• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Minimum width to not be a Corridor

M

Mech

Registered User
Joined
Oct 30, 2009
Messages
1,037
Location
Eastern PA
2018 IBC
A-3 Children Play Area, probably age 2 - 12(?)

The tenant space is mainly an open area (left side of image below) with the exception of a party room and closet (upper right corner with double doors) enclosed by walls to ceiling, toilet rooms and janitor closet, and a sensory room (kids area) enclosed with walls to the ceiling (lower right corner without any doors). Minimum corridor width is 44". Section 1020 corridors requires either a one hour corridor rating or sprinklers when the occupant load exceed 30 for an A occupancy. (A sensory room is for helping children focus, calm down, etc.)

If I shift the toilet rooms and janitor closet 39" to the left so the face of the janitor and party room walls align, how much further to the left must I shift these three rooms to eliminate a corridor condition? One of my coworkers' gut feeling is 5 feet.

1702415472128.png

Thanks in advance.
 
[BE] CORRIDOR. An enclosed exit access component that
defines and provides a path of egress travel.

Doesn't meet the definition of a corridor unless you put a door where it says 39".
 
Are you asking how short that 39" bottleneck has to be to not be a corridor, or are you asking if the entrance foyer is a corridor?
 
Rick18071 said:
[BE] CORRIDOR. An enclosed exit access component that
defines and provides a path of egress travel.

Doesn't meet the definition of a corridor unless you put a door where it says 39".
Click to expand...
Are you saying if that 39" was 20', it still wouldn't be a corridor without it being enclosed by a door?
 
Yankee Chronicler said:
Are you asking how short that 39" bottleneck has to be to not be a corridor, or are you asking if the entrance foyer is a corridor?
Click to expand...
I am asking how short the 39" bottleneck has to be to not be a corridor (and also not have the vestibule or foyer looking area be considered a corridor.) The exterior doors shown here are the second means of egress; the tenant space entrance / normal exit is at the other end of the space.

Perhaps my question should have been "Is this 39 inch bottleneck and adjacent foyer looking area a corridor?" My new follow up question is "Why or why not?"

When I wrote my initial post, my thinking was since:
1. the 39" bottleneck and foyer looking area have walls extending to the ceiling,
2. the 39" bottleneck and foyer looking area define a path of travel to the exit,
3. the sensory room is attached to the 39" bottleneck and foyer looking area,
then a corridor exists.

Since more than 30 people may egress through this defined path of travel to the exit from the larger play area to the second means of egress, then either the corridor must be rated or the building must be sprinklered. The building is not currently sprinklered and I am looking to avoid the requirement for sprinklers.

Even though there is no door on the Sensory Room, the floor plan looked like it would limit the awareness of occupants in one area to fire / smoke in the adjacent area. I thought if I shift the toilet and janitor rooms to the left, then the sensory room directly opens to the large open play area and it eliminates any possibility of having a corridor condition.

I just read and reread https://www.thebuildingcodeforum.com/forum/threads/hallway-vs-corridor.6180/ and https://www.thebuildingcodeforum.com/forum/threads/what-is-a-corridor.24710/ trying to make sense of corridors. My next line of thinking was that a corridor is a defined path of travel that:
1. is bound by walls and a ceiling,
2. leads to an exit, and
3. has at least one room or area with a door opening onto this defined path of travel.
However, the IBC definition does not make mention of item 3 directly above, so now my thinking reverts back to my initial thinking when I wrote the initial post that the 39" bottleneck and adjacent foyer looking area is a corridor.

Maybe I still do not have a proper understanding of corridors.
 
I’m curious why the left restroom is so large. The right one looks large enough to be compliant, is something else going into the left one?
 
Why is the bathroom on the left 2x the size of other other bathroom? Move the janitor's closet into the space of the lager bathroom, leave the small bathroom as it is, the space of the ordinal janitor closet then becomes part of the lobby.
 
You do not have to sprinkler the building if you provide a one-hour fire partition walls/ceiling assembly for your vestibule and 39" bottleneck portion along with 20-minute rated doors.
 
Mech said:
When I wrote my initial post, my thinking was since:
1. the 39" bottleneck and foyer looking area have walls extending to the ceiling,
2. the 39" bottleneck and foyer looking area define a path of travel to the exit,
3. the sensory room is attached to the 39" bottleneck and foyer looking area,
then a corridor exists.
Click to expand...

I tend to agree with this analysis. To that I would add that the foyer appears to be more than 10-feet deep from the exit doors to the wall of the Party Room. A vestibule is limited to 10 feet in depth. A vestibule can only -- be used for egress, which I take to mean that a vestibule can't do double duty as a waiting room. So I don't think this space qualifies as a vestibule. See IBC 1028.2

If it's not a vestibule, it's probably an exit access corridor.
 
Yankee Chronicler said:
A vestibule is limited to 10 feet in depth.
Click to expand...
Code section please

My understanding is that a vestibule has two set of doors in series, one set at the exterior of the building and the other located a short distance further in
the building. See the energy code for vestibule requirements which requires the double doors in series.

This is a vestibule IMHO
1702483513221.png
 
mtlogcabin said:
Code section please

My understanding is that a vestibule has two set of doors in series, one set at the exterior of the building and the other located a short distance further in
the building. See the energy code for vestibule requirements which requires the double doors in series.

This is a vestibule IMHO
View attachment 12288
Click to expand...
Agree. Vestibule's are specific to the boundary between indoor/outdoor and provide containment of conditioned air via the double door arrangement.
 
e hilton said:
I’m curious why the left restroom is so large. The right one looks large enough to be compliant, is something else going into the left one?
Click to expand...
The toiler room to the left will have a full size baby changing station. (This was drawn up by someone else and I questioned its size as well.)

TheCommish said:
Why is the bathroom on the left 2x the size of other other bathroom? Move the janitor's closet into the space of the lager bathroom, leave the small bathroom as it is, the space of the ordinal janitor closet then becomes part of the lobby.
Click to expand...
The women's room will have a full size baby changing station.

The lobby looking area is not designed to be a lobby, gathering place, foyer, vestibule, or a waiting area. The owner wanted it this way for some reason, probably fitting their layout to the existing building shell. The doors shown are existing, exit only doors, not entrance doors, and will only be used for emergencies.


mtlogcabin said:
You do not have to sprinkler the building if you provide a one-hour fire partition walls/ceiling assembly for your vestibule and 39" bottleneck portion along with 20-minute rated doors.
Click to expand...
I agree; but if we can shift the rooms to avoid a corridor, then the owner can eliminate fire rated construction, and fire rated doors. This is what led me to pose the original question.

Yankee Chronicler said:
If it's not a vestibule, it's probably an exit access corridor.
Click to expand...
It is not designed to be a lobby, gathering place, foyer, vestibule, or a waiting area. It would then be an exit access corridor. I did not find a definition for exit access corridor; but if it is a corridor and provides exit access, then I suppose it is an exit access corridor.
 
Getting back to the question that prompted the thread: what must the minimum spacing between opposite walls be before a particular room shape creates a corridor condition? Corollary: what makes a room a "corridor"?

There's been multiple previous threads on this forum regarding when a "room" becomes a corridor. I found the code commentary in this post helpful:
https://www.thebuildingcodeforum.com/forum/threads/a-corridor-by-any-other-name.30648/post-237275

1702504422474.png​
​
So if the commentary defines a key characteristic of a corridor being the limited sensory perception of what is occurring in the adjacent spaces - - the specific example being the inability to see, hear, or smell, a fire.

With that in mind, take a look at the floor plan in post #1, and ask yourself, what is the likelihood that this 1 meter long segment would prevent you from seeing, hearing or smelling a fire at either end of it?
 
Mech said:
The toiler room to the left will have a full size baby changing station. (This was drawn up by someone else and I questioned its size as well.)
Click to expand...
The smaller RR looks large enough for a koala-type changer. It folds up when not in use, and when folded down it still doesn’t take much space because you can get your knees under it.

Might want to push back, you can gain a lot of room there.
 
TheCommish said:
Mech,

There must be some very large babies if the Ladies room needs to be that large.
Click to expand...
You’d be amazed how ADA clearances chew up the space, especially if you determine that the changing table is not an shelf “associated” with the toilet clearances as an allowable encroachment.
 
looks like 5 foot turning circle will fit without a problem, the fold down changing table wound be above the knee space. if the changing table is located in only the Ladies' room, would it then be discriminatory that men do not have the same access to change table for their children?
 
Yikes said:
Getting back to the question that prompted the thread: what must the minimum spacing between opposite walls be before a particular room shape creates a corridor condition? Corollary: what makes a room a "corridor"?

There's been multiple previous threads on this forum regarding when a "room" becomes a corridor. I found the code commentary in this post helpful:
https://www.thebuildingcodeforum.com/forum/threads/a-corridor-by-any-other-name.30648/post-237275

​
So if the commentary defines a key characteristic of a corridor being the limited sensory perception of what is occurring in the adjacent spaces - - the specific example being the inability to see, hear, or smell, a fire.

With that in mind, take a look at the floor plan in post #1, and ask yourself, what is the likelihood that this 1 meter long segment would prevent you from seeing, hearing or smelling a fire at either end of it?
Click to expand...

The 2021 IBC Commentary offers this about corridors:

Corridors are regulated in the code because they
serve as principal elements of travel in many means of
egress systems within buildings. Typically, corridors
have walls that extend from the floor to the ceiling.
They need not extend above the ceiling or have doors
in their openings unless a fire-resistance rating is
required (see Section 1020).
While both aisles and corridors may result in a confined
path of travel, an aisle is an unenclosed or par-
tially closed component, while a corridor would be an
enclosed component of the means of egress. The
enclosed character of the corridor restricts the sensory
perception of the user. A fire located on the other side
of the corridor wall, for example, may not be as readily
seen, heard or smelled by the occupants traveling
through the egress corridor. The code does not specifically
state what is considered “enclosed” where corridors
are not fire-resistance rated. Where an egress
path is bounded by partial-height walls, such as workstation
partitions in an office, issues would be if the
walls provided a confined path of travel and limited fire
recognition in adjacent spaces by restricting line of
sight, hearing and smell.
Click to expand...

Since that 1 meter long [whatever] is bounded by full-height walls such that someone passing through it can't see what's burning in either of the two bounding spaces, maybe it is a corridor?

In looking that up, I realized for the first time that the IBC also has a definition for "Open-ended Corridor." Sounded promsing ... but it doesn't apply.

OPEN-ENDED CORRIDOR. An interior corridor that
is open on each end and connects to an exterior stairway or
ramp at each end with no intervening doors or separation from
the corridor.
Click to expand...

xx

xx
 
You must log in or register to reply here.
Top