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I'm working on an office fit-up, which is being fed from a dry system in an industrial facility.
I've already talked to them about providing a wet system, but that is not what they want to do. So, we've got a dry system feeding pendent sprinklers coming down to an acoustic ceiling. When using pendents on a dry system, we need to provide return bends. Does a return bend have to be for only one sprinkler, or could there be multiple heads on a single return bend? I'm picturing the pipe extending up from the main, then across horizontally, with multiple drops coming off of the horizontal. Is this an allowed approach? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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When hanging a 6-inch Schedule 10 pipe via trapeze hangers, the trapeze material is a 2.5-inch Schedule 40 pipe spanning 6 feet 6 inches. I’ve been instructed to use 3/8 rod and beam clamps for the trapeze hangers and then a heavy-duty 2.5-inch ring with a 1/2 button going down to the 6-inch pipe. The job is based on NFPA 2019. The table for NFPA 13 17.2.1.1 states that rods must be 1/2 for 6-inch pipe. I’ve been instructed that we are basing our decision on the following rule, which means we do not need to use a 1/2inch rod for the trapeze hangers themselves, only for going from the trapeze to the 6-inch pipe. 17.2.1.2 Rods of smaller diameters than indicated in Table 17.2.1.1 shall be permitted where the hanger assembly has been tested and listed by a testing laboratory and installed within the limits of pipe sizes expressed in individual listings. Is this correct? Is 3/8-inch rod or 1/2-inch rod appropriate here? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I'm trying to establish a way to avoid dry valves/dry systems to protect trash and line chutes early in project development. I've heard of freezing issues due to roof venting or other ways that cold air can fill the chute (perhaps from the bottom when trash room doors may be open to the exterior during severe cold).
I know most or maybe all of these fabricated chutes come with fire sprinklers, but are they usually essentially built-in dry barrel sprinklers? If not, how can we ensure they won't freeze without using a dry system? The specific chute submittal or product information is usually not available until well after space for a dry valve should be set aside. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We're designing a fire suppression system for a garbage truck maintenance facility which will include a welding bay. NFPA 13 (2019) is being used. I am using OH2 for the maintenance bay but I'm not sure about the welding bay.
Is a welding bay appropriately designated as Extra Hazard Group 1? I can't find anything in NFPA 13 that speaks specifically to welding. Thanks! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Regarding light fixtures as obstructions to sprinkler spray pattern per NFPA 13D - many hanging pendant light bases are slim (1”-2” off ceiling) and do not obstruct or prevent cold solder, but the lighting housing hanging below the base (anywhere from 12”-72”) is to be considered an obstruction? Are these described hanging pendant lights also to be considered obstructions and to remain 36” away? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I have a dry system that is tripping when the county runs their test on the hydrant using tankers and pumpers.
My question is, if I use a 3/4' relief valve, will it be enough? How much flow (gpm) will it flow, at its maximum flow rate? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What does “horizontally away from the sprinkler” mean?
I recently read a technical note regarding the ESFR obstruction rule. The example question was: *“In an existing building, a 6-inch-wide steel brace runs diagonally from column to column, forming an ‘X’ between four columns. The brace is located a minimum of 48 inches below the ESFR sprinkler deflectors. Should this brace be considered an obstruction to the sprinkler discharge pattern?”* The answer stated that the X-shaped braces are not considered an obstruction because they are located at least 1 ft away horizontally from the sprinkler (referencing NFPA 13, 2016 edition, 8.12.5.3(3)). My confusion is this: if something is located below the sprinkler, I would describe it as being vertically away, not horizontally away. Did I interpret the code incorrectly? Can someone clarify the difference between “vertically from the sprinkler” and “horizontally away from the sprinkler?" Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am performing a design on an existing system that was 3% AFFF and we are converting it to 3x3 NFF. Bladders, proportioners, concentrate lines are being replaced and all sprinklers being replaced to meet the specification for the new concentrate.
In the spec it has been requested to utilize the "water equivalency test method," which is outlined in NFPA 11. I've performed installs, inspections of foam systems for 10+ years, I've never seen this method installed and not very versed in how it really works, only from what I've read. There's not much information out there. Have you used this method? What have the requirements been for testing this method? Were you given outside specifications? Does any additional information exist for detail? I'm wanting to be sure we're compliant from a design and install perspective. I'm following the diagram supplied in NFPA 11-2016. "D.5.2.3 Water Equivalency Method. In this approach, water issued as a surrogate liquid in place of foam concentrate. The initial acceptance test(s) are conducted with the actual foam concentrate using equipment similar to that shown in Figures Figure D.5.2.2(b) and Figure D.5.2.2(c): real-time pressure, flow, and conductivity measurements are recorded with the actual foam concentrate to determine that the system is pro-portioning accurately. Immediately following this test, a water equivalency test at the exact same pressure and flows as in the initial foam discharge test is performed after isolating the foam concentrate tank. Example test setups are shown in Figures Figure D.5.2.3(a) and Figure D.5.2.3(b). This provides a baseline for comparison using water only for follow-on routine inspections and tests." Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe A customer wants to install a burglar alarm in a new building. They would like to add fire detection to the system. The building is not required to have a fire alarm system.
Can we run the heat and smoke detection off a security panel, or do we need to have a separate FACU? I have looked in NFPA 72 (2010 edition), and I see non-required systems in Chapter 23. I see if it is a combination system the fire signal takes priority. However, I’m still not sure if we can use a security panel. The state is under NFPA 72, 2010 edition and 2012 IBC & IFC. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Has anyone ever conducted puff testing for a gas fire suppression system?
The owner is requiring us to perform this test, but I have never done it on previous projects. I checked NFPA 2001, and its requirements for flow testing are not detailed enough. I would like to know the specific procedures for conducting this test, as well as the key considerations to keep in mind. Ideally, I'd like to find a specification document or procedure to follow. Advance Thanks！ Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe If a warehouse is getting a new tenant, and the AHJ requires a new C of O, does the sprinkler system need to meet current standards (NFPA 13-2022) or can the original standards (NFPA 13-2007) be used?
Specifically looking at Group A plastic protection requirements here. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA mentions some sidewalls specifically listed for installation up to 18" below the ceiling.
Does anyone know a manufacturer that makes them? All I can find is up to 12". Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Existing High Rise that was converted from office to residential (large Massachusetts program). I am the third party reviewer and they currently don't have a elevator recall.
Google searches point to that if the elevator doesn't change they don't need add recall, but for the "Trust but Verify" portion of this code investigation is turning up naught. Closest I can find is IEBC, Section 902.1.2 commentary, but as this is a change of occupancy I am not sure if I can apply Level 3 Alterations Requirements to Change in Occupancy. Is there an applicable code or standard reference that requires retrofit of elevator recall for an elevator that doesn't already have this capability? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are running into a lot of gas unit heaters in warehouses with ESFR protection.
Two issues have come up: (1) NFPA 13 2019 Table 9.4.2.5(a) clearly shows the high temperature zones around (horizontal discharge) heaters. Given there are no high temp ESFRs, we have told contractors they can install the heaters 7' below the sprinkler deflector. The GCs do not like this and claim they have not had this issue with other ESFR installs (not ours). (2) The heaters are large enough to be obstructions to ESFR sprinkler discharge. We must install a sprinkler underneath, but the same issue with the temperature rating comes up. We have considered somehow adding an additional "barrier" around the bottom of the heater, so that the ESFR sprinkler is 2'-0 below the heater (but directly under the barrier). This is also not a welcome idea by the GC. We also do not have an actual example of this approach. Is there information we are missing here? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a facility with an NFPA 13 Extra Hazard 1 sprinkler system.
The client's proposed location of the water storage tank is approximately 33-ft (10m) higher than the level of the protected building and around 100-ft (30m) away. The client's proposed pump house is closer to the building, separate from the tank. My question is - is there a maximum length for the suction feed from the tank to the pumphouse under NFPA rules (13, 20, 22)? I would rather locate the pump house next to the tank and run the delivery main to the building. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When does a Community Room trigger the need to use NFPA 13 as opposed to NFPA 13R? If the first floor of a 3-story apartment building is a meeting room, does the building, or perhaps the first floor need to meet NFPA 13?  Thanks in advance.
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When did NFPA 20 start requiring exterior access to Fire Pumps?
I have an older fire pump, sprinklers had to be tested at 50 years, and when this thing was installed, they had no exit door in the pump room. Current NFPA 20 in our jurisdiction (2016) calls for an exterior access door or access from an enclosed stairway or different exterior exit. The AHJ is aware of that. (Sections 4.13.2.1.1) Because it's an older system, I'm trying to see if the exterior exit requirement still applies to the system at the time of original approval. The oldest NFPA 20 I can get for free on NFPA Link is 1996. I cannot find this requirement or the "equipment access" section in this code beyond some parts about when a fire pump is installed wholly outside the building. Anyone with more experience than me know when this started? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a building that is changing from storage to a gymnasium.
Would the existing ESFR sprinklers be allowed to be used and spaced more than the 100 sqft? I have several sprinklers too far off walls in the existing placement. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a mixed-use building, retail ~6250 square feet on the ground floor with residential occupancy on the 2nd and 3rd floors. The building is a mix of wood construction with bar joists, with a ceiling attached to the bottom chord of the bar joist.
These bar joists have the bottom and top chords made of wood with 1" steel tubing to create the open bar joist. My question concerns 2016 NFPA 13, Section 8.15.1.2.4. Can I classify these open hybrid joists as noncombustible bar joists? The ceiling is flat without access to the space. The ceiling assembly between the retail and the 2nd floor residential is 1-hour rated. The big question is, can we use the exception 8.15.1.2.4 and not provide sprinklers in the space above the ceiling? If not, I was told that if the ceiling assembly was two hours that the sprinklers in the concealed space can be eliminated. I haven't been able to find this in the NYS Building and Fire Codes. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Thanks for showing up and sharing! Here are August 2025’s top contributors.
We installed UL Listed grooved fittings with a rating up to 300 psi. The churn pressure of the fire pump is reaching 355 psi. The AHJ is asking for UL Listing or FM Approval to be above this pressure.
Is it mandatory under NFPA to have a UL Listing or FM Approval for the grooved fittings to cover the churn pressure, or is up to 300 psi acceptable? What are our options here if we have to do anything? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 25 (2020) notes that standard response sprinklers are to be tested or replaced after 50 years in service, and quick response sprinklers after 20 years in service.
An issue arose regarding standard response 5mm glass bulb recess sprinklers installed / manufactured in 1990. The heads are RASCO Model F156. The data sheets note standard response. My understanding is that these sprinklers, being standard response, should have a 15-year service life before testing. Others in the trade have different opinions (including a manufacturer rep) due to the operating element being a glass bulb. Prior to contacting the manufacturer, I'd appreciate the forum's thoughts on whether the glass bulb or the fusible link is a determining factor in the required time for sprinkler testing. Thanks! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe My question is about small assembly occupancies and the total area of accessory occupancies per floor, with the 2021 IBC being the governing code. A small assembly occupancy can be considered part of the overall building occupancy if it is less than 750 sq ft and is accessory to that other occupancy (Section 303.1.2(2)).
My confusion comes when applying 508.2.3, which says that aggregate accessory occupancies cannot exceed 10% of the floor area. Is the small assembly occupancy still considered accessory, or is it part of the overall occupancy? Two scenarios have come up recently with multiple architects having differing interpretations. Assume the main occupancy is R-2. 1) Multiple small assembly occupancies scattered throughout the floor, that when added together, make up more than 10% of the floor area. Is the 10% in aggregate or is it per small assembly occupancy? One line of thought is that 303.1.2(2) is applied to each small assembly occupancy, meaning that they're all considered R-2. 2) A small assembly occupancy that is less than 10% of the floor area, but other accessory occupancies (storage for example) push the total accessory area over 10%. Does the small assembly occupancy not contribute to the 10% since it's considered part of the overall occupancy? Or does the small assembly occupancy + the storage occupancy need to be under 10%? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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