Exterior Wall of Fire Pump Room Require Rating?

7/20/2023

Architect here with a fire code question. We have a fully sprinklered building (ESFR), of Type II-B, tilt concrete construction.

The fire pump room is located on an exterior wall, and the only door into the pump room is from the exterior. We have 1-hr rated construction separating the fire pump room from the rest of the building.

The fire marshal is telling us that the exterior wall and door also have to be rated. I responded by pointing out the fire pump is required to be protected from the surrounding building, and that it does not need to be protected from the exterior, so exterior wall and door should not have to be rated.

Fire marshal disagrees and pointed to NFPA 20 4.14.1.1.2. That section does not specifically state that separation is required from the rest of the building, although Section 4.14.1.1.1 right before it does make that distinction, just like IBC/IFC do.

We have solid concrete walls that are inherently fire rated construction, so typically I would just say ok and label them rated. The issue is we are required to have ventilation in the pump room per NFPA 20, so we have a makeup air louver in the exterior wall. If we rate the wall, then my understanding is we will have to put a fire/smoke damper on that louver, which is added cost and unnecessary in my opinion.

Is your understanding that all walls have to be rated as the fire marshal is saying, or just the walls between pump room and rest of building?

I've done many buildings of this type in multiple states and this is the first time I've been told this. I'd appreciate your insight, thanks.

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11 Comments

Anthony

7/20/2023 07:28:09 am

TL;DR: Its reasonable for a fire official to intemperate table 4.14.1.1.2 as the full pump house connected to the building.

4.14.1.1.1 - is directly related to high rises, if you have a high rise this piece of code calls for a 2 hour rated wall.

if you don't have a high rise the room shall be "protected by fire-rated construction in accordance with table 4.14.1.1.2." To get my grammar lawyer hat on it is reasonable to conclude form this code that the construction is an encompassing term requiring all parts of a bulling, i.e the totality (walls and roof) of construction shall be in accordance with the table.

4.14.1.1.3 and its annex A material indicated this section should be referenced only for individual special hazards such as a local mist system inside an otherwise fully sprinkled building.

Todd E Wyatt

7/20/2023 08:26:07 am

The Exterior Wall (EW) of the Fire Pump Room (FPR) is not required to have a fire-resistance rating (FRR) per the scoping Code (e.g. 2021 IBC).

The IBC requires the FPR to be "separated from all other areas of the building by 2-hour fire barriers constructed in accordance with Section 707 or 2-hour horizontal assemblies constructed in accordance with Section 711, or both." Since this building (non High Rise Building) is protected by an Automatic Sprinkler System (ASPS), the FRR of the Fire Barriers (FB) can be reduced from 2-Hours to 1-Hour.

This section specifically states "separated from all other areas of the building" and not "separation from the exterior." That is not the intent of this separation requirement.

If the AHJ disagrees and insists (incorrectly) that the EW is required to have a 1-Hour FRR, acquiesce accordingly. The corresponding exterior door will be required to be 0.75-Hours. Openings (e.g mechanical louver) in the 1-Hour EW would not require a damper, however.

2021 IBC
Chapter 9 Fire Protection and Life Safety Systems
Section 913 Fire Pumps
913.1 General
Where provided, fire pumps for fire protection systems shall be installed in accordance with this section and NFPA 20.
Exception: Pumps for automatic sprinkler systems installed in accordance with Section 903.3.1.3, or Section P2904 of the International Residential Code.
913.2 Protection Against Interruption of Service
The fire pump, driver and controller shall be protected in accordance with NFPA 20 against possible interruption of service through damage caused by explosion, fire, flood, earthquake, rodents, insects, windstorm, freezing, vandalism and other adverse conditions.
913.2.1 Protection of Fire Pump Rooms
Fire pumps shall be located in rooms that are separated from all other areas of the building by 2-hour fire barriers constructed in accordance with Section 707 or 2-hour horizontal assemblies constructed in accordance with Section 711, or both.
Exceptions:
1. In other than high-rise buildings, separation by 1-hour fire barriers constructed in accordance with Section 707 or 1-hour horizontal assemblies constructed in accordance with Section 711, or both, shall be permitted in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2.
2. Separation is not required for fire pumps physically separated in accordance with NFPA 20.

Dan Wilder

7/20/2023 08:34:57 am

Not an IBC guy but....

IBC 2018
913.2.1 Protection - 1 HR per Section 707
707.4 - Sends you to 705 but says the fire-resistance-rated enclosure or separation requirements shall not apply (with the exception noted).
705.5 - Per Table 601 & 602
Table 601 - Type II-B Lists "0" all the way down unless it's non-bearing then look at 602
Table 602 - If you have 30' clear, no rating requirements.

Not sure of the Occupancy Group but S-1 & S-2 both allow a "0" rating down to 10' of fire separation. Group H is the only one that would need the full 30'.

Now, I may be looking at this wrong, so I'm open to some learning because I can see this being helpful in the future.

Scott Keeley

7/20/2023 08:45:01 am

As an AHJ, he is misinterpreting this section of the code. The exterior wall is not required to be rated. You could always file an appeal and take before the AHJ's construction and appeals board.

Glenn Berger

7/20/2023 08:53:55 am

From what you have said, you should be good from your building. You have not made any discussions on the surrounding buildings or other external equipment, for which protection may be required.

Jesse

7/20/2023 09:55:17 am

I'm gonna jump in with Glenn here. Is there an exterior exposure involved? Yard storage, Wildland-urban interface, exposing buildings with no adequate clear space separation?

7/20/2023 09:07:51 am

I think that Todd briefly touched on the most helpful fact above… even if the exterior wall was rated, the louver would not require a fire damper (unless it’s right next to a means of egress). If the mechanical engineer says otherwise, let me know and I can dig out the codes sections.

Franck

7/20/2023 09:42:44 am

Unless you have idle pallets (or other combustible load or building) close to the exterior wall, I don’t see any reason for fire rating requirements.
Pump room should be sprinkler protected as per last versions of NFPA 20 (so no exposure to the outside), and if no outside exposure…

Sean

7/20/2023 11:00:54 am

I think the NFPA 20 is pretty clear. 4.14.1.1.2 says "protected by fire rated construction", but Table 4.14.1.1.2 is specific in saying that the fire separation is required between the protected building and the pump room. The exterior is not part of the building, so no separation is required. Handbook commentary in the 2022 edition also clarifies this.

Similarly in IBC/IFC - 913.2.1 says rooms shall be separated from all other areas of the building. Exterior is not part of the building.

The only thing I can think of that would require rating would be if all exterior walls needed to be rated for exposure protection due to closely adjacent buildings, or if 2 close buildings are not separated and considered a single building where there is no public way; but assuming that is not the case here.

JP link

7/20/2023 01:38:07 pm

I will add in from a building code perspective since most others discussed the NFPA standards. In general, exterior wall ratings and allowances for openings originate from Table 601 and Section 705 from the IBC. These requirements stem from construction type and fire separation distance. The vent for the exterior wall could fall under the requirements of Section 705 for unprotected openings. If the other advice is not working, this may be an alternative solution by stating what your allowance is for unprotected openings for that wall based on fire separation distance.

Janak Patel

7/26/2023 12:01:09 pm

Per NFPA 20 (2019), Table 4.14.1.1.2, a fully sprinklered Pump Room separate from a fully sprinklered building (non-high rise), the exterior walls need to be at least 1 hour fire rated or 50 ft separated.
IBC (2018), Section 913.2.1, Exception 1 requires a 1-hr fire rated wall construction or a 'physical' separation per NFPA 20 (i.e. 50 ft).

Exterior Wall of Fire Pump Room Require Rating?

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