unenclosed stair to occupied roof

[MAGB]

We are designing a project with an open/unenclosed stair from the ground floor to the second floor, we would like to continue the stair unenclosed to the occupied roof deck where there would be a penthouse for the stair. I believe the occupied roof will be considered a story because it will have a pergola/shade structure on it. There is a second egress stair that is enclosed within a shaft between all stories

Per 119.3.1 would it be acceptable to have the stair unenclosed between the second story and roof because it only atmospherically communicates between the first and second floor? The stipulation states such interconnected stories shall to be open to other stories. The stair penthouse will open to the third/roof story, but I would not consider the roof open to the floor below. The penthouse would meet the requirements to be considered as part of the story below, but is this negated if the roof is a story instead of an occupied roof?

 

[classicT]

I'd say that your bigger issue is in that the roof will require a minimum of two exits. See 1006.

What you are proposing would be an exit access stairway. As such this stairway is not an exit. Therefore, you would be proposing to have the path of egress travel pass from the roof to the ground level (passes through two stories). This conflicts with 1006.3.2.

You need to provide two exits from the roof.

2021 IBC 1006.3.2 Path of Egress Travel​

The path of egress travel to an exit shall not pass through more than one adjacent story.
Exception: The path of egress travel to an exit shall be permitted to pass through more than one adjacent story in any of the following:

1. In Group R-1, R-2 or R-3 occupancies, exit access stairways and ramps connecting four stories or less serving and contained within an individual dwelling unit, sleeping unit or live/work unit.
2. Exit access stairways serving and contained within a Group R-3 congregate residence or a Group R-4 facility.
3. Exit access stairways and ramps within an atrium complying with Section 404.
4. Exit access stairways and ramps in open parking garages that serve only the parking garage.
5. Exit access stairways and ramps serving open-air assembly seating complying with the exit access travel distance requirements of Section 1030.7.
6. Exit access stairways and ramps between the balcony, gallery or press box and the main assembly floor in occupancies such as theaters, places of religious worship, auditoriums and sports facilities.
7. Exterior exit access stairways and ramps between occupied roofs.

 

[Yankee Chronicler]

We are designing a project with an open/unenclosed stair from the ground floor to the second floor, we would like to continue the stair unenclosed to the occupied roof deck where there would be a penthouse for the stair. I believe the occupied roof will be considered a story because it will have a pergola/shade structure on it. There is a second egress stair that is enclosed within a shaft between all stories

Per 119.3.1 would it be acceptable to have the stair unenclosed between the second story and roof because it only atmospherically communicates between the first and second floor? The stipulation states such interconnected stories shall to be open to other stories. The stair penthouse will open to the third/roof story, but I would not consider the roof open to the floor below. The penthouse would meet the requirements to be considered as part of the story below, but is this negated if the roof is a story instead of an occupied roof?

There is no section 119.3.1 in the IBC. Did you mean 1019.3.1? But the 2021 IBC has a section 1019.3, but it does not have a section 1019.3.1. Did Arizona amend that section?

 

[MAGB]

I'd say that your bigger issue is in that the roof will require a minimum of two exits. See 1006.

What you are proposing would be an exit access stairway. As such this stairway is not an exit. Therefore, you would be proposing to have the path of egress travel pass from the roof to the ground level (passes through two stories). This conflicts with 1006.3.2.

You need to provide two exits from the roof.

2021 IBC 1006.3.2 Path of Egress Travel​

The path of egress travel to an exit shall not pass through more than one adjacent story.
Exception: The path of egress travel to an exit shall be permitted to pass through more than one adjacent story in any of the following:

1. In Group R-1, R-2 or R-3 occupancies, exit access stairways and ramps connecting four stories or less serving and contained within an individual dwelling unit, sleeping unit or live/work unit.
2. Exit access stairways serving and contained within a Group R-3 congregate residence or a Group R-4 facility.
3. Exit access stairways and ramps within an atrium complying with Section 404.
4. Exit access stairways and ramps in open parking garages that serve only the parking garage.
5. Exit access stairways and ramps serving open-air assembly seating complying with the exit access travel distance requirements of Section 1030.7.
6. Exit access stairways and ramps between the balcony, gallery or press box and the main assembly floor in occupancies such as theaters, places of religious worship, auditoriums and sports facilities.
7. Exterior exit access stairways and ramps between occupied roofs.

Thank You!

 

[MAGB]

There is no section 119.3.1 in the IBC. Did you mean 1019.3.1? But the 2021 IBC has a section 1019.3, but it does not have a section 1019.3.1. Did Arizona amend that section?

I missed the 0 in 1019.3.1
We are on the 2018 IBC, I did not remember an amendment to that section, but will double check.

 

[Yankee Chronicler]

According to UpCodes (which I know is not infallible, but it's all I've got for Phoenix), there is no section 1019.3.1 in the 2018 Phoenix code. What there is, is section 1019.3, which lists eight conditions under which stairs do not need to be enclosed in a rated shaft enclosure. I assume you are looking at Condition 1:

1. Exit access stairways and ramps that serve or atmospherically communicate between only two stories. Such interconnected stories shall not be open to other stories.

Based on the definition of "story," I think your opening post was correct -- the pergola on the roof establishes another roof or ceiling, in which case I think the roof qualifies as a story. That would mean the stair serves three stories, which in turn means it can't be an open stair.