Engineered Wood Products

In addition to dimension lumber, a wide variety of engineered wood products (EWPs) are manufactured for use in wood-frame house construction. These products can provide equivalent or superior performance to dimension lumber, and are typically manufactured using less wood from small, fast-growing trees. EWPs make better use of forest resources. A description of the various types which are available follows. EWPs include products such as glue-laminated timber, wood I-joists and structural composite lumber.

Dimension lumber and other wood products are often combined in the manufacture of EWPs using glue or mechanical fasteners or both. The most common example is the engineered pitched-roof truss. Less common, but of increasing application, is the parallel-chord truss with metal or wood webs. Wood I-joists consisting of lumber flanges and plywood, wafer-board or oriented strandboard webs are also being used more frequently (Fig. 28).

All these products provide greater flexibility in design by virtue of their larger spans and their capability to house services. In addition, when used for the roof structure, they can accommodate higher insulation levels.

Parallel chord trusses and wood I-joist.

metal web

Parallel chord trusses and wood I-joist.

metal web

Structural Composite Lumber

Structural composite lumber is a subset of EWPs which includes products such as laminated veneer lumber (LVL) and parallel strand lumber (PSL).

Laminated veneer lumber consists of thin veneer panels laid parallel to each other, coated with a waterproof adhesive, and bonded by heat and pressure. Available in a wide variety of sizes and strengths, LVL may be cut into desired lengths for use as beams, columns, headers (lintels), joists, and as flanges in wood I-beams.

Parallel strand lumber is manufactured using thin veneer panels cut into narrow strips and then bonded together using a process similar to LVL. Members are available in a variety of widths, depths and lengths, and are primarily used as beams, columns and headers.

Finger-jointed studs are an alternative to milled lumber.

Wood Working for Amateur Craftsman

Wood Working for Amateur Craftsman

THIS book is one of the series of Handbooks on industrial subjects being published by the Popular Mechanics Company. Like Popular Mechanics Magazine, and like the other books in this series, it is written so you can understand it. The purpose of Popular Mechanics Handbooks is to supply a growing demand for high-class, up-to-date and accurate text-books, suitable for home study as well as for class use, on all mechanical subjects. The textand illustrations, in each instance, have been prepared expressly for this series by well known experts, and revised by the editor of Popular Mechanics.

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