Tim Mailloux
REGISTERED
thats not what it says
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elevator connecting 1st floor w/ mezzanine
- Thread starter Nicole Brooks
- Start date
- Featured
thats not what it says
Paul Sweet
SAWHORSE
The rated shaft requirement might also be to protect surrounding spaces from an equipment fire in the shaft, especially if it's a hydraulic or machine-room-less elevator.
tmurray
SAWHORSE
Maybe I'm the idiot because I'm not familiar with the US code process. So, when something is added to the code, there is a reason right? In our system, each code change is accompanied with a document like this: https://cbhcc-cchcc.ca/eng/public-review/2025_1/2025-proposed-changes-to-nbc-combined-file-2025-01-15.pdf.
It tells me as a building official exactly what the intent was behind a provision. If the intent of the enclosure is to prevent fire spread between floors, but it's an open mezzanine, it doesn't make much sense to enforce that provision in those circumstances. This need for discretion has been recognized by our supreme court, who indicated that they expect building officials to act with discretion and not "code enforcement robots" (their words). Furthermore, our supreme court has established simply because something does not comply with the code, does not automatically mean that it is a deficiency that must be corrected. The building official must apply their discretion in accordance with the code intent.
Yankee Chronicler
REGISTERED
Except that the wording of 713.4 (the code, not the commentary) explicitly says
Tim's interpretation is that zero stories connected is less than four, therefore even when a shaft connects zero stories it still requires a 1-hour rating. My interpretation (which, obviously, I think is consistent with both the letter and the intent of the code) is that "less than four" means "two or three." And I believe this is entirely consistent with section 713.4:
It says, right there, that a 1-hour rating is required when connecting less than four stories. And immediately after that it states that "The number of stories connected by the shaft enclosure shall include any basements but not any mezzanines." I don't know how it can be any plainer -- in considering how many stories a shaft connects, we don't count mezzanines.
And that's entirely consistent with what a mezzanine is -- a raised level within a single story.
Yankee Chronicler
REGISTERED
Tim Mailloux
REGISTERED
The mezzanine reference 713.4 is intended to guide us on how to count stories in a building that includes a mezzanine. The goal is to ensure that a building with three stories and a mezzanine doesn’t get penalized and is not required to provide a 2-hour rated shaft enclosure. According to 713.4, there are only two options available for shaft enclosure ratings: the first option is to have a 2-hour rated enclosure for buildings with four stories or more, and the second option is a 1-hour rated enclosure for buildings with less than four stories.
wwhitney
REGISTERED
You might be right about the intent (beyond my knowledge), but we can say unequivocally that "less than four" includes one and zero.
It could be plainer by saying that for 2 or 3 stories, a 1 hour rating is required, and for 4 or more stories a 2 hour rating is required. That implies that for 1 story, no rating is required, but even that could be explicitly stated.
But it doesn't do any of that, it just says "less than four". So the letter of the code clearly requires a 1 hour rating for 1 story.
Cheers, Wayne
Yankee Chronicler
REGISTERED
I disagree (obviously) with Tim Mailloux and wwhitney. I understand your arguments, and I find them unpersuasive.
In most jurisdictions, a question such as this would be resolved by the AHJ saying, "It means what **I** say it means." [IBC 104.1] In my state, such differences of opinion can be resolved only by submitting the question to the State Building Inspector for a formal interpretation.
In most jurisdictions, a question such as this would be resolved by the AHJ saying, "It means what **I** say it means." [IBC 104.1] In my state, such differences of opinion can be resolved only by submitting the question to the State Building Inspector for a formal interpretation.
Inspector Gadget
REGISTERED
Disclaimer: I'm a Canadian, using Canadian Codes.
I had a vaguely similar situation with a building whose work is still ongoing. The building had a legal, conforming interconnected floor space - that is, it had an open, unrated stair shaft connecting two floors. A designer argued that installing an elevator between those two floors did not require a rated shaft, since it would have been another interconnected floor space.
Our codes state that yes, you can do that, as long as the *machinery* is then isolated from the rest of the building with a rated assembly.
Given the frequent similarities I see between 'Murrican codes and NBC, does your code have a "if not rated shaft, then rated machinery room" clause or path?
I had a vaguely similar situation with a building whose work is still ongoing. The building had a legal, conforming interconnected floor space - that is, it had an open, unrated stair shaft connecting two floors. A designer argued that installing an elevator between those two floors did not require a rated shaft, since it would have been another interconnected floor space.
Our codes state that yes, you can do that, as long as the *machinery* is then isolated from the rest of the building with a rated assembly.
Given the frequent similarities I see between 'Murrican codes and NBC, does your code have a "if not rated shaft, then rated machinery room" clause or path?
Yeah, but a single story building cannot have a shaft, because it has to meet the code definition which is:
Since you aren't penetrating vertical openings through successive floors, the definition doesn't apply.
Tim Mailloux
REGISTERED
so a mezzanine doesn't have a floor? While its not counted as a story, it certainly has a floor.
[BF] SHAFT. An enclosed space extending through one or more stories of a building, connecting vertical openings in successive floors, or floors and roof.
Tim Mailloux
REGISTERED
3002.1 requires elevator hoistways to have shaft enclosures complying with 712 and 173
Nothing in 712 gets you out of providing a shaft enclosure for the hoistway.
713.2 requires that shaft enclosures be constructed as fire barriers.
713.4 gives you two options for the rating of the required fire barrier at the shaft enclosure, a 2 hour shaft enclosure or a 1 hour shaft enclosure, and then provides the direction to determine which you need to provide. There is no zero hour shaft enclosure option or exception listed.
While I think its silly to have rated shaft enclosure between a mezzanine and floor below, I have yet to see anything in the code that gets around the shaft enclosure requirement for an elevator hoistway.
steveray
SAWHORSE
Not if there is not an enclosure...Sorta
3002.1
A hoistway for elevators, dumbwaiters and other vertical-access devices shall comply with Sections 712 and 713. Where the hoistway is required to be enclosed, it shall be constructed as a shaft enclosure in accordance with Section 713.Tim Mailloux
REGISTERED
thats not what my 2021 IBC says......
3002.1 Hoistway enclosure protection.
Elevator, dumbwaiter and other hoistway enclosures shall be shaft enclosures complying with Sections 712 and 713
steveray
SAWHORSE
That is what it is supposed to say...
2024 doesTim Mailloux
REGISTERED
the wording of the 2024 code sections give more leeway with the elevator shaft enclosure, But IMO the the 2021 explicitly states a shaft enclosure of required.That is what it is supposed to say...
steveray
SAWHORSE
It's all about interpretation...