# Atrium Enclosure?



## Bobbi_O (May 10, 2017)

Hello all

I need a little help with this: 

NYS 2015 code: 
I am reviewing a 'B' occupancy with a 2 story atrium that connects the two stories and main corridor areas which is rated. The design currently does not enclose the atrium, just have a railing around the open side. So the 2 levels of corridors becomes one fire area. The opening in the floor is not large, although that does not apply here. BC Section 404 requires the atrium to be enclosed. The architect is using 404.5 Exception to not enclose the atrium, "connecting only 2 stories". However, Section 404.6 Exception 3, with the smoke control system, does not require the enclosure but does require the smoke control. This is a fully sprinklered building. 

My interpretation does not link the Section 404.6 Exception 3 to 404.5 Exception since 405.5 doesn't mention enclosure. I am requiring the atrium to be enclosed. Please let me know your thoughts on this. 
Thanks
_
§BC404.5 Smoke control.
A smoke control system shall be installed in accordance with Section BC909.
Exception: In other than Group I-2, and Group I-1, Condition 2, smoke
control is not required for atriums that connect *only two stories.*

§BC404.6 Enclosure of atriums: 
3. A fire barrier *is not required *between the atrium and the 
  adjoining spaces of any three floors of the atrium provided such
  spaces are accounted for in the design of the smoke control system.
_


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## Francis Vineyard (May 10, 2017)

http://www2.iccsafe.org/cs/committeeArea/pdf_file/BU_06_54_07.pdf


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## Bobbi_O (May 10, 2017)

Francis Vineyard said:


> http://www2.iccsafe.org/cs/committeeArea/pdf_file/BU_06_54_07.pdf


Huh ....this is excellent information, although I still don't like the answer. I always forget to check the IBC interpretations but that is probably because of the new codes for us here in NYS

Thank you


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## Francis Vineyard (May 10, 2017)

Bobbi_O said:


> Huh ....this is excellent information, although I still don't like the answer. I always forget to check the IBC interpretations but that is probably because of the new codes for us here in NYS
> 
> Thank you


Bobbi, I didn't know there was an interpretation until I saw it in the (2015) code commentary.


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## Bobbi_O (May 10, 2017)

Francis Vineyard said:


> Bobbi, I didn't know there was an interpretation until I saw it in the (2015) code commentary.


Thanks again - I guess I should invest in the commentary.


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## Francis Vineyard (May 10, 2017)

You're always welcome participate for free or invest here


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