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I have a class IV product stored in a HDPE hard body package. With the changes from NFPA 13 2016, edition to the 2025 edition, there are significant changes to the ability to store Group A plastics in legacy warehouses.
What compliance strategies are available to the FP community to remain in compliance while storing in these legacy buildings? A typical warehouse I'll see will have K16.8 @52 psi. This used to be acceptable for group A, but now it is not an option per the newer standard. Typically we're looking at structures over 35 ft. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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I have a warehouse sprinkler space where the owner has installed a Faraday-type cage (Ordinary Hazard I occupancy). The cage grid runs from floor to ceiling and is about 25% open space (75% obstructed).
I consider this cage as an obstruction, similar to a solid wall, and thus it ruins sprinkler coverage/spacing (standard spray sprinklers). However, I cannot find a code reference that addresses vertical grid obstructions or the acceptable percentage of open space for vertical grids. NFPA 13, 2019 Edition, Section 9.3.10 provides guidance for horizontal grid ceilings, and Section 10.2.7.2.2.1 is for grids in Light Hazard occupancies. Neither fit the bill. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We want to give a shout-out to our top Nov. contributors! Thank you for keeping the Forum a hot spot as we move into winter. Here are November's top contributors on the Forum:
From a designer's perspective, if a building is small and simple enough, and the owner doesn't care all too much about finishes, then locating a main fire alarm control panel and auxiliary equipment (like a transceiver) can often go near the front entry of a building.
In almost all other cases, I would prefer a back of house space. From an AHJ's perspective - what do you prefer to see for the main fire alarm control panel location? If the panel is anywhere but the front main entry, do you always mandate a fire alarm annunciator panel? NFPA 72 (2025 Edition) states that "All required annunciation means shall be located as required by the authority having jurisdiction to facilitate an efficient response to the situation." Is that your go-to reference to make sure that either the main panel or an annunciator is at the front entry? I understand the design side, but I'm interested in your thought process in terms of plan review and operationally what you would expect to see across a variety of projects. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Do we have to use ESFR sprinklers under conveyors, which have slope, solely because the roof system is ESFR?
What code basis—if any—would actually require ESFR protection under conveyors in this situation? I am currently designing a sprinkler system renovation on a package sorting facility that we did the original conveyor design on 4 years ago. The existing 500,000 sqft open warehouse had (13) k-22 ESFR systems that we did not design. I designed all the systems for the catwalks, mezzanines, and under conveyors using Standard 5.6k quick response, standard spray sprinklers (Reliable RA1425) with shielding under open grate flooring. The new systems all have their own risers coming off the existing 10" manifolds. It was all hydraulically calculated and approved by the city. Now we are designing / renovating the conveyor systems because the client added, removed & moved a bunch of conveyors. I removed all sprinklers and pipe from the areas being changed, and most of the new or changed areas we able to reuse existing outlets that we had demolished pipe from. We used the same pipe sizing scheme, same type of sprinklers, and redid all hydraulic calculations. BUT now the plan reviewer is rejecting the plans citing: THE SPRINKLER PROTECTING THE BUILDING ARE CLASSIFIED AS ESFR, THE SPRINKLER PROTECTING THE AREA UNDER THE CONVEYORS SHALL BE OF THE SAME TYPE AS PER NFPA 13, 2019, SECTION 9.5.5.3.3. I responded with NFPA 13 20.6.2, ESFR are only approved to a slope of 2:12 and most of the conveyors are way past that; and noted again that that the existing system is 5.6k. To which he responded: THE SPRINKLER PROTECTING THE BUILDING ARE CLASSIFIED AS ESFR, THE SPRINKLER PROTECTING THE AREA UNDER THE CONVEYORS SHALL BE OF THE SAME TYPE AS PER NFPA 13, 2019, SECTION 9.5.5.3.3 WE DO NOT UNDERSTAND THE RESPONSE TO THIS COMMENT, SECTION 20.6.2, WHICH ADDRESSED THE SLOPE OF THE ROOF NOT THE PROTECTION UNDER THE CONVEYOR. INDICATE WHICH STANDARD ADDRESSES THE HYDRAULIC CALCULATION FOR PROTECTION UNDER A CONVEYOR, WE CAN’T FIND THE SPECIFIC DESIGN CRITERIA FOR PROTECTION UNDER THE CONVEYOR USING ESFR SPRINKLERS. UNLESS THE SAME CRITERIA US FOR THE ROOF SYSTEM WILL APPLY UNDER THE CONVEYOR. Has anyone ever run into this? If have to use k-22 ESFR, it would be disastrous to the calcs, not to mention the existing system I am coming off of. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is there an NFPA 13 or 14 restriction for a combined sprinkler - standpipe dry system?
This is an open parking structure. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am working on a project that is building and connecting an open parking ramp to an existing building via an open bridge. The open garage will be going next to an existing building (different from the one it will be connecting to).
Does the open parking ramp need a dry standpipe? It will be just over 69 feet tall, and it doesn't look like there are elevators within the enclosed stairwells from the architect's rendering. I don't have a CAD background to compare to yet. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a code official who is requiring a full-size water meter on the fire line preceding double check backflow.
The backflow has a 3/4" meter and a small check on it with electronic connection capability for the water department. Are there any applicable code/standard references that mandate this? A 6-inch meter on the fire line would run about $15k. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does a zone control valve (floor control assembly) count towards the riser area limitation, as a sprinkler riser would? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  Is it necessary to apply special sprinkler design criteria for a membrane building?
Tension fabric buildings with polyethylene membrane are becoming increasingly common. In this case, the fabric is rated per NFPA 701 and other certs, so it will not propagate fire, but the manufacturer advertises that it will melt/burn under direct flame and release smoke and heat. Would this not affect the operation of the building's sprinkler system? FM 1-59 requires quick response sprinklers, which makes a lot of sense, but provides little to no evidence in support. I can see no similar requirements in NFPA outside special requirements for aircraft hangars; NFPA 102 seems like the main standard and is silent on the subject. Is there something I'm missing in NFPA? Is there any research out there on sprinkler performance in membrane structures that will melt and release heat? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Under NFPA 13, how far away should an intermediate temperature sprinkler be from a two-bulb, 500-watt bathroom heat lamp?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In a 3-story building with 3 standpipes, one of which is a combination standpipe/riser, and the standpipes are manual wet, with 50 psi.
On a 5-year test, how do I flow 1000 gpm (no pump) at 100 psi? Do I involve the fire department? The old hydraulic plates showed 70-50 at 260 flow. Three years later, they are showing 50-40 at 320 flow. So I cannot pass this, even though the water supply has diminished. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are completing a buildout for a spec suite; the shell warehouse building was just constructed and has a fire sprinkler supervising panel.
The fire department is saying we have to tie the duct detector into the fire alarm panel. This building does not have fire alarm, only sprinkler monitoring. Are they correct in saying we have to tie in the duct detector? Thank you! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a contract that calls for concealed, extended coverage horizontal sidewalls in an area with a Turf Switchblade Acoustic Ceiling. The issue I'm running into is that the Tyco RFIII EC HSW has a maximum distance below the ceiling of 12", and the acoustic has a maximum dimension of 9.4" down from the ceiling.
Therefore, I won't have the 4" minimum distance between the deflector and the obstruction. Has anyone else encountered this type of issue? Has anyone found a concealed sidewall extended coverage that can be 18" below the ceiling? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe According to NFPA 20, for any pump installation, the NPSH supplied must be at least equal to the NPSH required for the operating conditions specified.
So does the NPSHₐ need to be continuously maintained at or above the NPSHᵣ during pump operation? During the operation of the fire pump, the liquid level of the fire water tank will keep dropping, which may lead to a situation where the NPSHₐ is lower than the NPSHᵣ (unless the fire water tank is built at a very high elevation). Is this situation permitted? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are designing a project that has a porch area (approximately 88-ft long x 23-ft deep) at grade with occupied enclosed building space above it (the building overhangs the porch by 23-ft).
To avoid a costly dry-pipe system for this area, the CM is looking to serve this area from dry sidewalls connected to the buildings automatic wet sprinkler system. Is anyone aware of any dry sidewall heads (exposed or concealed) for this application that can throw 23-ft? The building will have a fire pump so the extra pressure would not be an issue. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am modeling the elevator pressurization system in CONTAM to demonstrate compliance with SBC 201 (IBC-based) requirements.
Normally, we use simplified spreadsheets, but code enforcement now requires performance verification through simulation. In a model where the elevator shaft is adjacent to a protected service lobby, shell and core area, and a loading bay, is it sufficient to demonstrate pressure differentials only along the egress path (shaft → lobby → stair), or should other adjacent but enclosed spaces also be included? What method do you recommend for extracting and presenting results—direct export from simulation (as in ASHRAE Applications, Fig. 21 Ch. 54) or summarized plots similar to Fig. 11.13 in the Handbook of Smoke Control Engineering, 2nd Ed.? Lastly, when modeling the shaft, should it be defined as a flow path with cross-sectional area and perimeter replicated across all floors, except the top floor? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For scissor stairs having 2 separate standpipe risers (one of them is a combined sprinkler and standpipe system) running 12 floors, how do we size the pump flow rate required?
Can we argue that we can use a 500GPM pump since the Risers are in close proximity to each other and are within one stairwell, or should we use a 750GPM pump following the NFPA 14 sizing of 500GPM plus 250 GPM per additional riser? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Could anyone point me to statistics to show how likely a single interlock pre-action sprinkler system is to spuriously or falsely activate?
A client is concerned about possible water damage in a high-voltage switchroom that could damage their gear and cause a lengthy business interruption. I have tried examining NFIRS data, but its format makes it difficult to analyze without a background in relational databases. I would like to explain the relative risk to the client in terms of 'it's a 1 in 100,000-year event you are concerned about' or whatever the stats point to. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe How do you coordinate what dialing out method with the client/telecom group, etc.?
A new fire alarm system, let's say a college building, for example, what do you typically see? Does the college have its own monitoring station? Do you dial out signals via cellular or internet, or both? Do dial-out signals go to both the college monitoring station (say, a life safety office) and a central monitoring station? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can someone explain NFPA 13 20.5.3.1.3 for Multiple Row Racks?
Unless the requirements of 20.5.3.1.3.1 or 20.5.3.1.3.2 are met, multiple-row racks without solid shelves shall be considered racks with solid shelves. Section 20.5.3.1.3.1 Multiple-row racks without solid shelves shall be considered open racks where both transverse and longitudinal flue spaces are provided at maximum 5 ft (1.5 m) intervals. 20.5.3.1.3.2 Multiple-row racks without solid shelves shall be considered open racks where transverse flue spaces are provided at maximum 5 ft (1.5 m) intervals and the rack depth does not exceed 20 ft (6.1 m) between aisles that are a minimum width of 3.5 ft (1.1 m). Does this mean you have to have a 6-inch flue space on all 4 sides of each pallet load every 5ft within the rack, OR a 6-inch transverse flue space every 5ft, but the rack cannot be deeper than 20ft? Is it one or the other, and do you see one more often than the other? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a quick question about estimating the pressure requirements for an automatic wet sprinkler system during the initial design phase.
Qm = d X (Area per Sprinkler) = (0.15) X (130sqft) = 19.5 gpm Estimated Total Flow (ETF) = Qm X N X F plus hose demand = (19.5 gpm) X (12 sprinklers) X (1.30 for spray pattern overage) + 250 gpm (Outside Hose Stream) = 554.2 gpm Minimum pressure needed for the system. = (19.5gpm/5.6K) = 12.13 psi for the most demanding sprinkler + another 20-35 psi for potential friction loss throughout the reference. The total estimated pressure needed would be 47.13 psi, not factoring in elevation change. The 20-35 psi for potential friction loss is an engineering judgement based on experience. What is the recommended potential friction loss for an initial design phase, and where would it be referenced at? I need to reference the source of recommended potential friction loss for the project. SFPE, NFPA or etc? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Question in relation to ESFR sprinklers. Per NFPA 13 2016 Section 8.12.5 - obstructions 12" to 24" wide, the sprinkler must be 2 feet away.
There is no specific code for obstructions larger than 24"; does this mean these obstructions would always require coverage beneath? I ask because I have a 36" cable tray - if it's centered between two branch lines, can I apply the code to half the obstruction? In this case, the head would be further than 2' from 18" of the obstruction on both sides. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project where there are small bumpouts on either side of a room that are sized just big enough to store an accordion ceiling partition when not in use. The partition divides a bigger classroom into two smaller classrooms when used.
Do I need to somehow have sprinkler coverage in the bumpouts? The small areas are only exposed when the partition is deployed, which results in two even smaller spaces on each side of the partition. NFPA 13 Section 9.2.9.1 seems like one possible code section to allow an omission. What are your thoughts on this allowance? Seems challenging to incorporate sprinkler protection in those small areas and not very practical for the low fire hazard they present. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe In an automated warehouse, is it feasible to replace the in-rack sprinklers with ceiling sprinklers on the upper racking levels?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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