A wood truss is a building material used in structural framing systems. It is comprised of a series of wooden triangles and framing members, which are connected by metal plates at each joint. This triangular shape gives the truss added strength and stability over traditional stick framing. Trusses are often referred to as open web systems due to the web-like appearance caused by the pattern of the triangles. The most commonly used trusses resemble railroad tracks, with ties arranged in triangular patterns, rather than parallel.
Wooden trusses are used to construct a large number of building components. They are frequently used to build floors and ceilings, and may even be used to frame exterior walls. Wood trusses are also one of the most common materials used in roof framing systems. In general, wood truss systems are used in homes and multi-family buildings, while steel trusses are used for commercial structures.
There are a number of different types of wood truss designs, though each relies on the same basic components. The interior triangles, known as “webs,” are supported by surrounding framing members, known as “chords.” Each joint on the truss is known as a “node,” and the overall length of the truss is called the “span.” The maximum height of the truss is its “peak,” while the “overhang” is the length at the base of the truss that is designed to hang over the edge of walls or other vertical framing members.
The simplest wood truss design is comprised of a single triangle, and may be used in roof or ceiling construction. Interconnected triangles in a single plane form planar trusses. Planar trusses are primarily used for floor and ceiling construction, and are the most commonly used type of truss design. When joined together, a series of planar trusses form a space truss, while is used for more complex roofing and framing systems.
Wood trusses offer a number of benefits over stick framing systems. The triangular shape is considered one of the most stable and secure structural designs, which allows for more elaborate framing capabilities. Trusses are designed to transfer the weight of the supported load to the nodes, rather than the chords or webs themselves. This means that the truss will generally only need support at the ends, which allows for longer spans than those permitted with stick framing.
In addition to their structural advantages, wood trusses also offer a number of other benefits. Because they are usually prefabricated at the factory, they can be quickly erected, which can lower labor costs as well as overall construction time. In comparison with stick framing, wood truss construction results in much less jobsite waste and requires less total material. Finally, trusses offer a high strength-to-weight ratio, which can result in smaller and less complex foundations and supplementary framing needs.
