high hardness and high abrasion resistance. It is suitable for wear and tear as a factor, such as brackets, bridge components, wooden houses and commercial buildings.