Using Char Methods to Demonstrate Fire Resistance of Exposed Wood Members

Technical primer on calculating fire resistance of exposed wood members using char rates established in Chapter 16 of the American Wood Council's National Design Specification (NDS) for Wood Construction. Covers calculation methods per IBC Sections 703.2, 703.3, and 722.1 for demonstrating fire-resistance ratings up to 2 hours. Addresses nominal char rate of 1.5 inches per hour, effective char rate for structural members including heat-affected zone, and application to various wood products including solid sawn lumber, glulam, LVL, PSL, LSL, and CLT. References AWC Technical Report 10 for background information and design examples. Provides guidance on adjustment factors for allowable design properties and coordination with Authority Having Jurisdiction.