I-joists are "I"-shaped engineered wood structural members that offer strength, versatility and economy for use in residential and light commercial applications. I-joists are comprised of top and bottom flanges of various widths united with webs of various depths. The flanges resist common bending stresses, and the web provides outstanding shear performance.

To simplify the specification and use of I-joists, APA introduced the APA Performance Rated I-Joist (PRI). The joist is limited to a L/480 live load maximum deflection (where L = span) for glued-nailed residential floor applications, a criteria which provides superior floor performance.

Design Properties

The following publications provide detailed information on I-joists: