Wood I-Joist Do's and Don'ts

As a technical representative for a major wood I-joist manufacturer, I work with architects, designers, engineers, and builders to help them to correctly use my company's engineered wood products. Much of my time is spent on job sites looking at installations that range in quality from exceptional to bad to alarming. Builders who have used solid-wood 2x10s for 15 years know what they can and can't do; when they switch to wood I-joists, however, they're confronted with a relatively new product that has somewhat different structural characteristics. I often see the product misapplied even by experienced builders. Some of these errors are caused by poor design, while others are the work of subcontractors who alter the joists after they've been installed.