We have a building that is constructed. It has a very deep footing.

The contractor originally submitted an Ames In-Building Riser, but it's too deep for the in-building riser in the building's (essentially) existing condition.

They proposed using C900 to come under the footing, without a sleeve, going below the 12" footing and then stubbing up into the riser room without thrust blocks.

We have concerns about restraint and a change of direction underneath the foundation.

NFPA 13 applies and C900 is a permitted material, which is what the contractor has suggested makes it acceptable.

Is routing C900 under a building footing, changing direction, and then stubbing into the building acceptable?

NFPA 20 says that if the test header supply main is more than 15 feet from the fire pump, it must be increased one pipe size or hydraulically calculated based on 150 percent of the rated pump capacity.

What form does the hydraulic calculation take?

Are we trying to determine if the main can flow 150 percent of the pump rating without running out of pressure?

How low a pressure would be acceptable?

Is this a one time calculation to size the main or is this a calculation that must be performed during each annual fire pump test?

Thanks in advance.

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The installation contractor and I have had an argument about how sprinklers should be spaced and calculated in a 13R system.

I have argued that per NFPA 13R Section 7.1.1.3.1, we should calculate 3 sprinklers in the greatest hydraulic demand area. This area is furthest from the riser and the calculation permits 16x16-ft spacing for the area that has the most sprinklers.

Section 7.1.1.3.1:
For each of the following situations, the number of sprinklers in the design area shall be all of the sprinklers within a compartment, up to a maximum of four sprinklers, that require the greatest hydraulic demand:

The contractor wants to remove a sprinkler in a single room and move a sprinkler 10 feet off of the exterior wall, but in NFPA 13R makes no mention of a single sprinkler proof calculation that could justify such a move.

There is no mention of a single sprinkler calculation in NFPA 13R permitting a spacing of 20x20, and so all sprinklers on the project can be only 16x16 if the greatest hydraulic demand is permitting it.

In NFPA 13D, it makes no mention of a single sprinkler calculation either, but does refer to single sprinkler operations in A.10.1. I did not feel comfortable designing a sprinkler system that was not up to code standards and need an outside opinion on this matter. Thanks in advance.

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I am trying to figure out how to protect an existing building that has never had a sprinkler system.

The building peaks at 46'-5" and in that area you can only have a max height of 25'-0 in storage, due to operable cranes in the bay.

Additionally, the building is constructed using 12" purlins, so ESFR pendants are out unless we want to put them on return bends.

I am trying to give the owner as much storage space as possible, and commodities as they plan to rent the building out to tenants in the future. I have searched through CMSA, CMDA, ESFR and storage to find a situation that best describes it.

The issue I always come up on, is the distance from top of storage to ceiling. Every scenario I have looked at, we seem to exceed the 10' or 20' maximum distance.

Does anyone have some criteria they used that is close to the situation above?

Thanks in advance.

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We are a structural engineer currently work for an architect on a small assembly hall project; a wedding venue that will seat over 99, which will require sprinkler protection.

The roof structure will be wood scissors trusses, 5’-7” deep at the center – see below.

​I mentioned to the architect that they will have to protect the “attic” space also with sprinklers.

In response, the architect said the owners want to finish the ceiling and insulate the attic space.

Where is it written about the maximum cavity size without sprinklers? Is it any cavity?

If so possibly we fill the entire attic space, which is small because of the unique scissors trusses. I don’t think this would be economical or practical.

But, what would the cavity depth have to be (underside of roof deck to top of batt or blown insulation) so that sprinkler protection of that concealed combustible space is not required?

I assume if this space is not sprinkler protected that “attic” compartments would be required. Any guidance on this matter would be appreciated. Thank you.

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3M recently announced they will no longer manufacture NOVEC 1230 by end of 2025 due to the presence of PFAS (https://news.3m.com/2022-12-20-3M-to-Exit-PFAS-Manufacturing-by-the-End-of-2025).

Other similar agents, such as FM-200, have similar environmental concerns due to having HCFCs.

Does anyone know a chemical fire suppression agent that doesn't have CFC or PFAS issues?

I know there is a new NFPA standard (770) on hybrid systems and that the Victualic Vortex is one such system, but not sure what other alternatives are out on the market. Thanks in advance.

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I have a situation where I need to protect a modular home manufacturing facility.

It has a paint both that's self-contained with its own sprinkler hookups, all the regulars of a tiny home making shop basically. They will have rack storage of wood products up to 20' high and wanted the design to be such that they could move the storage rack locations in the future if they wished.

NFPA 13 (2016) A.5.4.2 gives a list of some Extra Hazard Group 2 occupancies and it specifically lists (4) Manufactured home or modular building assemblies (where finished enclosure is present and has combustible interiors) I had made the assumption that ESFR was a worst case, safe bet design for the entire facility due to the amount of water you get from heads opening up.

The contractor is concerned with how code says one thing in one place and something open to interpretation in another place. Section 8.4.6.6 says "ESFR sprinklers designed to meet any criteria in Chapter 12 through Chapter 20 shall be permitted to protect light and ordinary hazard applications."

That's fine, but I just see that as just a statement.

When you get to the requirements for Storage, Section 12.6.7.1 says the following: "ESFR sprinklers designed to meet any criteria in Chapter 12 or Chapter 14 through Chapter 20 shall be permitted to protect any of the following: (1) Light hazard occupancies (2) Ordinary hazard occupancies (3) Any storage arrangement in Chapter 13 referencing OH1, OH2, EH1, and EH2 design criteria"

Item 3 is where I want to make the argument that we can in fact use ESFR sprinklers in an Extra Hazard Group 2 scenario.

Can ESFR be used for an Extra Hazard Group 2 situation like this?

I need some expert opinions/interpretations. Thanks in advance.

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I'm a plan reviewer for a project that's coming into our area. We have a local gym/special amusement facility that has several foam pit areas.

What is an appropriate sprinkler design criteria for a foam pit?

The plans call for a 5-ft platform, which leads us to believe the pit is 5-ft or less in depth, but we're not sure about the building on the platform of other foam pads; so there's a chance this depth could exceed 5-ft when it's all said and done and measured with a tape.

Best I can relate to for this type of situation is in NFPA 13 2022 edition, Section 4.3.1.7.2.4, which references Table 4.3.1.7.1.1. Also, I've referenced IFC 3203.7.1 for classification.

Is there any other information that you can point me to for guidance?

If so, it would be greatly appreciated.

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For a fire pump subject to NFPA 20, I know that the suction side requires an eccentric reducer, but “can” one be put on the discharge side?

I have a situation where we are removing and replacing existing pumps where both the suction and discharge are at the same elevation, but the new pumps have the discharge about 2.5” lower than the suction.

I am trying to find a solution to resolve this. Thanks in advance.

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Can the pipe from a remote FDC at the front of our building route under the building slab to connect to our fire pump room at the back of the building?

The Fire Pump Room is on the basement level.

This is for a six-story hotel with a partial basement along the back portion of the building that is open to a lower grade level in back. Here's a sketch below.

The fire marshal requires a remote FDC at the sidewalk in front of the building. Our fire pump room happens to be on the opposite side, in the back.

The most straightforward routing is below the building, but it is minimum 60' of run which certainly exceeds the 10' maximum distance allowed for the fire supply from NFPA 13.

Going above the first floor ceiling is challenging given all the interiors/ceilings, public spaces, and glass at the street front.

Given that the FDC pipe is normally-dry and not pressurized, do we have the same restrictions of 10' max below grade?

Even if not, can't say I'm thrilled about having that many joints below our building above. Thanks for your help/thoughts!

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Do open (exterior) stairs need standpipes?

If the stairs are more than 50% open, sprinkler protection is not required but what about standpipes?

This building has three stairways. Two are interior and one is open and on the exterior. Standpipes are provided in the two interior stairways.

Thanks in advance.

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Section 5.3.2.1 of NFPA 25, Gauges shall be replaced or tested every five years by comparison with a calibrated gauge.

Is it required for us to provide a sticker on the gauge to indicate it has been re-calibrated by the 3rd party, or will a sharpie inscription on the glass of the gauge be sufficient to meet this requirement?

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What is the required duration for a Secondary Water Supply within Seismic Zone?

IBC Section 403.3.3:
​
"The secondary water supply shall have a duration of not less than 30 minutes as determined by the occupancy hazard classification in accordance with NFPA 13."

Does this mean minimum 30 minutes, with the gpm/demand determined by NFPA 13?

Or the minimum duration is also determined by NFPA 13, such that the secondary water supply could require an even longer duration, like 60 minutes?

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I have a plan reviewer that is not accepting our proposed design for a manual standpipe calculation.

The calculation shows a required pressure on the fire department pumper truck to be a minimum of 217 PSI.

It has been confirmed that the pumper truck can reach and/or exceed 250 PSI.

The AHJ is requesting that we increase the standpipe from 4-inch to 6-inch, which is not alleviating the higher pressures as we are still above 175 PSI.

This would be a first for me to have to install pressure reducing hose valves on a manual wet standpipe.

My understanding per NFPA-14 (2016) 7.2.3.2 is that this is only an issue when the static pressures on the systems exceed 175 PSI (city static is 113 PSI).

So in essence, we are advising the fire department pumper truck operator to dial his pump up to 217, but this wouldn't be static, as they would be flowing out of the hose valve(s), correct?

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Has anyone dealt with the robotic parking garages?

The 2021 IFC/IBC Section 903.2.10.2:
​
Mechanical-access enclosed parking garages. An approved automatic sprinkler system shall be provided throughout buildings used for the storage of motor vehicles in a mechanical-access enclosed parking garage. The portion of the building that contains the mechanical-access enclosed parking garage shall be protected with a specially engineered automatic sprinkler system.

Some of the articles I read indicated a water mist with foam. Completely new thought processes to go through for these since there is very little access for fire personnel.

Any thoughts on where to begin or what to read would be appreciated. Thanks.

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In the introduction (Origin and Development) to the 2023 Ed. of NFPA 25, it mentions that several changes have been made to Chapter 5, "such as additional requirements to remove concealed sprinkler cover plates and inspect the sprinklers". I have scoured the text of Chapter 5, and cannot find this requirement anywhere.

Was this discussed but not implemented?

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For determining the capacity of a water storage tank, is the tank capacity calculated by the max flow extension of a pump curve or by 140% rated capacity? Or could it even be 120% of the pump rated capacity?

Looking for guidance on how the pump size and water storage tank size would be directly related.

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I am working on a 4-story multifamily building that's above a 1-level parking garage on the ground floor.

The exterior wall is less than 10-ft fire separation distance to the property line, requiring the exterior wall it to be 1-hour fire-resistance-rated.

Since it is an open parking garage, I need a lot of openings within this wall to provide ventilation. Denver has an amendment that allows 50% allowable openings with water curtains per NFPA 13.

Since the parking garage will have a dry system, is this even possible?

It seems like a very odd condition but again I need over 25% opening within the wall to comply as an open parking garage.

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For exposed copper piping in Ordinary Hazard occupancies, can the joints be soldered (sweat) together or must they be brazed?

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The maximum allowable protection area for a sprinkler listed is in Table 8.6.2.2.1(a) of NFPA 13 (2016 Edition).

Section 8.5.2.1.1(1)(b) says to choose the larger of twice the distance to the wall, or the distance to the next sprinkler.

Do we use the protection areas in Table 8.6.2.2.1(a) when applying this code section, or do you use the maximum allowable protection area for a sprinkler that's listed in the manufacturer's data?

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There was a warehouse that was struck by a tornado in 2021 which is in my jurisdiction, and we are now seeing some warehouses wanting to place pre-built tornado shelters within their buildings (which is great).

My question is: do the pre-built shelters need to have sprinkler protection?

My feelings are that the shelters are non-combustible, the only fuel-load would be from the 5-gallon bucket-style water closet and a privacy drape.

Obviously, a fire in this unit while occupied would not be tenable long before a sprinkler head would activate. I also understand that if a portion of a building that would normally be sprinklered (a school hallway) and is "hardened" to make it qualify as a shelter would still require sprinklers.

Thanks in advance for any help or guidance.

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Is missing a coverplate for a concealed sprinkler a deficiency in NFPA 25 that would be required to be corrected?

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So I am dealing with a building who stores plastic containers, I asked for the SDS sheets to find out what they say as far as protection.

The SDS sheets only mention water fog, dry chemical, foam, and carbon dioxide as suitable extinguishing agents; no water spray. The building currently has water spray. 

In the SDS under "Unsuitable Extinguishing Media" it lists "none known". Does this mean that water spray could be suitable for use even though it is not mentioned under extinguishing media?

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The architect has specified a solid panel ceiling in an 8-ft wide corridor.

The ceiling has a 4-inch gap that extends the width of the corridor. The gap is spaced every 8-ft.

The architect would like us to locate the sprinklers in the gaps so the ceiling has a clean look. The gaps are open to above. There are no sprinklers above the ceiling.

I believe the sprinklers should be installed in the solid part of the ceiling, not the gap, so heat can collect and activation is not delayed.

Am I correct?

​Thank you in advance for your responses.

We are working on a new (750 gpm) standpipe system.

When testing and setting the field adjustable 2-1/2" PRV hose valves, do you set each one flowing 250 gpm while also flowing 500 gpm elsewhere, to account for the hydraulically calculated design (i.e. lower inlet pressure per NFPA 14-11.5.5.1)?

Or do you just set each one only flowing 250 GPM by itself?

Thanks in advance.

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