# Is a Mezzanine considered a "floor"?



## Meadowbend99 (Oct 14, 2020)

I have a client doing an aerial gym, under 5,000 SF (w/ mezzanine).  They are wanting to put in an open mezzanine to increase their square footage with redundant apparatuses.  They'll be A-3, under 12,000 SF and under 300 occupants.  They do not want to add a sprinkler system.  Per sprinkler requirements for A-3 "The fire area is located on a floor other than a level of exit discharge serving such occupancies" would they be required to add a sprinkler system?  Per the definition of a mezzanine "An intermediate level or levels between the floor and ceiling of any story" makes it sound like it is not considered a "floor".  If it is considered a floor, would an exterior exit stair from the mezzanine be adequate.  Using 2015 IBC and IFC.


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## ADAguy (Oct 14, 2020)

Meadowbend99 said:


> I have a client doing an aerial gym, under 5,000 SF (w/ mezzanine).  They are wanting to put in an open mezzanine to increase their square footage with redundant apparatuses.  They'll be A-3, under 12,000 SF and under 300 occupants.  They do not want to add a sprinkler system.  Per sprinkler requirements for A-3 "The fire area is located on a floor other than a level of exit discharge serving such occupancies" would they be required to add a sprinkler system?  Per the definition of a mezzanine "An intermediate level or levels between the floor and ceiling of any story" makes it sound like it is not considered a "floor".  If it is considered a floor, would an exterior exit stair from the mezzanine be adequate.  Using 2015 IBC and IFC.


How many sq. ft will the mez be?


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## Meadowbend99 (Oct 14, 2020)

The footprint of the building is 3,500.  They would like the mezzanine to be 1500 SF, but to be 1/3 of the space it would need to be 1,050 SF.


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## classicT (Oct 14, 2020)

If it is a mezzanine per the requirements of _Section 505_, then is is part of the story below, which is presumably the level of exit discharge. See _Section 505.2_ as follows, with the key statements in red.

*505.2 Mezzanines*
A _mezzanine _or _mezzanines _in compliance with Section 505.2 shall be considered a portion of the _story _below. Such _mezzanines _shall not contribute to either the _building area _or number of _stories _as regulated by Section 503.1. The area of the _mezzanine _shall be included in determining the _fire area_. The clear height above and below the _mezzanine _floor construction shall be not less than 7 feet (2134 mm).


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## Meadowbend99 (Oct 14, 2020)

Thank you.  I had read that, but it didn't click.  Having it in red helps!


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## Meadowbend99 (Oct 14, 2020)

Meadowbend99 said:


> Thank you.  I had read that, but it didn't click.  Having it in red helps!


The fire marshal had indicated to my client that a sprinkler system was required for a mezzanine.


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## classicT (Oct 14, 2020)

Meadowbend99 said:


> The fire marshal had indicated to my client that a sprinkler system was required for a mezzanine.


Have you checked the local municipal codes for amendments? Perhaps they have a stricter requirement for sprinklers than the default IBC requirements.


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## Meadowbend99 (Oct 14, 2020)

classicT said:


> Have you checked the local municipal codes for amendments? Perhaps they have a stricter requirement for sprinklers than the default IBC requirements.


I checked, nothing in the amendments that relates.


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## mtlogcabin (Oct 14, 2020)

Meadowbend99 said:


> The fire marshal had indicated to my client that a sprinkler system was required for a mezzanine.


Like building inspectors they sometimes indicate things that can not be backed up with a code requirement


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## RLGA (Oct 14, 2020)

I assume you're using the occupant load factor for "Exercise rooms." There is no requirement in the IFC or the IBC that requires mezzanines to be sprinklered. However, if you read the requirements for Group A-3, Condition 3 states "The _fire area_ is located on a *floor* other than a l_evel of exit discharge_ serving such occupancies."

Notice that it does not use the word _story_. Yes, a mezzanine is not a story, but it is a floor, and it is located above the level of exit discharge. Refer to the _Commentary_, which states "The text does not make reference to 'story' but uses the term 'floor,' which could include *mezzanines *and basements."


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## classicT (Oct 15, 2020)

RLGA said:


> I assume you're using the occupant load factor for "Exercise rooms." There is no requirement in the IFC or the IBC that requires mezzanines to be sprinklered. However, if you read the requirements for Group A-3, Condition 3 states "The _fire area_ is located on a *floor* other than a l_evel of exit discharge_ serving such occupancies."
> 
> Notice that it does not use the word _story_. Yes, a mezzanine is not a story, but it is a floor, and it is located above the level of exit discharge. Refer to the _Commentary_, which states "The text does not make reference to 'story' but uses the term 'floor,' which could include *mezzanines *and basements."


Ron, I agree with your reading of _IBC 903.2.1.3_, particularly the use of the word floor in place of story.

However, I have in the past, not required sprinklers for an A-3 or other use with similar language in Ch. 9 because of the following language from Ch. 5.

*505.2 Mezzanines*
A _mezzanine _or _mezzanines _in compliance with Section 505.2 shall be considered a portion of the _story _below. ... (continues)

The leading statement of _IBC 505.2_ indicates that a mezzanine is considered a portion of the story below. The definition of 'level of exit discharge' (below), also uses the term story.

*EXIT DISCHARGE, LEVEL OF. *The _story _at the point at which an_ exit _terminates and an _exit discharge _begins.

My contestation is that the mezzanine is a separate floor that does contribute to fire area, but it is not an additional story. It is in fact, a portion of the story it is constructed within. Therefore, as a portion of the ground level story, the mezzanine is on the level of exit discharge, and does not trigger _IBC 903.2.1.3 #3._


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## RLGA (Oct 15, 2020)

That is a plausible interpretation. Note that the _Commentary _states "..._could _include mezzanines..."

I guess what I'm really saying is that the fire marshal's interpretation as presented by the OP is not an invalid interpretation (assuming that is what the fire marshal was using as their justification).


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## steveray (Oct 15, 2020)

I think I am more on board with Ron on this....as fire area is usually a sprinkler driver and the mezz is specifically a fire area....specific > general...?


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## classicT (Oct 15, 2020)

steveray said:


> I think I am more on board with Ron on this....as fire area is usually a sprinkler driver and the mezz is specifically a fire area....specific > general...?


So are you in favor of sprinkling a 5000sf building because it has a 1050sf mezzanine (mezzanine is not on the same floor level as the level of exit discharge)? Fire area is only 6050sf; half of the threshold area established by _IBC Section 903.2.1.3_?

That is the OP's question...


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## Tim Mailloux (Oct 15, 2020)

Im with Ron & Steve on this one.


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## mtlogcabin (Oct 15, 2020)

I disagree. It is quite clear that the mezzanine is included in the fire area.
It is also quite clear that a mezzanine is not a story, it is an intermediate area between stories. If this was just a raised area of 5 or 6 feet it would not be a mezzanine yet it would still be on the level of exit discharge
IBC 505.2
The area of the mezzanine shall be included in determining the fire area.

[BF] FIRE AREA. The* aggregate floor* *area* enclosed and bounded by fire walls, fire barriers, exterior walls or horizontal assemblies of a building. Areas of the building not provided with surrounding walls shall be included in the fire area if such areas are included within the horizontal projection of the roof or floor next above.

[BE] EXIT DISCHARGE, LEVEL OF. *The story* at the point at which an exit terminates and an exit discharge begins.

[BG] STORY. That portion of a building included between the upper surface of a floor and the upper surface of the floor or roof next above (see “Basement,” “Building height,” “Grade plane” and “Mezzanine”). A story is measured as the vertical distance from top to top of two successive tiers of beams or finished floor surfaces and, for the topmost story, from the top of the floor finish to the top of the ceiling joists or, where there is not a ceiling, to the top of the roof rafters.

[BG] MEZZANINE. An intermediate level or levels *between the floor and ceiling of any story* and in accordance with Section 505.


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## Tim Mailloux (Oct 15, 2020)

what is an Aerial gym? is this like gymnastics?

will they ever hold competition at the gym?


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## classicT (Oct 15, 2020)

Tim Mailloux said:


> what is an Aerial gym? is this like gymnastics?
> 
> will they ever hold competition at the gym?


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## RLGA (Oct 15, 2020)

In my opinion, it is not the area of fire area driving the sprinkler system, it is the location of the fire area, which includes the floor elevation of the mezzanine. When there is a Group A-3 on a floor (not a story) that is above the level of exit discharge, then a sprinkler system is required. The mezzanine is a "floor" and the level of exit discharge is at the floor level below (even though the mezzanine is part of that story). ClassicT provided one interpretation that is possible and I've provided another interpretation that is possible--this is just an extremely gray area of the code.


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## Meadowbend99 (Oct 15, 2020)

Tim Mailloux said:


> what is an Aerial gym? is this like gymnastics?
> 
> will they ever hold competition at the gym?


It's a gym that will use silks and lyras(rings).  They also have pole dancing classes.  So there are specific fixed apparatuses for each person with fairly sizeable clearances.  In the main room they'll have 20 spots for silks (2,000 SF), but I know the FM is concerned with what happens if they remove the apparatuses so we'll need to calculate as if there isn't fixed equipment, so more like 40 occupants for that room.    They wouldn't hold competitions with spectator seating but they'll have showcases on occasions and they should be able to handle that since their occupant load will end up being quite a bit more than what they can actually handle.


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## RLGA (Oct 15, 2020)

Meadowbend99 said:


> ...the FM is concerned with what happens if they remove the apparatuses so we'll need to calculate as if there isn't fixed equipment...


This irritates me to no end. You can say that about ANY building: "What if they move this wall?" "What if they take out all of the fixed seating?" etc. 

In this case, the use is still "Exercise"; so if the equipment is there or not, fixed or moveable, the occupant load factor is what it is.


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## Sifu (Oct 15, 2020)

IBC 505.2.1 indicates an increase in size from 1/3 to 1/2 if suppression and voice alarm.  Honestly I never looked at it from Ron's perspective, I have always considered floor and story to be interchangeable in this section.  Could it be that since the post indicates the desire was to have a mezzanine larger than 1/3 that is why the fire official said sprinklers required?  Would 505.2.1 need to indicate that sprinklers are required for a larger mezzanine if they were required in the first place?


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## Tim Mailloux (Oct 15, 2020)

Here in CT if its an A occupancy it gets a sprinkler system, end of story. So I guess I'm biased and see things how Ron sees them.


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## ADAguy (Oct 15, 2020)

As to Access" how will the mezzanine be accessible? 
Also if the bldg is sprinklered the underside of the mez would also then require sprinks, no?


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## mtlogcabin (Oct 15, 2020)

RLGA said:


> When there is a Group A-3 on a floor (not a story) that is above the level of exit discharge, then a sprinkler system is required.


Under this application any A-3 with a raised floor area would require a sprinkler system. A small church or community halls where there is a raised floor area 7 or 8 steps up for the speakers or entertainers to lecture or perform from, most will call that a stage or raised platform and never call for a sprinkler system to be installed.


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## Meadowbend99 (Oct 15, 2020)

ADAguy said:


> As to Access" how will the mezzanine be accessible?
> Also if the bldg is sprinklered the underside of the mez would also then require sprinks, no?


There will be stairs leading up.  It will be redundant apparatuses.


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## classicT (Oct 15, 2020)

ADAguy said:


> As to Access" how will the mezzanine be accessible?
> Also if the bldg is sprinklered the underside of the mez would also then require sprinks, no?


Mezzanine is not required to be accessible, as it is less than 3,000sf.

*1104.4 Multistory Buildings and Facilities*
At least one _accessible route _shall connect each _accessible story _and _mezzanine _in multilevel buildings and _facilities_.
*Exceptions:*

An _accessible route _is not required to _stories _and _mezzanines _that have an aggregate area of not more than 3,000 square feet (278.7 m2) and are located above and below _accessible _levels. This exception shall not apply to:
Multiple tenant facilities of Group M occupancies containing five or more tenant spaces used for the sales or rental of goods and where at least one such tenant space is located on a floor level above or below the _accessible _levels;
_Stories _or _mezzanines _containing offices of health care providers (Group B or I);
Passenger transportation facilities and airports (Group A-3 or B); or
Government buildings.

_Stories _or _mezzanines _that do not contain _accessible _elements or other spaces as determined by Section 1107 or 1108 are not required to be served by an _accessible route _from an _accessible _level.
In air traffic control towers, an _accessible route _is not required to serve the cab and the floor immediately below the cab.
Where a two-story building or facility has one _story _or _mezzanine _with an _occupant load _of five or fewer persons that does not contain _public use _space, that _story _or _mezzanine _shall not be required to be connected by an _accessible route _to the _story _above or below.


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## Pcinspector1 (Oct 15, 2020)

classicT said:


> View attachment 7056


The mezzanine will become an observation area with occupant load, the FM will most likely revisit this space later with occupant load issues. These facilities will have competition and the mezzanine will be used for viewing, increasing the OL. I've seen this before tables and chairs with 30-40 spectators during competition. 

The FM has a concern, code may not.


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## mtlogcabin (Oct 15, 2020)

You cannot base your code requirements on what may happen in the future within any building you must base your code requirements on what is presented to you at the time of permitting.


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## ADAguy (Oct 15, 2020)

How do you do redundant rings on the mezzanine or viewing from it without providing a lift?


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## classicT (Oct 15, 2020)

ADAguy said:


> How do you do redundant rings on the mezzanine or viewing from it without providing a lift?



Because it does not need to be on an accessible route.



classicT said:


> Mezzanine is not required to be accessible, as it is less than 3,000sf.
> 
> *1104.4 Multistory Buildings and Facilities*
> At least one _accessible route _shall connect each _accessible story _and _mezzanine _in multilevel buildings and _facilities_.
> ...


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## steveray (Oct 16, 2020)

But a stage or raised floor is not it's own fire area and generally does not have a "floor" below it.....



mtlogcabin said:


> Under this application any A-3 with a raised floor area would require a sprinkler system. A small church or community halls where there is a raised floor area 7 or 8 steps up for the speakers or entertainers to lecture or perform from, most will call that a stage or raised platform and never call for a sprinkler system to be installed.


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## ADAguy (Oct 16, 2020)

Not so, see item 2, what elements do you contend are not accessible?


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## Blazer (Oct 16, 2020)

Seems like a building with an abundance of foam and vinyl mats. I see why Fire Marshal wants it sprinklered. Place will burn to the ground before the fire department arrives I'm guessing what their thought process is. 

903.2.1.3 (3) The fire area is located on a floor other than a _*level*__ of exit discharge _serving such occupancies.

definition: *Mezzanine*. An intermediate _*level*_ or levels between the floor and ceiling of any story and in accordance with Section 505.


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## Bryant (Oct 23, 2020)

Interesting topic ! So to understand, I hope, is,  one thing here dealing with mezzanines, when speaking in terms of a level vs, floor and story of or mezzanine in. the difference between the two is whether or not it is inside the space between the ceiling and floor level. In other words as defined mezzanine means the intermediate level or levels between the floor and ceiling in accordance with section 505. Whereas a level is considered a story? So a mezzanine can be in the story of the building in question? obviously this one in the OP is a one story structure. But what if you built an addition lets say to the structure attaching it to the outside of the existing structure and by the way the addition is being called a mezzanine with three levels, (I'm thinking floors, but will go with it). and the warehouse is one floor.

So the back story and I wanted to upload a picture (plan) but it asks for an URL and I can not do that from work, to show how I have an unlimited building 1 story, sprinklered, with a 2 story addition already attached and are bounded by the 60" perimeter which puts a damper on things horizontally, but they are proposing this addition with a mezzanine intermediate levels  with the first floor directly communicating with the rest of the building with this first floor (addition )being called B use, same for second (second floor does not open up to the rest of the existing building) and the 3rd floor dedicated to being and employee cafeteria (that's another argument, I think its a full blown kitchen like in a Wegmans, grocery store with self serve, type 1 hood, chow line and check out aisle computer lounge, ping pong table). All areas accessible ( elevator) with an exterior and interior stairs connecting all floors, (levels) and they are calling it a mezzanine.

we can skip the area increase and the 1/3 of or 1/2 of the total to size up the mezzanine as allowed by 505.2.1. So what is confusing is, is this a one story addition with a mezzanine with intermediate floor levels or a 3 story building? 

Remember the first floor they knocked out the wall of the warehouse to connect with the addition so as to communicate with the space, plus they have a 12 x 12 atrium connecting all levels, I will floor opening instead to communicate all levels concurrently.  .

I the question is, would you call this mezzanine with intermediate floor levels or a 3 story building? 
Apologies for not being able to upload the file from the internet and long winded, been a tough week.

Thanks Bryant


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## mtlogcabin (Oct 23, 2020)

Blazer said:


> 903.2.1.3 (3) The fire area is located on a floor other than a _*level*__ of exit discharge _serving such occupancies.
> 
> definition: *Mezzanine*. An intermediate _*level*_ or levels between the floor and ceiling of any story and in accordance with Section 505.


The mezzanine is included in the same story and fire area as the "level of discharge exit"

[BE] EXIT DISCHARGE, LEVEL OF. *The story *at the point at which an exit terminates and an exit discharge begins.


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## Bryant (Oct 24, 2020)

I think I am not laying this out correctly. I still can't upload any pics or links without a url link, sorry.
So lets say you have 100,000 sq. ft. warehouse single story unlimited building and they are proposing to build an addition of what consists of 3 stories above grade. the designer is proposing to build the addition as an extension of the warehouse by attaching it to the warehouse.
One thing is apparent, can't be 3 stories with unlimited construction, hence the mezzanine approach.
So they want to knock out the 1st floor wall to communicate with the 3 story mezzanine (I think it is a 3 story addition) and by being a 1/3 of the total floor area of the warehouse doable. I guess my question rests on the interpretation of where does the mezzanines intermediate levels within the floor to ceiling truly begin? If by reading the definitions, I would think this has to be inside of the warehouse, not in a 3 story addition. Though by knocking out the first floor wall of the warehouse and communicating with the addition (mezzanine)on the first floor and a floor openings to the 2nd & 3rd levels, I don't see how that is compliant. And the fact that that have a full blown commerical kitchen for employees on the third floor (intermediate level) makes it more nonsensical to me. how do others see it. 

So 1 story warehouse, proposing a mezzanine in the form of a 3 story addition with the first floor opening directly (communicating)with the first floor directly and lets call it a mini atrium, though I tend to think floor openings like in an escalator setup 12 ft. by 12 ft. going up thru the second level and third level with a skylight to cap it off. Definitely communicating in more than one way, but for sake staying on topic, the mezzanine (addition) is now communicating with the ware house. So the question is, is this mezzanine compliant by definition of being within the floor ceiling of the warehouse. 

Sorry no specific code references, at home recovering from the mental meat grinder at work this past week, but the main sections IBC/VCC 505 and 507, 508 chapters for a reference.
I think it can not qualify as a mezzanine because it is not inside of the main building where the language seems to indicate. As an example and one of the exceptions where special industry complex's can have mezzanines up to 2/3 of the total area, think a smelting plant with mezzanines at intermediate levels within, the plant could be one story up 75 in height and have all this (floor areas) mezzanines inside from floor to ceiling...

Thanks


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## ADAguy (Oct 24, 2020)

Still doesn"t get it, code cannot be less than ADA minimums.
If for observation that cannot be denied to disabled viewers


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## Bryant (Oct 25, 2020)

Given this some thought on my time off from my job, go figure on Sunday and chomping at the bit. Lazy no code to reference today, winging it.

The question I should be asking is, I have  an unlimited building allowed by height and area meeting the 60 ft all around and they want to add more space. The building in question is about 30 +/- ft. considering this one story. they certainly could put mezzanines in most areas of this building, but have elected to basically build a 3 story addition and call it a mezzanine. Of which consists of 1st & 2nd flr as wide open business space, (1st floor communicating atmospherically with the warehouse) guessing the office weenie type setup and the third floor is a commercial kitchen with all the bells and whistles to entertain the employees with lunch and dinner with ping pong and computer lounge, ( don't know if it is a 24/7 operation kitchen, suspect not). All of this in a proposed addition to the warehouse. Interesting enough there was a 2 story addition done in the past, but thats on another's watch and do not believe it will change my setup at the moment, not saying it meets code in ALL aspects, but for sake of argument, staying on topic with the 3 story mezzanine.
When reading all the definitions for a mezzanine, it appears to address the building from within, not an addition to make a mezzanine. But wait, if I can add to the existing warehouse do I not in affect allow that by extension  to have a mezzanine? 

Then I think the question would be, can I have a 3 story unlimited area building, (depending on how you interpret mezzanine level & intermediate level) that answer would be no with present conditions in my mind. (creating 2 separate fire areas would be the way around it, i do believe.).

But how can you push the mezzanine outside the existing building while altering the height by the addition and creating another story? 

What I am flip flopping on is, can I create by extension a one story addition with 3 levels and butt it against the existing building that is only one story, in other words, I am adjusting the roof height at the addition to the max, I believe 75'  while the existing warehouse is at it's single story height 30 ft or so? 
I am leaning to not approving this design, others disagree...
Need some opinions...
Thanks in advance


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## Bryant (Oct 27, 2020)

Bryant said:


> Given this some thought on my time off from my job, go figure on Sunday and chomping at the bit. Lazy no code to reference today, winging it.
> 
> The question I should be asking is, I have  an unlimited building allowed by height and area meeting the 60 ft all around and they want to add more space. The building in question is about 30 +/- ft. considering this one story. they certainly could put mezzanines in most areas of this building, but have elected to basically build a 3 story addition and call it a mezzanine. Of which consists of 1st & 2nd flr as wide open business space, (1st floor communicating atmospherically with the warehouse) guessing the office weenie type setup and the third floor is a commercial kitchen with all the bells and whistles to entertain the employees with lunch and dinner with ping pong and computer lounge, ( don't know if it is a 24/7 operation kitchen, suspect not). All of this in a proposed addition to the warehouse. Interesting enough there was a 2 story addition done in the past, but thats on another's watch and do not believe it will change my setup at the moment, not saying it meets code in ALL aspects, but for sake of argument, staying on topic with the 3 story mezzanine.
> When reading all the definitions for a mezzanine, it appears to address the building from within, not an addition to make a mezzanine. But wait, if I can add to the existing warehouse do I not in affect allow that by extension  to have a mezzanine?
> ...


crickets


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## steveray (Oct 27, 2020)

Interesting...Never though of multiple levels of mezzanines.....


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## ADAguy (Oct 27, 2020)

still limited to 1/3rd the floor area total.


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## Tim Mailloux (Oct 27, 2020)

steveray said:


> Interesting...Never though of multiple levels of mezzanines.....





ADAguy said:


> still limited to 1/3rd the floor area total.


do you add up the area of all (3) mezzanines to determine the 1/3rd area limitation?


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## steveray (Oct 27, 2020)

Yep...there is some aggregate wording in there.....


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## Bryant (Oct 27, 2020)

steveray said:


> Interesting...Never though of multiple levels of mezzanines.....


that's what has me wondering, do we have a 3 story addition or an extension of the existing building and calling it a mezzanine. If I can find another to supply a plan cut or drawing without using an URL link to do it, it think it would be visually represented rather than trying to describe in totality.


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## Bryant (Oct 27, 2020)

Tim Mailloux said:


> do you add up the area of all (3) mezzanines to determine the 1/3rd area limitation?


Yes indeed. That is why they proposed removing the wall at grade level in order to communicate "atmospherically" with the mezzanine (addition) to the existing warehouse space. The question always comes back to is it inside of warehouse from floor to ceiling or outside of. The addition/mezzanine in my opinion is outside of, but you could argue for an extension of the existing building and since they call it a mezzanine, escape calling it a 3 story addition of which could not be part of an unlimited building and would in my opinion again. create another fire area and thus a fire resistance rating at that point of connection. This is where my troubles begin, what is it....
Thanks


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## steveray (Oct 27, 2020)

Bryant said:


> that's what has me wondering, do we have a 3 story addition or an extension of the existing building and calling it a mezzanine. If I can find another to supply a plan cut or drawing without using an URL link to do it, it think it would be visually represented rather than trying to describe in totality.


I am picturing a multilevel indoor driving range.....It could work....


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## Bryant (Oct 28, 2020)

steveray said:


> I am picturing a multilevel indoor driving range.....It could work....


That is a good analogy of use. I can see that as a multi tiered building with mezzanines at intermediate levels. Still the mezzanine levels are inside the building from floor to ceiling within that building. My problem is they are trying to have a one story building addition (the mezzanine piece) attached to the remaining warehouse, using the aggregate floor area of the warehouse to extract a 1/3 ratio for the mezzanine(s) in this case a three story building equally divided. The first floor area of the warehouse communicates atmospherically with the addition (mezzanine) at the first floor and someone was smart enough, I believe, to put basically an atrium of sorts (I would call it floor openings as an example escalator openings from one level to the next) so that the other two levels communicate atmospherically as well. On that, I had plenty of comments concerning the mechanical systems, but  that is another problem.
Anyway need to think more on this. I may be approaching this from the wrong angle, in that considering the most restrictive requirements for the use, which could include separating areas (fire areas) rated assembly between and so on.

I have an unlimited area building F1, S1, B existing 100,000. sq. ft.
proposed mezzanine addition 33,000 sq. ft. 3 levels, 1st & 2nd business ( B), 3rd (A2)  is totality a commercial kitchen for employees, cafeteria, dining lounge with computer lounge and ping pong table to boot and an outdoor patio, nice setup for a 3rd level mezzanine inside of a 3 story addition. 
All of this attached to the warehouse, with out exceeding the height and area for a IIB construction fully sprinklered building. 

I am missing a point of view backed up code, that is my dilemma, hence reaching out for advice. 
Unfortunately, many other projects that need equally undivided attention as well, time sensitive. I guess I'll save this one for bar talk gossip at the next code update training 
Thanks


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## Tim Mailloux (Oct 28, 2020)

Bryant said:


> The first floor area of the warehouse communicates atmospherically with the addition (mezzanine) at the first floor and someone was smart enough, I believe, to put basically an atrium of sorts (I would call it floor openings as an example escalator openings from one level to the next) so that the other two levels communicate atmospherically as well. On that, I had plenty of comments concerning the mechanical systems, but  that is another problem.



Without seeing plans and a building section Im not sure those upper (2) levels would meet the requirements of a mezzanine


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## Blazer (Nov 18, 2020)

Bryant said:


> I think I am not laying this out correctly. I still can't upload any pics or links without a url link, sorry.
> So lets say you have 100,000 sq. ft. warehouse single story unlimited building and they are proposing to build an addition of what consists of 3 stories above grade. the designer is proposing to build the addition as an extension of the warehouse by attaching it to the warehouse.
> One thing is apparent, can't be 3 stories with unlimited construction, hence the mezzanine approach.
> So they want to knock out the 1st floor wall to communicate with the 3 story mezzanine (I think it is a 3 story addition) and by being a 1/3 of the total floor area of the warehouse doable. I guess my question rests on the interpretation of where does the mezzanines intermediate levels within the floor to ceiling truly begin? If by reading the definitions, I would think this has to be inside of the warehouse, not in a 3 story addition. Though by knocking out the first floor wall of the warehouse and communicating with the addition (mezzanine)on the first floor and a floor openings to the 2nd & 3rd levels, I don't see how that is compliant. And the fact that that have a full blown commerical kitchen for employees on the third floor (intermediate level) makes it more nonsensical to me. how do others see it.
> ...


Mezzanine can only be 1/3 of the "open" floor area. I guess if it is a warehouse with no enclosed spaces you can be 1/3 the total floor area. 
You can have one story with really tall ceilings. It just so happens the ceiling is so tall you can put 2 levels of mezzanine (at least 7ft clear space). As long as 'aggregate area of a mezzanine or mezzanines within a room shall be not greater than 1/3 the floor area'


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## TheCommish (Nov 18, 2020)

Mezzanine can only be 1/3 of the "open" floor area. I guess if it is a warehouse with no enclosed spaces you can be 1/3 the total floor area.

Follow on questions, if Ihave a 75,000 sf. warehouse 36 feet tall and build a big cooler floor to ceiling say 5000 sq feet, this is now 70,000 sf. so the mezzanine can only be  23,100 sf.  Next, a room is proposed that takes up an additional 10,000 sf.  how is the existing mezzanine handled that is now too big?

next question, assuming or building is  75,000 less the 5000 sf. cooler, and a room is built that is 10,000 sf.  floor to ceiling, can I put a mezzanine in that room? If so do you calculate the mezzanine sizes based on the room the deduct that area from the building's overall mezzanine allowed area?


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## Tim Mailloux (Nov 19, 2020)

Are all three levels of the mezzanine open to the warehouse? Based on one of the descriptions in a previous post i understood that only the lower level of the mezzanine was open to the warhouse, and the 2nd and 2rd levels of the mezzanine were open to the 1st mezzanine level with a sort of atrium. If thats the case im not sure the upper mezzanine levels would qualify as mezzanines.


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## Bryant (Nov 20, 2020)

Tim Mailloux said:


> Are all three levels of the mezzanine open to the warehouse? Based on one of the descriptions in a previous post i understood that only the lower level of the mezzanine was open to the warhouse, and the 2nd and 2rd levels of the mezzanine were open to the 1st mezzanine level with a sort of atrium. If thats the case im not sure the upper mezzanine levels would qualify as mezzanines.


That's it! my thinking as well. There is a difference between level and story and when looking at this project, it is a 3 story addition on an unlimited area building of which is maxed out at 2 stories. Its one thing to extend the unlimited area, or if even to put an accessory structure (in this case a 3 story addition) to the main use. We can get into all the percentages of allowable area based on the aggregate area in play, but in my opinion the mezzanine is defined by definition as levels with in a story, not three stories in a mezzanine. Some would conclude by having a 12 x 12 hole in the floor (not unlike a thru floor opening for an escalator for example) to constitute the openness to the first floor as a continuation of. I don't think that is the intent. Anyway my supervisor is going to take it over, since I can not honestly say it meets the definition of a mezzanine as proposed as a 3 story addition.
I probably should have put up a poll laying out the argument for and against to see where the chips fall....


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## Tim Mailloux (Nov 20, 2020)

this is some of the code commentary to section 505.2.1, based on this commentary I am of the opinion that you can have multiple mezzanine levels as long as each mezzanine level is atmospherically open to the room or space the mezzanine is part of. The atrium condition you describe would not qualify IMO...
_
So as not to contribute significantly to a building’s inherent fire hazard, a mezzanine is restricted to a maximum of one-third of the area of the room with which it shares a common atmosphere. The area may consist of multiple mezzanines open to the same room at the same or different levels, provided that the aggregate area does not exceed the one-third limitation (this determination is based on the gross floor area of the mezzanines). If the area limitation is exceeded, the provisions of this section do not apply, the mezzanine level is considered an additional story and the area of the mezzanine would be included in building area_.


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## MHGuru (Nov 21, 2020)

Bryant said:


> That is a good analogy of use. I can see that as a multi tiered building with mezzanines at intermediate levels. Still the mezzanine levels are inside the building from floor to ceiling within that building. My problem is they are trying to have a one story building addition (the mezzanine piece) attached to the remaining warehouse, using the aggregate floor area of the warehouse to extract a 1/3 ratio for the mezzanine(s) in this case a three story building equally divided. The first floor area of the warehouse communicates atmospherically with the addition (mezzanine) at the first floor and someone was smart enough, I believe, to put basically an atrium of sorts (I would call it floor openings as an example escalator openings from one level to the next) so that the other two levels communicate atmospherically as well. On that, I had plenty of comments concerning the mechanical systems, but  that is another problem.
> Anyway need to think more on this. I may be approaching this from the wrong angle, in that considering the most restrictive requirements for the use, which could include separating areas (fire areas) rated assembly between and so on.
> 
> I have an unlimited area building F1, S1, B existing 100,000. sq. ft.
> ...





Bryant said:


> That's it! my thinking as well. There is a difference between level and story and when looking at this project, it is a 3 story addition on an unlimited area building of which is maxed out at 2 stories. Its one thing to extend the unlimited area, or if even to put an accessory structure (in this case a 3 story addition) to the main use. We can get into all the percentages of allowable area based on the aggregate area in play, but in my opinion the mezzanine is defined by definition as levels with in a story, not three stories in a mezzanine. Some would conclude by having a 12 x 12 hole in the floor (not unlike a thru floor opening for an escalator for example) to constitute the openness to the first floor as a continuation of. I don't think that is the intent. Anyway my supervisor is going to take it over, since I can not honestly say it meets the definition of a mezzanine as proposed as a 3 story addition.
> I probably should have put up a poll laying out the argument for and against to see where the chips fall....


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## MHGuru (Nov 21, 2020)

Bryant said:


> Yes indeed. That is why they proposed removing the wall at grade level in order to communicate "atmospherically" with the mezzanine (addition) to the existing warehouse space. The question always comes back to is it inside of warehouse from floor to ceiling or outside of. The addition/mezzanine in my opinion is outside of, but you could argue for an extension of the existing building and since they call it a mezzanine, escape calling it a 3 story addition of which could not be part of an unlimited building and would in my opinion again. create another fire area and thus a fire resistance rating at that point of connection. This is where my troubles begin, what is it....
> Thanks


This is an awesome subject. I have been doing research all day and came across this case study you may find interesting. Check it out, hope it helps.  https://www.peaklogix.com/portfolio/increased-facility-capacity/


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## Bryant (Nov 23, 2020)

MHGuru said:


> This is an awesome subject. I have been doing research all day and came across this case study you may find interesting. Check it out, hope it helps.  https://www.peaklogix.com/portfolio/increased-facility-capacity/


This is a case of the classic mezzanine, a level within the story. Could be several levels pending the allowable height of the existing structure. My example is a little more involved, and as outlined in the posts, is a 3 story addition, not a level(s) within a story. The long story short, they wanted to knock out the wall at the first story and extend out the footprint of the original building in order to create a mezzanine. with a 12 x 12 thru floor penetration going up to the skylight thru the 2nd & 3rd floors.. 
That dog won't hunt IMHO, simply because of definition for one, and secondly 3 story addition when the original building is an unlimited area building maxed out at 2 stories, even though they stay under the max building height for a unlimited area building.


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## ADAguy (Nov 23, 2020)

"very" interesting


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## Bryant (Nov 24, 2020)

ADAguy said:


> "very" interesting


how so? My supervisor is doing the project now, so no skin in the game. She said, he said is kinda what the consensus is. I didn't agree based on all the relevant code data, what is proposed and how they got there thru the code. Guess that's why I'm off the review . Never seen a mezzanine disguised as a 3 story addition before. I am all ears for anybody to opine on....


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## Rick18071 (Nov 25, 2020)

Had a existing building where they wanted to build a mezzanine that took 1/2 of the room it was in. The building would have needed sprinklers if 2 story. So they took a door off so the room that the mezzanine is in extended into the next room to make it one larger room. Now the mezzanine is less than 1/3 of this larger room.
 I don't understand how this makes things safer. Could someone explain?


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## steveray (Nov 30, 2020)

Rick18071 said:


> Had a existing building where they wanted to build a mezzanine that took 1/2 of the room it was in. The building would have needed sprinklers if 2 story. So they took a door off so the room that the mezzanine is in extended into the next room to make it one larger room. Now the mezzanine is less than 1/3 of this larger room.
> I don't understand how this makes things safer. Could someone explain?


Not sure that I would call taking the door off "openness"....But there are alot of exceptions....

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.


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## Rick18071 (Dec 1, 2020)

Here was another way a too large of a mezzanine was fixed by making an opening a mezzanine wall into a different room:





__





						Small mezzanine in even smaller room in a small building.
					

2009 IBC. Barn being converted to club house for gulf course with restaurant (A2)and pro shop (M). 5B construction 2050 sq ft., no sprinklers, all one fire area so A2 use with a mezzanine. Sprinklers are required if 5,000 sq. ft. or 2 floors. Pro shop has a door between it and the restaurant...



					www.thebuildingcodeforum.com
				




I still don't understand why by doing this to avoid sprinklers makes it safer. Maybe someone could tell me?


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## steveray (Dec 1, 2020)

Because when it is "one room or atmosphere" you are more likely to know there is a problem and get out....Just like a fire alarm, earlier notification = safer...


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## ADAguy (Dec 1, 2020)

Isn't a room enclosed vs a mezzanine opening into it unenclosed?
Removal of a door to the room does not result in the room no longer being called a room, or does it?


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## Rick18071 (Dec 1, 2020)

ADAguy said:


> Removal of a door to the room does not result in the room no longer being called a room, or does it?


The code says room or space with no definition of either.



steveray said:


> Because when it is "one room or atmosphere" you are more likely to know there is a problem and get out....Just like a fire alarm, earlier notification = safer...


But is still one room if the mezzanine is half the size of the room it is in rather than just a third.
I wonder if there were any studies and testing on this or it was just made up.


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## Bryant (Dec 4, 2020)

Rick18071 said:


> Had a existing building where they wanted to build a mezzanine that took 1/2 of the room it was in. The building would have needed sprinklers if 2 story. So they took a door off so the room that the mezzanine is in extended into the next room to make it one larger room. Now the mezzanine is less than 1/3 of this larger room.
> I don't understand how this makes things safer. Could someone explain?


IMHO, there is a loophole in how one could quantify a mezzanine (definition wise) when veiled as an addition. If you read my post from the beginning you will see a 3 story addition trying to quantify as a mezzanine in an unlimited area building of which can not be more than 2 stories. knocking out the first floor wall and using in my mind a floor thru penetration like for an escalator and call it a day with 3 levels on the addition?  Anyway, I'm not on that project anymore. Sometimes you have to stand your ground and let the BO make the call, absent my approval of course


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## Bryant (Dec 4, 2020)

Bryant said:


> IMHO, there is a loophole in how one could quantify a mezzanine (definition wise) when veiled as an addition. If you read my post from the beginning you will see a 3 story addition trying to quantify as a mezzanine in an unlimited area building of which can not be more than 2 stories. knocking out the first floor wall and using in my mind a floor thru penetration like for an escalator and call it a day with 3 levels on the addition?  Anyway, I'm not on that project anymore. Sometimes you have to stand your ground and let the BO make the call, absent my approval of course


meant to say by definition, story Vs. level......


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## Tim Mailloux (Dec 4, 2020)

based on the definition of openness (which SteveRay) posted several posts back I don't see the (3) story addition you describe as meeting the intent of a mezzanine.

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.


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