sprinklernotes
Noncombustible Stairs
You have asked the following question: "I have an enclosed noncombustible stairway that serves a basement, first, second, and third floors. I have a sprinkler at the top of the stair and under the lowest accessible landing in the basement. My question is about the first-floor landing that has one door that opens into the building and another door that is an egress to the outside. Referencing section 8.15.3.3, is the outside of the building a separate fire area where a sprinkler is required at this landing?" In response to your question, we have reviewed NFPA 13, 2016 edition as the applicable standard. Our informal interpretation is that sprinklers are not required at the landing. The purpose of section 8.15.3.3 is for a stair that serves two separated areas. A firewall or fire-rated partition would separate these two areas and the stairway serves both areas. The purpose of sprinklers at the floor landing is to keep the fire from transferring from one fire area, through the stairway, into the other fire area. Thus, section 8.15.3.3 applies to stairs serving two or more areas that have openings to each side of a firewall(s). Sprinklers are required to be installed in the stair shaft at each floor landing with multiple openings. Your application has multiple openings from the ground floor and directly to the outside. This requirement is not applicable for your arrangement. Figure A.8.15.3.3(a) shows a noncombustible stair shaft serving two sides of firewall where sprinklers would be required at the landing. The other context is multiple openings where the exit door from the stairwell leads to a horizontal exit or an enclosed bridge connector to another building or structure. This would require sprinklers under the landing. An exterior fire outside the building at the exit door transferring through the stairwell into the building is not a likely scenario. As such, sprinklers are not required under the landing with multiple openings where one door opens into the building and the other door is the egress to the outside.
