Inspection of I-Joists in Residential Construction: Fid-Bau Portal

Inspection of I-Joists in Residential Construction

Bouldin, John C. / Loferski, Joseph R. / Hindman, Daniel P.

Abstract

I-joists may be used as floor joist and roof-rafter members in residential construction but require different installation practices compared with solid-sawn lumber because of I-joist geometry and design. The building codes in this paper contain clear specifications for the installation of sawn-lumber products. Because I-joists are proprietary and installation requirements vary by brand, manufacturer literature is incorporated by reference into the building codes discussed herein. The engineered and proprietary nature of I-joists may be unfamiliar to carpenters and other trade professionals, resulting in installation errors. I-joist installations that do not comply with manufacturer specifications are considered code violations. Through use of the Delphi method, an expert-validated inspection methodology was developed by interviewing code officials, home inspectors, and engineered-wood-product manufacturers. This paper summarizes the results, including best practices for inspection methods and I-joist installation errors most likely to occur. Effective inspection methods include the top-down method, a circular inspection pattern on each level of the structure (the nautilus method), and a comparison of repeating members in a support structure (the pattern method). Common I-joist installation errors include improper (1) holes, cuts, and notches; (2) bearing; (3) bracing; (4) blocking; (5) hanger hardware installation; and (6) rim-joist installation. Application of the recommended inspection practices can improve the detection of I-joist construction errors.