# Corridor Width



## Marshal Chris (Apr 29, 2010)

Hello all..

Just FYI, I'm using NYS Version of I-codes and have a question on the verbage within 1016.2 Exception 4.

4.  Seventy-two inches (1829 mm)—In Group E with a corridor having a required capacity of 100 or more.

What's with the word "required" in there?

This is my situation, I have a corridor, constructed @ 66 inches, Group E (obviously).  It's for a preschool type occupancy.  Corridor wraps around the buidling, occupant load is

162 Children

27 Teachers

2 office staff

191 Total.

All classrooms have exits to outside, buidling sprinklered.  Stumbled on 6 foot width verbage during the "final" inspection.

I read the code as where the corridor is serving 100 or more, it needs to be a minimum 72 inches.

Anyone clarify?

Thanks.


----------



## mark handler (Apr 29, 2010)

you do not have a corridor that is serving 100 or more.

half of the rooms occupants, in an emergency, travel through the corridor, half of the rooms occupants, exit to outside


----------



## Coug Dad (Apr 29, 2010)

It sounds like the "required" capacity of the corridor could be less than 100 since the classroom have direct exits to the outside.  The key is if the classrooms are small enough that a single exit is permitted.


----------



## mark handler (Apr 29, 2010)

Coug Dad said:
			
		

> The key is if the classrooms are small enough that a single exit is permitted.


even if the room is "small enough that a single exit is permitted" and you have two exits, half are assumed to travel through each exit.


----------



## Coug Dad (Apr 29, 2010)

I disagree with your opinion, but half of 191 would still be less than 100 or the "required" egress capacity of the corridor.  What do you want them to do at this point?  Rip out the corridor walls to pick up a few inches?


----------



## Mule (Apr 29, 2010)

Okay, here's my opinion.

Required....There are specific guidlines when determining occupant loads. When we (BO's, DP, or Plan reviewers) determine the OL based on occupancy ans square footage of the room, we have an OL of X amount...Say 105 for grins.

A school, or whatever says, well there will never be that many people in there, there will only be 95 people in there because that the State allows per teacher or for whatever reason they give you.

You have a "required" OL of 105 even though the school says 95. Therefore the corridor width would be......

4. Seventy-two inches (1829 mm)—In Group E with a corridor having a required capacity of 100 or more.

Just my thoughts!


----------



## mtlogcabin (Apr 29, 2010)

> even if the room is "small enough that a single exit is permitted" and you have two exits, half are assumed to travel through each exit.


I have to agree with Mark on this one

1005.1 Minimum required egress width.

.... Multiple means of egress shall be sized such that the loss of any one means of egress shall not reduce the available capacity to less than 50 percent of the required capacity.


----------



## mark handler (Apr 29, 2010)

The occupant load evenly distributed among the exits, is a code basic.  It determains the exit width.


----------



## mark handler (Apr 29, 2010)

Mule said:
			
		

> A school, or whatever says, well there will never be that many people in there, there will only be 95 people in there because that the State allows per teacher or for whatever reason they give you.


It's based on Sq. ft not what the state says about how many teaches may or maynot be there.


----------



## mtlogcabin (Apr 29, 2010)

Ditto Mule

OL is based on SQ Ft not  what the schools teacher to student ratio is.


----------



## Coug Dad (Apr 29, 2010)

Is the 191 person occupant load calculated or assumed?


----------



## cda (Apr 29, 2010)

and if you only have two required exits in a 200 person building and one is blocked then what do half the people that were suppose to use that exit do???

I have heard this before and disagree, to me if 200 people are in a building with a corridor then 200 people could possibly use it and would have to be built to whatever code requriements there are.


----------



## Coug Dad (Apr 29, 2010)

cda, in most cases the code specifies minimum widths based upon the total occupant load. This is one case where it specifically deals with the "required" load on the corridor.  If the classrooms each have a direct exit to the outside, then the "required" load on the corridor is less than 100 so the 72 inch rule does not apply.


----------



## Marshal Chris (Apr 29, 2010)

the 191 is the calculated load.

CD,  I'm at a loss, I don't want them to rip out walls and make it six foot, I'm looking to see if I was reading it right, which I wasn't apparently, and  I suggested they seek a variance from the state.

if we consider the loss of one exit, being the outside direct exit, that adds a minimum of 6 more people (smallest classroom) in the corridor, making it 101.

I don't know if that statement even affects the required corridor width.


----------



## cda (Apr 29, 2010)

Coug Dad

I should have added if two exits are required, the one directly to the outside and the corridor

but even with that o me you still have a corridor which is noramly going to be used????????????


----------



## cda (Apr 29, 2010)

Well I stand maybe corrected in the 2003 commentary section 1016.2  it seems to say you can split the occcupant load, still disagree with that and it is the commentary

so Chris if you have a copy of the commentary read the first commentary paragraph


----------



## Marshal Chris (Apr 29, 2010)

Thanks everyone for your help.

Just curious, if there were 3 exits in the room, would it be 33%?


----------



## Marshal Chris (Apr 29, 2010)

cda said:
			
		

> Well I stand maybe corrected in the 2003 commentary section 1016.2  it seems to say you can split the occcupant load, still disagree with that and it is the commentary so Chris if you have a copy of the commentary read the first commentary paragraph


disregard.  asked and answered......


----------



## mark handler (Apr 29, 2010)

marshal chris said:
			
		

> thanks everyone for your help.  Just curious, if there were 3 exits in the room, would it be 33%?


yes but one would need to be 34% to equil 100%

BUT, DIREGARD MY COMMENTS, IF THE TWO OR MORE, EXITS BOTH ENTER THE SAME CORIDOOR


----------



## Marshal Chris (Apr 29, 2010)

I figured that, both the 34% and if it dumped to the same area inside the building.


----------



## permitguy (Apr 30, 2010)

I must be getting jaded.  This wouldn't be a case where I'd require a correction since it was obviously missed during both plan review and the rough inspection.  I was taught long ago that the only time a tape measure should come off your belt on a final inspection is when they were so close at rough that the finish materials may have made them non-compliant.  In those cases, there should be advanced warning to the contractor.  We're talking 6" off here.  This isn't a finish-out issue.  The inspectors responsiblity is to inspect to the approved plan - not to re-perform plan review after the job is done.

I wouldn't lose sleep over this one.  I feel confident you'll never see this quote:  "If that corridor had only been 6" wider, all those kids would still be alive."

Like I said, jaded.


----------



## Marshal Chris (Apr 30, 2010)

We don't do "rough" inspections except in the case of fire sprinkler piping.


----------



## permitguy (Apr 30, 2010)

Who is responsible for plan review and inspection of the means of egress?  This shouldn't be left for a final inspection any more than the sprinkler system should be.

I need to clarify my position, as it wasn't clear above.  I agree that this corridor is serving less than 100 occupants and doesn't need to be 72" anyway.  If the occupant load of each classroom is under 50, I wouldn't expect the DP to show the corridor as part of the egress plan for the classrooms at all.  The corridor isn't likely to be shown as an element for egress in the Fire Evacuation Plan required by the IFC, either.  I think the whole thing is a non-issue.


----------



## Marshal Chris (Apr 30, 2010)

The building dept does their own plan review and inspections.  We (Fire Marshal's Office) also do plan review for new construction, alterations and systems.

During the inspection, I was wondering how this had made it this far without someone else picking it up, however mistakes happen, and things have been known to slip by.  After reviewing further, I've already agreed that it's a non issue, but a great learning experience for me.

As far as inspections...  We have a hard enough time keeping up with everything as is.  We don't have time to do rough inspections for all systems and alterations.  The party gets a permit, they construct, calls us for a final.  Sometimes, big ticket items have come up at our finals.  I know it sounds dysfunctional...


----------



## Marshal Chris (Apr 30, 2010)

And further..  I do believe the building dept makes rough inspections..  However, at a final inspection for interior alterations at a PA, I picked up that the 1 hr fire wall and rated door were missing at the bottom of a rated stairway.  The job was finaled and approved by the building department without the 1 hr wall.


----------



## peach (May 2, 2010)

In reality, the rooms that dump directly to the exterior of the building are going to be the primary exits from those rooms.  Only if the emergency is directly outside one or two of the rooms will the corridor be used.  That's what required fire drills are for.


----------



## Plans Approver (May 2, 2010)

Here's my nickel's worth ...From the OP: Corridor wraps around the buidling, occupant load is 162 Children,  27 Teachers,  2 office staff,  191 Total.  All classrooms have exits to outside.Since the corridor "wraps" the building, I envision something like below.Corridors A & B serve occupant loads of less than 100 each, a *required capacity* of less than 100. Each corridor requires a minimum width of 44" (disregarding the classroom doors to the exterior, those doors may not be available due to a fire at an adjacent building, a barbeque lunch gone bad, etc.). If you use 1/2 out the exterior and 1/2 out the corridor, then the required corridor could be 36" wide, a *required capacity* less than 50, but 42" wide to meet accessibility requirements.66" is sounding pretty good. Is there a plan you can post?

View attachment 123


View attachment 123


/monthly_2010_05/E-Corr..jpg.c61c55a7dd2ca17370fe9b8db540f4d3.jpg


----------



## peach (May 2, 2010)

I agree, Dan.. thanks


----------

