The purpose of this report is to investigate the implications of installing sprinkler systems in ceilings with a ceiling slope exceeding the maximum permitted by NFPA 13, being 9.5 ° or 18.44 ° depending on the type of sprinkler system. The objective of the report is to present a comparison and analysis of sprinkler activation times and patterns for sprinkler systems installed in ceilings with different slope angles, using Fire Dynamics Simulator version 6 Release Candidate 1. The problem has been defined as: how does the ceiling slope angle where sprinklers are provided affect the activation of sprinklers? It has been demonstrated that a ceiling slope of up to 26.57 ° may not affect the sprinkler activation pattern. It has also been demonstrated that the increased sprinkler activation times and changed patterns exhibited for sprinkler systems in sloping ceilings may be a result of a combination of excessive ceiling height and ceiling slope angle, subject to discussion. Reduced Response Time Index and activation temperature can reduce activation pattern discrepancies and reduce activation times. The intent of the sprinkler system may not be compromised when ceiling slopes exceeding those specified in NFPA 13 are introduced. The author