Exit path

[Sifu]

If a space requires two exits, is it permitted to place them so that you must pass the first one in a corridor to get to the second as long as the first is within the CPET distance?

Example: Consider an assembly space at the end of a corridor. The assembly space requires two exits, both of which are along the corridor leading to the assembly space. There is no other compliant exit path from the assembly space.

 

[steveray]

I think I know what you are saying, but not sure, and I sorta view/treat large rooms the same way....If the room only has one door to the corridor, likely not, because of this:


1006.2.1 Egress based on occupant load and common
path of egress travel distance. Two exits or exit access
doorways from any space shall be provided where the
design occupant load or the common path of egress travel
distance exceeds the values listed in Table 1006.2.1.

 

[JPohling]

Not sure I understand your layout. Are you saying that the exit paths fully converge within the CP distance and then within the max CP distance you have access to two separated exits? Is this within the large room?

 

[bill1952]

I think if the two means of egress share a portion of a corridor, it misses the intent of the code. A fire in that section of corridor sours all means of egress - does no good to go back through assembly space and try other exit access door.

It gets tricky. One theatre project I worked on had a small balcony - a mezzanine - with maybe 100 occupants. Two doors out, two stairs down to lobby. You could go straight from foot of stairs to separate exit discharge, never crossing paths. All good. The weakness was in middle of stairs they shared a landing - albeit one large enough you could divide it and still have two adequate landings. Hard to say it didn't meet the letter of the code, but not sure they were separate enough to meet intent.

I guess if that section of corridor is wide enough that you can diagram separate means of egress and the paths never cross or truley merge, you might get away with it.

 

[Sifu]

Sorry, it is convoluted as he!!. Here is a snippet. This is the second floor. The two doors marked with an X are not viable due to occupant loads and number of exits. Stair 1 is an open stair, 2 & 3 are stair cores. All of the occupants from the lounge/bar plus some from the patio, plus some from the residential area (plan north) must egress to exit 1,2, or 3. Stair 1 & 2 do not offer the required separation. On your way to stairs 1 & 2, occupants converge, and if 1 & 2 can't be the two required exits, then 3 would come in to play, however the convergence is even longer. The CPET is about 110' to stair 1, & 127' to stair 2. (CPET is exceeded). This is but one issue of many, but I am trying to anticipate the solutions and want to make sure I address everything relevant. As I see it, the only option is to MAKE the door leading to the patio compliant, which would mean adding another path off of the patio. CLEAR AS MUD.

 

[bill1952]

I'm not clear but looks like second moe is between electric room and toilet room to be modified? I agree the corridor between restroom and open to below is not two separated moe.

Why can't open stairs be 50% of required egress? Still don't have two separate imho.

 

[Sifu]

I'm not clear but looks like second moe is between electric room and toilet room to be modified? I agree the corridor between restroom and open to below is not two separated moe.

Why can't open stairs be 50% of required egress? Still don't have two separate imho.

I think the open stair can be one of the required exit paths, but the adjacent stair core isn't far enough away to be the 2nd. But, like you say, the path to any of them isn't separate and distinct...also imho.

 

[RLGA]

If a space requires two exits, is it permitted to place them so that you must pass the first one in a corridor to get to the second as long as the first is within the CPET distance?

Example: Consider an assembly space at the end of a corridor. The assembly space requires two exits, both of which are along the corridor leading to the assembly space. There is no other compliant exit path from the assembly space.

Thank you for the illustration, but I have been working on a response on and off all day today, so what I have created is more basic than your situation, but I will post it anyway for discussion purposes.

If the corridor dies at the second exit access doorway (See Diagram A below), you have just created a dead-end corridor, which would be limited to 20 feet for Group A occupancies. Thus, the separation of exit access doorways is less than 20 feet, which in turn means the overall diagonal of the space would be less than 60 feet (if sprinklered) or 40 feet (in nonsprinklered).

The 2015 IBC changed the definition of CPET in many ways, with a couple of them causing me irritation. One change eliminated the provision of merging paths. Another change deleted the last sentence about travel distance and incorporated it into the first sentence. And another change added that the CPET is measured from the "most remote point within a story." I do not have a problem with the first two changes; however, that third change plus the addition of "...or exit access doorways" has caused more confusion than anything. In other words, Diagram A might be acceptable if the red diamond is not the "most remote point within the story," or the AHJ interprets the definition that the path from the bottom room has two paths to two exit access doorways even though those two paths briefly merge in the dead-end corridor.

The 2018 IBC attempted to correct this by changing the phrase "from the most remote point within a story" to "from the most remote point of each room, area or space." Even then, the AHJ could interpret Diagram A to comply with the 2018 IBC definition. However, I would interpret the gray shaded portion in Diagram B as an "area," and the common path would be measured as shown.

Diagram C shows how doors would be arranged under normal or more common circumstances to limit CPET distance.

In my opinion, we need to revert to the 2012 IBC definition.

 

[RLGA]

Sorry, it is convoluted as he!!. Here is a snippet. This is the second floor. The two doors marked with an X are not viable due to occupant loads and number of exits. Stair 1 is an open stair, 2 & 3 are stair cores. All of the occupants from the lounge/bar plus some from the patio, plus some from the residential area (plan north) must egress to exit 1,2, or 3. Stair 1 & 2 do not offer the required separation. On your way to stairs 1 & 2, occupants converge, and if 1 & 2 can't be the two required exits, then 3 would come in to play, however the convergence is even longer. The CPET is about 110' to stair 1, & 127' to stair 2. (CPET is exceeded). This is but one issue of many, but I am trying to anticipate the solutions and want to make sure I address everything relevant. As I see it, the only option is to MAKE the door leading to the patio compliant, which would mean adding another path off of the patio. CLEAR AS MUD.

View attachment 9163

There is a lot going on here and I have several questions:

1. Occupants above the green line must egress through the lounge/bar to get to an exit?
2. How long is that corridor to the north?
3. Is the green line a fire wall or horizontal exit?
4. If these are the only stairs, what is the overall diagonal of the story?
5. What happens in the story to the left and below (off picture)?

 

[TheCommish]

I was believe that the 1/2 diagonal distance must be manainted for the total exit access path to the exit entrance.

 

[Jay Smith]

When the occupants come out of the lounge and are faced with a decision to go north or south, why doesn’t the CPET end there?

 

[steveray]

I interpret it the same way as Ron..

 

[Sifu]

There is a lot going on here and I have several questions:

1. Occupants above the green line must egress through the lounge/bar to get to an exit?
2. How long is that corridor to the north?
3. Is the green line a fire wall or horizontal exit?
4. If these are the only stairs, what is the overall diagonal of the story?
5. What happens in the story to the left and below (off picture)?

There is a lot going on here and I have several questions:

1. Occupants above the green line must egress through the lounge/bar to get to an exit [No, there two exits to the north, but are not separated adequately]
2. How long is that corridor to the north? [188', 150' to the first exit access at an elevator lobby, 188' to a stair core at the end]
3. Is the green line a fire wall or horizontal exit? [it is a 2-hr fire barrier, I assume acting as a horizontal exit, but they don't illustrate it]
4. If these are the only stairs, what is the overall diagonal of the story? [There are 3 stair cores and the open exit access stair. It is an "L" shape and the farthest diagonal of the story is 488'. The two stair cores in my snippet and one at each end of each leg of the "L"]
5. What happens in the story to the left and below (off picture)? [That wing travels 248' to the west. There is a stair core at 200', and it continues to a fire wall at 248'. There is an "exit" in that fire wall, to another building, but I am not counting that, since I have been given NO data on it (one of my many comments)]

Here is an over-all...if you can read it.

 

[Sifu]

When the occupants come out of the lounge and are faced with a decision to go north or south, why doesn’t the CPET end there?

The lounge occupants are stuck in the middle. As RLGA said, lots going on. The patio requires two exits based on OL, they only provide a single stair off the patio, though I don't know where it goes...across a pool deck? (another comment). That means the double doors into the lounge need to be an exit off the patio, or they provide another somewhere else. So that eliminates that path as designed. For them to go north, they would need to go through two doors. The first swings correctly (on this page, another comment) but the second is the required exit from the north corridor, so it swings the wrong way (and the first door must swing opposite to what is drawn for the exit path from the north corridor). That eliminates the north path. This leaves only south.

To help clarify a very little, the DP has incorrectly calculated his occupant loads and may think only a single exit access is required from the north corridor (didn't include the gross area in the calculation). This explains SOME of the design...but not all, so not sure if that is a valid assumption.

 

[Sifu]

I completed my first review, even with multiple comments condensed as typicals, I have 122 comments (A, M, accessibility & P only). I am almost embarrassed, I feel like I am the problem, not them, but I spent an incredible amount of time verifying the validity of every one (like this one). Many are related to the over-riding issues:
-Incorrect occupant load calculations
-Incorrect analysis of the allowable areas
-Incorrect area calculations
-Incorrect mixed use strategies

I have a meeting with the design team next week to discuss the major issues. This is a huge complex of buildings, including stadiums, dorms, public spaces, etc., all in some form of current development, not finished. I have not been involved on any level with anything but this, but I am told by other reviewers and BO's that they have all been this messy. This plan was developed over two years ago, and just revived, I am pretty sure it has been worked on by several DP's in several segments. The plans were clearly not ready for prime time. Glad to get paid by the hour. I feel like I should cut y'all in somehow.