Shaft Wall Requirements for Tall Mass Timber Buildings

In-depth technical guide examining shaft enclosure requirements for the three new tall mass timber construction types (IV-A, IV-B, IV-C) introduced in the 2021 IBC. Covers comprehensive analysis of allowable materials, noncombustible protection requirements, fire-resistance ratings, and other design considerations for stairs, elevators, and MEP chases in multi-story buildings. Addresses specific requirements for mass timber use in shaft walls, protection time calculations, contribution to FRR through combination of timber charring and noncombustible protection, and detailed construction specifications. Includes practical guidance on detailing floor-to-shaft and roof-to-shaft wall intersections, with consideration of structural loads, acoustics, and fire barrier continuity.