# What do you call this?



## bldginsp

I want to get the discussion going and then I'll give you the ICC interpretation.  Sorry I'm computer stupid and don't know how to draw this and attach it so I'll describe and maybe someone will attach what I'm describing.

You have a office building that is square with offices along the exterior wall.  You also have offices located in a square in the middle of the building.  You have "hallways" attaching all of the offices together and have three exit discharges; one on the upper left, one on the upper right, and one in the middle on the bottom.

1. What are these spaces called that lead to the exit discharges?

2. How do you determine if they are rated and the occupant load?


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## rshuey

1. Exit Access

2. Takes a few sections, dont forget about access doorways(if any) or exit travel distance.


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## Coug Dad

1. Corridors?

2. sprinklered?  Occupant load?


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## Mule

Sounds like a two story.

1. Agree with rshuey

2. May not need any rating at all. Too many scenarios.

Occupant load? Square footage divided by 100


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## bldginsp

Coug Dad said:
			
		

> 1. Corridors?2. sprinklered?  Occupant load?


A single cooridor?  Not sprinklered.  Lets say for grins the back offices on the back "cooridor" has 31.


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## bldginsp

Mule said:
			
		

> Sounds like a two story.1. Agree with rshuey
> 
> 2. May not need any rating at all. Too many scenarios.
> 
> Occupant load? Square footage divided by 100


Only a single story, total occupancy is 31 for grins.


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## jpranch

Can you scan the drawing and save it as a pdf? Then you could attache it here. I think the big question is sprinkler system? If sprinklered the corridors do not have to be rated. Business use = 100 gross per person. But you also have to account for other occupant loads such as 15 net for conference rooms, etc... With 3 exits I would assume that the occupant load is over 30?


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## bldginsp

rshuey said:
			
		

> 1. Exit Access2. Takes a few sections, dont forget about access doorways(if any) or exit travel distance.


Common path of travel is 25 feet to the exit access.  Hint, I was looking more for cooridor.


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## bldginsp

jpranch said:
			
		

> Can you scan the drawing and save it as a pdf? Then you could attache it here. I think the big question is sprinkler system? If sprinklered the corridors do not have to be rated. Business use = 100 gross per person. But you also have to account for other occupant loads such as 15 net for conference rooms, etc... With 3 exits I would assume that the occupant load is over 30?


I'll make this simple, I have many exit discharges because of the total travel distance, no sprinkler.  Is this a cooridor and with the load I gave does it need rated?  Tell me how you all determine the occupant load of the cooridor, not the building.


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## bldginsp

You're going to love the answer I got from ICC.  We just need some discussion here.


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## Mule

The occupant load does not require it but the travel distance may require one.

Edit...you say ol 31? Table 1017.1 requires a rated corridor for B occupancy with an occupant load over 30.


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## jpranch

Beg to differ on the occupant load trigger. 2006 IBC Table 1017.1.


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## Mule

BUT if you have 3 exits because of travel distance then you may not have an occupand load of 31 because you are only splitting the occupant load to different exits and then it would just be a hallway. Only one exit is with under 49 ol.


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## Mule

jp, I edited while you begged to differ1    We actually said the same thing!


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## jpranch

Sure. I have seen many buildings / spaces with an occupant load of 49 with a single exit. Legal but always makes me a little nervious.


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## Mule

Mule said:
			
		

> BUT if you have 3 exits because of travel distance then you may not have an occupand load of 31 because you are only splitting the occupant load to different exits and then it would just be a hallway. Only one exit is with under 49 ol.


What I am saying is that if the exits are layed out so that any of the hallways would not have more than 30 OL then you could have 3 hallways exiting 31 occupants. Then rating would not be required.


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## jpranch

But the occupant load is for the whole space, building, or combined spaces?? >30 rated regurdless of the corridor capacity.


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## cda

bldginsp::::

existing???

new???

remodel????


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## bldginsp

Mule said:
			
		

> What I am saying is that if the exits are layed out so that any of the hallways would not have more than 30 OL then you could have 3 hallways exiting 31 occupants. Then rating would not be required.





			
				jpranch said:
			
		

> But the occupant load is for the whole space, building, or combined spaces?? >30 rated regurdless of the corridor capacity.


Now were getting into the meat of the discussion I was looking for.  How many cooridors do we have?

jpranch, are you asking a question or making a statement?

cda, a new building.


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## jpranch

statement.

2006 IBC Handbook Fire & Life Safety Provisions:


In buildings not equipped with an automatic sprinkler system throughout, corridors are

required to be fire-resistance-rated in all occupancies, based upon the occupant load served.

When a corridor serves an occupant load greater than 10 in a Group R occupancy or more

than 30 in a Group A, B, E, F, M, S or U occupancy, 1-hour fire-resistance-rated corridor

walls are required. Where the occupant load reaches the levels specified, it is appropriate to

afford those persons in the exit corridor some additional protection from potential fire

occurring in the enclosed spaces bordering the corridor. Therefore, a minimum separation
​for the corridor of 1-hour fire resistance is deemed necessary.


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## bldginsp

jpranch said:
			
		

> statement.2006 IBC Handbook Fire & Life Safety Provisions:
> 
> 
> In buildings not equipped with an automatic sprinkler system throughout, corridors are
> 
> required to be fire-resistance-rated in all occupancies, based upon the occupant load served.
> 
> When a corridor serves an occupant load greater than 10 in a Group R occupancy or more
> 
> than 30 in a Group A, B, E, F, M, S or U occupancy, 1-hour fire-resistance-rated corridor
> 
> walls are required. Where the occupant load reaches the levels specified, it is appropriate to
> 
> afford those persons in the exit corridor some additional protection from potential fire
> 
> occurring in the enclosed spaces bordering the corridor. Therefore, a minimum separation
> ​for the corridor of 1-hour fire resistance is deemed necessary.


As stated above, "when a corridor serves an occupant load", how do you calculate the load of the corridor?  I have got to figure out how to scan the plan and paste.


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## jpranch

You don't. With corridors you calculate capacity only to ensure it can handle the occupant load. To get the occupant load of a building or space within a building see IBC Section 1004 and Table 1004.1.1. Or you could just hire me a $120.00 an hour? LOL!


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## Mule

In buildings not equipped with an automatic sprinkler system throughout, corridors are required to be fire-resistance-rated in all occupancies,

BUT what if it's not a corridor? What if it's a hallway? If it's a hallway then no protection is required.

The original post said "You have "hallways" attaching all of the offices together and have three exit discharges;"

Notice the quotes around hallways. So the design professional has designed the office so that you have three different areas each with it's own hallway to exit into. If there wasn't three different exits then a rated corridor would be required.

Quote jp "With corridors you calculate capacity only to ensure it can handle the occupant load."

But you don't have a corridor. You have 3 groups of offices that each have an OL of less than 30 so there is a "hallway" for each group of offices. Now if each group of offices didn't have an independent hallway THEN a rated corridor would be required.

At home...and I don't have a codebook... I'll sleep on it and I will throw some more irons in the fire in the AM.


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## jpranch

Mule, with all do respect please fine me a definition of a "hallway" in the code? Perhaps only found in the legacy codes? Corridors have never been well defined in the I codes. It's a decision made by the AHJ. Hallway? Does not exist.


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## Mule

Hey jp, you an I know each other good enough to know that this is just one of those "sit down, drink a beer with a buddy" type of discussions so I don't see any of your comments as being....B!TCH! SHOW ME! Okay, still haven't opened the codebook but if there are separate exits provided and none of the areas that the exits support have an OL of over 30 then why would they need to be a rated corridor. Let's call the hallway an exit passageway.

View attachment 277


View attachment 277


/monthly_2010_12/572953bb3eaf0_ExitPassageway.jpg.bafe7baa91fa92082a61f076f711e59a.jpg


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## bldginsp

I've got it drawn but too many KB.  How do I shrink it to attach?


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## jpranch

Mule, that looks like 2 different tenant spaces to me. So the means of egress is specific to that tenant.


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## bldginsp

bldginsp said:
			
		

> I've got it drawn but too many KB.  How do I shrink it to attach?


201 KB is the size of the drawing.


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## Mule

Scroll down and click on the Image Resizer on the right.

Image Resizer


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## Mule

I guess we really need the original image. On my picture I was trying to show more or less that you could have one building which has an OL of more than 30 and not require rated corridors.

I wonder why you and I (besides bldginsp) are the only ones in this discussion? Maybe we have the others thinking!    And it sure does hurt to think!


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## Yankee

jpranch said:
			
		

> Mule, that looks like 2 different tenant spaces to me. So the means of egress is specific to that tenant.


 But the shared dividing walls may need a rating between tenant spaces


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## jpranch

Na, Too small. Just use non-separated mixed use of business to business.


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## bldginsp

Finally, thaks Mule.  I hope this comes thru.  For the discussion of this topic, lets assume that all of the code applies for distances, door sizes, etc.  What I'm looking for here is:1. If you take the OC and divide it in accordance with the number of exit discharges, like I was taught by BOCA, to determine door size and corridor width, is that the "corridor load"?  If so, is that how you determine if it is rated?2.  How many corridors do you have here?

View attachment 278


View attachment 278


/monthly_2010_12/OFFICE.jpg.985d25b91d2cb0f9c5e4cfc2d4fa06fc.jpg


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## jpranch

If non-sprinklered the corridors in this proposed plan have to be rated.

"corridor load"? No such animal. Now corridor capacity, thats another issue. BOCA? Know it very well.


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## bldginsp

Mule said:
			
		

> I guess we really need the original image. On my picture I was trying to show more or less that you could have one building which has an OL of more than 30 and not require rated corridors.I wonder why you and I (besides bldginsp) are the only ones in this discussion? Maybe we have the others thinking!    And it sure does hurt to think!


I do wish others would join in on this discussion.  I believe this would initiate some code changes.


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## bldginsp

jpranch said:
			
		

> If non-sprinklered the corridors in this proposed plan have to be rated."corridor load"? No such animal. Now corridor capacity, thats another issue. BOCA? Know it very well.


OK lets go with corridor capacity then.


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## jpranch

Ok. Lets. What is the width of the corridor and please tell us if the building is fully sprinklered???


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## bldginsp

Table 1017.1 of the International Confusion Code, hence ICC, states at the top of the second column, occupant load served by corridor.  Same as corridor capacity?


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## bldginsp

Non sprinklered, and lets say 44 inches wide.


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## bldginsp

We call the NEC the National Exception Code also.


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## jpranch

The capacity of the corridor is 220.


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## jpranch

View attachment 624

	

		
			
		

		
	
Looks like your total occupant load is about 84. In the event of a fire if one of the exits is bolcked then the other would have to handle the entire load. Just another way to look at it.

View attachment 279


View attachment 279


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## Mule

Okay..throw my picture away and we'll get back to the original question.

CORRIDOR. An enclosed exit access component that defines

and provides a path of egress travel to an exit.

From what is described the building only needs an exit passageway because the travel distances are within 200 feet of a exit. If the distance was more than 200 feet then a rated corridor must be provided to protect the occupants until they reach an exit.

TABLE 1017.1

CORRIDOR FIRE-RESISTANCE RATING

OCCUPANT LOAD SERVED BY CORRIDOR

Without sprinkler system

A, B, E, F, M, S, U      Greater than 30    1hr

Key word...Served by corridor. Greater than 30 OL.

You do not have an OL greater than 30 because the DP has provided 3 exit passageways (hallways    )


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## SBerg

I've been following this thread and in my experience as a plans examiner I have determined that this structure shall have 1 hour fire rated corridors constructed in accordance with Section 708.

The minimum corridor width shall be 44".

The corridor is the entire exit access, all of the corridor sections are connected and not separated by the use of a horizontal exit thereby requiring the rated corridor enclosures and the 1/3 hour rated door assemblies.


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## SBerg

Exit passageways are protected and have no openings to adjoining spaces and only lead to an exit.


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## bldginsp

Looks like we are the only ones left.  Here is the staff interpretation.  Corridor is singular.  This building has only one corridor as shown.  You were right earlier that there is no hallways just adjacent spaces to the main use.  If you install doors to enclose any portion of the exit access you have an additional corridor and the doors don't have to be kept closed just as long as they make an enclosed exit access componet.  You take the indicated load of the/that corridor from the plans and apply any rating to that corridor, so according to them I can install doors and cut down the load to no more that 30 occupants and apply the same logic of the blocked exit to the corridor(s) and not rate any of the corridors as long as the load doesn't exceed 30.  What a crock of crap.


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## bldginsp

From my training from BOCA, "the required capacityof a corridor is determined by dividing the occupant load that must use the corridor for exit access by the number of exits to which the corridor connects.  The capacity of the corridor must never be less than the capacity of the exit to which it connects".  This is how I have done it for the past 18 years.


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## jpranch

bldginsp said:
			
		

> Looks like we are the only ones left. Here is the staff interpretation. Corridor is singular. This building has only one corridor as shown. You were right earlier that there is no hallways just adjacent spaces to the main use. If you install doors to enclose any portion of the exit access you have an additional corridor and the doors don't have to be kept closed just as long as they make an enclosed exit access componet. You take the indicated load of the/that corridor from the plans and apply any rating to that corridor, so according to them I can install doors and cut down the load to no more that 30 occupants and apply the same logic of the blocked exit to the corridor(s) and not rate any of the corridors as long as the load doesn't exceed 30. What a crock of crap.


I think the staff has been spending too much time in Washington. Your approach on capacity is right on target. I can certainly see where the word "served" can create some confusion. Dam I miss the old BOCA & CABO codes!


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## SBerg

Agreed, adding doors do not make separate corridors, it only adds a door to an exit path creating additional confusion in an emergency.


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## globe trekker

SBerg stated:



> The minimum corridor width shall be 44".


 Wouldn't Section 1017.2, Exception # 2 require only a 36" minimum corridor width?bldginsp,

Sometimes, alot of the forum members read and follow the various topics on here,

but because of limtations on their time / other responsibilities / or just choosing

to read and follow along, they / we do not join in. Please do not take any

offense. For the most part this a great bunch of people on here, with lots of

experience and a willingness to help.

.


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## SBerg

The noted exception is for building occupant capacity. Not corridor capacity.

Table 1005.1 is used when determining total occupant load egress with through exits.


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## globe trekker

I am not following how ' jp ' came up with an Occupant Capacity of 220.

Can someone please provide the formula or code section.

Thanks!  

.


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## bldginsp

globe trekker said:
			
		

> SBerg stated: Wouldn't Section 1017.2, Exception # 2 require only a 36" minimum corridor width?
> 
> bldginsp,
> 
> Sometimes, alot of the forum members read and follow the various topics on here,
> 
> but because of limtations on their time / other responsibilities / or just choosing
> 
> to read and follow along, they / we do not join in. Please do not take any
> 
> offense. For the most part this a great bunch of people on here, with lots of
> 
> experience and a willingness to help.
> 
> .


No offense taken.  I just wanted to see how others were handling the same situation since the ICC takeover.  I believe there needs to be some committee research into the way it's worded and some clarification needs to be inserted.  I enjoy a good debate because I always learn something from it.


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## jpranch

globe, That was not the occupant load. It was the capacity of the 44" corridor. 44" / 0.2 = 220. Of course the capacity is always determined by the smallest egress component. Sooo, bldginsp is right on target. Look for the bottle necks!


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## bldginsp

jpranch said:
			
		

> I think the staff has been spending too much time in Washington. Your approach on capacity is right on target. I can certainly see where the word "served" can create some confusion. Dam I miss the old BOCA & CABO codes!


Amen to that jp, I got your message but I wanted to get this out there for others to view.  I can't believe some of ICC's logic.  This has been a great discussion in my book.  I'll be awaiting Mule's input on this whole thing.


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## KZQuixote

jpranch said:
			
		

> globe, That was not the occupant load. It was the capacity of the 44" corridor. 44" / 0.2 = 220. Of course the capacity is always determined by the smallest egress component. Sooo, bldginsp is right on target. Look for the bottle necks!


Jpranch

Yes this is a very informative thread. How would the 36" back doors affect the capacity given that there is a double door at the main entrance?

bldginsp,

"The doors don't have to be kept closed" I'm assuming that they would either need to be closed or close automatically in an emergency. Am I missing something?

THanks

Bill


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## bldginsp

KZQuixote said:
			
		

> JpranchYes this is a very informative thread. How would the 36" back doors affect the capacity given that there is a double door at the main entrance?
> 
> bldginsp,
> 
> "The doors don't have to be kept closed" I'm assuming that they would either need to be closed or close automatically in an emergency. Am I missing something?
> 
> THanks
> 
> Bill


Not according to ICC as long as they make up the "enclosed" corridor.  Go figure.


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## Mule

Okay...now that a floor plan has been posted. I agree that all corridors shall be rated in this situation.

Are ya'll happy now?  

You know what though...this is the way a topic should be handled. Did you guys notice that there weren't any degrading comments and everybody was civil? That's the way it should be all the time. We can disagree with each other and still be civil.

Now.....I still think there are situations where the OL could be over 30 and still not require the hallway    to be a rated corridor.


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## jpranch

"Are ya'll happy now? :smile: "

Mule, lmao! Thanks, I needed that.


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## bldginsp

Mule said:
			
		

> Okay...now that a floor plan has been posted. I agree that all corridors shall be rated in this situation.Are ya'll happy now?
> 
> You know what though...this is the way a topic should be handled. Did you guys notice that there weren't any degrading comments and everybody was civil? That's the way it should be all the time. We can disagree with each other and still be civil.
> 
> Now.....I still think there are situations where the OL could be over 30 and still not require the hallway    to be a rated corridor.


And Mule, I bet that somewhere out there, when someone was following along and just reading, they learned something.  That's what this thread was all about and thanks for the computer lesson, even I learned something, how to resize pictures.


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## FredK

Glad a picture was posted.  One corridor with three exits provided.  1-hr rating if no sprinklers.

If you decide to block off any part of the existing corridors then with the less than 30 no rating just be sure there's no dead ends.

Some times the picture is worth a better wait and response than thinking about all the other possiblities IMHO.


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## SBerg

So, if the ICC guru's say it's acceptable to divide the corridors into smaller spaces to accomplish less than 31 occupant loads do they require 20 minute door assemblies? Or is it acceptable to move from one clear space (corridor) to a smoke-filled space to find an exit? I believe the ICC interpretation is incorrect. JMHO.

AND if the corridors are divided, are rated door required? I only ask because these rated doors are required to have seal, latches and closers.  Now how do they handle accessibility, specifically door maneuvering spaces?


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## bldginsp

SBerg, I hear your concern and I agree with you on their interp.


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## Mule

SBerg said:
			
		

> So, if the ICC guru's say it's acceptable to divide the corridors into smaller spaces to accomplish less than 31 occupant loads do they require 20 minute door assemblies? Or is it acceptable to move from one clear space (corridor) to a smoke-filled space to find an exit? I believe the ICC interpretation is incorrect. JMHO.AND if the corridors are divided, are rated door required? I only ask because these rated doors are required to have seal, latches and closers.  Now how do they handle accessibility, specifically door maneuvering spaces?


If the corridors are split so that the OL is under 30 then no requirements for doors exist because it is no longer required. That is what I have been trying to get at from the very beginning. It all depends on how the building is layed out. You may have a building that has a total OL of over 30 but still not require rated corridors. Just like the ICC interpretation. .........I wish I had an icon to stick out my tongue!


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## mtlogcabin

> You know what though...this is the way a topic should be handled. Did you guys notice that there weren't any degrading comments and everybody was civil? That's the way it should be all the time. We can disagree with each other and still be civil.


Just read the entire post and I agree with the others. Corridor should be rated and the ICC answer is ridiculous.

Mule: Well said


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## bldginsp

Mule said:
			
		

> If the corridors are split so that the OL is under 30 then no requirements for doors exist because it is no longer required. That is what I have been trying to get at from the very beginning. It all depends on how the building is layed out. You may have a building that has a total OL of over 30 but still not require rated corridors. Just like the ICC interpretation. .........I wish I had an icon to stick out my tongue!


Yep Mule that's exactly what was said by ICC.  Does it make good sense to do it that way, probably not but all I have to show in court when something goes wrong is that it met the building code in effect at the time.  In this scenario it was, as I consider a good friend to say, "Built to Code = Building the worst that the code will allow"!


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## FM William Burns

Little late but.................. based on title of the topic......the answer is "a code violation or deficiency".  I agree with others whereas exhibited; the corridor requires a 1-hour fire resistance rating regardless of what the ICC staff may have said.  In the event the facility had (3) separate tenants and the corridors were closed and subdivided the building to only serve the tenant, the rating would be moot and I think that's what ICC intends in their explination but as described and depicted, the *building* exceeds the OL kicking in a rated assembly, period.


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