BDCS Notes - Wood

Pros of Using Wood:

1. Available

2. Low Cost

3. Ease of Use

4. Durability

5. Good for Use in Compression

Used extensively for buildings, bridges, utility poles, floors, roofs, trusses, and piles.

Engineered Wood Products: Laminates, plywood, and strand board.

Trees: A woody plant that attains a height of at least 20 ft., has a self-supporting trunk with no branches for about 4 ft. Over 600 species of trees in the United States.

Trees are classified as either endogenous or exogenous, based on type of growth. Endogenous trees, such as bamboo, grow with intertwined fibers. Wood from endogenous trees not used for engineering applications. Exogenous trees grow from the center out by adding concentric layers of wood around the central core. Structural applications for wood primarily concern the use of exogenous trees.

Exogenous trees are classified as either deciduous or conifers, producing hardwoods and softwoods, respectively.

Softwoods are softer, less dense, and easier to cut than hardwoods (although Balsa is a hardwood). They are also used more in construction than hardwoods. Hardwoods are typically used for furniture and decorative veneers (because of their nice grain pattern).

Deciduous trees shed their leaves at the end of each growing season. There are about 40 different kinds of deciduous trees used for commercial hardwood production.

Conifers (evergreens) have needlelike leaves and normally do not shed at the end of the growing season. They grow continuously through the crown to produce a uniform stem and homogenous characteristics. Softwood comes from 20 different kinds of conifers. The softwood is primarily used for structural purposes. The rapid maturing of conifers makes them a renewable resource.