This issue enquires whether a sprinkler system is required for an outdoor bike rack situated beneath a noncombustible projection connected to a noncombustible building. It focusses on determining if the covered area requires fire protection under NFPA requirements, while being open and used for temporary guest bicycle storage.

Question 1. If a noncombustible structure has a noncombustible outside projection over a single-level outdoor bike rack for guest use, does the existence of the rack need sprinkler protection?

Answer- NFPA 13, 2013 Edition, Section 8.15.7 mandates sprinkler protection beneath outside projections when flammable materials could potentially overload the interior sprinkler system and jeopardise fire protection.

The annexe note to Section 8.15.7.5 clarifies that short-term transient storage, such as for delivered packages or the presence of planters and newspaper machines, does not constitute combustible storage. Sprinkler protection is not necessary for combustible furniture on balconies used by occupants.

This rule applies to significant quantities of wood, paper, or plastics stored under exterior projections for long-term exhibition or retailing, such as at a mercantile or home improvement store.

A bicycle rack with temporary storage does not fall under the scope of this clause as it uses minimum combustible materials. This situation does not require sprinkler protection under the external projection.

A 10,000-gallon subterranean water storage tank powers a pump vault with a 250 GPM vertical turbine fire pump.  The engineer recommended a 12-inch supply line from the tank to the pump vault, but the tank supplier fears it may be too long.

Question 2. Are there any guidelines in NFPA 20 or NFPA 22 for sizing the supply line from the subsurface tank to the pump vault?

Ans. NFPA 20 specifies the size of the suction line from the tank to the pump, while NFPA 22 offers relevant guidelines.

According to NFPA 22, Section 14.2.2 “Size of Discharge Pipe,” discharge pipes from tanks with a volume of 25,000 gallons or less must be at least 6 inches in size.

However, NFPA 20 ultimately controls suction pipe size. NFPA 20, 2013 version, Section A.7.2.2.2 states that the approach channel or intake pipe shall not exceed 2 feet per second (0.7 m/s), while the wet pit should not exceed 1 foot per second (0.3 m/s). (Refer to Figure A.7.2.2.2.

Self-storage facilities have a non-combustible overhang that covers the “Loading Space” area on the exterior. The design team believes that this is an outside loading dock and hence requires sprinkler protection. The owner claims that the overhang is non-combustible and the room is not meant for permanent storage.

Question 3. What are the NFPA 13 (2019) standards for this scenario?

Ans. Based on the information provided, the “loading area” looks to be an external loading dock. Sprinkler protection is necessary, even if there is no permanent storage beneath the non-combustible overhang.

This view is reinforced by Annex Section A.5.3.2(8), which indicates outside loading docks. Exterior loading docks that solely handle common combustibles should be classed as OH2. For handling flammable and combustible liquids, hazardous materials, or storage, exterior and interior loading docks should be protected based on occupancy and materials handled, as if stored in that configuration.

The committee believes sprinkler protection is important for loading docks, even if no combustibles are stored (see annexe wording). This objective is emphasised by the following statements: “Exterior loading docks only used for loading and unloading of ordinary combustibles should be classified as OH2” “As if the materials were actually stored in that configuration.”

Sprinkler protection is necessary when flammable materials are present, regardless of storage purpose, according to these statements.

This guidance, provided in the annexe, is not legally enforceable. Nonetheless, it outlines the technical committee’s recommendations and aim for the standard.

 A 20-inch spherical duct beneath the ceiling connects two sprinkler heads. See the linked section views for more information.

Question 4. According to the 2016 edition of NFPA 13, what are the appropriate blockage rules?

Ans. The information presented makes it unclear if the 20-inch round duct is an obstacle to the nearby sprinklers or a permitted obstruction.

The duct may be considered an authorised obstruction if the following conditions are met:

• If the duct is within 18 inches of the neighbouring sprinkler(s), it is considered an impediment to the development of the sprinkler discharge pattern and requires compliance with Section 8.5.5.2. Section 8.5.5.2.2 requires compliance with sprinkler type-specific obstruction standards (Sections 8.6–8.12).
• If the neighbouring sprinklers are standard spray pendant type and the top of the duct is below the level of the sprinkler deflector, Section 8.6.5.2.1.1 (for obstructions within 18 inches of the deflector) requires Section 8.6.5.2 to be followed.
• According to Section 8.6.5.2.1.3, sprinklers must be situated at least three times the maximum dimension of the blockage. The duct measures 20 inches, which equals 60 inches.
• The duct’s horizontal position requires a maximum clear distance of 24 inches. Section 8.6.5.2.1.3 (A).
• Section 8.6.5.2.1.4 only applies the three times rule (8.6.5.2.1.3) to structural members in areas classified as light or ordinary hazards. Ducts are not considered structural members; hence, section 8.6.5.2.1.4 applies.

The given drawings do not indicate if the nearby sprinkler deflector is over the top of the duct. Visually, the top of the duct appears to be level or slightly above the obstacle. If this is the case, Section 8.6.5.2.1.2 will apply.

• According to Section 8.6.5.2.1.2, solid continuous impediments must be situated with the top level or above the plane of the deflector.

The provisions of Section 8.6.5.1.2 must be followed. This concept is also stated in Annex Section 8.6.5.2.1.4.

• The conduit impacts two sprinklers, making it a solid continuous blockage (as defined in Section 3.3.18.1).
• Section 8.6.5.1.2 provides four solutions to minimise obstacles, including beam and soffit rules.
• If the rules in Section 8.6.5.1.2 are not followed, the two pendant sprinklers are considered obstructed. The impacted sprinklers must be changed, and additional sprinklers may be needed to protect under the duct.

It’s important to note that if the sprinklers aren’t normal spray, they must follow the appropriate obstruction standards. Section 8.8.5 applies to extended coverage pendant sprinklers. Section 8.8.5 does not confine the four-times rule solely to structural members.

This question asks whether all underground piping in a seven-building industrial complex must comply with the material standards listed in Table 10.1.1.1 of NFPA 24 (2019 edition). It focuses on the applicability of fire protection piping requirements for a new shared 8-inch residential water and fire main serving multiple buildings.

Question 5. An industrial complex with seven buildings is installing a new 8-inch residential water and fire main. Is it necessary for all underground pipe in the complex to meet Table 10.1.1.1 of NFPA 24’s 2019 edition?

Ans. The answer is “no”. Section 10.1.1.1 outlines one of three pipe material possibilities for private fire service mains.

Section 10.1.1 allows the three following options for approved underground plumbing materials:

• Pipe constructed according to the specifications indicated in Table 10.1.1.1.
• 10.1.1.2: Pipe designated for use as a private fire service main.
• 10.1.1.3: Steel pipe with an external coating and internal galvanisation for fire department connections. This option is not applicable to the situation given.

Underground piping for fire service mains must meet AWWA or ASTM requirements (Table 10.1.1.1) or be made of materials approved for this purpose (Section 10.1.1.2).

Section 1.1.3 of NFPA 24 provides an exemption to these standards. This section explains that NFPA 24 does not apply to:

• Water utility-controlled mains, or
• Water utilities operate private mains for fire protection and household water.

Water utilities often adhere to their own standards for pipe materials, ensuring reliable and acceptable performance.

NFPA 24 does not specify what constitutes “operated as a water utility”, but a critical factor is whether the private water supply is as reliable as a public utility.

A fire prevention system consists of many wet sprinkler risers connected by a common water source.

Question 6. 

A: Is it necessary to do a main drain test for each riser, or may it be reduced to one per vertical standpipe or representative location?

B: Does NFPA 13 require a general information sign for each riser, or may it be reduced to one per floor or zone?

Ans. The standard requires a main drain acceptance test for each system, as per NFPA 13. Each riser supports several sprinkler systems, requiring a separate main drain test for each. Testing simply the top sprinkler system on each riser is insufficient to validate water supply performance across all systems supplied by that riser.

The standard mandates a general information sign to be erected at each system riser, near the control valve. Clear labelling or numbered valve manifolds is crucial for precisely identifying each indication and its associated system. These indications provide a summary of the design principles for each system.

According to NFPA 13, a system riser is an aboveground horizontal or vertical pipe that connects the water supply to the system mains. It comprises a control valve, pressure gauge, drain, and water flow alarm mechanism.

A general information sign would be needed at each of the six sprinkler system risers.

Description: We are inspecting an existing sprinkler system in a PVC manufacturing facility. The sprinkler system planned and installed in 2025 is classed as Ordinary Hazard Group II (OH2). However, if PVC is a Group A material, an Extra Hazard Group II (EH2) design may be necessary.

Question 7. Is the raw PVC material classified as either Group A or Group C plastic?

Ans. The design professional is normally responsible for determining hazard or commodity categorisation for a project. However, the following response may provide guidance in reaching this decision.

According to NFPA 13 (2025 edition), plastics are classified as Group A, B, or C for storage purposes based on heat of combustion, burning characteristics, and packaging configuration (Section 20.4).

Raw PVC, especially in its unplasticized or rigid state, is classified as a Group C plastic due to its low combustibility during storage. NFPA 13 allows up to 20% plasticiser content in a Group C/Class III commodity. Manufacturers rarely provide these percentages; thus, they must be confirmed individually.

The occupancy in this example looks to be manufacturing, not storage, which is important to consider when designing sprinkler systems.

While raw PVC material held on-site may be classified as a commodity under Section 20.4, it does not apply to materials used in active manufacturing processes.

Commodity classification is not suitable for determining sprinkler design parameters in a production setting.

The current sprinkler system is rated as Ordinary Hazard Group II (OH2), suitable for moderate fire hazards. Upgrading a system to Extra Hazard Group II (EH2) is unnecessary without a major storage component.

Sprinkler system design must align with the occupancy’s danger classification as established in Chapter 4, rather than commodity classifications for storage scenarios.

This question seeks to determine if ESFR (Early Suppression Fast Response) sprinklers can be spaced 12 feet 6 inches apart within a 25-foot bay created by solid structural elements in a building with a 30-foot ceiling. It focuses on compliance with NFPA 13 (2019 edition) spacing requirements, considering both sprinkler performance and obstruction criteria.

Question 8. According to the 2019 edition of NFPA 13, may ESFR sprinklers be spaced 12 feet 6 inches apart within a 25-foot bay generated by solid structural components in a structure with a ceiling height of 30 feet, resulting in two lines of sprinklers per bay?

Ans. Section 14.2 of NFPA 13, 2019 edition, specifies the maximum spacing and coverage area for ESFR (Early Suppression, Fast Response) sprinklers.

The standard specifies a maximum separation of 12 feet for ESFR sprinklers in buildings with ceiling heights up to 30 feet. The norm prohibits exceeding this separation, regardless of the structural bay width (25 feet).

Section 14.2 specifies a maximum separation of 12 feet between ESFR sprinklers in buildings with ceiling heights up to 30 feet. Section 14.2 prohibits exceeding the maximum spacing limit.

The ESFR’s “shift rules,” which allow for minimal changes in sprinkler arrangements to avoid obstructions, underline this necessity. However, these sections specifically say that the distance between sprinklers cannot exceed 12 feet.

Standard spray sprinklers can have branch lines spaced 12 feet 6 inches apart in 25-foot bays, resulting in two lines per bay. However, ESFR sprinklers cannot use this design technique. ESFR design standards do not allow for this level of spacing freedom.

ESFR sprinklers cannot be placed 12 feet 6 inches apart in a 25-foot bay of a building with a 30-foot ceiling height.

This question explores whether NFPA standards require fire pumps to start before system activation to ensure timely water delivery in dry pipe or preaction sprinkler systems. It focuses on meeting water delivery time requirements and whether pre-starting pumps is a mandated method under NFPA guidelines.

Question 9. Do NFPA standards mandate pre-starting fire pumps to meet water delivery schedules for dry pipe or preaction sprinkler systems?

Ans. The NFPA specifications do not require a fire pump to pre-start to meet water supply requirements for dry pipe or preaction systems.

The NFPA 2025 version covers this issue in Section 10.5.2.3, Fire Protection Equipment Control.

Section 10.5.2.3.1 allows the fire pump to start the motor before the pressure-sensing device initiates the start sequence for special water control equipment (e.g., deluge valves, dry pipe valves). The control circuit for the special fire protection equipment can bypass the pressure-actuated switch of the pump controller. This is particularly.

This is relevant for fire pumps that supply deluge systems, which are generally not pressure-actuated. Pressure-actuated configurations are commonly employed because the

Pumps provide wet and dry systems, as well as deluge systems.

• According to Section 10.5.2.3.2, the fire pump controller shall automatically start the motor when the fire protection equipment is activated.
• According to Section 10.5.2.3.3, the motor start sequence begins with the opening of the control circuit loop for the special fire prevention equipment. This design ensures that a break or disconnection in the control circuit triggers pump start, increasing reliability. The commentary to Section 10.5.2.2.1 provides additional insights.

The standard allows for the pre-starting of fire pumps to satisfy water supply times for specified systems, such as dry or preaction. However, this is not essential.

The project entails bidding on an NFPA 13 residential high-rise, with construction starting in January 2026 and lasting around 18 months. A temporary standpipe will be installed during the project’s building phase. The general contractor has requested weekly testing of the temporary standpipe system during construction.

There is currently no code need for weekly testing of a temporary standpipe in a structure under construction.

Question 10. Is there any information or advise available about this request?

Ans. NFPA 241, 2025 edition, Section 4.7.2.1.3 mandates testing standpipes for integrity in accordance with the Fire Prevention Program when additional segments are installed during construction.

Annex Section A.4.7.2.1.3 clarifies that the temporary standpipe system should remain intact and ready for use during construction. When adding new floors or sections, it’s important to ensure that the system is still pressurised and operational. If the location is freezing, a visual inspection or a pressure test with water or air can be performed. The intention is not to demand a 2-hour hydrostatic test for each new pipe added to the system.

NFPA 241 requires verification of the standpipe system’s operating status in accordance with the project’s Fire Prevention Program, without specifying a specific testing technique. The standard also does not specify a testing frequency.

Monthly testing may be included in a fire prevention plan, depending on site conditions and AHJ standards.

This question addresses whether five-year internal pipe inspections are mandatory under NFPA 25, even if the Authority Having Jurisdiction (AHJ) does not enforce them. It examines the balance between NFPA code requirements and local enforcement practices in determining compliance responsibilities.

Question 11. Are five-year internal inspections needed under NFPA 25? The AHJ argues that this jurisdiction does not enforce the requirement and thus is not required.

Ans. NFPA 25 mandates many internal inspections.

The most prevalent is the internal examination of plumbing, which is described in Section 14.2. Internal inspections of strainers, limited orifices and check valves are needed every five years, as outlined in various chapters of the standard.

Although NFPA 25’s internal inspection standards have been in place since 1992, the Authority Having Jurisdiction (AHJ) regularly fails to enforce them.

Unless waived by a local or state ordinance, these standards must be met regardless of enforcement by the AHJ.

According to Section 4.1.1 of NFPA 25, the building owner is responsible for performing all necessary inspections, testing, and maintenance in conformity with the standard.

This question refers to Figure 25.4.2.3.1(e) in the 2025 edition of NFPA 13 and clarifies the requirement for in-rack sprinklers based on vertical storage spacing. It suggests that if pallet loads or shelf levels exceed 15 feet apart, two tiers of in-rack sprinklers are needed to comply with the standard’s fire protection guidelines.

Question 12. According to Figure 25.4.2.3.1(e) in the 2025 edition of NFPA 13, the 15-foot maximum vertical spacing means that if pallet loads or shelf spacing exceed 15 feet, two levels of in-rack sprinklers are required for compliance.

Ans. Figure 25.4.2.3.1(e) of the 2025 version of NFPA 13 specifies a maximum height of 15 feet for a single level of in-rack sprinklers, measured from the floor.

The elevation view in the illustration shows a bracket indicating the maximum height, but it is somewhat misaligned and does not extend to the level of the in-rack sprinklers, which may cause misunderstanding.

The number limits storage height above the top level of in-rack sprinklers to 5 feet.

If you install a single level of in-rack sprinklers at 10 feet to clear pallet loads, Figure 25.4.2.3.1(e) does not apply. A second level of in-rack sprinklers may be necessary in this scenario.

Figure 25.4.2.3.1.1(b) could be a viable alternative, although it would require a larger ceiling-level design density.