Fire area separation -- fire barrier v. fire wall

[kurt999]

IBC 2018

903.2.3 Group E
"An automatic sprinkler system shall be provided for Group E occupancies as follows:
1.Throughout all Group E fire areas greater than 12,000 square feet (1115 m2) in area.
2.The Group E fire area is located on a floor other than a level of exit discharge serving such occupancies.
Exception: In buildings where every classroom has not fewer than one exterior exit door at ground level, an automatic sprinkler system is not required in any area below the lowest level of exit discharge serving that area.
3.The Group E fire area has an occupant load of 300 or more."

I've confused myself a bit on this -- once the fire area is greater than 12,000 SF -- is a fire wall or a fire barrier required to separate non-sprinklered fire areas?

Thank you --

 

[Joe.B]

Lot's of unknowns, such as construction type. Check out Table 506.2

 

[Joe.B]

And don't forget the footnotes.

 

[RLGA]

I've confused myself a bit on this -- once the fire area is greater than 12,000 SF -- is a fire wall or a fire barrier required to separate non-sprinklered fire areas?

Either one or both. See the definition of a fire area in Chapter 2.

 

[steveray]

The FB is the easier one to build....And 2 hours BTW..

 

[Paul Sweet]

The entire building must be sprinklered if a sprinkler system is required by code. A fire wall creates 2 buildings (one sprinklered and one not), a fire barrier doesn't.

 

[princeofpen]

Regardless of the 12,000 sq ft max I highly doubt you can get less than 300 in an E space of even 10,000 sq ft. You have to meet all 3 criteria

 

[RLGA]

The entire building must be sprinklered if a sprinkler system is required by code.

Not necessarily--it depends on the triggering requirement:

• For allowable height and area, sprinklers are required throughout.
• Where a sprinkler system is used for the protection of incidental uses, it is only required for the incidental use.
• For Group B Ambulatory care occupancies, a sprinkler system is only required for the floor on which it is located and any stories below down to the level of exit discharge.
• For Group B laboratories, a sprinkler system is only required throughout the fire area where lithium-ion or metal batteries are researched, developed, and tested.
• For Group E, a sprinkler system is only required within the Group E fire area.
• For Group H occupancies (except H-5), a sprinkler system is only required within the Group H occupancy.
• For Group S-1 storage of distilled spirits or wine, a sprinkler system is only required in the Group S-1 fire area serving that purpose.
• For Group S-1 storage of upholstered furniture and mattresses, a sprinkler system is only required in the Group S-1 fire area serving that purpose.
• For underground buildings, only the portion below and up to the level of exit discharge is required to have a sprinkler system.
• Where stages are provided, only the stage requires a sprinkler system.
• For all other occupancy groups, a sprinkler system is required throughout.
• Some other code provisions only allow trade-offs when the building is sprinklered throughout.

I am sure other provisions allow only a limited coverage for a sprinkler system, but these are the few that I could quickly list.

It should go without saying that where a sprinkler system within a building is permitted to have limited coverage, it may still be required to be installed throughout the building by a provision that mandates installation throughout the entire building.

 

[Paul Sweet]

A building needs to be totally sprinklered to be able to take advantage of any of the sprinkler "trade-offs" such as height & area increases, reduction of fire ratings, deletion of smoke dampers at duct penetrations in corridor walls, etc.

If the existing building took advantage of any of these it will become non-conforming if it becomes partially sprinklered by using a fire barrier instead of a fire wall. Extending the sprinkler system into the addition is likely to be the less costly way of meeting code.

 

[RLGA]

A building needs to be totally sprinklered to be able to take advantage of any of the sprinkler "trade-offs" such as height & area increases, reduction of fire ratings, deletion of smoke dampers at duct penetrations in corridor walls, etc.

If the existing building took advantage of any of these it will become non-conforming if it becomes partially sprinklered by using a fire barrier instead of a fire wall. Extending the sprinkler system into the addition is likely to be the less costly way of meeting code.

Agreed, since these were included as my first and last bullet points.

One thing many people do not understand is that a building separated by fire walls is only considered multiple buildings for "the purposes of determining area limitations, height limitations and type of construction" per Section 503.1. For all other purposes, a building with fire walls is a single building. Thus, if Section 903.2 or any other section requires a building to be "sprinklered throughout" (except for Chapter 5), and the building has fire walls, the sprinkler system would be required in all portions of the building--even those separated by fire walls. This situation would also apply if a sprinkler is required throughout a particular story or a number of stories, if not the entire building.

The above is applicable to new buildings; however, the IEBC allows a sprinkler system to be limited to areas requiring it, provided the area is separated from the rest of the building with fire-resistance-rated construction. (This is a general statement and not meant to address all conditions where the IEBC requires sprinkler systems.)