sprinklernotes
Omitting Sprinklers in Atrium Areas.
You have asked the following questions: “We have a 5-story building with a full height atrium and smoke evacuation system. The atrium ceiling is in excess of 55 feet in height. Are automatic sprinklers required above all balconies and walkways in the atrium space?” In response to your question, we have reviewed the 2015 IBC and NFPA 13, 2016 edition as the applicable standard. Our informal interpretation is sprinkler protection is required for the balconies and walkways. The starting point is that NFPA 13 does not allow the omission of protection based on high ceilings. With that being said we will have to look at the building code to determine if the walkways and balconies can omit sprinkler protection. The IBC in Section 404.3 says An Approved automatic sprinkler system shall be installed throughout the entire building. This tells us regardless of the building occupancy or use, the fact it has an atrium is a trigger to require a fire sprinkler system. There are two exceptions to Section 404.3. Exception number one allows us to omit sprinkler protection from the areas adjacent to or above the atrium provided they are separated by no less than two-hour fire barriers. The second exception allows us to omit sprinkler protection from the ceiling of the atrium area provided the ceiling is located more than 55 ft above the floor below. Now the basis for the omission of sprinklers stems from Section 404.2 Use. The floor of the atrium shall not be used for other than low fire hazard uses and only approved materials and decorations in accordance with the International Fire Code shall be used in the atrium space. When you have a very low fuel load and a rather tall ceiling, it’s questionable whether the sprinklers will activate. Combine this with the fact that there is a very large volume of air to contain the heat and smoke, it makes sense that sprinklers can be omitted. The exception to omit sprinklers from the ceiling from atriums does not apply to walkways or balconies adjacent to the atrium where the effective ceiling from floor to ceiling is typically 8 to 10 ft (whereby sprinklers will readily activate). If the exception intended to apply to all areas within the atrium, it would not have explicitly stated “from the ceiling of the atrium”. In closing, sprinkler protection will be required for the balconies and walkways inside and around the perimeter of the atrium.
