Close Off Part of a Stairwell in High Rise

[jar546]

If a high rise R2 is 18 stories and an engineer is proposing to close off part of the 2nd floor stairwell to make room for non-essential equipment, can this be done?

 

[TheCommish]

Does not seem to reduce the width, therefore the capacity, I would say yes

 

[steveray]

Is the landing supporting the new "B" wall rated? As the "non-affiliated stuff" can't be in the exit enclosure, the exit enclosure is now the B wall and the rating and support provisions need to be correct...

 

[Yankee Chronicler]

steveray is correct. Typically, stairs themselves are not rated construction because they are contained entirely within a rated exit enclosure. Once you erect a rated wall on the landing to modify the size and shape of the exit enclosure, everything that supports that new wall will have to have a 2-hour fire-resistance rating. Also, the ceiling of the newly-created equipment space will have to provide a 2-hour separation from the third floor landing above.

 

[jar546]

Is the landing supporting the new "B" wall rated? As the "non-affiliated stuff" can't be in the exit enclosure, the exit enclosure is now the B wall and the rating and support provisions need to be correct...

 

[jar546]

So, for the record, neither the Fire Marshal nor I will allow this change to occur in an existing building. The existing building code puts a stop to it.

 

[steveray]

View attachment 15648

I’m good with the U419, but the supporting construction would need to be 2 hours…. And any other egress width complications….And the 2 hour joint between that and the concrete…

 

[Paul Sweet]

And the landing above (ceiling).

 

[steveray]

And the landing above (ceiling).

They could put a lid in in theory....