Zoning and NFPA 13 vs NFPA 72

[Glorified Plumber 84]

I'm looking for some guidance on how to address NFPA 13, 2016e. section 8.2.4.2. The floor control valve, check valve, main drain valve, and flow switch required by 8.2.4.1 shall not be required where sprinklers on the top level of a multistory building are supplied by piping on the floor below.
8.2.4.3 also states that if the entire building is under system area limitations, floor control valves are not required either.

The issue that we face is that NFPA 72 states (2016e, section 10.17.5.1) States every floor "For the purpose of alarm annunciation, each floor of the building shall be considered as a separate zone."

How can these 2 codes be solvent together?

The Annex of NFPA 72 has the following, which I'm not incredibly familiar with. Does this read that a single zone control for the top floor and floor below is compliant as long as the flow device is annunciated separately from other fire alarm devices? Or that each floor needs annunciation from separate water flow devices?

Fire alarm system annunciation should, as a minimum, be sufficiently specific to identify a fire alarm signal in accordance with the following:

Waterflow switches on sprinkler systems that serve multiple floors, areas exceeding 22,500 ft2 (2090 m2), or areas inconsistent with the established detection system zoning should be annunciated individually.
(4)

 

[cdafd]

You are talking about NFPA!!

One is electrical and one is plumbing.

Anyway

For NFPA 72 you post a section on Annunciation,,, which is total separate subject than floor control valve.

Normally if a riser is serving another floor above, from below it will have either one flow switch for the entire building or a separate floor control valve for floor of and floor above.

A lot depends on how the fire sprinkler system is laid out.

Not sure if this helps

 

[Glorified Plumber 84]

NFPA 13, 2016e. section 8.2.4.2. The floor control valve, check valve, main drain valve, and flow switch required by 8.2.4.1 shall not be required where sprinklers on the top level of a multistory building are supplied by piping on the floor below.

We frequently come across this scenario, where you would feed the top floor sidewalls from the floor below. NFPA 13 seems to address this by stating the above. The flow switch specifically is the point of contention though. NFPA 13 states it isn't required for the scenario described, and the single flow switch/control valve from the floor below is good. However some AHJ's have used NFPA 72 ANNUNCIATION as the reason this isn't allowed.

I'm just trying to figure out if NFPA 72 really does require every floor's sprinkler system to have it's own water flow switch, as NFPA 13 does not require that.

 

[Glorified Plumber 84]

Below is from the Annex of NFPA 72. Number 3 specifically seems to address this scenario, but I'm not an expert in Fire Alarms so I'm not 100% clear on what it means. I'm thinking it's saying that if you have waterflow devices that serve multiple floors, then those devices should annunciate separately than the floor's fire alarms. As in, show up on the panel as something like 4th/5th floor sprinkler flow or something?


A.10.18.5

Fire alarm system annunciation should, as a minimum, be sufficiently specific to identify a fire alarm signal in accordance with the following:

(1)

If a floor exceeds 22,500 ft2 (2090 m2) in area, the floor should be subdivided into detection zones of 22,500 ft2 (2090 m2) or less, consistent with the existing smoke and fire barriers on the floor.
(2)

If a floor exceeds 22,500 ft2 (2090 m2) in area and is undivided by smoke or fire barriers, detection zoning should be determined on a case-by-case basis in consultation with the authority having jurisdiction.
(3)

Waterflow switches on sprinkler systems that serve multiple floors, areas exceeding 22,500 ft2 (2090 m2), or areas inconsistent with the established detection system zoning should be annunciated individually.
(4)

In-duct smoke detectors on air-handling systems that serve multiple floors, areas exceeding 22,500 ft2 (2090 m2), or areas inconsistent with the established detection system zoning should be annunciated individually.
(5)

If a floor area exceeds 22,500 ft2 (2090 m2), additional zoning should be provided. The length of any zone should not exceed 300 ft (91 m) in any direction. If the building is provided with automatic sprinklers throughout, the area of the alarm zone should be permitted to coincide with the allowable area of the sprinkler zone.

 

[cdafd]

I would say when looking at the sprinkler system,,, apply NFPA 13 First,

Then apply NFPA72, to what you wind up with.

It is hard to give a specific answer,

1. When there are many ways to set up a fire sprinkler system.

2. Plus, what the AHJ, enforces, wants, ETC.

NFPA is the design standard, not everything in them are always required

 

[UFT12]

Don't get confused by 72. 72 practically says, wherever you have a flow switch, treat it as separate alarm zone. Now, where should you have flow switches (accompanied by the rest of the assembly) is governed by 13. There are requirements imposed, there are also allowances for omission.

 

[Glorified Plumber 84]

Right on, thanks for the input. I'm pretty sure we are compliant but the AHJ doesn't agree so was just looking for some guidance on if anyone had this come up and if there was code/standard data to support one way or the other.

 

[cdafd]

Are you the fire sprinkler company???

And there is a separate fire alarm company?

 

[Glorified Plumber 84]

Yep.

 

[cdafd]

I would say this unfortunate is a case by case item. And an AHJ/ Inspector item.

In away you are at their mercy.

My only comment would be, if they are requiring something ask for the code or standard section, to back it up.

If it cannot be provided, or not being enforced correctly,,, they cannot require it.

Just like there are numerous items in NFPA 13, that a fire sprinkler company, does not include, or misses, in their submittal.

 

[Glorified Plumber 84]

Well thanks for the responses regardless. We discussed this and the reasoning behind their requirements is sound. In a 7 story non high rise building that has 70 units per floor, if a water-flow device activates that states "either the 6th or 7th floor water flow", no one wants a fire crew being forced to go through 2 stories of units looking for the fire.

On our end though we bid jobs to code, and design to code, and can't possibly account for every AHJ's thoughts on best fire fighting practices so that's really the only reason things like this are frustrating, but I also understand the flip side as well.