The client was responsible for the design for a new rock climbing gym requiring sprinkler protection. There was some confusion on what design criteria should be used for the overhead sprinkler system. The building was approved as Group A-3 which typically meets light hazard criteria, but given the exposed wood structures and foam padding they were not sure if ordinary hazard was justified in this situation or not.
We advised that the IBC occupancy classifications, in this case A-3, only indicate when a sprinkler system would be required. It defers all matters regarding specific design criteria of the sprinkler system to NFPA 13.
Given that the building has quantities in the moderate to high range of high combustibility material, sounds like your climbing gym would meet ordinary hazard Group 2 requirements. Depending on the type of climbing walls constructed, their size, and location, you could be looking at large combustible concealed locations, potential shielding of combustibles, and obstructions to discharge as well.