actured from weaker tree fibers, such as aspen and poplar. The wood chips are treated with resins, and formed into beams, studs, and I-joists. Lengths of engineered lumber can also be glued together to create laminated beams.
Engineered lumber components eliminate natural defects, such as knots, and do not warp or bow as traditional sawn lumber does because moisture from the wood is removed during manufacturing process. Deeper laminated beams and I-joists are able to carry greater loads with fewer members than are traditional wood beams.
The price of engineered lumber·generally from 12 percent to 15 percent higher than traditional wood framing. Because engineered-wood structures can be framed quickly, however, there is a potential labor savings. Many of the resins used in manufacturing engineered lumber are petroleum-based. Thus, the environmental acceptability of these products remains an issue.
Another framing alternative to sawn lumber is light-gauge steel. One advantage of a steel-framed house
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