Corridor Egress

[tudorvac]

Good morning fellow code enthusiasts!We are currently experiencing a disagreement in our office as to the requirements for the number of exits required from a corridor, and I feel like everyone is taking crazy pills (except for me). The question revolves around whether corridors require more than one exit. I have always attributed the number of exits required in Section 1015 to rooms and spaces that had a calculated occupant load, and not corridors which I considered an egress pass-through space. I am now being told by very experienced and knowledgeable persons (old farts) that if the corridor is serving more than 50 occupants, it is required to have 2 exits. This blew my mind because I had never considered this, and I am having a hard time tracking it through the code. My thought had always been that you could dump 500 occupants into a corridor leading to one exit, and if it met all of the various egress requirements it would be allowed.Here are the parameters:2009 IBCAssembly occupancy (A-1, Theater)SprinkleredUnrated corridorsTravel distances are within limitsDead-ends are within limitsSee the attached diagram for a simple visual.

View attachment 2017

Please let me know how you would interpret this type of scenario and if you have any questions.Thanks in advance! and Happy Holidays!View attachment 2017

/monthly_2013_12/572953ef811f4_Exitdiagram.jpg.c5b9932932536e90f8d04e00413f52ec.jpg

 

[JPohling]

The old farts are right! Not sure how you could even misinterpret that? Your last parameter tells it all.............."dead-ends are within limits" There is no such thing as a dead end corridor if only one exit is required. With one exit required there will always be a dead end, only once two exits are required do dead ends come into play.

 

[cda]

With the ibc there are several variables that kick in exit requirements

Travel distance

Exit width

Sprinklers

Occupant load

2009

1005

1008

1014

1015

1016

1018

Table1018

1020

1028

In the example it is assuming that half the people will go one way and the other half will go the other.

People do not work like that

I would say each corridor is required two exits.

Some support is even with one theater it is dumping 75 , if that theory is used into one corridor making two exits required

 

[JBI]

Ask them to quote a code section. 'Corridors' are a component of 'exit access', the 50 person limit requiring two (or more) 'exits' is for the assembly space, not the corridor.

 

[cda]

Also, thought there was a change with a set up like this in regards to exit width or something, where you dump multiple theaters into a corridor

not sure if 2007, 2009, 2012?

 

[cda]

""""""I have always attributed the number of exits required in Section 1015 to rooms and spaces that had a calculated occupant load, and not corridors which I considered an egress pass-through space. I am now being told by very experienced and knowledgeable persons (old farts) that if the corridor is serving more than 50 occupants, it is required to have 2 exits""""""""""

I would say this is true if you had only one corridor in your set up, it would require two exits.

 

[mtlogcabin]

Corridors require 2 exits when the dead end is exceeded. The walls are constructed as fire partitions

Your drawing could be depicting an exit passageway (1023) and is permitted with one exit if constructed as 1-hour fire barrier and/or horizontal assemblies in accordance with sections 707 and 711.

1023.5

Except as permitted in Section 402.8.7, openings in exit passageways other than exterior openings shall be limited to those necessary for exit access to the exit passageway from normally occupied spaces and for egress from the exit passageway.

 

[JBI]

mtlogcabin, The OP idetified the component as a 'corridor' - a component of exit access. An exit passageway is a component of the exit. Different beasts.

CORRIDOR. An enclosed exit access component that defines and provides a path of egress travel to an exit.

EXIT PASSAGEWAY. An exit component that is separated from other interior spaces of a building or structure by fire-resistance-rated construction and opening protectives, and provides for a protected path of egress travel in a horizontal direction to the exit discharge or the public way.

I can't open the graphic up, but it appears that each space has one door at each end, leading into one corridor or the other. From there both corridors are one-way only to egress the building. I was thinking that CPET might be an issue but CPET really starts once you enter the corridor (from inside the rooms you automatically have two ways out), it's not until you enter one of the corridors that you must all travel the same direction to the exterior. Interesting floor plan though.

 

[Gregg Harris]

1028.1 General. Occupancies in Group A and assembly occupancies accessory to Group E which contain seats, tables, displays, equipment or other material shall comply with this section

1028.2 Assembly main exit. Group A occupancies and assembly occupancies accessory to Group E occupancies that have an occupant load of greater than 300 shall be provided with a main exit. The main exit shall be of sufficient width to accommodate not less than one-half of the occupant load, but such width shall not be less than the total required width of all means of egress leading to the exit. Where the building is classified as a Group A occupancy, the main exit shall front on at least one street or an unoccupied space of not less than 10 feet (3048 mm) in width that adjoins a street or public way.

Exception: In assembly occupancies where there is no well-defined main exit or where multiple main exits are provided, exits shall be permitted to be distributed around the perimeter of the building provided that the total width of egress is not less than 100 percent of the required width.

1028.3 Assembly other exits. In addition to having access to a main exit, each level in Group A occupancies or assembly occupancies accessory to Group E occupancies having an occupant load greater than 300, shall be provided with additional means of egress that shall provide an egress capacity for at least one-half of the total occupant load served by that level and comply with Section 1015.2.

Exception: In assembly occupancies where there is no well-defined main exit or where multiple main exits are provided, exits shall be permitted to be distributed around the perimeter of the building, provided that the total width of egress is not less than 100 percent of the required width.

 

[mtlogcabin]

The OP idetified the component as a 'corridor' - a component of exit access. An exit passageway is a component of the exit. Different beasts.

Agree and that is what I was trying to point out.

Just cause it looks like a corridor it may not be constructed as such and vice versus.

Sometimes some topics are confusing if not clearly defined.

 

[tudorvac]

Thanks everyone for the responses!

Don't focus on the diagram too much, it's just for illustrative purposes. The actual proposed plan has a central lobby which contains the main exit as well as other required egress features. There are also other factors which complicate the project and make exit passageways or other exits from the corridor difficult and/or costly. The disagreement we are having is specifically over the theater secondary exits which lead to single-exit corridors.

I understand that the theater rooms require the 2 exits, but I don't understand why 1 of those 2 required exits would have to be broken down into 2 additional exits. It seems to me that we have determined that one exit is enough for half of the assembly room, so why is it not enough for the same group of people once they get into the corridor? For example: All other things being equal, if you had a building similar to the previous diagram but containing only a single assembly room, instead of the three proposed, then would those corridors each require 2 exits?

Thanks again!

 

[tudorvac]

Thanks mt and JBI.

You're right mt, an exit passageway would be the ideal solution, but the project is on the 2nd floor of an existing II-B building with bar-joist construction. The exit passageway would add a lot of fire-protection for existing unrated assemblies.

 

[cda]

"""containing only a single assembly room, instead of the three proposed, then would those corridors each require 2 exits"""

problem is you are talking camels and elephants

assembly room requires two exits

once you get out of the assembly room you still need two exits out of the building either by corridor or not by corridor depending on the building layout and 100 other things

 

[cda]

Thanks mt and JBI.You're right mt, an exit passageway would be the ideal solution, but the project is on the 2nd floor of an existing II-B building with bar-joist construction. The exit passageway would add a lot of fire-protection for existing unrated assemblies.

so how is it meeting ground level?? exit

1028.2 Assembly main exit. Group A occupancies and assembly occupancies accessory to Group E occupancies that have an occupant load of greater than 300 shall be provided with a main exit. The main exit shall be of sufficient width to accommodate not less than one-half of the occupant load, but such width shall not be less than the total required width of all means of egress leading to the exit. Where the building is classified as a Group A occupancy, the main exit shall front on at least one street or an unoccupied space of not less than 10 feet (3048 mm) in width that adjoins a street or public way.

 

[tudorvac]

"""containing only a single assembly room, instead of the three proposed, then would those corridors each require 2 exits"""problem is you are talking camels and elephants

assembly room requires two exits

once you get out of the assembly room you still need two exits out of the building either by corridor or not by corridor depending on the building layout and 100 other things

Thanks, cda.

I apologize if it's confusing, I was trying to simplify it with the drawing I attached. When you are looking at the drawing, please assume the corridors lead directly to the exterior so there are two independent exits out of the building. All of the required exiting is being met except for two exits from the corridors being used by more than 50 occupants, which is what I don't see as being required. In your opinion, is the diagram meeting code or would you require two exits from each corridor?

 

[tudorvac]

The main theater entrance/exit is in front of a set of unenclosed exit stairs which lead to a building main entrance/exit.

 

[cda]

I would require two exits from each corridor

The occupant load they are handling is 225

Or make it an exit passageway

 

[steveray]

Note the use of the word "SPACE" in this code section......not room.....

SECTION 1014 EXIT AND EXIT ACCESS DOORWAYS

1014.1 Exit or exit access doorways required.

Two exits or exit access doorways from any space shall be provided where one of the following conditions exists:

1. The occupant load of the space exceeds the values in Table 1014.1.

2. The common path of egress travel exceeds the limitations of Section 1013.3.

3. Where required by Sections 1014.3, 1014.4 and 1014.5.

Exception: Group I-2 occupancies shall comply with Section 1013.2.2.

TABLE 1014.1 SPACES WITH ONE MEANS OF EGRESS

 

[steveray]

Once you get into an actual exit enclosure (fire barriers), you get some relief.....

 

[cda]

Where is Peach when you need a tie breaker

 

[tudorvac]

Note the use of the word "SPACE" in this code section......not room.....SECTION 1014 EXIT AND EXIT ACCESS DOORWAYS

1014.1 Exit or exit access doorways required.

Two exits or exit access doorways from any space shall be provided where one of the following conditions exists:

1. The occupant load of the space exceeds the values in Table 1014.1.

2. The common path of egress travel exceeds the limitations of Section 1013.3.

3. Where required by Sections 1014.3, 1014.4 and 1014.5.

Exception: Group I-2 occupancies shall comply with Section 1013.2.2.

TABLE 1014.1 SPACES WITH ONE MEANS OF EGRESS

Thanks for your input steveray.

I struggle with condition 1 being applied because I have never considered a corridor as 'having' an occupant load, only as 'serving' an occupant load. Table 1004.1.1 does not list an occupant load factor for corridors.

 

[cda]

Thanks for your input steveray.I struggle with condition 1 being applied because I have never considered a corridor as 'having' an occupant load, only as 'serving' an occupant load. Table 1004.1.1 does not list an occupant load factor for corridors.

yes it does, you get back to net and gross

FLOOR AREA, GROSS. The floor area within the inside perimeter of the exterior walls of the building under consideration, exclusive of vent shafts and courts, without deduction for corridors, stairways, closets, the thickness of interior walls, columns or other features. The floor area of a building, or portion thereof, not provided with surrounding exterior walls shall be the usable area under the horizontal projection of the roof or floor above. The gross floor area shall not include shafts with no openings or interior courts.

FLOOR AREA, NET. The actual occupied area not including unoccupied accessory areas such as corridors, stairways, toilet rooms, mechanical rooms and closets.

 

[tudorvac]

yes it does, you get back to net and grossFLOOR AREA, GROSS. The floor area within the inside perimeter of the exterior walls of the building under consideration, exclusive of vent shafts and courts, without deduction for corridors, stairways, closets, the thickness of interior walls, columns or other features. The floor area of a building, or portion thereof, not provided with surrounding exterior walls shall be the usable area under the horizontal projection of the roof or floor above. The gross floor area shall not include shafts with no openings or interior courts.

FLOOR AREA, NET. The actual occupied area not including unoccupied accessory areas such as corridors, stairways, toilet rooms, mechanical rooms and closets.

Typically you're correct, but we have fixed seats so we are using the seat count to determine the occupant loads not the gross or net square footage. The fixed seat occupants are the only ones using the corridors.

 

[cda]

no waiters, projectionist, cleaning staff, manager, whatevers???

N/A

I would still say that the corridor needs two exits