Exit path

[Sifu]

I have a condition I have not run across before. An old building, built in 1974, non-suppressed, code unknown. It has two wings, separated by a common area with elevators. One wing is 4 story, the other 3 story. Each wing has an exit stair. On the 4th floor, the occupants can access the exit stair in their own wing, but to access the 2nd exit they must travel down their corridor, across the common space, through an exterior door, and across the roof of the adjacent wing to reach the roof-top exit stair doorway, then they are in the protected (assumed) exit stair. There are lots of other peculiarities with this building, but the over-riding question is: Is this configuration a code violation?

*The corridor connecting the exits should be a 1-hr fire partition, but there is no corridor, because its a roof!

*They are theoretically moving from a protected corridor, to an unprotected "path" then back into a protected stair. But is an open path less protection than the 1-hr fire partition.

*They are calling it a type III-A, which should translate to III-1hr from the UBC. Which means the roof should be 1-hr.

 

[cda]

I thought roof walk exits use to be approved??

 

[Sleepy]

Does IBC (2015) Section 1021 Egress Balconies help? I'm not sure you could describe a rooftop path as a "balcony", but I'm not sure you couldn't either.

 

[JCraver]

Aren't they essentially at the exit when they pass through the exterior from the common area onto the roof? What's the construction / rating of the wall where that exterior door is, and the roof they're stepping out on to?

What kind of work are they doing on the building (assuming this is why you're aware of the situation?)?

 

[Sifu]

Classified as a III-A, the exterior wall would be required to have a 2-hr rating. The egress balcony could be looked at as possible solution but I am not sure how the path could be maintained in the winter, or if it is really the intent to cross a roof. But it certainly is possible that was the way it was looked at.
The scope of work does not have a lot to do with the issue, except that the code analysis, showing the MOE, CPET, EATD etc, leaves me with several questions I would like to have answered. And when I point out that they have not done some of those things correctly I almost have no choice but to ask that their exit strategy is. It is somewhat of an exercise in self-education, but my CBO does want questions like this asked and will often require them to be addressed. The desired outcome is that they can show me how they are meeting code, and we all have a nice day.

 

[Builder Bob]

I am not sure how that would be code complaint as the (SBCCI and current code) mandate that once a level of protection of egress is granted, it cannot be lowered until you reach the exit discharge (i.e. public way)

 

[Mr. Inspector]

Why a code issue? Are they doing work to the building?

 

[Sifu]

While it is accurate that the corridor should be constructed as a rated fire partition, I am wondering if this was approved on the basis that the open air path is not considered as a lessening of protection. Not sure I see it that way but I need to entertain the idea it was approved under. I don't think it would count as an exit discharge since it is not a public way.

CDA, you use the term roof-walk. Is or was that a thing at some point? I am gonna search that term in the old UBC's.

New information-I was told by an inspector who has been there that that the path to the second exit is enclosed by a chain link fence..........not sure that helps clear anything up.

 

[JBI]

If it was approved at the time of original construction it is compliant as long as nothing has 'changed'..
You would need to know exactly what (if any) Codes were in effect at time of original construction.

 

[Builder Bob]

The stairway in a fire barrier not a fire partition...... the roof walk would have to be supported by the roof ceiling assembly of 1 or two hours - all supporting construction - basement to uppermost floor would have to be the same rating at the Horizontal Exit. If building has a fire sprinkler system, they are also leaving the umbrella of protection from the fire sprinkler system as well.

IN the 60's, a concept was used for smoke free enclosures and the stairway was usually separated from the building by a small walkway (10 feet) and not separated but open on the outside wall to prohibit trapping of smoke in the open stairway.

IEBC performance base design may be the answer to this one...

 

[Sifu]

The reason this comes into question: The altered tenant space requires two exit access doors based on occ. load. They must be separated by 1/2 the diagonal of the space, measured in a straight line to the center of the threshold. The DP has shown the measurement along the path of travel of the corridor. It does not meet the minimum distance otherwise. The only way the distance is allowed to be measured that way is if the interior exit stairs are connected by a 1-hr fire partition, and with the situation I have described, they are not.

They have altered the spaces to the extent that they now must have a 1-hr fire partition connecting the stairways per IBC 1015.2.1, and as described they do not. What complicates this is that even before the alteration, they would have been required to have a 1-hr fire partition since the corridor serves >30 and is non-suppressed (basically the same as the 1970 UBC), even though that is a different section that triggers it. So even though the MOE hasn't really changed, the driver behind the design of the MOE has.

There is no indication as to which code was enforced, but guessing at 1970 UBC. The exit arrangement in that code was a little different, and it didn't give the option to measure down the corridor. Either way they have changed the requirements of the MOE from what currently exists and by the current code it wouldn't meet the letter of the code. I am trying to figure out if it ever met code. The building was built under a different jurisdiction, but is now ours.

We do not have the IEBC adopted.

 

[Builder Bob]

SIfu - are you in the 2012 IBC? Otherwise you are very limited in what you can do in existing buildings except bring them up to current code..... what a nightmare.

 

[Sifu]

Yes, 2012 IBC. The original plan was submitted but didn't show the details for the 3 story wing, it just showed a stair core in the middle of a blank space. I assumed they simply weren't showing me the details of the other wing because they thought it was not in the scope.......which it wouldn't have been if they didn't need the connecting corridor. In other words, I wouldn't have even known enough to ask the question. So I wrote a comment letter back to the architect, asking them to show me the layout for the other wing and verify the connecting 1-hr corridor, again I was assuming they could! After the letter was sent one of my inspectors came in and I told him about it, he is the one who informed me that it was an open roof. The comment had already been sent and I just figured they would get the picture. They did, and even though I didn't mention anything specific about the exit path across the roof, their email back to me seemed a little frantic, kind of like they knew it was a potential problem.

I'm afraid I poked the bear again. This one will go up the food chain.