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exit stair termination

JsBach

 We are doing an interior finish out for an assembly space (850 occupants or so) going into a multi-story shell building (currently being designed by another architect). One of the fire rated stairs that will be required to meet our exit capacity is discharging into the center of an underground or partial underground parking garage. I am not sure that a parking garage meets the definition of an exit discharge into a public way.

 Does anyone have any thoughts on this, and can they explain why or why not this would meet  code.

 
Apr 25, 15 2:27 pm
Carrera

I don't think so based on Life Safety Code definition of "Public Way":  “Any street, alley, or other similar parcel of land essentially open to the outside air deeded, dedicated, or otherwise permanently appropriated to the public for public use and having a clear width and height of not less than 10 feet ”. Note emphasis on “outside air”.....I agree that it's not a clear topic, because I have done projects where I defined something like that as “exit refuge”…moving people to another building that’s fire protected/separated. That fact that it is unclear allows you to interpret if it's a necessity…think too it matters how far people would have to travel through the garage to get “outside”. Attached a link where this is discusses to give you a place to start.

http://www.ct.gov/dcs/cwp/view.asp?a=4219&q=494822

Apr 25, 15 4:49 pm  · 
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geezertect

Miles will be offering his consulting services shortly.

Apr 25, 15 6:27 pm  · 
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citizen

^ As well he should, in this (but not every) case.  

Apr 25, 15 7:21 pm  · 
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JeromeS

Ask the AHJ for a determination...

Apr 25, 15 10:05 pm  · 
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bklyntotfc

Means of egress - and their fire rated enclosures generally have to extend to the exterior of the building.  In NYC, you can have one means of egress open into a building lobby, as long as the lobby is directly open to the street/yard.

If you read the means of egress section of the code you're using, I'm pretty positive you'll see language about this in there right at the beginning.

Apr 26, 15 3:04 pm  · 
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JsBach

 Thanks for the input so far. I am in between a rock and a hard place as usual. Trying to convince both my managers and our client that what the shell architect has planned will not meet our exit requirements. When I asked the question, the answer I was given was to prove that we couldn't exit into the parking garage. I don't think I am going to find any language in the code stating "thou shalt not exit a fire stair into the middle of a parking garage".

I would understand if the stairway exited into a garage where the exit was adjacent to street access, but in this case it's 75-100' away. Also, when looking at the shell architects exit plan, they are showing an exit arrow BACK INTO the stair.

Now for the big question, why am I doing code research on a Sunday, because I can't sleep when I have questions like this in my head.

Apr 26, 15 4:32 pm  · 
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curtkram

Sounds like you`re not exiting into a parking garage, but rather through the parking garage.  Can you exit through a parking garage in the same way you exit through a lobby?

Apr 26, 15 4:47 pm  · 
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JsBach

 Curtkram, from what I gather, once you enter a fire rated exit pathway, you have to exit out the building. When you are exiting through a lobby it is usually a situation where you never  entered a fire rated passageway. That's just a normal exit.

 Another issue that is going to come up is, even if we exit into the garage, if we have to include further travel distance to outside of the garage, we are going to be over the max travel distance.

 So, I think the answer to my questions, I think we need to continue a fire rated corridor to a public way exit discharge. The problem is how do I "prove" that to my bosses and the client. I don't really care if I end up being wrong either, if we can exit through the parking garage, then all is easy.

Apr 26, 15 6:03 pm  · 
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I think if it was ground floor and appropriately fire separated you could argue for it, but given that it is underground I doubt any code official would let it fly. Is there a way to move the stair so that you can have a small fire corridor to get to the exterior?
Apr 26, 15 6:04 pm  · 
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JeromeS

Maximum travel distance...

Apr 26, 15 7:13 pm  · 
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curtkram

as i recall, sometimes only half your exits need to be fire rated.  dose that ring a bell?  I didn't look it up.  it's probably some sort of exception that only applies in some instances.

if it does have to be rated, then you're right that you need to maintain the rating all the way outside, and if your travel distance is too far, then it's too far.

Apr 26, 15 7:19 pm  · 
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JsBach

 Josh, we have the option on the ground floor to provide a fire rated corridor from the center stair to outside the building. I know that is the solution, again I just have to "prove" that the existing design won't fly.

 Curtram, I think what you are referring to is that half of the people need to be able to exit out the main entrance in assembly buildings. The other thing to note is that the max travel distance goes to the entrance of the fire stair, then you can virtually go as far as you want. Otherwise you would never be able to do a high rise building.

Apr 26, 15 7:39 pm  · 
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gruen

Horizontal exit. That might be the correct option. ALSO might not work in your case, depends on the arrangement of the buildings. If the assembly building is on top of the parking garage then can you call the two buildings actually separate buildings? I doubt it. 

 

I think your boss needs to "prove" why this works without a rated corridor to daylight. 

I think it's clear that:

1) most buildings require 2 means of egress (IE: 2 exit stairs). Yours requires 3, correct?

2) generally, these all need to be rated, because they are shafts

3) once you enter a rated exit component, you cannot exit the rated exit component into a unrated portion of the building unless it's a lobby with a CLEAR (IE: visually clear) means to the exit door. And you can only do that with 1 of the exit stairs. 

4) There's an argument to be made for smaller buildings that if your total travel distance is less than the allowed maximum (including distance on the stairs) then you could enter and exit a rated shaft. But I suspect that your building is too large. 

There are many reasons why this is a cruddy idea. The best arguments FOR it are:

1) you might be able to put in a horizontal exit

2) you might separate it into two buildings w/a firewall

3) you are exiting from a high hazard (assembly) into low hazard (utility or storage - parking garage) (honestly, this is a weak argument)

4) your travel distance is short (??)

The best arguments against it are:

1) you are exiting underground

2) you are NOT exiting to a public way

3) you are entering a rated exit component and exiting it before getting to the public way

4) possibly too long of a travel distance

 

Final thought before I start wondering why I'm wondering about code on a sunday night:

How the heck do you get OUT of the parking garage once this stair dumps you into it? If you are underground, do you need another stair to get out? Or are you expected to walk up the ramp? If you are expected to walk up the ramp, then it's probably not accessible. You only need 1 accessible exit (double check me on that) but if this is the accessible exit, then the vehicle ramps are not accessible. I know wheelchairs won't go down the stair, but accessibility is for people with crutches too. 

Apr 26, 15 8:21 pm  · 
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JsBach

 How the heck do I get out of the parking garage. Well that's kind of sketchy. I don't have the plans with me, and I just started looking at them Friday afternoon. The shell building occupancy plan looked kind of schematic to me, I only had a pdf and there were no clear ramps or stairs. All of the travel distance information shown on the garage level showed travel from the perimeter back TO the stair (?).

 To me this seems like a big lack of communication. We frequently have these battles with shell architects where they just don't really pay that much attention to our criteria, then whine after we try to get our permit or start construction that they have to make alterations. If I didn't mention it, I don't think the building is finished permitting yet. For further information, our finish out is a multi-cinema, that's what our group works on exclusively, so we know most of the codes and requirements.

 The main staircase is open from the upstairs lobby all the way through the downstairs lobby, no need to fire rate this, it's a common design element we have in most of our projects. There are 3 total stairs I think, technically you only need 2 except for travel distance issues, and the fire rated ones are their specifically because of travel distance. Again, you can take your full 250' up to the entrance of the fire stair. The central stair where we are having the concern is critical to exiting a couple of the theaters, the travel distance is too far to use the others.

 I will have to ask about considering it as two buildings, I don't see how though.

 So far the only language in the code I have found for stairs in parking garages pertain more towards multi-level parking garages with stairs between levels. The codes aren't as stringent for these on where the stair discharges. I just can't find anything about other uses dumping into a garage.

 I always worry that even if for some reason this got through the city, it still wouldn't meet code and set our firm up for a massive lawsuit. I still haven't found anything yet that "proves" this works or doesn't work. It's a definition thing, is a parking garage open air as far as the code is concerned.

Apr 26, 15 11:16 pm  · 
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gruen

I've used a parking garage as a second exit from the same level that the parking garage is on. In other words: ground floor is majority parking garage with a small portion of "building" associated w/it. One exit straight out of the "building" and the second exit from the "building" through the parking garage. Of course, it was all on grade and there was a clear visual path from the "building" to the exit of the parking garage. 

I'm thinking through the mixed use thing - assembly + utility (or storage, not sure which you are calling your parking garage). You'll have an occupancy separation between them but probably not the 3 or 4 hour fire wall that you'd need to call them 2 separate buildings, correct? If they are stacked one above the other you'd need 3 or 4 hour structure as well as the 3 or 4 hour horizontal assembly. So, I bet you don't have 2 separate buildings. 

 

buildings "exit" into parking garages all the time - that's how people get to their cars (LOL). 

Anyone with tower experience who wants to chime in here? 

Apr 26, 15 11:40 pm  · 
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JsBach

 To tell the truth Gruen, I haven't designed a parking garage or a building with one. I did talk to one guy in the office who said that he had done multi-family stairs dumping into a garage. I wasn't clear if it dumped into the center or was on the perimeter.

 Like I mentioned earlier, I could be dead wrong. Maybe exiting into the center of an open air garage is common, I just can't find any specific language in the code that answers this.

Apr 27, 15 12:12 am  · 
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Carrera

Not much "high rise experience" other than being in them.... always wonder about discharge capacity.... ground exits look like mouse holes when measured against the mass, know high rise hotels have stairs but that's not where I'm going if I sense trouble.... stairs might be safe refuge, but speed is paramount... close friend in the elevator biz says they're working on pressurized elevator cabs, mostly because of speed, but will be used for fire exiting by default.... big needed development... guess we learned about stairs on 9/11.

I can think of many examples to help the OP, but he/she needs evidence in a book, thought I provided that.

Apr 27, 15 7:25 am  · 
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Volunteer

What happens with egress if the fire originated in the underground garage?

Apr 27, 15 8:02 am  · 
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Non Sequitur

Strange, all my exit stairs are always separated from those heading to the parking levels. They are stacked in plan, but in my multi-storey projects, once you're in the exit stair, there is only one way out, and it's immediately out at grade.

Apr 27, 15 8:29 am  · 
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shellarchitect

not sure if this will really help, but I've done exits through covered loading dock areas or similar situations what aren't clearly a "public way" and had to clearly mark the full width of the egress path to its termination point. (floor paints and signage)  Had to discuss it with the local building officials each time too.  We used CCI for that, just prepared documents for them to present.

Definitely need to coord. the exits arrows with the shell arch, not sure I understand why your exiting down through the garage and the shell arch. is exiting up to somewhere else (maybe I'm missed)

don't forget to check the width of the stair too

Apr 27, 15 8:43 am  · 
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midlander

I worked on a convention center which included meeting rooms and offices above the exhibit halls - some of the stairs from these went to corridors UNDER the parking garage and back up to exit at grade. The entire corridor was rated and I think sprinklered. Not a cheap solution, but necessary to avoid corrdidors cutting through either the main exhibition space or the lobby.

The key issue as I recall was that the code (IBC-200X?) only permitted exit discharge AT GRADE and then only for 50% of the occupancy load. So, per IBC no not ok to exit through a below grade garage.

this part from 1027 is what Im thinking of:

1. A maximum of 50 percent of the number and capacity of interior exit stairways and ramps is permitted to egress through areas on the level of exit discharge provided all of the following are met:

Apr 27, 15 10:18 am  · 
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bklyntotfc

For God's sake, carefully read the code.  Means of Egress section includes multiple references to the fact that a means of egress cannot be through other spaces, through spaces occupied by other tenants/uses, etc.

So while the code doesn't say "you can't exit through a garage," it does say you can't egress through other spaces.  Is the garage a space?  Yes.  Then you can't egress through it.

This is not allowable, not even close...although I do like the idea of there being a large fire in this building, and people having to egress through a space filled with vehicles each w/ +/- 20 gallons of a highly flammable liquid in them.  That sounds like a good idea.

And I wouldn't necessarily spend time figuring out how the shell architect is going to make the egress work, that's their problem, not yours.

Apr 27, 15 10:32 am  · 
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Brud-G

Do at least 50% of the other exits in the building discharge directly to the exterior? If so, the exit discharge through the parking area might be acceptable.

Apr 27, 15 3:42 pm  · 
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geezertect

I know this sounds crazy, but why not talk it over with someone at the applicable building department?  Just a thought.

Apr 27, 15 4:38 pm  · 
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∑ π ∓ √ ∞

^BING^

Correct answer.

Apr 27, 15 6:19 pm  · 
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bklyntotfc

Brud-G...how would that be acceptable?  There's a fire in the building, we rush down the stairs, to find that we've exited into a parking garage that's engulfed in flames...oh well.

This will not meet code.

Beyond that, it would be a stupid idea.  Imagine trying to get everyone going down the stairs to stop, and turn around to go back to the other exit.  Not going to work.  Or imagine that you're unlucky enough to let the stair door close behind you before you realize you don't want to go that way.  That door is probably automatically locked itself when it closed to prevent unwanted access.  It'll open just fine if you push the panic bar from the inside, but you're not on the inside.  So you're done for.

With very few exceptions (one egress into lobby that has immediate street access, single family houses, etc.) egress is to the street or yard.

Apr 28, 15 12:51 pm  · 
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shellarchitect

as I mentioned above - exiting into an enclosed loading area can be acceptable.

I agree that exiting into an underground parking deck is a different animal

Apr 28, 15 2:14 pm  · 
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∑ π ∓ √ ∞

bklyn, not all stairs are part of the required means of egress. so, brud-g is correct.

Apr 28, 15 2:20 pm  · 
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