George McGerd
Bronze Member
I am designing a large, 3-story high school (use group E), new-construction, 2018 IBC and 2018 NFPA 101 (LSC) are applicable. Obviously it will be fully-sprinklered IAW all applicable codes.
The building will feature a large, 3-story volume "space" located in the center, inside of which will be a communicating / convenience stair connecting all three stories. The stair will NOT serve as one of the required means of egress. The 3-story volume will be completely open to the first floor (level of exit discharge) but will be fully enclosed from the second and third stories by a glass curtainwall, designed a ‘smoke barrier’. There will be no operable windows or fenestration within the curtainwall smoke barrier. The only openings on the 2nd and 3rd stories will be doors for access leading directly to the communicating stairway, which will be automatically closing upon the detection of smoke.
Here are my assumptions:
1. Smoke control and protection requirements of IBC Section 909 will not be required since this ‘atrium’ doesn’t actually ‘connect’ any of the stories. By definition ‘connect’ means to be ‘open’ to or ‘communicate’ with another stories. The automatically closing doors do not serve to ‘connect’ the stories.
2. Smoke protection features required under the LSC ‘atriums’ Section 8.6.7 are NOT applicable because the volume is not considered a true ‘atrium’ by definition, due to the fact that the 2nd and 3rd stories are enclosed and separated from the remainder of those floors by the curtainwall smoke barrier.
3. Fire protection analysis required under LSC ‘atriums’ Section 8.6.7 is not applicable, same rationale as point 2 above.
4. The curtainwall smoke barrier enclosure does not have to be fire rated under IBC or LSC since the stories aren’t ‘connected’. Reference IBC 404.6, exception 4, and LSC 8.6.6(4)(a).
5. Sprinklers are not required to be placed at 6’-0” intervals alongside the curtainwall smoke barrier, as otherwise required by LSC due to it not being classified as a true ‘atrium,’ and as otherwise required by IBC 404.6.1.1, since I’m tapping exception 4 instead of exception 1.
Please shoot holes in my assumptions. Let me know if I’m overreaching on this one. I tend to try to do that sometimes.
Thanks !!!
The building will feature a large, 3-story volume "space" located in the center, inside of which will be a communicating / convenience stair connecting all three stories. The stair will NOT serve as one of the required means of egress. The 3-story volume will be completely open to the first floor (level of exit discharge) but will be fully enclosed from the second and third stories by a glass curtainwall, designed a ‘smoke barrier’. There will be no operable windows or fenestration within the curtainwall smoke barrier. The only openings on the 2nd and 3rd stories will be doors for access leading directly to the communicating stairway, which will be automatically closing upon the detection of smoke.
Here are my assumptions:
1. Smoke control and protection requirements of IBC Section 909 will not be required since this ‘atrium’ doesn’t actually ‘connect’ any of the stories. By definition ‘connect’ means to be ‘open’ to or ‘communicate’ with another stories. The automatically closing doors do not serve to ‘connect’ the stories.
2. Smoke protection features required under the LSC ‘atriums’ Section 8.6.7 are NOT applicable because the volume is not considered a true ‘atrium’ by definition, due to the fact that the 2nd and 3rd stories are enclosed and separated from the remainder of those floors by the curtainwall smoke barrier.
3. Fire protection analysis required under LSC ‘atriums’ Section 8.6.7 is not applicable, same rationale as point 2 above.
4. The curtainwall smoke barrier enclosure does not have to be fire rated under IBC or LSC since the stories aren’t ‘connected’. Reference IBC 404.6, exception 4, and LSC 8.6.6(4)(a).
5. Sprinklers are not required to be placed at 6’-0” intervals alongside the curtainwall smoke barrier, as otherwise required by LSC due to it not being classified as a true ‘atrium,’ and as otherwise required by IBC 404.6.1.1, since I’m tapping exception 4 instead of exception 1.
Please shoot holes in my assumptions. Let me know if I’m overreaching on this one. I tend to try to do that sometimes.
Thanks !!!