The 2021 International Building Code was amended to include provisions on the requirement for a “drainage space or material” to be installed behind exterior cement plaster and in front of the also required water-resistive barrier. This paper provides information that delves into the specific code language and provides guidance on what it means to the contractor. A collaboration of the AWCI Sub-Committee on Lath and Plaster followed by a peer review by key experts in the industry produced this informative document.
