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Egress Through Non-rated Lobby

M

mbeppu

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Joined
Jan 27, 2021
Messages
4
Location
Portland, OR
Hello Folks.

My team and I are in the preliminary design phase for a fire station in the suburb of Seattle area. The building has two stories which requires two interior exit stairways. The code is IBC 2018. Please see the Level 1 plan from the attached link. The most of the occupancy in the shown administrative area is Business while Sleeping Rooms (SR) are R-2. The assembly type is 5B.

Both stairways have 1 hour-rated enclosure at the Level 2 while its open to the corridor on the level 1.

I understand that IBC 1016.2 permits the egress from 50% of interior exit stair pass through elevator lobby. However, our lobby is not the "elevator lobby" mentioned in IBC 1016.2. In my understanding, the "elevator lobby" in 1016.2 is 1 hour-rated enclosed elevator lobby.

The common knowledge tells me that the egress from one of those stair (stair #1) is allowed to intervene the entrance lobby while the other (stair #2) NEED TO DIRECTLY EGRESS TO OUTSIDE. However, I'm having difficulty to find the solid proof for this in the Chapter 10. I am wondering that this may be interpreting the 1016.2 mistakenly.

If only the egress from stair #1 is allowed to intervene other space, the stair #2 need be flipped so that it can egress directly to outside. However, we don't want to do this for fire fire fighters who are working upstairs to respond quickly, and move down to the Apparatus Bay (Pink area at the bottom of plan) in case of emergency.

One of my coworker suggested that the lobby may not be recognized as intervening space. I assume this is because the stair is not enclosed on the Level 1. If this is true, I can maintain the stair #2 as it is currently. However, I cannot find a proof for this in the Chapter 10 neither. Can anyone advise please?

Thank you !

Plan
 
Fire sprinkler through out building??

I take the plan is 2nd floor?

Do you even need two exits??

R-2? Are you providing a eero in Every sleeping room??
 
A view of the 1st floor would help.
Don't understand the 2 stairways are enclosed but one is not on the 1st floor?
Are the stairways enclosed because of travel distance?
Just 2 floors?
 
SORRY, my previous post was for another thread, somehow I must have clicked here so disregard for this thread.
 
Section 1016.2 applies to the exit access (i.e., getting to the exit) and not the exit discharge (i.e., leaving the exit). You need to look at Section 1028.1, Exception 1, for an exit stair discharging through areas on the level of exit discharge.
 
""In my understanding, the "elevator lobby" in 1016.2 is 1 hour-rated enclosed elevator lobby.""""""

Once again fire sprinkler system???

Check 3006.3 Hoistway Opening Protection

To see if a rated lobby is required, I am thinking no.
 
cda said:
""In my understanding, the "elevator lobby" in 1016.2 is 1 hour-rated enclosed elevator lobby.""""""

Once again fire sprinkler system???

Check 3006.3 Hoistway Opening Protection

To see if a rated lobby is required, I am thinking no.
Click to expand...
Thank you very much for your responses.

cda:
The though out of building is equipped with automatic fire sprinklers.
The elevator lobby doesn't have to be fire rated.

RLGA:
1028.1 states that no more than 50% of number and minimum width or required capacity of interior exit stairways and ramps is permitted to egress through AREAS on the level of discharge provided all of the following conditions are met..."
The question is that, is the corridor recognized as the AREA described here? Again, the stair #2 is not enclosed on the Level 1. So it's continuous though the corridor to the exit. To me, this egress route is "direct" enough. In another word, the AREAS are more like specific rooms such as sleeping room, office etc.

Pardon me for not specifically replying to every folks as I need to work for so many other staff as well. I still appreciate all of you who advised me.

Thanks.
 
mbeppu said:
1028.1 states that no more than 50% of number and minimum width or required capacity of interior exit stairways and ramps is permitted to egress through AREAS on the level of discharge provided all of the following conditions are met..."
The question is that, is the corridor recognized as the AREA described here? Again, the stair #2 is not enclosed on the Level 1. So it's continuous though the corridor to the exit. To me, this egress route is "direct" enough. In another word, the AREAS are more like specific rooms such as sleeping room, office etc.
Click to expand...
If stairs are not enclosed then they are not exit stairs--they are exit access stairs. Unenclosed exit access stairs are permitted between two stories. Exit access stairs are not required to discharge directly to the exterior because they are not exit stairs; thus, Section 1028.1 does not apply. Travel distance, however, must be measured from the most remote location on the second story to and down an exit access stair, and then from the exit access stair to an exterior door. Once through the door, that is the point where the exit discharge begins.
 
Just out of curiosity, why are you considering the sleeping rooms Group R-2? Are there more than 16 occupants in the Group R-2 occupancy? If not, then this should be classified as Group R-3.
 
So, I figured that one stair at least can be the Access Stair per 1017 Travel Distance Section. The occupancy is Business for the majority of part of the Administrative and Operational rooms, and the maximum travel distance is 300ft which we can easily conform for the both stairs. So, the both stairs don't need fire-rated enclosures on the Level 2 neither.

cda:
Occupancy of 29 is wrong. I was mistakenly looking at the table 1006.3.3(2) which is meant for single exit stair condition.

RLGA:
I think you are right. the occupancy should be R-3.

Thank you again to both!

Masa
 
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