2018 IBC Section 1020 Corridors

[cda]

I am not sure if this applies here. The walls are fire partitions for sure, and have a rating of at least 30 minutes (we use a 1-hour UL-U311 for sound). This typically comes into play about the exterior walls and the interior load bearing walls. In VB these supporting construction walls do not have to be fire-rated. The part I was looking for clarity on is the table 1020.1 if it applies to floors, too. Elsewhere in the code they indicate that corridors might need additional fire protection than normal.

Not into structural or similar

But seems like the corridor walls have to be “ supporting construction” to include the floor that supports them.

as in comply with 708.4

 

[hughdint]

But seems like the corridor walls have to be “ supporting construction” to include the floor that supports them.

So do you think that if the corridor walls were supporting construction for the floors (and possibly vice versa) that would make the floors need to be rated, except for in type VB construction? I agree with that, but I think it is more clearly covered in other parts of the code.
I am getting more comfortable with the idea that the table 1020.1 only refers to the walls and that figure 708.4(2)(B)&(C) are only meant to depict the uppermost corridor ceiling. Thank you so much for your input. I really appreciate it.

 

[cda]

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

Enclosed,,, as in to include the floor??

en·close​

(ĕn-klōz′) also in·close (ĭn-)
tr.v. en·closed, en·clos·ing, en·clos·es also in·closed or in·clos·ing or in·clos·es
1.
a. To surround on all sides; close in

 

[hughdint]

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

Enclosed,,, as in to include the floor??

en·close​

(ĕn-klōz′) also in·close (ĭn-)
tr.v. en·closed, en·clos·ing, en·clos·es also in·closed or in·clos·ing or in·clos·es
1.
a. To surround on all sides; close in

I was looking for the code definition of enclose but this seems like it WOULD include the floor and ceiling. It is had to tell what you are trying to tell me.

 

[cda]

I was looking for the code definition of enclose but this seems like it WOULD include the floor and ceiling. It is had to tell what you are trying to tell me.

That I agree with you, normally a corridor is four walls

 

[hughdint]

That I agree with you, normally a corridor is four walls

In my case it is just two walls, a floor and a roof.

 

[rgrace]

I'll throw in my opinion to the question "Does Table 1020.1 refer to walls, floors and ceilings or just walls?"

The first sentence of Section 1020.1 says "Corridors shall be fire-resistance rated in accordance with Table 1020.1" Corridor is defined as "An enclosed exit access component that defines and provides a path of egress travel." You cannot "enclose" an exit access component with just two walls. Perhaps the confusion lies in the second sentence where is states that the walls have to comply with the requirements for fire partitions. I believe this is simply a clarifier, meaning corridor walls do not have to comply with the requirements for fire walls or fire barriers. Without this sentence, who knows, an AHJ may require corridor walls to be fire walls. This sentence is not suggesting that the ceiling or floor of the corridor enclosure need not be fire-resistance rated. The first sentence already requires them to be.

 

[rgrace]

That I agree with you, normally a corridor is four walls

Isn't something with four walls considered a "room"?

 

[cda]

Isn't something with four walls considered a "room"?

No

 

[mtlogcabin]

I assume you are a VB construction

2018 IBC
708.4.1 Supporting construction.
The supporting construction for a fire partition shall have a fire-resistance rating that is equal to or greater than the required fire-resistance rating of the supported fire partition.

Exception: In buildings of Types IIB, IIIB and VB construction, the supporting construction requirement shall not apply to fire partitions separating tenant spaces in covered and open mall buildings, fire partitions separating dwelling units, fire partitions separating sleeping units and fire partitions serving as corridor walls.

 

[hughdint]

I'll throw in my opinion to the question "Does Table 1020.1 refer to walls, floors and ceilings or just walls?"

The first sentence of Section 1020.1 says "Corridors shall be fire-resistance rated in accordance with Table 1020.1" Corridor is defined as "An enclosed exit access component that defines and provides a path of egress travel." You cannot "enclose" an exit access component with just two walls. Perhaps the confusion lies in the second sentence where is states that the walls have to comply with the requirements for fire partitions. I believe this is simply a clarifier, meaning corridor walls do not have to comply with the requirements for fire walls or fire barriers. Without this sentence, who knows, an AHJ may require corridor walls to be fire walls. This sentence is not suggesting that the ceiling or floor of the corridor enclosure need not be fire-resistance rated. The first sentence already requires them to be.

Yes, this was my initial interpretation as well, and this is the entire source of my bosses reasoning as to why he thinks it is just walls.
I could also understand an interpretation where two corridors over each other would not be separated from each other.

 

[hughdint]

I assume you are a VB construction

2018 IBC
708.4.1 Supporting construction.
The supporting construction for a fire partition shall have a fire-resistance rating that is equal to or greater than the required fire-resistance rating of the supported fire partition.

Exception: In buildings of Types IIB, IIIB and VB construction, the supporting construction requirement shall not apply to fire partitions separating tenant spaces in covered and open mall buildings, fire partitions separating dwelling units, fire partitions separating sleeping units and fire partitions serving as corridor walls.

I get the supporting construction exception for type VB, but I do not think it really applies to what I have. The floors of the breezeway do not support the walls. The walls are already fire-rated. I am more looking for the rating of the floor/ceilings between breezeway levels. I think that I have justification either was so I will just do what my boss wants (un-rated breezeway floors) and let a code official tell me different.

 

[mtlogcabin]

1020.1 Construction.
Corridors shall be fire-resistance rated in accordance with Table 1020.1. The corridor walls required to be fire-resistance rated shall comply with Section 708 for fire partitions.
The 1st sentence tells you to follow the table to determine if a fire rating is required based on the occupancy type and the occupant load served by the corridor. the rating required and the type of fire sprinkler required.
The second sentence yells you the walls shall be constructed as fire partitions and sends you to 708 for how to construct them and the exceptions that may apply to the construction requirements based on construct type or occupancy.

[A] 102.1 General.
Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall be applicable

This is specific for Types IIB, IIIB and VB construction the floors are not required to be rated


708.4.1 Supporting construction.
The supporting construction for a fire partition shall have a fire-resistance rating that is equal to or greater than the required fire-resistance rating of the supported fire partition.

Exception: In buildings of Types IIB, IIIB and VB construction, the supporting construction requirement shall not apply to fire partitions separating tenant spaces in covered and open mall buildings, fire partitions separating dwelling units, fire partitions separating sleeping units and fire partitions serving as corridor walls.

 

[brokenkeys]

The code can't address every scenario, nor can it address every interpretation of it, but sometimes my officials play the 'what-if' game when trying to express the intent of the code. So let's play (also, I'm in Florida, based on IBC 2018, which may differ):

Per this interpretation; corridors include floors and ceilings and your walls are fire partitions (per the second sentence of 1020.1) and they're also exterior walls (per your description), then per 708.5, exterior walls (705) takes precedent and, under certain circumstances, your walls could be 0-hour. You could have 1/2 hr rated floors, 1/2 hr rated ceilings and 0 hour walls. Which makes no sense.

Another scenario; what if you had a 1A, hazardous building; floor construction needs to be 2 hour rated and per this interpretation the floor also needs to be 1 hour rated. So does that mean it needs to be 3-hr, or does the most restrictive apply? And on and on.

I see how someone can arrive at this interpretation but it's too vague and creates too many questions. I believe if the intent was to include floors and ceilings then it would be stated as such.