Basement exit and travel distance requirement

[max8176]

Hi, from California here, I have an existing basement in a 4-story building, fully sprinklered, and not sure if one or two exits is required. Basement will be mainly storage and utility spaces so occupancy load is below 29 person per Table 1006.2.1. Currently, I have two exit stairway out of the basement. However, likely, a fire pump is no longer required and we can eliminate the fire pump room and Stair ST04 as a direct exit to exterior for the fire pump room is not needed.

My question is then can we just live with having Stairs ST03 in place? I am a bit confused with the common path of travel requirement from the same table here. And what about Table 1006.3.4(2)? Any comment is welcome and thanks in advance.

 

[max8176]

I think this more define my question. What if I leave Door B04 in place after removing Stairs ST04 and fire pump room? Will then my common path of travel happens within the storage space

 

[classicT]

I see a number of things going on that really complicate answering your question.

1. I do not believe that you have accurately defined the most remote point for measurement of the CPET/max exit access travel distance.
2. What does the red line represent (it is not CPET nor exit access)? Extend down the corridor to door B04 if you intend to represent CPET, as that is the point where an occupant has to make a choice (presuming ST04 remains).
3. If ST04 is removed, blue line would appear to represent CPET and exit access travel distance.
4. Orange line does not represent CPET nor exit access travel distance.
5. Is ST04 an interior exit stairway? If so, the fire pump room (B09) is prohibited from opening into the stairway (CBC 1023.4; not a normally occupied space).

 

[max8176]

I see a number of things going on that really complicate answering your question.

1. I do not believe that you have accurately defined the most remote point for measurement of the CPET/max exit access travel distance.
2. What does the red line represent (it is not CPET nor exit access)? Extend down the corridor to door B04 if you intend to represent CPET, as that is the point where an occupant has to make a choice (presuming ST04 remains).
3. If ST04 is removed, blue line would appear to represent CPET and exit access travel distance.
4. Orange line does not represent CPET nor exit access travel distance.
5. Is ST04 an interior exit stairway? If so, the fire pump room (B09) is prohibited from opening into the stairway (CBC 1023.4; not a normally occupied space).

1.) Yes, I might not but I am just using it as an example and get some answer in understanding this. In current configuration I believe the CPET (blue line) will be over the limit of 100 feet.
2.) I am not sure which line, RED or BLUE is the CPET in this configuration. But it seems like you said RED is the CPET in current configuration and should be extends to Door B04. BLUE is the CPET if ST04 gets removed. What happen if Door B04 is to remain for this room/ space? Will then the CPET locates within this space then?
3.) See #2.
4.) I see. What is the difference of Table 1006.3.4(2) and Table 1017.2 in regard to the Exit Access Travel Distance?
5.) Stairs ST04 exit directly to the street level above. We were told that Fire Pump room needs to have direct access to exit to the exterior of the building, in this case through this stairway. If we are to keep fire pump remains, can we add a door inside the 2-hour stair enclosure to resolve this issue?

 

[steveray]

1.) Yes, I might not but I am just using it as an example and get some answer in understanding this. In current configuration I believe the CPET (blue line) will be over the limit of 100 feet.
2.) I am not sure which line, RED or BLUE is the CPET in this configuration. But it seems like you said RED is the CPET in current configuration and should be extends to Door B04. BLUE is the CPET if ST04 gets removed. What happen if Door B04 is to remain for this room/ space? Will then the CPET locates within this space then?
3.) See #2.
4.) I see. What is the difference of Table 1006.3.4(2) and Table 1017.2 in regard to the Exit Access Travel Distance?
5.) Stairs ST04 exit directly to the street level above. We were told that Fire Pump room needs to have direct access to exit to the exterior of the building, in this case through this stairway. If we are to keep fire pump remains, can we add a door inside the 2-hour stair enclosure to resolve this issue?

View attachment 12862

In your situation, I would measure CPET to door 304 in that you have to go by it before you have the choice of the second one....If those stairs go away it is all the way to the other stair...Good catch by CT on the FP not opening into the stair....

 

[max8176]

In your situation, I would measure CPET to door 304 in that you have to go by it before you have the choice of the second one....If those stairs go away it is all the way to the other stair...Good catch by CT on the FP not opening into the stair....

From my response to CT above, what if Door B04 is to remain for this room/ space? Will then the CPET locates within this space then? Also, what is difference bewteen Table 1006.3.4(2) and Table 1017.2 in regard to the Exit Access Travel Distance?

 

[steveray]

From my response to CT above, what if Door B04 is to remain for this room/ space? Will then the CPET locates within this space then? Also, what is difference bewteen Table 1006.3.4(2) and Table 1017.2 in regard to the Exit Access Travel Distance?

If B04 remains, that is where the CPET stops.....The 2 tables, one is CPET (choice of 2 exits) and one is "total" travel distance...

 

[max8176]

If B04 remains, that is where the CPET stops.....The 2 tables, one is CPET (choice of 2 exits) and one is "total" travel distance...

I meant if ST04 is removed but the door B04 stays and opens into the same big storage space, does it mean the CPET will be inside that space then? Table 1006.3.4(2) is this one:


Look like the EATD can be 100 feet but I am still short even with CPET inside the room/space? Table 1017.2 is more like for all exit access travel distance with 2 or more exits?

 

[classicT]

1.) Yes, I might not but I am just using it as an example and get some answer in understanding this. In current configuration I believe the CPET (blue line) will be over the limit of 100 feet.
2.) I am not sure which line, RED or BLUE is the CPET in this configuration. But it seems like you said RED is the CPET in current configuration and should be extends to Door B04. BLUE is the CPET if ST04 gets removed. What happen if Door B04 is to remain for this room/ space? Will then the CPET locates within this space then?
3.) See #2.
4.) I see. What is the difference of Table 1006.3.4(2) and Table 1017.2 in regard to the Exit Access Travel Distance?
5.) Stairs ST04 exit directly to the street level above. We were told that Fire Pump room needs to have direct access to exit to the exterior of the building, in this case through this stairway. If we are to keep fire pump remains, can we add a door inside the 2-hour stair enclosure to resolve this issue?

View attachment 12862

1. Ok, as long as you are aware.
2. Neither the red nor blue represent CPET. The CPET would be from the most remote point to directly in front of door B04. That is the point where an egressing occupant makes the choice to either continue forward or turn and enter the exit (assuming ST04 remains and is an interior exit stairway).
3. See #2.
4. Table 1006.3.4(2) only applies if you have a single exit - meaning ST04 is removed. 1017.2 applies regardless of if ST04 remains or is removed, and is the max distance an occupant can travel before reaching an exit (not all exits, just the closest).
5. I would not permit such a "fix". The fire pump room should have a separate access, and probably should have been located on the main level, but that's on the original design.

 

[max8176]

1. Ok, as long as you are aware.
2. Neither the red nor blue represent CPET. The CPET would be from the most remote point to directly in front of door B04. That is the point where an egressing occupant makes the choice to either continue forward or turn and enter the exit (assuming ST04 remains and is an interior exit stairway).
3. See #2.
4. Table 1006.3.4(2) only applies if you have a single exit - meaning ST04 is removed. 1017.2 applies regardless of if ST04 remains or is removed, and is the max distance an occupant can travel before reaching an exit (not all exits, just the closest).
5. I would not permit such a "fix". The fire pump room should have a separate access, and probably should have been located on the main level, but that's on the original design.

4.) Look like per Table 1006.3.4(2), I have exceed the limit for single exit even with the fire sprinkler exception. So I would need a second exit out of the basement. On the side note, can I define it as non-occupyable space so I am not required to provide a egress path from that space? We have so much storage space in the basement and probably not going to use all spaces down here.

5.) I looked at another of one of the recent project and the City (San Francisco) approved this configuration.

 

[classicT]

4.) Look like per Table 1006.3.4(2), I have exceed the limit for single exit even with the fire sprinkler exception. So I would need a second exit out of the basement. On the side note, can I define it as non-occupyable space so I am not required to provide a egress path from that space? We have so much storage space in the basement and probably not going to use all spaces down here.

5.) I looked at another of one of the recent project and the City (San Francisco) approved this configuration.

4. No. Storage space may not be habitable, but is occupiable space.
5. Ok. Not sure how or why. Information sure, but nothing to go on. Not justification for you in any way either.

 

[mtlogcabin]

I think you exceed the 100 ft exit access travel distance in this area also. If I am seeing things correctly the building is 50 feet wide.
What code was the building constructed under? CPOT was not in the legacy codes. However, the UBC required 2 exits out of a basement.



1997 UBC
1004.2.3.2 From individual floors. For the purposes of Section1004.2, floors, stories, occupied roofs and similar designations of building levels other than basements and mezzanines shall be considered synonymous. Every occupant on the first story shall have access to not less than one exit and not less than two exits when required by Table10-A. Every occupant in basements and on stories other than the first story shall have access to not less than two exits.

EXCEPTIONS:
.6. Floors and basements used exclusively for the service of the building may have access to only one exit. For the purposes of this exception, storage rooms, laundry rooms, maintenance offices and similar uses shall not be considered as providing service to the building

I believe you need to keep both exits out of that basement

 

[Yankee Chronicler]

You seem to be unclear on what common path of travel means. It is the distance an occupant must travel from the most remote point to a point where they have access to two (or more) remote exits in different directions. If there is only one means of egress from a story, then the common path of travel and the exit access travel distance are the same.