Summary: This collection of frequently asked questions (FAQs) addresses a wide range of fire prevention system and building code issues. The scenarios include post-fire sprinkler system testing, canopy materials, and concealed areas with composite wood joists. Notable points include the contrast between membrane and through penetrations in fire-rated structures, the need for sprinkler protection in greenhouses near educational establishments, and water delivery time concerns in a dry pipe system for idle wood pallet storage.
The responses consistently refer to relevant codes, including NFPA 13 and the International Building Code, to ensure compliance and safety. These FAQs are a helpful resource for professionals interested in fire protection engineering since they highlight the complex considerations in many scenarios while emphasising the need to adhere to code standards for successful fire safety measures.
A membrane penetration is a single breach in the floor-ceiling assembly, while a thorough penetration is a rupture on both sides. Regarding horizontal assemblies (floor/ceiling):
- Section 714.5.2 specifies membrane penetration standards, with exception 5 allowing for the annular area generated by a fire sprinkler with a metal escutcheon without requiring fire stopping.
- Section 714.5.1 specifies the criteria for through penetrations, including fire-stopping.
IBC Section 505 defines a single mezzanine as part of the level below, not a separate story or occupiable floor.
According to 905.3.1, a standpipe is only required for buildings with four or more stories or an occupiable floor 30 feet above or below the level of fire department truck access.
The 2021 IBC defines a mezzanine as an intermediary level between the floor and ceiling of a story, in accordance with Section 505.
The 2021 IBC defines a mezzanine as an intermediary level between the floor and ceiling of a story, in accordance with Section 505.
According to the 2016 edition of NFPA 13, a remote FDC can service several systems (Sections 8.17.2.4.3-8.17.2.4.4). According to Section 8.17.2.4.3, for multiple systems, the FDC must be linked to both the supply and system control valves. Section 8.17.2.4.4 clarifies that the criteria for multiple systems do not apply if the FDC is linked to subsurface plumbing.
The appropriate document for connecting the FDC to the subsurface is NFPA 24.
The 2016 edition of NFPA 24, Section 5.9, covers distant fire department connections. Section 5.9.5.7 discusses the concept of a distant FDC that serves many buildings. This clause requires an FDC to provide a sign specifying which buildings it serves.
The use of a remote FDC requires approval from the AHJ, as per NFPA 24. According to NFPA 13, Section 8.17.2.4.6, the FDC must be located near a fire department or at a location approved by the authority having jurisdiction.
To charge the FDC in the event of a fire in another building, there is no need to isolate one building by shutting down water at its fire riser. The non-fire building’s closed sprinkler system will not be affected by greater pressure from the FDC due to its inactivity.
According to NFPA 13, Section A.17.2.3, the function of a sprinkler system’s FDC is to supplement pressure, not to deliver specific flow or meet system demands.
Residential construction rules and NFPA 13D require smoke alarms to be installed in all residences. According to Section 4.4 of the 2016 edition of NFPA 13D, smoke alarms must meet NFPA 72 standards. As all residences are required to have smoke alarms, NFPA 13D rarely requires a local alarm.
This is not to suggest that a local alarm or even a fire alarm is not acceptable; nonetheless, they are not necessary.
NFPA 13D encourages cost-effectiveness and does not require their usage.
It’s important to note that NFPA 13D systems may require a local waterflow or fire alarm, depending on the contract or municipal law.
According to Section 4.5.1 of the System Protection Area Limitations, a single sprinkler system riser cannot cover more than 52,000 square feet of floor space for a light or ordinary hazard occupancy.
The expression “on any one floor” refers to the maximum area of a single floor, not the total area of all floors.
A single sprinkler system is authorized in this scenario since no floor exceeds 52,000 square feet.
Section 16.9.11.1 only requires floor control valve assemblies for multistory buildings over two floors in height; hence, floor control valve assemblies are not necessary.
The International Building Code (IBC) and NFPA 13 do not allow for the omission of sprinkler protection when adding a greenhouse to an existing building with sprinklers. According to NFPA 13, 2022 edition, Section 4.1.1, buildings with automatic sprinkler systems must have sprinklers in all areas, unless specified otherwise. NFPA 13 prohibits omitting sprinklers from greenhouses.
If the greenhouse is a distinct building, automatic sprinkler protection may be required under IBC Chapter 9 and Section 903.
Table 7.2.3.6.1 provides water supply times based on protective requirements, with shorter times as the hazard level increases.
Idle pallet storage 12 feet high does not match the definition of high-piled storage, which is defined as storage over 12 feet high. However, the parameters for idle pallet storage align with general storage requirements.
Idle pallet storage is dangerous as it generates great heat and quickly spreads flames during a fire. Pallet storage design requirements can lead to increased flow compared to high-piled commodity storage, such as Group A polymers. To achieve high-piled storage requirements, the delivery time for idle pallets must be minimal.
To calculate sprinklers within an 800 square foot building, apply the density area approach and adhere to 28.2.4.2.4 requirements. To proceed, obtain agreement from the authority having jurisdiction (AHJ) that Section 28.2.4.2.5 does not apply to this building due to its small size and lack of additional sprinkler flow requirements. The annex note A.28.2.4.2.4 (which described the method for adding the flow required by 28.2.4.2.5) was relocated to A.28.2.4.2.5 during the first draft of the 2025 edition of the standard (see FR-1254). This action indicates that the committee believes these are separate ideas and may support your case when discussing them with the AHJ. The language used in these sections may make it difficult to sell. If the building or sprinkler system is expanded in the future, permits and proof of hydraulic capacity are required to protect the additional area.
The second option would be to use the room design process. Since 28.2.4.2.5 is in the Density/Area Technique section, it is not applicable to the room design method. Although the stand-alone building has non-rated walls, the room design approach does not require outside walls to be fire-resistant. According to Section 19.2.3.3.4, “all interior walls enclosing the room shall have a fire resistance rating equal to the water supply duration.”
The outer walls do not need to be rated, and the charging statement in Section 19.2.3.3.1 applies to the room design technique. This section states that water delivery needs for sprinklers should be based on the room with the highest demand.
Section 29.7 of the NFPA 13 2019 version lends support to this idea. This section covers changes to existing systems and piping, not sprinkler replacement. However, it does state:
- 29.7.1 – Modification of existing piping systems tested at system working pressure.
- part 29.7.2 requires testing at 200 psi for 2 hours when more than 20 sprinklers are affected. However, this part does not apply to this project as it only involves 10 sprinklers.
- 29.7.3- When modifications cannot be separated, test at system working pressure. This section applies to replacing sprinklers on an existing system, as they cannot be isolated.
In Annex A.5.2 of NFPA 25 (2020), there are suggestions for coping with post-fire issues. This appendix section suggests:
- Inspect all sprinklers in the fire area.
- For small fires (managed by one or two sprinklers), replacing only the activated sprinkler may suffice.
- Soot-covered sprinklers should be replaced.
In the event of a significant fire, it may be necessary to replace the first ring of sprinklers encircling two operational sprinklers due to heat damage to the reaction mechanism.
The annex section is not part of the standard’s criteria, so site-specific conditions must be considered.
Sprinklers are not required for canopies, roofs, porte-cocheres, balconies, decks, or similar projections made of non-combustible, limited-combustible, or fire retardant-treated wood, as defined in NFPA 703, Standard for Fire Retardant-Treated Wood and Fire-Retardant Coatings for Building Materials. This is according to Section 8.15.7.2 of the 2010 edition of NFPA 13.
The need for noncombustible materials extends beyond structural members to include the canopy finish.
To prevent fires from spreading into the joist channel, the material should be placed perpendicular to it. This piece can be applied without sheathing the full composite wood joist. This is obvious from the necessity to utilize a “material equivalent to the web construction.”
For ceilings fitted with metal channels (1 inch max), 3 1/2 inch batt insulation should be put at the bottom of joist panels.
8.15.1.2.6 only addresses whether sprinklers can be omitted from a combustible concealed compartment. Section 11.2.3.1.5 should also be addressed. The nearby area for sprinkler operation must be 3,000 square feet, unless an exception is granted (see 11.2.3.1.5.2).
Section 11.2.3.1.5 is not about omitting sprinklers but rather about compensating for probable fires in exposed spaces. If a fire is not controlled in the unprotected space, a larger design area is required to compensate for the larger fire that may break through to a sprinklered area.
To avoid extending the design area, the conditions are more severe. According to Section 11.2.3.1.5.2(10), composite wood joist construction requires “adjacent joist channels” to be fire-stopped in quantities of no more than 160 cubic feet, using materials equivalent to 1/2 inch gypsum board.
This varies from the criteria of 8.15.1.2.6 in two ways:
- According to 8.15.1.2.6, firestop materials must be similar to web construction, although 11.2.3.1.5.2(10) specifies that they should be equivalent to 1/2 inch gypsum board.
- According to 8.15.1.2.6, individual joist channels must be fire-stopped to a volume of 160 cubic feet. However, 11.2.3.1.5.2(10) requires “adjacent joist channels” to be fire-stopped to a volume of 160 cubic feet, which may necessitate installing fire-stopping between channels.
Courtesy: Roland Asp, CET, TechNote 507
