There is limited prior research related to protection of storage under ceilings with slopes steeper than 2/12. Previous studies exist from FM Global, University of Maryland/Custom Spray Solutions, the Fire Protection Research Foundation, and National Fire Sprinkler Association (NFSA), but there are still many open questions related to the protection criteria for storage under sloped ceilings. The questions include, but are not limited to; sprinkler activation pattern relative to fire source location, and optimal sprinkler installation orientation.
There are many different parameters related to this design challenge. Some of the key parameters include the slope of the ceiling, the commodity being stored, types of sprinklers (including ESFRs), sprinkler orientation, and sprinkler spacing. Some possible protection design solutions to sloped ceiling facilities are to use higher densities or larger calculation areas than for storage under flat ceilings.
Further modeling analysis will be beneficial in order to understand the potential protection challenges related to sloped ceilings, and to determine the range of scenarios that should be studied further through testing. The information from this work as well as information gathered from testing could help inform the NFPA 13 requirements.
The Fire Protection Research Foundation initiated this project to ultimately determine the impact of sloped ceilings on protection of storage and develop the technical basis for the NFPA 13 Technical Committees for new requirements and guidance. This report, "Protection of Storage Under Sloped Ceilings - Phase 1" authored by Kenneth E. Isman, Stephen J. Jordan, Andre W. Marshall and Noah L. Ryder from Custom Spray Solutions, covers the first phase of this project with the objective to develop a test plan based on the review of current range of typical storage configurations and modeling.
A separate FM Global report titled “Numerical Modeling of Sprinkler Activations and Spray Transport Under Sloped Ceilings” contains the results from the modeling effort and can be downloaded.