Horizontal exit?

[Yankee Chronicler]

Exception #2 covers a majority of the situations I've ever seen that might otherwise require a standpipe near a horizontal exit.

 

[Sifu]

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.

Not exit enclosures. Standpipe exception would not apply. Egress convergence acknowledged as not an issue. All of it moot. I finally thought my way out of it. My hang up was adding the OL from the A4 use across the fire wall to the educational side, but those uses would not be concurrent to the E uses, so even if 2000 people were using the gym for an event, they would not be doing it at the same time as the E use on the other side, therefore the number of exits would be compliant.

 

[Yankee Chronicler]

Not exit enclosures. Standpipe exception would not apply. Egress convergence acknowledged as not an issue. All of it moot. I finally thought my way out of it. My hang up was adding the OL from the A4 use across the fire wall to the educational side, but those uses would not be concurrent to the E uses, so even if 2000 people were using the gym for an event, they would not be doing it at the same time as the E use on the other side, therefore the number of exits would be compliant.

That's the way our State Building Inspector and the Department of Education plan reviewers have treated it since ... forever. A typical high school will have three major assembly spaces: a cafeteria, a gymnasium, and an auditorium. We actually do plan for egress for concurrent occupancy of all three, although they are usually in different areas of the building so they don't usually share all means of egress. Where the concurrent occupancy comes into play is for plumbing fixture counts, and the state has decided that we don't have to plan for all three spaces to be occupied to maximum capacity simultaneously for purposes of plumbing fixture count.