I have a small medical clinic space, B-Business occupancy. 1-story, non-sprinklered building. I have the space set up like a racetrack...offices and exam rooms- around the perimeter, supports spaces in the middle and an exit at the west end and an exit in the northeast corner of course connected to the racetrack corridor. IBC 2018 states 150 sf/person so my occupant load is roughly 42 people. I have two exits due to common path of travel distance requirement, I am maintaining 75' common path of travel and maintaining 20' dead end corridors. Table 1020.1 says I need a 1-hour rated corridor...Table says OCCUPANT LOAD SERVED BY CORRIDOR...if greater than 30 then 1-hour rated corridor. I am struggling with the verbiage of the table. I have this racetrack corridor, of course I have 42 people that could use different portions of this racetrack corridor. With 2 exits, that says "basically" that 21 people go out the west exit and 21 go out the northeast exit...do I need to rate the corridor? Is my assumption of splitting the exiting a load of poop. Can I add a 3rd exit door to "remove" 12 occupants from the calculation above and now at 30 occupants (not greater than 30) I dont need to rate? Let me know if I am looking at this correctly. Thanks in advance.
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Corridor rating (IBC 2018)
- Thread starter Vlab20
- Start date
mtlogcabin
SAWHORSE
Yes I am afraid it is.
mark handler
SAWHORSE
As you stated "OCCUPANT LOAD SERVED BY CORRIDOR", it does not say by half the corridor. what happens if one side is blocked. everyone will need to exit through the open exit. that could exceed the occupant load.
redeyedfly
Registered User
A typical wall is 1hr. The only real difference would be firestopping the penetrations.
steveray
SAWHORSE
And rated doors and making the walls go to the deck.....
mtlogcabin
SAWHORSE
BayPointArchitect
Sawhorse
poop
Sifu
SAWHORSE
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- Sep 3, 2011
- Messages
- 2,813
I am imagining your plan, and I am having trouble seeing it as a corridor. Most of these types of spaces are open to other areas, not "an enclosed exit access component". Are you sure you don't have an "aisle"? My understanding is that when you have a corridor, by definition enclosed, there is more risk because people on the other sides of the enclosure are not familiar with or not aware of what is going on in the spaces they are not in. So if you enclose it, it has a higher level of protection. But an aisle, which is unenclosed, does not carry that elevated risk because it is open and the occupants are generally familiar with the surroundings and activities. At a glance I would say if this is a single occupant, with individual offices, exam rooms, nurse stations, etc., you do not have corridors. Think about how many big office buildings we have been in with more than 50 of people on a floor in cubicle. They don't use corridors to get out, they use aisles.
Or I have no idea what I am talking about.
Or I have no idea what I am talking about.
Genduct
Registered User
I agree with you. that without a real plan, you can only guess what is required. So, do you really need a Fire Barrier or Fire Partition? You will need a Properly sized, clear Egress Path to get out. And a Fire Alarm System to warn you about areas you don't see. Beyond that, we can only guess
mtlogcabin
SAWHORSE
1/2 hour rating
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.
708.3 Fire-resistance rating.
Fire partitions shall have a fire-resistance rating of not less than 1 hour.
Exceptions:
1. Corridor walls permitted to have a 1/2-hour fire-resistance rating by Table 1020.1.
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.
708.3 Fire-resistance rating.
Fire partitions shall have a fire-resistance rating of not less than 1 hour.
Exceptions:
1. Corridor walls permitted to have a 1/2-hour fire-resistance rating by Table 1020.1.
steveray
SAWHORSE
Sifu
SAWHORSE
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Without the plans I can't accurately assess whether it is a corridor, or an aisle. I agree, if there is an actual corridor, then the requirements for corridors apply. But if the "pathway" the post is referring to is not enclosed, then there is no corridor. I do not believe the code requires corridors, but it does require aisles as an exit access element. An aisle becomes a corridor once it is enclosed and serves as an exit access element, thereby increasing the risk of fire recognition. Notice the commentary stipulates that "enclosed" is a moving target, subject to evaluation of the use and context, which is where plans would help. IMHO, for example, my Dr.'s office consists of a large square space, with a circulation path that racetracks around the space. Exam rooms bound the outside perimeter of the path, and some on the interior, as well as several nurses stations, open work stations, and individual waiting areas. In many areas, you can see from one side of the path to the other side of the path through the open spaces and rooms in between. This, to me, is not an enclosed corridor.
I will admit this is not the first time this issue has come up, and I have made decisions based on this understanding, so I may be opining from a place of confirmation bias, but I can be convinced I am wrong. I just haven't been convinced yet.
[BE] CORRIDOR. An enclosed exit access component that
defines and provides a path of egress travel.
Corridors are regulated in the code because they
serve as principal elements of travel in many means
of egress systems within buildings. Typically, corridors
have walls that extend from the floor to the ceiling.
They need not extend above the ceiling or have
doors in their openings unless a fire-resistance rating
is required (see Section 1020).
While both aisles and corridors may result in a confined
path of travel, an aisle is an unenclosed or partially
closed component, while a corridor would be an
enclosed component of the means of egress. The
enclosed character of the corridor restricts the sensory
perception of the user. A fire located on the other
side of the corridor wall, for example, may not be as
readily seen, heard or smelled by the occupants traveling
through the egress corridor. The code does not
specifically state what is considered “enclosed”
where corridors are not fire-resistance rated. Where
an egress path is bounded by partial-height walls,
such as work-station partitions in an office, issues
would be if the walls provided a confined path of
travel and limited fire recognition in adjacent spaces
by restricting line of sight, hearing and smell.
I will admit this is not the first time this issue has come up, and I have made decisions based on this understanding, so I may be opining from a place of confirmation bias, but I can be convinced I am wrong. I just haven't been convinced yet.
[BE] CORRIDOR. An enclosed exit access component that
defines and provides a path of egress travel.
Corridors are regulated in the code because they
serve as principal elements of travel in many means
of egress systems within buildings. Typically, corridors
have walls that extend from the floor to the ceiling.
They need not extend above the ceiling or have
doors in their openings unless a fire-resistance rating
is required (see Section 1020).
While both aisles and corridors may result in a confined
path of travel, an aisle is an unenclosed or partially
closed component, while a corridor would be an
enclosed component of the means of egress. The
enclosed character of the corridor restricts the sensory
perception of the user. A fire located on the other
side of the corridor wall, for example, may not be as
readily seen, heard or smelled by the occupants traveling
through the egress corridor. The code does not
specifically state what is considered “enclosed”
where corridors are not fire-resistance rated. Where
an egress path is bounded by partial-height walls,
such as work-station partitions in an office, issues
would be if the walls provided a confined path of
travel and limited fire recognition in adjacent spaces
by restricting line of sight, hearing and smell.
no aisle...these are enclosed corridors. There is no open work area. All rooms surrounding the space are enclosed rooms.
So based on some posters here, I will need to rate all of these corridors (flesh colored) as 1-hour rated and all the doors will be 45 minute with closers.For the sake of discussion, here’s a clinic plan that is not far off from the OP’s description. Suppose the total occupant load of the spaces other than the waiting room is 42.
As I look at Table 1020.1 it says...OCCUPANT LOAD SERVED BY CORRIDOR. This plan has 3 exit points which means I have in general 14 people exiting at each door. But if there is a fire at one of the doors I can safely say that 21 people use one door and 21 use the other remaining door. Does that not say "less than 30 occupants are served by the corridors"?
redeyedfly
Registered User
Looks like corridors to me.For the sake of discussion, here’s a clinic plan that is not far off from the OP’s description. Suppose the total occupant load of the spaces other than the waiting room is 42.
If you're in the MN portion of the midwest, they have added a real definition for corridors above the model code.
"CORRIDOR. “Corridor” means an interior passageway having a length at least three times its width, having walls, partitions, or other obstructions to exit travel over 6 feet (1829 mm) in height on two opposing sides and having openings from rooms or similar spaces."
I consider my corridors as corridors in this case. Jay Smith posted a great example of what I am facing
We did see at least that question addressed. Every space that uses that corridor for exit access counts toward the occupant load served by the corridor, without dividing it by the number of exits.
I am assuming corridors. What I am trying to avoid is rating that corridor. If my occupant load is 42 people for the entire space/building that "seems" to ppoint to I have to rate the corridor based on Table 1020.1 which says OCCUPANT LOAD SERVED BY CORRIODR is greater than 30 people = 1-hour rating. BUT if I add just one additional exit door I am distributing or lessening the number of occupants during exiting in the Corridors. With 3 exits I have 14 occupants in general exiting each of the 3 exit doors., if there is a fire blocking one of the doors, then the distribution is 21 people per the remaining two doors.
ALSO, There is commentary language in the 2015 IBC...Where the corridor serves a limited number of people (second column in Table 1020.1), the fire-resistance rating is eliminated because of the limited size of the facility and the likelihood that the occupants would become aware of a fire buildup in sufficient time to exit the structure safely.
If I add a 3rd exit door I basically have only 21 people using each of the remaining doors thus staying under the 30 occupants served by the corridor.
So based on the above...if you go to Jay Smith's post of a floor plan, the flesh colored area- would be considered "the corridor". And because more than 30 occupants could be running around in the corridor it needs to be rated? My thought...this plan has 3 exits and thus multiple exit paths in the corridors. This would allow less people using each of the different corridors to exit thus meeting the verbiage, OCCUPANT LOAD SERVED BY CORRIDOR
redeyedfly
Registered User
I think you have a decent argument. I would pitch it to the plan reviewer and negotiate.