Choosing Engineered Beams For Heavy Loads And Long Spans

There aren't many residential job sites today that don't incorporate some form of engineered lumber, a class that includes everything from plywood and OSB sheathing to trusses and I-joists. Because of the predictable spanning and load-bearing capabilities of engineered wood beams, builders, designers, architects, and engineers have made them a common framing component in buildings with wide open spaces and big daylight openings.

Defects, like knots and voids, are never more than one layer deep in laminated veneer and glulam lumber, effectively canceling them out. Predictable performance values make it a simple matter for manufacturers to publish load tables and sizing charts, available at the lumberyard, and to offer design software on their Web sites. In addition, most...