This report describes the use and procedures for placement of wet- and dry-mix shotcrete in underground rock excavations. Its purpose is to serve as a guide for designers and contractors in selecting, preparing and applying shotcrete of acceptable quality in the variety of ground conditions encountered in underground work. The contents of this report include design considerations, engineering properties, shotcrete equipment, application techniques and quality control. Specifications for shotcrete are treated as well. The appendices provide supplemental information dealing with the use and engineering properties of fiber and regulated-set cement shotcrete, capabilities and specifications of shotcrete machines and some recommended guidelines for placing shotcrete underground.