Proper placement is the most important element in achieving good shotcrete results. Most defects that occur in shotcrete are due to poor placement. Shotcrete success depends largely on the skill and actions of the nozzleman. The nozzleman’s goal is to achieve adequate compaction and good encasement of the reinforcement (if present) with no entrapped rebound or hardened overspray. For this reason, it is important to require that the nozzleman be ACI certified for the application. There are specific certifications for both wet and dry processes as well as vertical and overhead applications. If the nozzleman is certified, the probability that you will get the desired results is significantly increased. For more information on certification, visit the ASA website, www.shotcrete.org, and click on Certification.