False Hemlocks | Pseudotsuga
The False Hemlock (Pseudotsuga) is a highly valued tree in the construction industry because its wood is extremely durable and strong. It is abundant in North America, but you may also find it in eastern Asia. Other communities call it Douglas Fir, Douglas Spruce, Douglas Tree, Oregon Pine, Red Spruce, or Yellow Spruce. This evergreen tree can be medium-size or gigantic, with flat, soft, linear leaves occurring singly. Male and female trees produce cones. This tree prefers well-drained, moist soil in areas with direct or little sunlight. These areas must either have cool moist winters or long hot summers.
Douglas Fir is often used for framing in residential and commercial buildings, as well as in the construction of bridges, poles, and beams. The wood is also used for siding, roofing, and flooring, and can be finished in a variety of ways to suit different design aesthetics. In addition to its use in traditional wood construction, Douglas fir is also used in the production of engineered wood products, such as laminated veneer lumber and oriented strand board, which are used for structural and non-structural applications.
The lifespan of a Douglas fir tree (Pseudotsuga menziesii) can vary depending on a number of factors, including the tree's genetics, environmental conditions, and the presence of diseases or pests. In general, Douglas fir trees can live for several hundred years, with some individuals living for over 1000 years. However, the average lifespan for a Douglas fir tree is typically between 400 and 800 years.
Douglas fir (Pseudotsuga menziesii) is rated as being comparable to or slightly stronger than other common construction lumber species such as southern yellow pine and spruce-pine-fir. In terms of its mechanical properties, Douglas fir has a high bending strength and stiffness, as well as a good resistance to shock loads. It also has a good weight-to-strength ratio, making it an efficient choice for use in structural applications.