Are "Stacked" Mezzanines a possibility??

[indyarchyguy]

2012 IBC (2014 Indiana). We have an existing, unlimited area Industrial building, fully-sprinklered, Construction Type II-N, F-2 Occupancy. In one area of the building there is an existing mezzanine (40 x 50). The process equipment extends from the main floor and through the mezzanine floor. The mezzanine is enclosed on three sides and fully open on one side. On that side is an open egress stair to the main floor. They need to modify the process equipment and that equipment will now extend upwards and will require a 2nd mezzanine level which will match the original. They will extend the structure upwards and install a new roof. This mezzanine would be fully enclosed on all four sides.

They would move the existing egress stair to the corner and provide egress to each mezzanine to the main floor. The travel distance of 400-lf by table is not an issue with maximum egress from the top mezzanine to an exterior egress door is approximately 185-lf. They shall install a new elevator which provides personnel and materials access to each mezzanine. They also desire for the stair to extend to the roof for maintenance issues. By table the occupant load is 20 occupants per mezzanine at 100 sf/occupant. An open stair is the most optimal for area of the mezzanine.

Is there any reason this can't still be a mezzanine? I have had multiple mezzanines used for theater projects, etc., but for some reason this is beginning to bother me. Your help is most appreciated. Thank you.

 

[classicT]

How does the upper mezzanine comply with the openness requirements?

505.2.3 Openness​

A mezzanine shall be open and unobstructed to the room in which such mezzanine is located except for walls not more than 42 inches (1067 mm) in height, columns and posts.
Exceptions:

1. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the occupant load of the aggregate area of the enclosed space is not greater than 10.
2. A mezzanine having two or more exits or access to exits is not required to be open to the room in which the mezzanine is located.
3. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the aggregate floor area of the enclosed space is not greater than 10 percent of the mezzanine area.
4. In industrial facilities, mezzanines used for control equipment are permitted to be glazed on all sides.
5. In occupancies other than Groups H and I, which are no more than two stories above grade plane and equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, a mezzanine having two or more exits or access to exits shall not be required to be open to the room in which the mezzanine is located.

 

[steveray]

Seems possible, but the details matter

 

[bill1952]

These wouldn't fall into the equipment platform category would they?
BG]EQUIPMENT PLATFORM. An unoccupied, elevated platform used exclusively for mechanical systems or industrial process equipment, including the associated elevated walkways, stairways, alternating tread devices and ladders necessary to access the platform (see Section 505.3).

505.3 Equipment platforms.​

Equipment platforms in buildings shall not be considered as a portion of the floor below. Such equipment platforms shall not contribute to either the building area or the number of stories as regulated by Section 503.1. The area of the equipment platform shall not be included in determining the fire area in accordance with Section 903. Equipment platforms shall not be a part of any mezzanine and such platforms and the walkways, stairways, alternating tread devices and ladders providing access to an equipment platform shall not serve as a part of the means of egress from the building.

 

[indyarchyguy]

These wouldn't fall into the equipment platform category would they?
BG]EQUIPMENT PLATFORM. An unoccupied, elevated platform used exclusively for mechanical systems or industrial process equipment, including the associated elevated walkways, stairways, alternating tread devices and ladders necessary to access the platform (see Section 505.3).

505.3 Equipment platforms.​

Equipment platforms in buildings shall not be considered as a portion of the floor below. Such equipment platforms shall not contribute to either the building area or the number of stories as regulated by Section 503.1. The area of the equipment platform shall not be included in determining the fire area in accordance with Section 903. Equipment platforms shall not be a part of any mezzanine and such platforms and the walkways, stairways, alternating tread devices and ladders providing access to an equipment platform shall not serve as a part of the means of egress from the building.

The killer on this, in my professional opinion, is that they are occupied. There is a proposed control room on the upper level which basically allows for one person in there to regulate. There will be up to 10 workers on both of these platforms. So, am I being too literal?

 

[indyarchyguy]

How does the upper mezzanine comply with the openness requirements?

505.2.3 Openness​

A mezzanine shall be open and unobstructed to the room in which such mezzanine is located except for walls not more than 42 inches (1067 mm) in height, columns and posts.
Exceptions:

1. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the occupant load of the aggregate area of the enclosed space is not greater than 10.
2. A mezzanine having two or more exits or access to exits is not required to be open to the room in which the mezzanine is located.
3. Mezzanines or portions thereof are not required to be open to the room in which the mezzanines are located, provided that the aggregate floor area of the enclosed space is not greater than 10 percent of the mezzanine area.
4. In industrial facilities, mezzanines used for control equipment are permitted to be glazed on all sides.
5. In occupancies other than Groups H and I, which are no more than two stories above grade plane and equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, a mezzanine having two or more exits or access to exits shall not be required to be open to the room in which the mezzanine is located.

It does not. Hence part of the issue. Unless I provide a second means of egress, or I get them access to another means of egress (my initial thought is they could access a stair on to the roof outside which then provides egress to the exterior via a ladder or hatch. Of course, the later means re-entering the building of which I am not a fan.

 

[bill1952]

The killer on this, in my professional opinion, is that they are occupied. There is a proposed control room on the upper level which basically allows for one person in there to regulate. There will be up to 10 workers on both of these platforms. So, am I being too literal?

You're probably right.