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I am doing CMDA overhead sprinklers for in-rack class 4 storage at 15' - a new system.
As I was navigating through NFPA 13 2022 Chapter 21, I came to 21.4, which seems to be where I should be. My question is: 21.4.1.1.1 is where you start, which states that if it's a new sprinkler system, the demand shall be determined in accordance with 24.4.1.2.2.1. BUT, I skipped that and went on to 21.4.1.2.1.1, which seems to be for the EXACT SAME CRITERIA (unless I cannot read/comprehend, which is possible)! So when would you use 24.4.1.2.2.1 over 21.4.1.2.1.1? When we use 24.4.1.2.2.1 with the modification chart, we get a density of 0.297, and when we use 24.4.1.2.1.1, it calls for 0.30. So they're pretty much the same... but I'm not seeing why you would ever use 24.4.1.2.1.1 since 24.4.1.1.1 directs you to 24.4.1.2.2.1 and bypasses the other. Hopefully, this makes sense. --- 21.4.1.1 General 21.4.1.1.1 Ceiling sprinkler water demand for new systems shall be determined in accordance with 21.4.1.2.2.1 for single and double row racks or... 21.4.1.1.2 Ceiling sprinkler water demand for the modification of existing systems... 21.4.1.2 Protection Criteria for Single or Double-Row Rack Storage of Class I-IV Commodities over 12 ft Up to and Including 25 ft in Height. 21.4.1.2.1 New Systems Criteria for Single- or Double-Row Rack Storage of Class I-IV Commodities Stored Over 12 ft Up to and Including 25 ft in Height. 21.4.1.2.1.1 For single- or double-row racks for Class I, II, III, or IV commodities, encapsulated or nonencapsulated, the ceiling sprinkler demand.... shall be selected from the criteria in Table 21.4.1.2.1.1(a) through Table 21.4.1.2.1.1(c) that are appropriate for... and shall be modified as appropriate by 21.4.1.4. --- Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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In a four-story educational building, we have a large pipe chase that wraps around the men’s and women’s restrooms on each floor. The highlighted area in the attached sketch is the pipe chase area.  The wall on the left (with the red arrows pointing at it) is a 1 hour rated shaft wall. All the other walls around the pipe chase are non-rated wall assemblies. There are doors (blue boxes) giving access to this area in three different locations. There isn’t any equipment or sources of ignition located inside the chase, just plumbing pipe.
While the area is not to be used for storage, we are concerned that the presence of the doors will allow people to do so. The Architect/Engineer has directed us not to protect this area with sprinklers. Are sprinklers required inside this chase or can they be omitted as directed by the A/E? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'm working on a fire protection design for a new apartment building. The architect is adding what they're calling horizontal exits throughout the building, which will increase the number of required standpipes per the local building code (IBC-based, 2025) Section 905.4. Per the exception to 905.4.2, I do not believe we will need hose connections on both sides of every horizontal exit within the building. I think additional standpipes and hose connections will only be required in the center of the building. Other than the egress stairwells, where are standpipes and hose connections required to be located? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  Thank you all for taking the time to make the Forum a better place! We appreciate our Top March 2026 Contributors.
I have a plan reviewer requiring calculations (CFH) for a diesel fuel tank because the vent extends further than the UL label is calculated for.
What are the guidelines and how is this calculation performed? The comment: "Provide the required emergency vent capacity, in Cubic Feet Per Hour (CFH), for the primary and secondary fuel tank emergency vents. The venting capacity should be indicated on the UL label on fuel tank. The shop drawings don't list the emergency vent capacity. Note: The capacity listed on the UL label is calculated with the vent within 12 inches of the tank body. If the vent is extended above the tank more than 12-inches, additional calculations are required to account for the additional piping and height above the fuel tank. These calculations are required to be computed by a registered engineer." Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a client with a 10-story office building/parking garage, a fire pump in the below-grade level, and a combined wet standpipe with a manifold on the roof for testing. The building is getting some age on it, and when performing a flow test from the roof manifold, the roof drains will leak water into the top floor offices.
The question that was posed to me by the building manager was, "Can we tie into the bottom of the standpipe and run a new test connection to the outside at ground level?" Shooting the water over the side of the building is not really an option, doable, yes, but not really an option. Just wanting some thoughts on this, my initial response was no, but then I had never been posed with this question either. If not, is it possible to permanently tie somewhere else, or conduct the test in a different way? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 14 requires PRV redundancy when more than two hose connections are supplied downstream of a PRV.
Does NFPA 13 have a similar requirement for sprinkler systems, or can multiple sprinkler systems be controlled by a single PRV? We are proposing to feed a riser manifold controlling (6) sprinkler systems to be supplied by a single ORV without a redundant loop. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 13 Section 16.2.4 concerning protective coverings for sprinklers only references spray booths and mixing rooms.
I have a building that produces particulates in the air (a chip and tortilla factory). The concern is that we replace these sprinklers, and they will quickly need to be replaced again in a couple of years (96 total). I want to put on cellophane bags to protect them. The existing sprinklers are standard response. I plan to go to the AHJ for their approval, but I wanted to get the opinion of others who may have experienced something like this. Thank you in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can a fire pump test report be used in place of a hydrant flow test?
For an existing building, a fire pump flow test has to be done annually. It should include all the information a hydrant flow test provides to perform a hydraulic calculation for an existing building modification. Is there any code basis for taking this approach? I have an AHJ that keeps pushing back on this approach for determining the water supply information. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is a water storage tank for an NFPA 13 system required to be UL listed, or does it need to simply be NFPA 22 compliant?
I was always taught that a tank had to be at least UL Listed for fire protection, but I have a supplier telling me otherwise, and the price he offers is less than half that of a UL/FM tank. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a consultant showing a 6" wet sprinkler riser routing through the 1st floor of a building, supplying sprinklers, then heading to a stairwell to supply a wet manual standpipe. I am confident that supplying a standpipe downstream of a sprinkler system is not allowed, as there would be no way to fight the fire with hoses without the ability to shut off the sprinkler system, but keep the standpipe live.
Can someone shed some light on the code referring to this in either NFPA 13, 14, or even FM Global that details standpipes can feed sprinkler systems in a combination setup, but a sprinkler system cannot feed a standpipe? Thanks in advance! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a curved roof structure over a waterpark that has a top of steel of 37'-6" on the ends and 59'-8" at the peak. Portions of the roof are also retractable, leaving little to no steel to hang from. In these areas where the roof retracts, joist girders are 16'-8" apart east to west, and we have purlins running north to south that are over 18' apart. We were looking at potentially using EC heads, but have a pretty good roof pitch, or using standard heads and spacing couplings between girders; however, hangers would be 16ft apart. How might you attack this, given the wide spans of the joist girders in one direction and purlins in the other? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  We are adding new in-rack sprinklers to a Class IV Commodity with an existing CMDA sprinkler system above.
Using NFPA 13, 2022, I am so confused on whether I need to use 25.3 or if I can use 25.8 for modification? I was told that 25.8 is only for modification of the in-rack sprinklers, not the system above, but I am not seeing it that way. The verbiage to me is not clear at all. When adding new in-rack sprinklers to an existing CMDA system protecting Class IV commodities, should the design follow NFPA 13 (2022) Section 25.3, or can it be treated as a modification under Section 25.8? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a warehouse that is 408,240 SF with a ceiling height of 39 feet. I want to fill the warehouse with pallet racking for Class III commodities. Pallet racking will be back-to-back with a 10 foot for reach trucks.
IFC table 3206.2 calls out the max pile dimension and the max pile volume. How do these limits affect how long my racking aisle can be, and if I'm limited on continuously racking out the warehouse? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have an old Convent building (3-stories with long corridors) that currently has a Type III manual wet standpipe system and no sprinklers. They are remodeling and are installing sprinklers throughout, and want to remove the standpipe system.
As the AHJ, I would like to keep the standpipes but remove the hose cabinets, essentially to make it Class I. Is there a relevant code path to keep the standpipes even though, for new construction, they would not need them? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe The International Residential Code (IRC 2021) Section 310.1 states: "Basements, habitable attics and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court having a minimum width of 36 inches (914 mm) that opens to a public way."
My building code official is reading this as sleeping rooms in attics and basements need an escape window. I am reading "Basements, habitable attics and every sleeping room " as a list of 3 without the use of an Oxford comma. Any sleeping room needs an escape window, right? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Dealing with CMSA sprinklers, NFPA 13 2019 edition, Section 13.2.8.2.2: "(1) Upright sprinklers shall be permitted to be attached directly to branch lines less than or equal to 4 in. nominal in diameter."
Would this include 4" pipe, which is actually 4½" in diameter? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 13R can the pipe to the FDC upstream of the check valve to the FDC be CPVC?
I don't think so, but I ran across a couple of projects where this was done. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project under the 2015 International Codes that is building onto an existing fitness center/gym. The existing building has an A-3 occupancy under 12,000 SF, but an occupant load over 300 people. The total fire area of this existing building is 22,300 SF. Also, the building is not sprinklered.
There is a new building going directly next to the existing building that will connect the two (they share a wall). The new building is an aquatic center (pool and splashpad) with an A-3 occupancy under 12,000 SF, but an occupant load over 300 people. The total fire area of this new building is 13,000 SF. The architect was originally trying to see if sprinklers could be removed from the scope (since there are none in the existing building), but based on the occupancy and square footage of the new building, sprinklers will be required (IBC 903.2.1.3). Since sprinklers are required in the new building, the architect is trying to determine what type of separation is required at the two buildings (fire partition, fire barrier, or fire wall) to avoid requiring retrofitting sprinklers in the existing building. My take on it was to provide a "Fire Wall" to completely separate the buildings and not calling the existing plus new spaces a "single building" which could push us into requiring sprinklers throughout the existing building. In addition, IBC 903.2.1 indicates that sprinklers "shall be provided throughout buildings and portions thereof used as Group A occupancies provided in this section" and sprinklers "shall be provided throughout the story where the fire area containing Group A-1, A-2, A-3, or A-4 is located and throughout all stories from the Group A occupancy to, and including, the levels of exit discharge serving the Group A occupancy." I then looked at the commentary on Group A-3 occupancies (903.2.1.3) which stated "an automatic sprinkler system is required throughout the fire area containing the Group A-3 occupancy, including the entire story where the Group A-3 occupancy is located..." Based on 903.2.1 and the commentary on 903.2.1.3 it sounds like anything less than a "fire wall" used to completely separate the buildings, we would need to sprinkler the entire floor that the A-3 occupancy exists including the adjacent building since the are connected and share a wall. The architect's code consultant said I was wrong and that sprinklers are only required within the "fire area" and a "fire barrier" is sufficient. In addition, IBC 903.1.1 indicates that if the code requires a building to be sprinklered then they are to be provided throughout. NFPA 13 (2019) also indicates that if a building is protected by a sprinkler system, then sprinklers are to be provided in all areas except for omissions indicated in the standard. I brought up this NFPA requirement and the code consultant said I was also wrong with this and that sprinklers are only limited to fire areas and aren't required to be installed throughout the building. I would appreciate any thoughts on this, thank you. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In NFPA 13 2019, Section 10.2.9, designers can omit sprinklers from inside ceiling pockets as long as their construction is less than 1,000 cubic feet of non- or limited-combustible material, their depth is shallower than 36 inches, and the entire floor below them is sprinklered with quick-response sprinklers.
For instance, a 15x10 pocket ceiling of 2 feet depth with quick response sprinklers in the surrounding ceiling and of non-combustible construction is allowable. For a skylight less than 32 square feet and any depth, designers can omit sprinklers per Section 9.3.16. Additionally, an unlimited number of such 32 square foot skylights are permitted without additional sprinklers, provided that they are at least 10 feet from the nearest skylight or ceiling pocket. There is ambiguity, however, if a skylight exceeds 32 square feet. What is the guidance on shallow skylights? Where are skylights defined, either as in the category of ceiling pockets or distinct from ceiling pockets? If there is a 15x10 skylight with a 2-foot depth and non-combustible surrounding construction, would it be different from an equivalent ceiling pocket in terms of sprinkler activation? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a question as to whether or not sprinklers are required at an exterior canopy with the following properties: - adhered TPO roofing membrane, polyisocyanurate insulation, metal deck, steel framing members, insulated metal panel soffit (ie. Centria FormaWall Dimension Series).
The canopy is not considered a separate building. No combustible materials will be stored below. The projection is more than 4 feet wide. I was following the MeyerFire canopy flow chart but basically got stuck on the question, "Is projection constructed with noncombustible..." due to the roof insulation and the insulated metal panel soffit. Does roof insulation in the insulated metal panel soffit make the construction combustible, therefore requiring sprinkler protection for the canopy? Thank you in advance for your help! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have an EH1 dry system, and will be installing the inspector's test manifold with 4 outlets. We know that it's 2 outlets from the two remote branch lines, but I do not see in NFPA 13 if we should tie the line together so only 1 Inspector's Test Valve (ITV) would need to be operated to flow all 4 outlets, or if we'd install 2 ITV's valves next to each other, 1 valve for each remote line so the air is exhausting through each line independently. Any input would be appreciated! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  Does FM Global allow the use of 8k-factor sprinkler heads in HC-3 areas?
The ceiling is only 11 ft. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What was the name of the old system for protecting schools (corridor-only sprinkler protection with a sprinkler above the classroom doors)?
I have two existing schools with the old system that I will need to modify. Any code references would be greatly appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are working with an insurance agent on replacing an existing warehouse system with ESFR sprinklers; the edition they are applying is NFPA 13 2025.
Previously, in the 2016-2022 editions, there has been a section provided for ESFR obstructions regarding the bottom chords of bar joists or open trusses; however, this doesn't appear to be addressed in the 2025 edition. The insurance agent is suggesting we follow Table 14.10.2.1(a) for the obstruction of the bottom chord of the bar joist, which would require us to install the ESFR pendents up to 4 feet away from the bar joist. Is this the correct obstruction table to follow, or are we missing a section in the 2025 edition that permits the deflector to be installed a minimum of 6 inches away from the bottom chord, as outlined in the previous editions? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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