Shared Rated Egress Corridor - 3rd Stair - Super High Rise

[JVL]

I've got a super-high rise building with 3 stairs. One stair is exiting through the lobby, the other two therefore need to exit directly to exterior correct? Can I do a rated corridor at the ground level leading to the exterior for the most interior stair, and then have the other stair also tap into that corridor? I've got the room to increase width where they converge if req'd.

 

[RLGA]

You can have an exit passageway connect the stairway to the exterior, but not a corridor. And no, the two stairways cannot lead to a single exit passageway if the three exits are required. If three exits are required and two stairways lead to a single exit passageway, then those two stairways converge to create only one exit from the building.

 

[JVL]

Thanks! Sorry - you are correct, it will be an exit passageway, not corridor. I guess i'm wondering if 3 exits are really required? I know a maximum of 50% of the number and capacity of exit enclosures is permitted to egress through the lobby on the level of discharge, but that the required egress width of two must be maintained if the fire department commandeers it... is the third stair considered an exit enclosure? I think i'm out of luck here, but just checking.

 

[RLGA]

Is the height of the high-rise more than 420 ft. above the grade plane or does any story have an occupant load greater than 500? If you answer yes to either of those, then three exits are required.