Open Stair around Elevator Shaft in R-2 Apt Bldg

[strycker001]

We are currently working on a 4-story R-2, Type 5A Construction fully sprinkled NFPA 13R building under the IBC 2012 code. We have 2 required 2-HR Exit Egress Stairs located at the opposite ends of the building. There is an elevator centrally located in the building and we have proposed an open stair serving the 4 stories that wraps around the 2-HR elevator shaft. There is a door entering into the elevator lobby / stair area that has a 1-HR rating separating this space from the Main Corridor.

Being that this stair does not serve as a required Exit Egress Stair, are we required to still provide doors on the stair to not allow them to be open to more than one level above / below? The rated door along the corridor is providing the smoke enclosure.

 

[RLGA]

What you are creating are vertical openings in the floors; thus, you must comply with one of the protection methods in Section 712 regardless of whether or not the stairs are required for egress.

In your case, your options are:

• Section 712.1.1 - Shaft enclosures
• Section 712.1.6 - Atriums

Section 712.1.12, Unenclosed stairs and ramps, would be applicable, but it directs you to Sections 1009.2 and 1009.3. Section 1009.2 requires exit stairs to be enclosed and Section 1009.3 requires exit access stairs to be enclosed unless one of the exceptions applies. In your case, none of the exceptions apply.

Since a shaft enclosure is contrary to what you want, your only option would be to call it an atrium, which requires compliance with Section 404.

 

[Tim Mailloux]

On a side note, check your allowable area. Generally you are not allowed to take the sprinkler area increase with an NFPA-13R system. You only get the increase with an NFPA-13 system

 

[strycker001]

On a side note, check your allowable area. Generally you are not allowed to take the sprinkler area increase with an NFPA-13R system. You only get the increase with an NFPA-13 system

We did not use the area increase for the 13R sprinkler. We were allowed the 1-story height increase as well as the area increase due to frontage however under 2012 IBC.

 

[Paul Sweet]

It's best to avoid atriums (atria?) that connect more than 2 stories so you don't have to get into smoke control systems. (IBC 404.5)

 

[strycker001]

So continuing this thread, we are still at odds with the local reviewers. We have conceded that the 20-min doors need too be installed to stop the communication between floors at floor 2 & 3. Now the issue is being brought up of 'Corridor Continuity'. They are contending that the alum storefront doors entering the Elevator Lobby space need to be 20-min doors. Originally, before these revisions, they approved the storefront door as-is. Now they are wanting this pair of doors changed to be 20-min so that the corridor rating is kept to 1-HR (30-min with sprinkler). The contractor is using 5/8" Type-X firecore gypboard on all walls, therefore all walls are rated to this anyway. Keep in mind, this is not an egress stair. We have the required 2-hr stair towers at each end of the building. Link to sketch:

https://imgur.com/a/SNyJfD3

 

[cda]

So continuing this thread, we are still at odds with the local reviewers. We have conceded that the 20-min doors need too be installed to stop the communication between floors at floor 2 & 3. Now the issue is being brought up of 'Corridor Continuity'. They are contending that the alum storefront doors entering the Elevator Lobby space need to be 20-min doors. Originally, before these revisions, they approved the storefront door as-is. Now they are wanting this pair of doors changed to be 20-min so that the corridor rating is kept to 1-HR (30-min with sprinkler). The contractor is using 5/8" Type-X firecore gypboard on all walls, therefore all walls are rated to this anyway. Keep in mind, this is not an egress stair. We have the required 2-hr stair towers at each end of the building. Link to sketch:

https://imgur.com/a/SNyJfD3

So if I walk out of the elevator area, through the alum doors,, am I in a rated corridor???


If so, unless I am missing something, I would say yes the doors have to be rated.

 

[strycker001]

So if I walk out of the elevator area, through the alum doors,, am I in a rated corridor???


If so, unless I am missing something, I would say yes the doors have to be rated.

Yes, through the Alum Storefront would be the rated corridor. The AHJ has now accepted putting a door (20-min w/ closer) to both sides of the elevator entry to close off the stair to the Elevator Lobby, thus making the Elevator Lobby rated to the 1-hr (30-min) required and keeping the Alum Storefront that has been installed.

But going forward, we are using this same building (3 built, 4 to be built) but under 2015 IBC/VaCC code. Now they contend that even with the design as mentioned above, they want the stair to be rated to 2-HR because it connects 4 stories. But if we have doors closing off each stair run at each floor, is this still considered a 4-story stair? They are not open like in a typical 2-HR egress stair tower where it communicates to 4 stories.

 

[RLGA]

Yes, through the Alum Storefront would be the rated corridor. The AHJ has now accepted putting a door (20-min w/ closer) to both sides of the elevator entry to close off the stair to the Elevator Lobby, thus making the Elevator Lobby rated to the 1-hr (30-min) required and keeping the Alum Storefront that has been installed.

But going forward, we are using this same building (3 built, 4 to be built) but under 2015 IBC/VaCC code. Now they contend that even with the design as mentioned above, they want the stair to be rated to 2-HR because it connects 4 stories. But if we have doors closing off each stair run at each floor, is this still considered a 4-story stair? They are not open like in a typical 2-HR egress stair tower where it communicates to 4 stories.

What you have is a series of exit access stairways per Section 1019 and not an exit stairway. Each exit access stairway connects only two stories (thus, 1-hour protection is all that is required) and the two stories connected by each access stairway are not open to other stories. Since your two other stairs provide the required exit stairways, this series of stairs is not a required means of egress and is not required to be continuous.

 

[strycker001]

What you have is a series of exit access stairways per Section 1019 and not an exit stairway. Each exit access stairway connects only two stories (thus, 1-hour protection is all that is required) and the two stories connected by each access stairway are not open to other stories. Since your two other stairs provide the required exit stairways, this series of stairs is not a required means of egress and is not required to be continuous.

Thank you for the reply. This is what we thought as well. Once you exit to the corridor at the elevator lobby, you have to re-enter the 1-HR rated stair that will take you to the next level. There is no 4-story connection other than it is stacked in the same location. No shaft is possible with this configuration. But the AHJ is still contending this would require 2-HR all the way to the underside of the roof trusses.