# Clarification of Common Path Distance



## brr (Mar 6, 2020)

I have seen several references online to the common path travel distance being the from the remotest point of travel distance to a point in which there are two ways to an exit _or_ to the next higher level of protection. Where in the IBC code does it describe the point of "two choices"? What I'm wondering specifically is with a Group B office suite configuration with an OL less than 50 that is nonsprinkled and no rated walls or corridors within the suite, and has a point more than 75' to any exit door or exit component door leading to a rated corridor. Am I thinking about the suite the wrong way - should I be thinking of it as one large room (with obstacles that take form of partitions), and, like a room, you have to just worry about the distance between exits?

Among other references to this, I came across this very well articulated video:


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## RLGA (Mar 6, 2020)

In the definition of "Common Path of Egress Travel" in Chapter 2.


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## cda (Mar 6, 2020)

brr said:


> I have seen several references online to the common path travel distance being the from the remotest point of travel distance to a point in which there are two ways to an exit _or_ to the next higher level of protection. Where in the IBC code does it describe the point of "two choices"? What I'm wondering specifically is with a Group B office suite configuration with an OL less than 50 that is nonsprinkled and no rated walls or corridors within the suite, and has a point more than 75' to any exit door or exit component door leading to a rated corridor. Am I thinking about the suite the wrong way - should I be thinking of it as one large room (with obstacles that take form of partitions), and, like a room, you have to just worry about the distance between exits?
> 
> Among other references to this, I came across this very well articulated video:




Sounds like in your example, two ways out is not required??


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## cda (Mar 6, 2020)

Good reading


http://www.specsandcodes.com/articles/code_corner/The Code Corner No. 29 - Travel Distance.pdf


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## mtlogcabin (Mar 6, 2020)

A simple way to look at one room/spce for compliance with CPOT is if the perimeter of the room exceeds 150 feet then you will need two exits from that room or space


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## brr (Mar 6, 2020)

cda said:


> Sounds like in your example, two ways out is not required??


The total internal distance for the common path is over 75'. I'm looking for advice on understanding the common path portion of the code.
To rephrase the question as a hypothetical: Say a common path is 74', then comes to a point with two choices, both paths are another 74' to a rated corridor. The total travel distance within the suite is 148'. This is OK with code?


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## RLGA (Mar 6, 2020)

brr said:


> The total internal distance for the common path is over 75'. I'm looking for advice on understanding the common path portion of the code.
> To rephrase the question as a hypothetical: Say a common path is 74', then comes to a point with two choices, both paths are another 74' to a rated corridor. The total travel distance within the suite is 148'. This is OK with code?


Yes, provided that that distance plus the additional distance to an exit is within the permitted travel distance, and that is measured to only one of the available exits--not all exits are required to be within the stipulated travel distance


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## ADAguy (Mar 25, 2020)

Back in the day there was a hose stream max. distance from the entrance to a room to its farthest wall?


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## JPohling (Jun 16, 2022)

brr said:


> The total internal distance for the common path is over 75'. I'm looking for advice on understanding the common path portion of the code.
> To rephrase the question as a hypothetical: Say a common path is 74', then comes to a point with two choices, both paths are another 74' to a rated corridor. The total travel distance within the suite is 148'. This is OK with code?


Yes, provided that that distance plus the additional distance to an exit is within the permitted travel distance, and that is measured to only one of the available exits--not all exits are required to be within the stipulated travel distance


Ron,  Is it possible to clarify this a bit.  I have a Fire Marshal that is telling us that we need to be in the exit stair to terminate measuring of common path.  We typically stop our measurement at the doors from the suite to the rated corridor.  It is typically another 25-50 feet or so to the stair tower doors.  Your response to brr's question seems consistent with our measurement strategy.  our common path is 100' as we are fire sprinkled.  We typically make sure that we have the ability to head in two distinct paths within the common path distance, but not to the "exit".  Thank you


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## RLGA (Jun 16, 2022)

JPohling said:


> Ron,  Is it possible to clarify this a bit.  I have a Fire Marshal that is telling us that we need to be in the exit stair to terminate measuring of common path.  We typically stop our measurement at the doors from the suite to the rated corridor.  It is typically another 25-50 feet or so to the stair tower doors.  Your response to brr's question seems consistent with our measurement strategy.  our common path is 100' as we are fire sprinkled.  We typically make sure that we have the ability to head in two distinct paths within the common path distance, but not to the "exit".  Thank you


The measurement of the common path of egress travel (CPET), as the definition states, is to a point where the occupant has two separate and distinct paths to at least two exits--it does not state that it is measured to an exit unless there is only one exit permitted per Section 1006.3.3 (2018 IBC).


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## JPohling (Jun 17, 2022)

RLGA said:


> The measurement of the common path of egress travel (CPET), as the definition states, is to a point where the occupant has two separate and distinct paths to at least two exits--it does not state that it is measured to an exit unless there is only one exit permitted per Section 1006.3.3 (2018 IBC).


Thanks Ron,  I just needed confirmation and to be able to respond concisely.


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