Fire Rating of Electrical Room

[glzath]

Wasn't sure where to post this so my apologies if it's in the wrong forum area ...

IBC 2012
Unlimited area
Fully sprinklered
Type IIB
F-1 Use

We will be adding a 1500 SF electrical room on the 2nd floor of an expansion, and per NFPA 13, to avoid having to sprinkler the electrical space we'll have to provide a 2-hour enclosure. Walls and ceiling will not be an issue, but the question(s) is about the floor.
We are planning on designing a UL rated assembly for the floor which will provide spray applied fireproofing to the floor joists/beams and decking.
1) The room extends a bay and a half ... fireproof the underside of just the room footprint or the addition 1/2 bay, too?
2) Would the first floor columns supporting the second floor steel under the room also require fireproofing?

Thanks in advance,
Gary

 

[steveray]

If allowed they would be fire barriers and the supporting construction (to the foundation) would have to be 2 hr rated as well....I don't believe I would allow it in a building that required a sprinkler system, or at least not easily....

 

[glzath]

If allowed they would be fire barriers and the supporting construction (to the foundation) would have to be 2 hr rated as well....I don't believe I would allow it in a building that required a sprinkler system, or at least not easily....

Thanks Steve. Can you clarify what you would not allow? The 2nd floor unsprinklered electrical room?

 

[steveray]

CT amends 903.1.1 to be very limiting and then it has to meet on of the exceptions in NFPA 13 as well.....

 

[glzath]

We start with the 903.3.1.1.1 Exemptions 1, 2 & 3

1. Any room where the application of water, or
flame and water, constitutes a serious life or
fire hazard. (The electrical room will have high voltage panels, motor control centers and a couple transformers)
2. Any room or space where sprinklers are considered
undesirable because of the nature of
the contents, when approved by the fire code
official. (See above)
3. Generator and transformer rooms separated
from the remainder of the building by walls
and floor/ceiling or roof/ceiling assemblies
having a fire-resistance rating of not less than
2 hours. (The room will have a similar function)


And then go to NFPA 13 (2016) 8.15.11.2 Sprinklers shall not be required in electrical equipment rooms where ... (3) Equipment is installed in a 2-hour fire-rated enclosure ...

We have used this on a few projects, just not a second floor application. Once the client gives final approvals, we will be contacting the AHJ for sure.

 

[cda]

Thanks Steve. Can you clarify what you would not allow? The 2nd floor unsprinklered electrical room?

We would require the room to have sprinklers, unless this is for the CIA or similar with a vital mission.

Electrical stuff does burn. Once it burns, place out of commission for awhile anyway.

 

[mtlogcabin]

Unless it contains generators or transformers it does not give you a get out of jail card for NFPA 13. If the room does then NFPA 13 is out and the AHJ can direct you to NFPA 12, 12A, 17, or 2001 for an automatic extinguishing system. Your choice for what will work for what is in the room

 

[steveray]

If it is hot enough in the electrical room to set off the sprinklers, there is already a problem.