elevator connecting 1st floor w/ mezzanine

[Nicole Brooks]

Just checking to make sure I've got this right and haven't missed some code section. A mezzanine is not considered a "floor" so therefore an elevator connecting the first floor and mezzanine would not need to be located in a rated shaft, correct?

 

[walker.t]

A mezzanine is not considered a "floor" so therefore an elevator connecting the first floor and mezzanine would not need to be located in a rated shaft, correct?

I get what you’re saying about the concept of a mezzanine being part of the room (per 505.2), but I do not see a provision specifically granting an exception to rating elevator shaft enclosures that serve only a room and a mezzanine.

It seems odd to think of an elevator serving only one story (because the mezzanine is not counted as a story,) but the shaft is “connecting” less than four stories and would need to be rated per 713.4. Plus, as a typically unoccupied space, the elevator shaft would be a concealed space but can’t be fire blocked, which supports the need for the rated shaft enclosure.

712.1.10.2 specifically mentions vertical openings for elevators in parking garages, but 712.1.11 (regarding vertical openings between a mezzanine and the floor below) does not specifically mention elevators - if the intention was to include elevators I would think they would have mentioned elevators.

 

[GEe]

I get what you’re saying about the concept of a mezzanine being part of the room (per 505.2), but I do not see a provision specifically granting an exception to rating elevator shaft enclosures that serve only a room and a mezzanine.

It seems odd to think of an elevator serving only one story (because the mezzanine is not counted as a story,) but the shaft is “connecting” less than four stories and would need to be rated per 713.4. Plus, as a typically unoccupied space, the elevator shaft would be a concealed space but can’t be fire blocked, which supports the need for the rated shaft enclosure.

712.1.10.2 specifically mentions vertical openings for elevators in parking garages, but 712.1.11 (regarding vertical openings between a mezzanine and the floor below) does not specifically mention elevators - if the intention was to include elevators I would think they would have mentioned elevators.

I think I would interpret that differently. I would read 712.1.11 as a blanket allowance of vertical openings to a mezzanine and so there is no need to specifically note elevators as is done with more qualifications at 712.1.10 for parking garages.

Similary, where 713.4 rerfences shaft enclosures connecting "less than four stories," I would read 1, 2, or 3 stories -- but not a non-story horizontal assembly.

 

[Tim Mailloux]

If your providing a CMU shaft for the elevator with is typical in low rise construction, you are already 99% of the way to having a rated enclosure.

 

[Yankee Chronicler]

A mezzanine is, by definition, not a story. Therefore, an elevator serving only one story plus a mezzanine level within that story is not connecting ANY stories. It's effectively no different from a platform lift serving an open stage (platform) at the front of an auditorium.

3002.1 Hoistway enclosure protection. Elevator, dumbwaiter
and other hoistway enclosures shall be shaft enclosures
complying with Sections 712 and 713.

So we have to look at IBC 712 and 713. IBC 712 addresses vertical openings. With a mezzanine, there aren't any vertical openings, so we don't need to look at 712. But, if we do, we find that the code is waiting for us:

712.1.11 Mezzanine. Vertical openings between a mezzanine
complying with Section 505 and the floor below shall be
permitted.

The commentary for 712.1.11 says:

Section 712.1.11 recognizes that vertical openings
between a mezzanine and the floor below are actually
an advantage. The limited-size mezzanine is considered
a part of the story below in accordance with Section
505.1. The openness between the mezzanine level
and the floor below allows smoke or other hazards to
be readily observable to occupants of both levels.

So then let's look at IBC 713:

713.1 General. The provisions of this section shall apply to
shafts required to protect openings and penetrations through
floor/ceiling and roof/ceiling assemblies. Interior exit stairways
and ramps shall be enclosed in accordance with Section
1023.

The commentary on this section says:

This section applies to vertical shafts enclosing vertical
openings, such as vertical exhaust ducts; gas flues;
metal chimneys; vertical supply ducts; return and outdoor
air ducts; elevator hoistways, linen chutes and
trash chutes. All openings or penetrations in floor/ceiling
or roof/ceiling assemblies are required to be protected
with a vertical shaft enclosure, except for the
permitted uses in Section 712.

Section 713.4 does not apply. The elevator in question is not connecting stories, it will be entirely contained within one story. In fact, a mezzanine could be accessed by an unenclosed platform lift.

 

[e hilton]

Just checking to make sure I've got this right and haven't missed some code section. A mezzanine is not considered a "floor" so therefore an elevator connecting the first floor and mezzanine would not need to be located in a rated shaft, correct?

Does the elevator only have 2 stops, or does it go to other floors?

 

[Nicole Brooks]

Does the elevator only have 2 stops, or does it go to other floors?

only has 2 stops.

 

[Tim Mailloux]

Needs to be 1 hour rated IMO

• 3002.1 Sates that elevators enclosures shall be shaft enclosures complying with 712 & 713
• 712.1.1 shaft enclosures states that vertical openings within a shaft enclosure shall comply with 713
• 713.4 requires shaft enclosures connecting less than 4 stories be 1 hour rated, and you shaft certainly connects less than 4 stories

 

[Tim Mailloux]

Section 713.4 does not apply. The elevator in question is not connecting stories, it will be entirely contained within one story. In fact, a mezzanine could be accessed by an unenclosed platform lift.

713.4 does apply as it states the shaft enclosures connecting less than 4 stories shall be one hour rated. A zero storie connection is less than 4 stories.

 

[Yankee Chronicler]

713.4 does apply as it states the shaft enclosures connecting less than 4 stories shall be one hour rated. A zero storie connection is less than 4 stories.

So your argument is that a shaft contained entirely within one story "connects" less than four stories, so has to be rated as 1-hour?

I respectfully disagree. If it's all one story, there are no stories being connected, only two levels within one story. It's no different than a platform lift from the orchestra level to the stage level at the front of an auditorium.

 

[Tim Mailloux]

this is from the 2021 code illustrated

713.4 Fire-resistance rating.
To provide an acceptable level of protection for vertical openings between floors, this section mandates that all shaft enclosures have a fire-resistance
rating at least equivalent to the rating of the floor being penetrated, but never less than 1 hour.
Therefore, in Type I construction, or where the shaft enclosure connects four or more stories, a minimum 2-hour enclosure is mandated. A shaft enclosure is never required to have a higher fire-resistance rating than 2 hours.

 

[Yankee Chronicler]

But a mezzanine is never required to have a fire separation from the main level of the story (singular) in which it is located. In fact, one of the fundamental premises for safety on mezzanines is that the mezzanine should be open to the main level below so that occupants of the mezzanine can be aware if a fire occurs on the main level. Enclosed mezzanines have stricter requirements than open mezzanines to account for this.

IMHO, 713.4 means "stories" when it says "floors." I don't think you should look at the last sentence of IBC 713.4 alone. You have to read it in the context of the full section:

713.4 Fire-Resistance Rating
Shaft enclosures shall have a fire-resistance rating of not less than 2 hours where connecting four stories or more, and not less than 1 hour where connecting less than four stories. The number of stories connected by the shaft enclosure shall include any basements but not any mezzanines. Shaft enclosures shall have a fire-resistance rating not less than the floor assembly penetrated, but need not exceed 2 hours. Shaft enclosures shall meet the requirements of Section 703.2.1.1.

It's all about connecting stories, and it specifically excludes mezzanines.

 

[Tim Mailloux]

It's all about connecting stories, and it specifically excludes mezzanines.

I agree that mezzanines are excluded in the calculating the number of stories that a shaft enclosure connects. IMO the intent of that is so that a mezzanine in a 3 story building doesn't bump the shaft enclosure up to a 4 story enclosure that would need to be 2 hour rated.

In the OP's situation the shaft enclosure between the story and the mezzanine would be connecting zero stories as the mezzanine is not counted in the number of stories connected .......But zero stories is less than 4 stories

'.............and not less than 1 hour where connecting less than four stories............'

 

[Yankee Chronicler]

If it's all one story, it's not connecting anything.

Do you require a 1-hour shaft enclosure for the platform lift to the stage in a high school auditorium?

 

[Tim Mailloux]

If it's all one story, it's not connecting anything.

Do you require a 1-hour shaft enclosure for the platform lift to the stage in a high school auditorium?

does that platform lift require a shaft enclosure like an elevator does

 

[Tim Mailloux]

are we at least in agreement that chapter 30 requires the elevator be in a shaft enclosure?

 

[Yankee Chronicler]

IBC 2021:

3002.1 Hoistway enclosure protection. Elevator, dumbwaiter
and other hoistway enclosures shall be shaft
enclosures complying with Sections 712 and 713.

712.1 General. Each vertical opening shall comply in accordance
with one of the protection methods in Sections 712.1.1
through 712.1.16.

712.1.1 Shaft enclosures. Vertical openings contained
entirely within a shaft enclosure complying with Section
713 shall be permitted.

712.1.9 Two-story openings. In other than Groups I-2
and I-3, a vertical opening that is not used as one of the
applications specified in this section shall be permitted if
the opening complies with all of the following items:

1. Does not connect more than two stories.
2. Does not penetrate a horizontal assembly that
separates fire areas or smoke barriers that separate
smoke compartments.
3. Is not concealed within the construction of a wall
or a floor/ceiling assembly.
4. Is not open to a corridor in Group I and R
occupancies.
5. Is not open to a corridor on nonsprinklered floors.
6. Is separated from floor openings and air transfer
openings serving other floors by construction
conforming to required shaft enclosures.

713.1 General. The provisions of this section shall apply to
shafts required to protect openings and penetrations through
floor/ceiling and roof/ceiling assemblies. Interior exit stairways
and ramps shall be enclosed in accordance with
Section 1023.

Since there is no requirement in section 712 to protect vertical openings within a story (i.e. through a mezzanine floor), the requirements of section 713 don't apply. But, even if you want to look at section 713, it still doesn't apply to an elevator shaft within a space containing a mezzanine:

713.4 Fire-resistance rating. Shaft enclosures shall have a
fire-resistance rating of not less than 2 hours where connecting
four stories or more, and not less than 1 hour where
connecting less than four stories. The number of stories
connected by the shaft enclosure shall include any basements
but not any mezzanines. Shaft enclosures shall have a
fire-resistance rating not less than the floor assembly penetrated,
but need not exceed 2 hours. Shaft enclosures shall
meet the requirements of Section 703.2.1.1.

So mezzanines are not "connected stories." Therefore, no rating is required by section 713. And since section 3002.1 calls for the hoistway enclosure to be in accordance with 712 and 713 ==> the hoistway enclosure does not have to be rated.

 

[wwhitney]

Seems to me the number of connected stories is 1. 1 story is connected by the shaft, in this case two different levels within the story.

Cheers, Wayne

P.S. Not knowledgeable about this part of the code, just about counting. : - )

 

[mp25]

IMO no fire rated shaft necessary. The reason for rated shafts is to prevent spread of fire/smoke between stories. Mezzanine and the main space are part of the same story. If there is a fire on the main floor, it affects the mezzanine, and vice versa. Enclosing the elevator in a shaft does nothing to help protect either level from each other.

 

[Tim Mailloux]

So mezzanines are not "connected stories." Therefore, no rating is required by section 713. And since section 3002.1 calls for the hoistway enclosure to be in accordance with 712 and 713 ==> the hoistway enclosure does not have to be rated.

IBC 2021:







Since there is no requirement in section 712 to protect vertical openings within a story (i.e. through a mezzanine floor), the requirements of section 713 don't apply. But, even if you want to look at section 713, it still doesn't apply to an elevator shaft within a space containing a mezzanine:



So mezzanines are not "connected stories." Therefore, no rating is required by section 713. And since section 3002.1 calls for the hoistway enclosure to be in accordance with 712 and 713 ==> the hoistway enclosure does not have to be rated.

IBC 2021:







Since there is no requirement in section 712 to protect vertical openings within a story (i.e. through a mezzanine floor), the requirements of section 713 don't apply. But, even if you want to look at section 713, it still doesn't apply to an elevator shaft within a space containing a mezzanine:



So mezzanines are not "connected stories." Therefore, no rating is required by section 713. And since section 3002.1 calls for the hoistway enclosure to be in accordance with 712 and 713 ==> the hoistway enclosure does not have to be rated.

713.1 doesn't even contain the word story or stories, but it does mention penetrations in floor/ceiling assemblies and roof/ceiling assemblies. I think we can agree that a mezzanine has a floor assembly. And like a mezzanine, a roof is not a story but 713 has requirements to protect shaft openings thru roofs.


713.1 commentary: This section applies to vertical shafts enclosing vertical openings, such as vertical exhaust ducts; gas flues; metal chimneys; vertical supply ducts; return and out-door air ducts; elevator hoistways, linen chutes and trash chutes. All openings or penetrations in floor/ceiling or roof/ceiling assemblies are required to be protected with a vertical shaft enclosure, except for the permitted uses in Section 712. The purpose of shafts is to confine a fire to the floor of origin and to prevent the fire or the products of the fire (smoke, heat and hot gases) from spreading to other levels. For interior exit stairways and interior exit ramps, the requirements in Section 1023 are applicable.


IMO unless there is a permitted use in 712 that forgoes protecting the vertical opening one has comply with 713. For 712.1.9 to apply, the vertical opening needs to comply with all 6 of the listed conditions. IMO a vertical opening concealed within an elevator shaft would not comply with item #3. So now we are back to 713.

 

[Yankee Chronicler]

And 713.4 explicitly says mezzanines don't count.