Horizontal exit?

[Sifu]

If a high school gym requires 4 exits (based on OL), and two of them are through a fire wall, then through the school to reach the discharge, does that automatically make them horizontal exits?

 

[steveray]

No....But that one is a little tricky...Basically, if you don't need them to be an HE, they are not....

 

[RLGA]

Yes, a fire wall complies with all the requirements for a horizontal exit, provided you have the refuge area capacity on the school side of the fire wall.

 

[Sifu]

Of the 4 exits, there are two on each end. The two on each end are not separated by enough to meet the 1/3 requirement, so the other two must be used to get the required separation, and unless the two that traverse the fire wall are counted, the CPET would be exceeded from the most remote point, and the capacity would be insufficient without all of them. The way I see it they are horizontal exits because they are required, but I expect push back so I want to be sure.

 

[steveray]

They are required exits, but they only need to be exit access doors likely....To me that is where the rub comes in.....You have access to the proper number of exits beyond the "HE" doors, so CPET is met, and I assume you don't have a TD issue, so they are not required to be an HE, just exit access through a firewall...

 

[Sifu]

They are required exits, but they only need to be exit access doors likely....To me that is where the rub comes in.....You have access to the proper number of exits beyond the "HE" doors, so CPET is met, and I assume you don't have a TD issue, so they are not required to be an HE, just exit access through a firewall...

Yes, the rub is what requires them to be HE's? If they met number, capacity, CPET, and separation without them, then they would be "extra" exit access doors. But without them, none of this is met, so they are "required" exit access doors. Since they are required, then my thinking is the MOE on the other side must meet the requirements for that load, OR the refuge area kicks in and a HE exists....with a few other additional elements of an HE. EATD is already mt since it is only measured to one of the doors. CPET would be met either way as long as those exit access doors exist in any form, as does separation, so now it becomes a capacity issue. If capacity is met, do they escape the HE designation?

If they must have the egress capacity to handle 1/2 to OL from the gym in order to not be an HE, distributed equally among the other exit access/discharge doors, they will be short. Not sure you will be able to make out anything from the snippet, but can't hurt.

 

[steveray]

Can't really tell from that....but the simplest I can put it is that if they don't need to be an EXIT (HE), and are just exit access doors in a FW then they are not HE...

 

[princeofpen]

I can't see a CPET issue with a gym. Your ability to egress within 75' to choose a right/left direction is not an issue. Exit travel distance may lead you through a firewall at an exit but it would be just that not a horizontal exit unless you needed to end your exit travel distance. In other words I'd expect it to be noted as a horizontal exit if said exit door was 249' from another remote point if that makes sense. Once you go through said exit into another building you have discharged out of the fire/panic building you were in and your exit distance from that point doesn't matter hence the need to provide sq/occupant on both sides of a horizontal exit.
My 2 cents

 

[princeofpen]

As far as the remoteness of exits on the drawings above I'd have issue with the movable partition obscuring the view of the exits plan "N" and would want other exit doors added to the corridor plan "E" . Basically separate the gym into 2 areas with their own stand alone egress with the dividing wall in place and you'd be good to egress regardless of if the wall was extended or not.

 

[Sifu]

In the drawing, the 3 doors at the top plus the single door at plan bottom right equal the OL from the space. So even though they indicate a capacity at the bottom doors through the FW, they are not included in the capacity of the main exit doors on the refuge side of the FW (left and right double doors). The bottom right door from the gym with an egress load of 186 is also not included on the refuge side. So the egress system is based on the concept that all occupants of the gym will exit towards the top of the drawing, and if they don't, the OL of the refuge side would exceed capacity of the main doors on the left and right.

As I understand it, as a horizontal exit, the capacity of the refuge side discharge doors must equal the load from only that side, not including the capacity coming from the other side. This is because the HE allows a protected state while they await exit. Conversely, if the doors are not treated as HE's, then the capacity of those side doors would need to account for a properly distributed load from the gym. Saying none of the gym occupants will go towards the bottom isn't distributed, and goes against common sense, and the concept of exiting the way you came in.

 

[Yankee Chronicler]

No....But that one is a little tricky...Basically, if you don't need them to be an HE, they are not....

I have to disagree. A horizontal exit is a horizontal exit if it meets the definition -- the definition doesn't care if you need the exit or if it's excess.

HORIZONTAL EXIT. An exit component consisting
of fire-resistance-rated construction and opening protectives
intended to compartmentalize portions of a building thereby
creating refuge areas that afford safety from the fire and smoke
from the area of fire origin.

Compare to an exterior exit door in an occupancy allowing 200 feet of exit access travel distance. By your logic, if there's an exterior door 75 feet from the most remote point and a second, identical, door 150 feet from the most remote point -- the first door isn't an exit because it doesn't need to be.

FWIW, this actually came up a number of years ago. I did a plan review for a school addition/alteration project. The original auditorium was being kept intact, but the west side had originally been an exterior wall and had exit doors to the outdoors. The project built a new classroom wing in that location, leaving the auditorium with zero doors discharging directly to the exterior, and completely enclosed in fire walls. The code at the time said that not more than 50% of the exits could be through horizontal exits.

I referred it to the state. The ruling from on high was that, even though all the exits were now going to be horizontal exits, the total exit access travel distance through the fire walls to exterior exit discharge doors was withing the allowable exit access travel distance, so therefore the condition was deemed acceptable. Which sounds alot like what steveray said ... except that the state did NOT say that the doors through the fire walls were not horizontal exits just because the school didn't need them to be horizontal exits.

 

[steveray]

I have to disagree. A horizontal exit is a horizontal exit if it meets the definition -- the definition doesn't care if you need the exit or if it's excess.



Compare to an exterior exit door in an occupancy allowing 200 feet of exit access travel distance. By your logic, if there's an exterior door 75 feet from the most remote point and a second, identical, door 150 feet from the most remote point -- the first door isn't an exit because it doesn't need to be.

FWIW, this actually came up a number of years ago. I did a plan review for a school addition/alteration project. The original auditorium was being kept intact, but the west side had originally been an exterior wall and had exit doors to the outdoors. The project built a new classroom wing in that location, leaving the auditorium with zero doors discharging directly to the exterior, and completely enclosed in fire walls. The code at the time said that not more than 50% of the exits could be through horizontal exits.

I referred it to the state. The ruling from on high was that, even though all the exits were now going to be horizontal exits, the total exit access travel distance through the fire walls to exterior exit discharge doors was withing the allowable exit access travel distance, so therefore the condition was deemed acceptable. Which sounds alot like what steveray said ... except that the state did NOT say that the doors through the fire walls were not horizontal exits just because the school didn't need them to be horizontal exits.

You can disagree...we all make mistakes....

[BE] EXIT. That portion of a means of egress system between the exit access and the exit discharge or public way. Exit components include exterior exit doors at the level of exit discharge, interior exit stairways and ramps, exit passageways, exterior exit stairways and ramps and horizontal exits.
EXIT, HORIZONTAL. See "Horizontal exit."
[BE] EXIT ACCESS. That portion of a means of egress system that leads from any occupied portion of a building or structure to an exit.
[BE] EXIT ACCESS DOORWAY. A door or access point along the path of egress travel from an occupied room, area or space where the path of egress enters an intervening room, corridor, exit access stairway or ramp.
[BE] HORIZONTAL EXIT. An exit component consisting of fire-resistance-rated construction and opening protectives intended to compartmentalize portions of a building thereby creating refuge areas that afford safety from the fire and smoke from the area of fire origin.

If you don't need it to be an exit, it does not have to be....If I built an "enclosed" exit access stair, would it have to meet exit enclosure requirements? No only exit access stair requirements.

Let me put it another way....As an HE can be separated by a fire barrier, not just FW, do all doors through fire barriers need to meet HE requirements?

Of course, I am ASSUMING that the FW is there to deal with an H&A issue, not "intended to compartmentalize portions of a building...."

 

[jj1289]

Only if the RDP identifies it as an HE and it meets all of the criteria. If an HE is not called for on the construction documents, then one does not exist.

In the situation of a exiting through a firewall, then the occupant load would be cumulative.

 

[Sifu]

Of course, I am ASSUMING that the FW is there to deal with an H&A issue, not "intended to compartmentalize portions of a building...."

You would be correct. It is there to cut the area down. I think once they put it in place they stopped analyzing it. But because the exit capacity below the FW is not adequate for the combined loads, now they must compartmentalize, even if that was not the intent.

The heartburn I have starts with the exit strategy. 1200+ occupants in the space, can all be handled via the top exits. If there were no other exits out of the space, they fit but would exceed CPET, not offer separation, and not provide the required number of exits. So they added in the bottom exits, this cuts CPET, provides separation and makes the number hit 4. The problem is the influx of those occupants to the other side of the FW will overload the exits on that side. So for me, this means they need an HE with area of refuge, and the other requirements of an HE. Maybe they don't think they need it since the top gym exits can handle the load, but I think that is wrong because they must be there to satisfy the other requirements. (bold indicates the concept I am not completely certain of and the reason for this thread) Plus, if you enter that way, you are likely to exit that way, and if you show occupants a shiny new door with panic hardware and exit signs, they will use it for that very purpose.

Since the bottom exits are required (even if not based on capacity) they have an occupant load, which the plans call 732. Those 732 people now must be joined with the OL of the other space and the exits now must be sized for the combined OL served....unless you have an HE, which allows them to be sized based only on the original load of the space....because they have extra protection by 1) standpipes, 2) refuge area 3) smoke dampers. The exiting is slowed down, but it's ok since they are "protected".

I think if there were enough exit/access doors to satisfy all the requirements and these were extra, then they would not need to be considered HE's. But since they do not, I think they must be HE's. It is possible the DP has not considered this at all, having stopped at gaining the allowable area with the FW. They have enough refuge area so it isn't going to be a redesign. I think they only need to change fire dampers through the FW to fire/smoke, and add standpipes. I will have the conversation and see what they say.

 

[steveray]

So they added in the bottom exits, this cuts CPET, provides separation and makes the number hit 4. The problem is the influx of those occupants to the other side of the FW will overload the exits on that side.

This makes a little more sense other than "adding" the bottom exits but it seems like they were already there as an entrance?

And yes, if they are using the bottom doors to satisfy remoteness, they have to show the proper occupant load all the way to the discharge whether it is the HE or a different discharge. If the downstream doors cannot accommodate the OL, HE it is or fix/ enlarge the other doors....Told you it was tricky....

 

[Sifu]

This makes a little more sense other than "adding" the bottom exits but it seems like they were already there as an entrance?

And yes, if they are using the bottom doors to satisfy remoteness, they have to show the proper occupant load all the way to the discharge whether it is the HE or a different discharge. If the downstream doors cannot accommodate the OL, HE it is or fix/ enlarge the other doors....Told you it was tricky....

Tricky doesn't begin to cover this one. In addition to the added OL/horizontal exit issue, we have egress convergence from above. So there are a lot of what-if's. They have not one a very good job of demonstrating their exit strategy, or accurate OL, so that is comment #1. Beyond that, I think if they use an HE, everything will work on the first floor...until the 2nd comes in to play, where they have exceeded the CPET, EATD, and not met the number of exits. This could change the first floor strategy all by itself. Going to be an enlightening conversation.

 

[Yankee Chronicler]

The problem is the influx of those occupants to the other side of the FW will overload the exits on that side. So for me, this means they need an HE with area of refuge, and the other requirements of an HE. Maybe they don't think they need it since the top gym exits can handle the load, but I think that is wrong because they must be there to satisfy the other requirements. (bold indicates the concept I am not completely certain of and the reason for this thread) Plus, if you enter that way, you are likely to exit that way, and if you show occupants a shiny new door with panic hardware and exit signs, they will use it for that very purpose.

Since the bottom exits are required (even if not based on capacity) they have an occupant load, which the plans call 732. Those 732 people now must be joined with the OL of the other space and the exits now must be sized for the combined OL served....unless you have an HE, which allows them to be sized based only on the original load of the space....because they have extra protection by 1) standpipes, 2) refuge area 3) smoke dampers. The exiting is slowed down, but it's ok since they are "protected".

Nope. The occupant loads are not cumulative.

1026.4.2 Number of exits. The refuge area into which a horizontal
exit leads shall be provided with exits adequate to meet
the occupant requirements of this chapter, but not including the
added occupant load imposed by persons entering the refuge
area through horizontal exits from other areas. Not less than
one refuge area exit shall lead directly to the exterior or to an
interior exit stairway or ramp.

 

[Sifu]

Nope. The occupant loads are not cumulative.

Those 732 people now must be joined with the OL of the other space and the exits now must be sized for the combined OL served....unless you have an HE,

They are not cumulative IF there is a horizontal exit per 1026.4.2. Otherwise, the exits must be sized for all spaces served.

 

[Yankee Chronicler]

Those 732 people now must be joined with the OL of the other space and the exits now must be sized for the combined OL served....unless you have an HE,

They are not cumulative IF there is a horizontal exit per 1026.4.2. Otherwise, the exits must be sized for all spaces served.

Yes, of course. But a horizontal exit is defined by the code (which I quoted above). A horizontal exit is a horizontal exit if it meets the definition. It doesn't magically become a horizontal exit only if the architect puts a big "HORIZONTAL EXIT" note on the drawing with a big arrow pointing to the HE door(s). If it meets the definition ==> it's a horizontal exit, and the occupant loads are not cumulative. If it doesn't meet the definition, the occupant loads are cumulative.

 

[Sifu]

Yes, of course. But a horizontal exit is defined by the code (which I quoted above). A horizontal exit is a horizontal exit if it meets the definition. It doesn't magically become a horizontal exit only if the architect puts a big "HORIZONTAL EXIT" note on the drawing with a big arrow pointing to the HE door(s). If it meets the definition ==> it's a horizontal exit, and the occupant loads are not cumulative. If it doesn't meet the definition, the occupant loads are cumulative.

Which is my point. Without a refuge area, standpipes and smoke dampers it does not meet the definition or criteria criteria to be considered a horizontal exit, therefore the exits must be calculated with the full load it serves. If, however, they provide the refuge area, the standpipes, and the dampers, then the exit doors on the refuge side can remain sized for only their original load. As of now, they are sized for only the refuge side load, but there is no horizontal exit...as designed. They may have an area large enough for the refuge area, but it needs to be demonstrated based on the number of occupants which is somewhere around 1100 depending on a realistic exiting plan. Then all they need to do is provide standpipes and fire and smoke dampers and they will meet the definition and criteria to be a horizontal exit and ease the occupant load used for the MOE sizing on the refuge side.

There is a lot going on here.

The egress convergence question is still a concern. The refuge are must be sized for the load of those seeking refuge, plus the original load of the refuge area. What I'm not convinced of is the occupants coming from above. Those occupants must exit from the stairs into the same corridor being used for the refuge area before getting to the exit doors. If those occupants are included, the refuge area size may be too small. I think they need to be included since I'm not sure this is the intent of the egress convergence section, and they are using the same corridor to get to the discharge (about 65' on each end) before they arrive at discharge.

The overall scheme is to dump 1100+ from the HE on the same level, plus 500+ from above, plus 200+ original occupants, all out into the corridor. About 1900 occupants, two exit access with a capacity of 900 each. None of this includes to non-required exit access doors with 0 calculated occupant load from an adjacent wing of the school. Suffice it to say they are maxing it out, as they are entitled to, but I think they may be stretching it too far.

 

[steveray]

The overall scheme is to dump 1100+ from the HE

There is over 2000 people in the gym?

 

[Sifu]

There is over 2000 people in the gym?

The loads they calculate as crossing the fire wall come from two locations, 732 from the gym, 294 from the cafeteria. Their calculated occupant load is about 2000 for the gym during worst case use as a chairs only event with bleachers, and 485 in the cafeteria during a chairs only use as an audience.

 

[Yankee Chronicler]

Which is my point. Without a refuge area, standpipes and smoke dampers it does not meet the definition or criteria criteria to be considered a horizontal exit, therefore the exits must be calculated with the full load it serves. If, however, they provide the refuge area, the standpipes, and the dampers, then the exit doors on the refuge side can remain sized for only their original load. As of now, they are sized for only the refuge side load, but there is no horizontal exit...as designed. They may have an area large enough for the refuge area, but it needs to be demonstrated based on the number of occupants which is somewhere around 1100 depending on a realistic exiting plan. Then all they need to do is provide standpipes and fire and smoke dampers and they will meet the definition and criteria to be a horizontal exit and ease the occupant load used for the MOE sizing on the refuge side.

There is a lot going on here.

The egress convergence question is still a concern. The refuge are must be sized for the load of those seeking refuge, plus the original load of the refuge area. What I'm not convinced of is the occupants coming from above. Those occupants must exit from the stairs into the same corridor being used for the refuge area before getting to the exit doors. If those occupants are included, the refuge area size may be too small. I think they need to be included since I'm not sure this is the intent of the egress convergence section, and they are using the same corridor to get to the discharge (about 65' on each end) before they arrive at discharge.

The overall scheme is to dump 1100+ from the HE on the same level, plus 500+ from above, plus 200+ original occupants, all out into the corridor. About 1900 occupants, two exit access with a capacity of 900 each. None of this includes to non-required exit access doors with 0 calculated occupant load from an adjacent wing of the school. Suffice it to say they are maxing it out, as they are entitled to, but I think they may be stretching it too far.

Where is there any requirement for the refuge side of a horizontal exit to be equipped with standpipes? It's not in IBC 1026.4, and it's not in the definition.

Yes, it is understood that the exit doors from the refuge side are sized only for the original occupant load of that area. Doesn't matter. The whole point of a horizontal exit is that it is the EXIT from the fire side. Once those occupants have passed through the horizontal exit, they are considered by the code to be out of [immediate] danger. True, the capacity of the refuge area has to be sized to accommodate both occupant loads ... but it's sized at a ratio of 1 person per 3 square feet, which is denser than any normal occupant load for any occupancy.

The code tells us that the occupant load from a story above or below is NOT added to the occupant load of the story of exit discharge. "Converging" occupant loads are added only when the level of exit discharge is an intermediate level, with egress from the story below the level of exit discharge and from the story above the level of exit discharge converging at the level of exit discharge.

How is an exit stair from above discharging into the refuge area of a horizontal exit? That's an entirely separate question, and I don't see any way it can happen -- irrespective of convergence (which doesn't apply). Once in an exit enclosure, discharge from the enclosed exit can only be directly to the exterior, to an exit passageway, or through an exit lobby or vestibule IF it meets the specific requirements for same. A stair from an upper story that dumps into a space on a lower story isn't an "exit," it's a convenience stair.

 

[steveray]

Where is there any requirement for the refuge side of a horizontal exit to be equipped with standpipes? It's not in IBC 1026.4, and it's not in the definition.

Yes, it is understood that the exit doors from the refuge side are sized only for the original occupant load of that area. Doesn't matter. The whole point of a horizontal exit is that it is the EXIT from the fire side. Once those occupants have passed through the horizontal exit, they are considered by the code to be out of [immediate] danger. True, the capacity of the refuge area has to be sized to accommodate both occupant loads ... but it's sized at a ratio of 1 person per 3 square feet, which is denser than any normal occupant load for any occupancy.

The code tells us that the occupant load from a story above or below is NOT added to the occupant load of the story of exit discharge. "Converging" occupant loads are added only when the level of exit discharge is an intermediate level, with egress from the story below the level of exit discharge and from the story above the level of exit discharge converging at the level of exit discharge.

How is an exit stair from above discharging into the refuge area of a horizontal exit? That's an entirely separate question, and I don't see any way it can happen -- irrespective of convergence (which doesn't apply). Once in an exit enclosure, discharge from the enclosed exit can only be directly to the exterior, to an exit passageway, or through an exit lobby or vestibule IF it meets the specific requirements for same. A stair from an upper story that dumps into a space on a lower story isn't an "exit," it's a convenience stair.

[F] 905.4 Location of Class I Standpipe Hose Connections​

Diagram
Class I standpipe hose connections shall be provided in all of the following locations:

1. In every required interior exit stairway, a hose connection shall be provided for each story above and below grade plane. Hose connections shall be located at the main floor landing unless otherwise approved by the fire code official.
   Exception: A single hose connection shall be permitted to be installed in the open corridor or open breezeway between open stairs that are not greater than 75 feet (22 860 mm) apart.
2. On each side of the wall adjacent to the exit opening of a horizontal exit.
   Exception: Where floor areas adjacent to a horizontal exit are reachable from an interior exit stairway hose connection by a 30-foot (9144 mm) hose stream from a nozzle attached to 100 feet (30 480 mm) of hose, a hose connection shall not be required at the horizontal exit.