NFPA 13 and FM Global Loss Prevention Data Sheet 2-0 provide guidance on how to install Control Mode sprinklers in the presence of obstructed ceiling construction, but the installation guidelines for Suppression Mode sprinklers in the presence of obstructed ceiling construction is much more stringent. Historically there has been very little test data or modeling analysis to support the installation guidelines currently available for Suppression Mode sprinklers protecting a storage environment. This presentation will discuss the current installation guidelines for sprinklers protecting storage in the presence of obstructed ceiling construction, recent numerical computer modeling conducted by FM Global to investigate the principal effects of obstructed ceiling construction on sprinkler activation, as well as large-scale fire testing that was conducted by FM Global based on the results obtained through computer modeling. Wes is a member of the Society of Fire Protection Engineers and an NFPA member serving on both the NFPA 13 Installation and NFPA 13 Discharge committees. Wes has been with FM Global for over 33 years and is currently responsible for data sheets related to the protection of storage, as well as the installation guidelines for sprinklers that are used for storage protection.