Elevator shaft separation from remainder of building

[Yikes]

This is as much a building code question as an elevator question:

A two story elevator shaft has an overrun roof that protrudes above the roof of the Type II-B building it's in:


The elevator has a cab-mounted motor, which triggers the following fire-rating requirement for the shaft by the local AHJ: ASME A17.1-2004 SECTION 2.7 MACHINE ROOMS AND MACHINERY SPACES 2.7.1.1.1 “Spaces containing machines, control equipment, sheaves, and other machinery shall be separated from the remainder of the building by a fire resistive enclosure conforming to the requirements of the building code.”
The shaft currently has one-hour rated walls that comply. The roof of the shaft overrun is nonrated (exposed 2x10 joists). CBC 601 says the roof for Type II-B can be 0 hour rated.

The local elevator inspector says that the shaft enclosure per 713.12 must have a one-hour rated roof-ceiling assembly per ASME A17.1-2004 - 2.7.1.1.1.

I say that 2.7.1.1.1 defines the extent of the fire resistive enclosure: it must separate the space from the remainder of the building. The top of the elevator shaft is not contiguous with the remainder of the building. It has its own roof that is above the roof level of the rest of the building, as seen in the aerial view below. Thus the entire space of the shaft is in compliance with section 2.7.1.1.1 for being separated from the remainder of the building by fire resistive enclosure.

Who is right?

 

[TheCommish]

In Massachusetts's the top of the shaft regardless of where the shaft ends must maintian the rating

 

[MKALLAY]

Per the text you quote above, it says the fire resistive enclosure should be "conforming to the requirements of the building code.” I would look to IBC Sections 713.6 and 713.12 (or other as per applicable edition) for justification - typically exterior walls enclosing shafts are rated only if required per section 705 based on separation distance.

 

[Yikes]

Per the text you quote above, it says the fire resistive enclosure should be "conforming to the requirements of the building code.” I would look to IBC Sections 713.6 and 713.12 (or other as per applicable edition) for justification - typically exterior walls enclosing shafts are rated only if required per section 705 based on separation distance.

Agreed. My question is specifically about the roof of the shaft.

 

[Paul Sweet]

ASME A17.1-2004 2.7.1.1.1 "Spaces containing machines, control equipment, sheaves, and other machinery shall be separated from the remainder of the building by a fire- resistive enclosure conforming to the requirements of the building code"

IBC 3002.1 "Elevator, dumbwaiter and other hoistway enclosures shall be shaft enclosures complying with Sections 712 and 713."

IBC 713.12 "A shaft enclosure that does not extend to the underside of the roof sheathing, deck or slab of the building shall be enclosed at the top with construction of the same fire-resistance rating as the topmost floor penetrated by the shaft, but not less than the fire-resistance rating required for the shaft enclosure."

Your roof would only have to be rated if there is a state or local amendment requiring a fire-rated roof.

 

[Yikes]

Paul, that's what I think.

This is further clarified in the 2022 CBC, with no technical change from the code requirements of the 2019 CBC 2020 LABC applicable to our project.
I just wish I could get the elevator inspector to see it that way.
See https://www.iccsafe.org/building-sa...ures-in-the-2021-international-building-code/







In other words, a IIB building has a nonrated roof.