Dead End Corridor

[duckbill]

The 2009 IBC, Section 1018.4, Exception 2, permits a 50 ft. dead end corridor in an R-2 occupancy when the building is sprinklered throughout per Section 903.3.1.1. I am reviewing a plan which has a 75 ft. dead end corridor with a door at the 50 ft. mark. The door is hold-open with mags and is to be connected the the fire/smoke alarm for closure. The architect claims the door will close during emergency situations and the actual dead end corridor length will be 50 ft. as required. The architect has met the common path of egress travel from the most distant apartment to the main corridor.

Has anyone reviewed and/or approved a scenario like this?

 

[cda]

1. Are two ways out required from this area???

2. No would not approve it, even with the door. There are instances where the alarm may not activate and you still have a dead end issue. Plus kind if same statement with the door open you have a built in dead end.

3. What is past the door, once it is closed???

 

[Papio Bldg Dept]

This is probably not applicable, but how wide is your corridor? I am not sure if it is still in the NFPA, but I believe there is an exception for width as well.

We have not had to review one with hold open doors. I would think if smoke detection is provided and tied into the door activation, then we might consider an alternative design solution (but I doubt it would make it past our State Fire Marshall's 2000 101 NFPA review desk).

 

[Big Mac]

I too would like to know if there is another way out of the area beyond the 50' where the doors close if the fire alarm is activated. If not, it must be considered part of the dead end corridor, door or no door.

 

[duckbill]

Thank you for your responses.

cda - past the door are entries to four more aparments. This is a 75' long dead end corridor with apartment entries the entire length. The apartments at the end of the dead end meet the common path of egress travel from the most remote spot in the apartment, down the 75' corridor to a T junction with the main corridor where you have your choice of two directions of exiting. To meet the 50' restriction on dead end corridors, the architect placed a door which is to close upon activation of smoke/fire alarm.

Papio Bldg Dept - The corridor is 72" wide, 75' long with a double 3/0 door at the 50' mark.

 

[Papio Bldg Dept]

Duckbill...the width exception won't apply to you as it is 2.5 times the width. I have heard multiple reasons for limiting the length of dead-end corridors, the two most common being to prevent people from having to go too far down a corridor before realizing there is no exit in that direction effectively increasing the time it takes to exit a building, and that smoke accumulation in a corridor contributes to disorientation with exits where distances exceed 2.5 times the corridor width.

interesting article: http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/tn/tn270.pdf

It is the opinion of the writer, however, that any changes

in the eXisting regulations should be made only after further

detailed study of the problem reveals more factual information on

how both fire and human beings will act under varying conditions

in a variety of occupancies.

 

[brudgers]

The 2009 IBC, Section 1018.4, Exception 2, permits a 50 ft. dead end corridor in an R-2 occupancy when the building is sprinklered throughout per Section 903.3.1.1. I am reviewing a plan which has a 75 ft. dead end corridor with a door at the 50 ft. mark. The door is hold-open with mags and is to be connected the the fire/smoke alarm for closure. The architect claims the door will close during emergency situations and the actual dead end corridor length will be 50 ft. as required. The architect has met the common path of egress travel from the most distant apartment to the main corridor. Has anyone reviewed and/or approved a scenario like this?

The architect is FOS. Cross corridor doors don't create two corridors.

 

[cda]

You have a dead end situation, even with the door there

How many floors is the building????

 

[duckbill]

cda - Yes, we have a dead end situation, but the architect believes having the doors at 50' complies with the requirements. My concern is that the corridor users would continue through the doors only to find they had traveled an additional 25' to the actual dead end and now have to travel 75' back the the exit at the main corridor. The building is two stories with this corridor on the second floor.

 

[kilitact]

Doesn't appear to be a dead end situation, with or without the door at 50 ft.Sec. 1018.5 starts out by stating if two exits or exit access is required.

 

[Coug Dad]

Cross corridor doors can eliminate the dead end, but the common path of travel limitation still apply.

 

[cda]

cda - Yes, we have a dead end situation, but the architect believes having the doors at 50' complies with the requirements. My concern is that the corridor users would continue through the doors only to find they had traveled an additional 25' to the actual dead end and now have to travel 75' back the the exit at the main corridor. The building is two stories with this corridor on the second floor.

Once again,

1. If the door is open you have a dead end corridor situation already in place

2. The fire alarm does not go off every time there is an incident

3. There is a dead end situation, tell them to fix it or appeal it!!!!

 

[cda]

Doesn't appear to be a dead end situation, with or without the door at 50 ft.Sec. 1018.5 starts out by stating if two exits or exit access is required.

He said prior to the door two exits were required.

So if you are wondering around the corridor prior to the door, you could wonder into a dead end situation

 

[mtlogcabin]

The architect has met the common path of egress travel from the most distant apartment to the main corridor.

The dead end requirements come into play when 2 exits are required

Please clarify

Is this a corridor off of the "main corridor" and is the main corridor served by 2 exits.?

 

[duckbill]

Kilitact - There are more than four apartments on the second floor which by 2009 IBC, Table 1021.2, requires more than one exit.

 

[duckbill]

mtlogcabin - Your question is exactly right, this is a 75' dead end corridor at a 90 degree angle to the main corridor and the main corridor has two exits - one at either end.

 

[zigmark]

What purpose is the corridor serving beyond the 50' mark? Why not eliminate/block off that portion? Or are the units accessed beyond that point? Are they trying to eliminate fire separation between units by having the corridor run between them full length? Is it possible they are spending a lot of time and effort to avoid one thing and creating a separate issue? Or is this a case of a designer/owner vested in a design and unwilling to change? Maybe there is an different approach for some other issue they are concerned with that would allow the elimination of this feature. Just a thought.

ZIG

 

[mtlogcabin]

Kilitact - There are more than four apartments on the second floor which by 2009 IBC, Table 1021.2, requires more than one exit.

Table 1021.2 requires 2 exits from the story not from an area with more than 4 apartments

Exception #4 below permits 125 ft in a sprinklered R-2 as a common (single) path of travel. Therefore 2 exits are not required and this is not a dead end corridor.

1018.4 Dead ends.

Where more than one exit or exit access doorway is required, the exit access shall be arranged such that there are no dead ends in corridors more than 20 feet (6096 mm) in length.

1014.3 Common path of egress travel.

In occupancies other than Groups H-1, H-2 and H-3, the common path of egress travel shall not exceed 75 feet (22860 mm). In Group H-1, H-2 and H-3 occupancies, the common path of egress travel shall not exceed 25 feet (7620 mm). For common path of egress travel in Group A occupancies and assembly occupancies accessory to Group E occupancies having fixed seating, see Section 1028.8.

Exceptions:

1. The length of a common path of egress travel in Group B, F and S occupancies shall not be more than 100 feet (30 480 mm), provided that the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.

2. Where a tenant space in Group B, S and U occupancies has an occupant load of not more than 30, the length of a common path of egress travel shall not be more than 100 feet (30 480 mm).

3. The length of a common path of egress travel in a Group I-3 occupancy shall not be more than 100 feet (30 480 mm).

4. The length of a common path of egress travel in a Group R-2 occupancy shall not be more than 125 feet (38 100 mm), provided that the building is protected throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.

 

[brudgers]

OK, I opened the code book.

1. IBC 2009 1018 is clear that doors constitute an obstruction in a corridor (but are allowed by exemption. It is therefore not the case that doors create two corridors.

2. A full NFPA 13 (903.3.1.1) sprinkler system is required to have a 50' dead end corridor. A 13R system (903.3.1.2) won't meet the requirement. 3. Furthermore, the 50' dead end corridor requirement in IBC 2009 is equivalent to the common path of travel limit from an apartment door to the choice of two exits in NFPA 101. IMO, this means that experience dictates that longer dead ends are unsafe (i.e. this, for once, isn't just IBC pulling a number out of their *** (they're just cribbing from NFPA instead)).

However, it should be clarified that the dead end requirement in an apartment building is not driven by the idea of people taking the wrong path during an emergency. Unlike other occupancies, apartment dwellers are highly familiar with their surroundings and the occupant load is not sufficient to create a pile up in a dead end like one would see in an assembly occupancy.

Instead the provision is driven by the likelihood of an exit access corridor being blocked by fire or other extraordinary events.

If this set of plans were on my desk, I'd offer to send it to the state licensing board for review.