Tiered Seating floor

[Examiner]

Given:

Church upper balcony seating area.

Construction Type II-B

Un-sprinklered

The balcony’s main level floor structure is non-combustible but tiered seating is to be on metal stud framing (supported by the balcony’s main floor) with fire-retardant-wood floor decking.

Questions:

The tiered seating is not exactly considered a permanent platform is it?

Is there anything in the Code to allow the floor of the tiered seating to be combustible if the Construction Type is to be non-combustible?

Would putting the fire-retardant-wood floor decking on top of a metal floor decking that is supported by a non-combustible framing system comply with a non-combustible floor?

 

[north star]

>>> >>> >>>

Examiner,

Not exactly sure of your description of tiered seating. Tiered seating can be

'permanent', or 'temporary'. Section 410.4.1 in the `06 IBC describes

"temporary" [ RE: platforms ] as installed for not more than 30 days.

Temporary seating [ i.e. - uses ] can be allowed / permitted for up to 180

days...... See Section 107 in the IBC.

Section 410.4 - PLATFORM CONSTRUCTION: "Permanent platforms shall be

constructed of materials as required for the type of construction of the

building in which the permanent platform is located.......... Permanent platforms are

permitted to be constructed of fire-retardant-treated wood for Type I, II,

and IV construction where the platforms are not more than 30 inches (762 mm)

above the main floor, and not more than one-third of the room floor area and

not more than 3,000 square feet (279 m2) in area............... Where the space

beneath the permanent platform is used for storage or any other purpose other

than equipment, wiring or plumbing, the floor construction shall not be less than

1-hour fire-resistance-rated construction............. Where the space beneath the

permanent platform is used only for equipment, wiring or plumbing, the underside

of the permanent platform need not be protected."

Section 410.4.1 - TEMPORARY PLATFORMS: "Platforms installed for a

period of not more than 30 days are permitted to be constructed of any

materials permitted by the code......... The space between the floor and the

platform above shall only be used for plumbing and electrical wiring to platform

equipment."

<<< <<< <<<

 

[hlfireinspector]

Not to hi-jack the tread but just wondering:

How did we get a unsprinkler A-3 with a balcony?

903.2.1.3 Group A-3. An automatic sprinkler system

shall be provided for Group A-3 occupancies where one

of the following conditions exists:

1. The fire area exceeds 12,000 square feet (1115

m2);

2. The fire area has an occupant load of 300 or more;

or

3. The fire area is located on a floor other than the

level of exit discharge.

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[globe trekker]

hlfireinspector,

I do not think that you are hijacking the thread, but rather contributing to it.

Would Section 903.3.1.1.1, #4 [ in the `06 IBC ] exempt the sprinkler requirements

for the balcony?

.

 

[Examiner]

Existing Church getting a balcony. There are Code issues but the support for the seating is the question. Tiered seating is "rows of seats in rising series". I do not think that the rows would be considered permanent platforms. If they were; where does the 1/3 rule of the space apply? The balcony or the 1st floor of the Sanctuary. The 1st floor of the Sanctuary has a permanent platform for the pastor and choir. Oh, and the choir is on tiered seating as well. The top choir row is more than 30-inches above the 1st floor. That height may affect the floor construction as well.

 

[north star]

= = =

Examiner,

I would think that the 1/3 floor area would apply to the existing Sanctuary

[ room ] floor area.

According to the terms within the IBC, you may be referring to a "new"

mezzanine vs. a balcony.

From Section 1602.1: Balcony, Exterior: "An exterior floor projecting

from and supported by a structure without additional independent supports."

From Section 502.1: Mezzanine: "An intermediate level or levels between

the floor and ceiling of any story and in accordance with :Next('./icod_ibc_2006f2_5_sec005.htm')'>Section 505."

I did not see any references for an "interior balcony".

If your platforms are going to be installed higher than 30 inches above

the main floor, would this be a small mezzanine? There seems to be

some ambiguity at play here. Plus, it's late in the day and I am already

spent!

= = =

 

[JBI]

Short answer: Yes, the metal studs with FRT Plywood would be allowed in this construction type.

 

[brudgers]

Generally, balcony's in sanctuaries are mezzanines because it greatly simplifies egress.

Classifying it as a story would probably be a mess.

I would say the FRT is more than 30" above main floor when classified as a mezzanine.

There is no way in hell it's temporary.

 

[texasbo]

John - I'd like the long answer.

I too would think the balcony qualifies as a mezzanine. I have no problem calling the arrangement a permanent platform. However, what does the code mean when it says no more than 30" above main floor? Does it mean the floor below the platform, or does it mean the main floor of the building? Taking the conservative approach, I'd not allow it in Type II.

But what if the building was truly a two-story building, with both floors the same area? What is the main floor then? If you considered the first floor the main floor, then does that mean you can never have FRT wood on a second floor? Is that what the code intends? I'm not sure. I think it's another area of ambiguity.

 

[north star]

* * *

To all:

For the benefit of all on this forum, I am respectfully requesting everyone to

please watch / monitor their use of inappropriate language.

As professionals we simply do not need to show disrespect to others and use

"four letter" words. Thank you for your cooperation!

* * *

 

[north star]

# # #

texasbo,

Not sure of the 30" requirement either! Section 1013.1, Exception #2 allows

this type of application.

FWIW, Section 1025.5 DOES mention 'Interior balconies', ...regarding

egress requirements though!

# # #

 

[north star]

% % %



FWIW, here are some pics. of some types of church interior balconies / mezzanines:

& & &

 

[Examiner]

Code Congress had stated to me the following;

The interior balcony can be a mezzanine if it does not exceed the floor area restrictions of a mezzanine or a second floor with a large floor opening.

In Type II-B the floor construction of the Balcony’s tiered seating must be of non-combustible construction. Although the framing of the upper rows transfer their floor loads to the balcony’s main level floor; the upper rows are carrying the floor loads at their height. It would be up to the BO to accept the FRTW if it is placed on top of a metal floor deck. However FRTW as the structural floor alone would not be allowed in the Balcony area in a Type II-B construction.

The Choir area that is on the permanent platform at Sanctuary’s main floor has a row or two above the 30-inch limit. Code Congress said that those rows above the 30-inch limit would also have to be non-combustible.

I did not ask if the Choir rows could be supported from the permanent platform which is FRTW but if you think about it the rows above the 30-inch limit from the main floor would have to be supported back to the main floor which is non-combustible.

 

[brudgers]

% % %

FWIW, here are some pics. of some types of church interior balconies / mezzanines:

No FRT in Type II, for these.

 

[brudgers]

I did not ask if the Choir rows could be supported from the permanent platform which is FRTW but if you think about it the rows above the 30-inch limit from the main floor would have to be supported back to the main floor which is non-combustible.

If the choir risers are movable, then they could be FRT, IMO.

 

[hlfireinspector]

hlfireinspector,I do not think that you are hijacking the thread, but rather contributing to it.

Would Section 903.3.1.1.1, #4 [ in the `06 IBC ] exempt the sprinkler requirements

for the balcony?

.

Sprinklers shall not be omitted from any room merely because it is damp, of fire-resistance rated construction or contains electrical equipment. I see it is an existing church adding a balcony. The additional square footage and the addition of a floor not on exit discharge level ,I feel, would drive the need for sprinkler protection.

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