# What is a corridor?



## Spector_51 (Jan 10, 2019)

I know right! sounds simple enough.  Been in building code enforcement for 25 year now so wait for it please!

Definition from ICC 2012  *CORRIDOR.* An enclosed _exit access _component that defines and provides a path of egress travel.

Now for some context. For 25 years I have thought that when you have a hallway (purposely avoiding the term corridor for this context)  where an occupant is led by design (think of the base of a funnel) to a single exit. you have a corridor. I am raising with due to the word enclosed in the definition.  Getting right to the matter, does enclosed mean "all six sides".  Or better yet, if I have a large room, say an office cube farm, that is connected to said "hallway", and the hallway leads to an exit stair,  however, said room is not separated from the hallway with doors, is this still a corridor.

For purposes of this discussion this is a sprinklered B use, therefore the fire rating is not required.

this question is being raised in the application of Section 1018.5.


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## cda (Jan 10, 2019)

If you have this condition 

For purposes of this discussion this is a sprinklered B use, therefore the fire rating is not required.

Than if you have a corridor or not does not matter

Will have to look at 1018.5


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## cda (Jan 10, 2019)

*Since you have a non rated corridor *
*I am thinking it does not apply!!’*



*1018.5Air movement in corridors.*
Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts.

Exceptions:


1.Use of a corridor as a source of makeup air for exhaust systems in rooms that open directly onto such corridors, including toilet rooms, bathrooms, dressing rooms, smoking lounges and janitor closets, shall be permitted, provided that each such corridor is directly supplied with outdoor air at a rate greater than the rate of makeup air taken from the corridor.


2.Where located within a dwelling unit, the use of corridors for conveying return air shall not be prohibited.


3.Where located within tenant spaces of 1,000 square feet (93 m2) or less in area, utilization of corridors for conveying return air is permitted.


4.Incidental air movement from pressurized rooms within health care facilities, provided that the corridor is not the primary source of supply or return to the room.


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## ADAguy (Jan 10, 2019)

Back in the day, you have what we now call "open office" large areas (rooms?) with cubicles no more than 60" tall. 
Cubes interconnected by paths between them (corridors?) that don't extend to the ceiling and yes fully sprinklered.


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## mtlogcabin (Jan 10, 2019)

Fire rated or not, sprinklers or not, the section applies to all corridors. The intent of the section is to keep smoke from migrating from the adjacent rooms into the corridor thus making it useless as a means of egress



cda said:


> *1018.5Air movement in corridors.*
> Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts.


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## cda (Jan 10, 2019)

mtlogcabin said:


> Fire rated or not, sprinklers or not, the section applies to all corridors. The intent of the section is to keep smoke from migrating from the adjacent rooms into the corridor thus making it useless as a means of egress




But

If the corridor is not required to be rated

It is not required to have rated doors 

It is not required to have any doors

So with no doors, the smoke and fire is going to sneak into the non rated corridor


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## mtlogcabin (Jan 10, 2019)

If the corridor is not required to be rated

It is not required to have rated doors 

It is not required to have any doors Then it is not a corridor by definition because it is not enclosed. BTW IMHO a corridor is enclosed when it has a floor, two walls, a ceiling and doors separating it from the rooms it serves. It is not required to have doors on the ends to require a fire rating. The required fire rating is to protect the occupants of a corridor from fire in the adjoining rooms 
So with no doors, the smoke and fire is going to sneak into the non rated corridor


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## cda (Jan 10, 2019)

Agree


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## Spector_51 (Jan 10, 2019)

all i want to know is if there are not six sides to this entity, whatever we want to call it- is it still a corridor?

the situation is in this building there is no drop ceiling  and no plan to duct return air.  designer show transfer grills from adjoining and connected space to this "corridor".

They are seeking a code modification to 1018.5 the basis of which is the definition of corridor is not met as there is no door or separation between the "Cube farm" and the hallway.

I say the space (hallway) should be identified first as either a corridor or not and then the rest of the code applies.

I also say it is a corridor.

I equate this to an atrium where you have an unprotected floor opening connecting two stories.  This condition is still an atrium however most of the code sections in atriums do not apply to two story atriums. 

I really wish to focus this forum as my original post suggests.

I seem to remember a different definition of corridor that was more focused on the single path of egress matter and less on the enclosure issue


Many thanks.


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## cda (Jan 10, 2019)

Spector_51 said:


> all i want to know is if there are not six sides to this entity, whatever we want to call it- is it still a corridor?
> 
> the situation is in this building there is no drop ceiling  and no plan to duct return air.  designer show transfer grills from adjoining and connected space to this "corridor".
> 
> ...




There is the exit passage way. 
Which is normally a one way exit


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## cda (Jan 10, 2019)

But if you say it is s non rated corridor and they meet the requirements for non rated

To me end of story 

Even though some of it looks like a corridor 

Not sure if I am missing something


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## ADAguy (Jan 10, 2019)

hmmmm ??


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## mtlogcabin (Jan 10, 2019)

Spector_51 said:


> Or better yet, if I have a large room, say an office cube farm, that is connected to said "hallway", and the hallway leads to an exit stair, however, said room is not separated from the hallway with doors, is this still a corridor.



2012 IBC
If the "hallway" serves more than 30 people then Table 1018.1 requires you to install doors thus turning your "hallway" into a corridor.



Spector_51 said:


> as there is no door or separation between the "Cube farm" and the hallway.


Then why do you need transfer grilles?


Spector_51 said:


> designer show transfer grills from adjoining and connected space to this "corridor".


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## mtlogcabin (Jan 10, 2019)

*What is a corridor?*

According to a UBC instructor I had many years ago a corridor is similar to leading cows to slaughter. Once the people enter the corridor they are being led by design down a specific path with little or no options for escape. So protection of the corridor from fire and smoke is essential.


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## RLGA (Jan 11, 2019)

If the "hallways" or "corridors" are created by moveable cubicle partitions or permanent low-wall partitions, then they are neither "hallways" nor "corridors" but _aisles_. Thus, the requirements for corridors never factor into the situation. However, the requirements of Section 1017 for aisles do come into play.


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## Sifu (Jan 11, 2019)

I have a job where the 2nd floor corridor is supposed to be rated as a non-sprinkled corridor.  It is open at the end where the 2 story stair connects.  The remainder of the openings into the corridor (tenant spaces) are covered by doors.  I got a little hung up on the word "enclosed" too.  But after reading the commentary, which indicates one of the reasons for the "enclosed" part is due to sensory perception, I decided the open end wasn't a critical part of the enclosure.  So if a user can't see what is happening on the other side [of a corridor, hallway etc], then a higher level of protection is required as a "corridor", thus the rating requirement.  Since a 2-story open stair is allowed by code I don't see the requirement to enclose the end of the corridor at the steps.  But I understand the confusion, and I am not 100% certain of my evaluation.


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## Rick18071 (Jan 17, 2019)

If there are waiting rooms and rest rooms with no doors open to a corridor they would be part of the corridor so when you need a one hour wall it needs to include going around these rooms too. So if you have a room that is open at the end of a required rated corridor that whole room would need 1 hour walls or a rated door.


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## rgrace (Jan 18, 2019)

mtlogcabin said:


> Fire rated or not, sprinklers or not, the section applies to all corridors. The intent of the section is to keep smoke from migrating from the adjacent rooms into the corridor thus making it useless as a means of egress



I just wanted to bring this back up. Thanks mtlogcabin ! This statement about 1018.5 is brutally accurate but appears to be getting lost in this string. Rated, not rated, sprinklered or not, combustible or not, high-rise, low-rise, mid-rise, multi-tenant, single-tenant (greater than 1,000 sq.ft.), none of it matters. The intent of this section is to keep our egress means free from filling with smoke by means of the air distribution systems installed in the building.


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## cda (Jan 19, 2019)

rgrace said:


> I just wanted to bring this back up. Thanks mtlogcabin ! This statement about 1018.5 is brutally accurate but appears to be getting lost in this string. Rated, not rated, sprinklered or not, combustible or not, high-rise, low-rise, mid-rise, multi-tenant, single-tenant (greater than 1,000 sq.ft.), none of it matters. The intent of this section is to keep our egress means free from filling with smoke by means of the air distribution systems installed in the building.




But if not rated 

Doors are not required

So smoke will sneak into all areas


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## CityKin (Mar 11, 2020)

4,500 SF unsprinklered dentist office, exam rooms have no doors..... Is this a corridor?  Does it need to be rated if it serves an occupant load over 30?  I am never sure how to define "corridor"


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## CityKin (Mar 11, 2020)

Sorry, I tried to post an image.  I thought I was a sawhorse and could post images.  I pay every year ..


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## cda (Mar 11, 2020)

CityKin said:


> Sorry, I tried to post an image.  I thought I was a sawhorse and could post images.  I pay every year ..




Have to use real money

Hit your profile and

Hit upgrade and see what it says

Plus send Jar a message to look at your account


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## classicT (Mar 11, 2020)

CityKin said:


> Sorry, I tried to post an image.  I thought I was a sawhorse and could post images.  I pay every year ..


Please check out this post.

https://www.thebuildingcodeforum.com/forum/threads/sawhorses-and-supporters-please-read.28239/


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## cda (Mar 11, 2020)

CityKin said:


> 4,500 SF unsprinklered dentist office, exam rooms have no doors..... Is this a corridor?  Does it need to be rated if it serves an occupant load over 30?  I am never sure how to define "corridor"




Are two exits required??

If yes, without seeing the picture, you have a corridor 

Are you sure on occupant load,,, seems high


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