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I'm designing a sprinkler system for a wood chips warehouse where the material will be stored directly on the floor of a covered shed. I classified the hazard as Class III according to NFPA 13; however, I was unable to determine the appropriate type of sprinkler to use, as the storage method is not addressed in the standard's tables.
How would you classify wood chips stored directly on the floor? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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I am working on a retrofit project where the owner wants to replace the existing electric baseboard heaters with electric cove heaters. Being a radiant heater, NFPA 13 clearly states that sprinklers within the high and intermediate temperature zones would need to be changed out to suit.
I am getting pushback from the design team, given the small size and low power (1KW) of the heaters. NFPA 13 seems petty cut and dry on this. Am I missing something? Anyone run into this before? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are currently discussing with the authorities regarding obstructions and their implications subject to FM Global design requirements (FM 2-0, 2021-10).
Specifically, the scenario involves a round duct (2.3 ft / 700 mm in diameter) positioned 12 inches (300 mm) below the sprinkler deflector in a non-storage application. Is it necessary to install sprinklers below the duct in this case? Below is a relevant excerpt from FM 2.0 (2021-10): 2.5.2.5.4.1 Any object up to 4 ft (1.2 m) wide, as measured in the object’s least dimension and in a plane that is parallel to the floor, does not qualify as an obstruction to the sprinkler’s discharge pattern. I would like to clarify whether any object up to 4 feet wide is considered not an obstruction, regardless of the vertical distance from the deflector (or thermal element). Alternatively, must we adhere to the 3 feet (0.9 m) clearance requirement? Your expertise and clarification on this would be greatly appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Hi, I am asking a follow up question to the post, "What's Required to be in a Shop Drawing?"
Having completed working drawings for contractors in NYC in the past, everything on the NFPA 13 Chapter 23 list was required. I've even been asked to resubmit for lack of a graphic scale, "jerks!" Ever since then, it has been my opinion that the Working drawings should be able to be used as a standalone reference, meaning no other document retrieval should be required to completely understand the system layout and duplicate the calculations. I'm currently reviewing shop drawings prepared by an extremely reputable FP engineering firm, and many of the required items from the checklist are missing. Of the applicable items, the explanation is that the information such as compass point, building sections, water service line, etc., are part of the CD set and therefore not required. Pipe elevations are included in the calcs, so they are not required on the drawings. Fire sprinkler and major valve manufacturer and model numbers are included in the product data, which, by the way, was not submitted by the contractor with the drawings and calcs as specified and is not this engineer's fault. Having said that, when sealing working drawings for contractors, we would require that information on the drawings so that it was clear to other entities that the equipment being provided matched the calcs. They also said that cut lengths are not required because these are not fabrication drawings. They said the quantity of sprinklers doesn't matter because there is only 1 riser and they are all the same temperature. I have complete confidence in this engineer, I'm just wanting to check myself for future reviews. For the record, I'm of the opinion that this should be returned and resubmitted with the product data. Other than that, things like graphic scales, compass points and other minor missing line items I would say minor correction to be included in the Owner's Record Copy. I don't know how many times I've asked for FP information for a building and the only information available is the working drawing. Am I wrong in thinking it should be as easy as possible to duplicate the calcs with only the working drawing available? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am preparing an assessment for adding a fire protection sprinkler system to an approximately 9,000 sqft existing single-story building that is a state half-way house for juveniles after being released from detention. Fewer than 16 occupants excluding staff.
The architect has deemed it Group R-3 occupancy (although I wonder if Group R-4 Condition 1 is more appropriate.) IFC 903.3.1.2 permits NFPA 13R throughout Group R, and this meets the three stated conditions for this section. Section 903.1.3 allows NFPA 13D in some applications; the list is separated by semicolons and includes R-3 and R-4 condition 1. However, more square feet of this facility is dedicated to non-residential purposes (meeting rooms, classrooms, kitchen, etc.). This seems counter to the scope of NFPA 13D. Even the IFC commentary mentions the use of 13D, but for one- and two-family dwellings. And I'd prefer an FDC and more than a 10-minute water duration. I'm a sprinkler guy, and not a building code expert. My gut says NFPA 13R is most appropriate (and I will ask the building code official), but what nuance am I missing here? Budget-wise NFPA 13D is way more favorable, but it just doesn't seem right. I'd like to know if both NFPA 13D & NFPA 13R are acceptable options for this type of building. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Question regarding a mechanical closet and/or plenum. We have what I'll call a mechanical closet because it houses an electric AC/heating unit for an apartment using NFPA 13. The sprinkler designer/contractor is calling it a plenum/small space and is omitting sprinklers. The plans do not show any sprinkler coverage. Is this closet a plenum or small enough space to omit sprinkler protection? Is there code justification for this? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  Is ESFR ever permitted as a dry system (for applications like unheated warehouses)?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'm designing a system that has multiple, narrow tenant spaces divided by 2-hour rated fire walls.
When using density/area method, the square root × 1.2 design area doesn't include enough space to satisfy the 1500 square foot requirement. In this case, would I extend the area further parallel along the branch lines, extend it along the main into the adjacent space, or call it good where it's at? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Valve Cabinet Clearance Is there any code which requires a minimum clearance for a valve cabinet. I typically say 36” or 1m (in Canada) as that is the typical clearance required in front of equipment. But I have been asked if there is any supporting reference for this specifically and I can’t find one for hose cabinets.
Just hose valves in a cabinet or where they are not to obstruct egress. Looking to see what others use and if they have any code reference. Along a similar thought - does anyone know if equipment access clearances can overlap, or do they need to be independent of each other? Can clearances overlap? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are preparing drawings and hydraulic calculations for the storage of XLPE & XLEVA foam panels in an existing warehouse equipped with an Ordinary Hazard Group 2 (OH2) sprinkler system.
Based on NFPA 13, these products would fall under Group A plastics; however, independent testing indicates they do not exhibit the same ignition characteristics as standard polyethylene. • XLPE (Cross-Linked Polyethylene) is chemically or physically cross-linked, enhancing its fire resistance. • XLEVA (Cross-Linked Ethylene Vinyl Acetate) contains EVA, further modifying its properties. Third-party testing found that these materials did not have the same ignition characteristics as Group A Plastics. Here are notes from the test report: 1. The specimen did not ignite. 2. The specimen ignited but self-extinguished prior to burning into the timing zone. 3. The material stopped burning before it burned for 60 seconds from the start of timing and did not burn more than 51 mm from the point where timing was started. 4. The test was discontinued at 5.0 minutes. The customer plans to store 4' x 8' panels on wood pallets in a solid pile arrangement exceeding 5 feet in height. Given that an OH2 system does not support Group A plastic storage above 5 feet, I'm looking for input on whether the test data could justify a reduced design density under NFPA 13 or if this scenario would require a performance-based design approach. Does NFPA 13 allow adjustments based on fire testing like this? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Can you omit fire sprinklers in HVAC towers where the entire building is sprinklered?
The HVAC towers have a full-size door and HVAC equipment inside. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Before people say, "Ask the AHJ," I am him; he is me.
I have an applicant who has combined plots of land with a mid-rise and some detached townhouses. A shared fire line supplies the two structures, but only the mid-rise FACP monitors the supply tamper. The townhouse FACP will not know if the water is off (except for the tampers at the risers within the townhouse). The buildings are owned by the same ownership. They are arguing they are technically meeting IBC 2015 903.4 "Valves controlling the water supply for automatic sprinkler systems, pumps, tanks, water levels, and temperatures, critical air pressures, and waterflow switches on all sprinkler systems shall be electrically supervised by a listed fire alarm control unit." It is being monitored, but the fire marshal and I are of the opinion this doesn't provide monitoring for the townhouse and does not meet the intent of the code. Does anyone have any thoughts on whether a shared line can be monitored by only one building that it serves? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a small 580 sq. ft. attic, fed by a dry system, next to a wet system in a retail outlet mall. They are 2 separate systems at the valve assembly. The ceiling for the dry system is 10-ft higher than the wet system.
Would a phantom flow be required here? If so, would it be added at the valve assembly, where they meet? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are working on hydraulic calculations for a military hangar, and we are referencing UFC 4-211-01, which calls for the design area to be 0.20 over 5000 sqft.
The hangar is 60 feet tall at its peak. To prevent overflow, we are proposing K5.6 sprinklers for the area. Are K5.6 sprinklers allowed, or does UFC 3-600-01 apply where buildings 45-ft up to 60-ft would require minimum K11.2 sprinklers? The area is overflowing by around 600 gpm. Any advice on this would be helpful. Thanks. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For forward-flow test connections, is a 4-ft length of pipe inside the heated space required?
NFPA 13 Section 16.10.4.9 would require this of any main drain test connection. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am designing a wet pipe fire sprinkler system in a one story Group B occupancy (16-ft high). The building is about 90,000 sqft in area. The building will be fully sprinklered with two zone control valve assemblies.
The fire department is asking to add fire hose valve cabinets as the interior remote areas of the building are more than 130 feet from an exterior door, only citing that its required by IBC 2021. Is this correct? I can't find this requirement. Any help is appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For a fire sprinkler system, if you have a loop running around a typical hip-roof attic, and you have a center riser, can you tie it into the loop in two locations?
NFPA 13 doesn't really discuss when a looped system turns into a gridded system. None of the branch lines would be connected, so in my opinion this would be acceptable as long as you meet the discharge time through the remote inspector's test connection. What are your thoughts? Is this a gridded or double-loop systems? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What is the industry standard or method used for determining the design area size in order to do the hydraulic calculations for Window Sprinklers in terms of the "Adjacent Sprinklers?"
What is the definition of "Adjacent Sprinklers?" Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe When dealing with combustible soffits, what are the conditions where a soffit is big enough to warrant a sprinkler inside?
In our case, we have wood constructed soffits with sprinkler protection below and adjacent to the soffit. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe How would you recommend protecting a dry room for battery operations, such as battery testing or packaging?
I've been designing these with dry systems but was curious if there are any codes to omit sprinklers, or if anyone uses clean agent systems? If you use something alternatively, why do you go that direction? Moderator's Note: Dry Rooms for batteries have less moisture to avoid corrosion and any chemical reaction for the batteries, which would degrade or reduce performance. Very low moisture is the key for a dry room for batteries. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a sprinkler system in a 75,000 sqft self-storage facility. There are upright sprinklers that are within 2" of a vertical support Unistrut that is used to separate storage spaces. Would this be considered obstructed? What is the code-basis for evaluating a vertical obstruction like this?  Does anybody have experience with locating diesel fire pump fuel tanks in exterior locations where the local ambient temperature can drop to below freezing point?
We have an unavoidable situation where we have to locate the fuel tank outside the pump room and we're hoping not to have to build a heated enclosure. NFPA 20 seems to require a heated enclosure, but FM not so much. I am aware that condensation and fuel deterioration are issues to be dealt with, but I was thinking maybe good quality thermal lag of the tank and feed/return fuel piping may be sufficient with just a roof structure above the fuel tank. What are your thoughts on this? any thanks in advance for your thoughts and advice Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a 35' tall, 79,103 ft², non-combustible building, which is a cooler in a cheese factory. There are two dry systems at the ceiling uses CMDA heads. There are single and double row racks throughout the cooler. The top of the rack 22' top of storage is roughly 26'. The racks have a single layer of 5.6K in-rack sprinklers at the top of the 3rd level. There are 5 levels of storage, which includes the storage setting on top of the racks. The in-rack sprinklers have their own valve at the riser. It is a Class II commodity to 30'. The original design was done years ago and my question is not about the original design. In a single portion of the cooler the owner is taking a 32' section of the existing racking out and installing new racking. The new racking will have the same amount of levels. The bottom 3 levels will have a "cooling cell," one on each level.  I have never heard of a cooling cell on a rack like this. Not sure what the cooling cell is made of. Does a cooling cell increase the protection level from Class II? If so, how much would it change the commodity classification? Does NFPA 13 even address something like this? My assumption is that it will increase the hazard and call for greater level of protection. I have asked for the data sheet for the cooling cell and hope that it gives direction for fire sprinkler coverage. I have attached a picture, which really doesn't give a lot of information. Has anyone run into this before? Thank you! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe My jurisdiction (I am the AHJ) has had several buildings built with private hydrants supplying the sprinkler system where the main comes into the building, through the RPZ, feeds the sprinkler system/standpipes, and leaves the building and feeds the hydrant(s).  This has always seemed counterintuitive to me, at best. I feel we are "robbing Peter to pay Paul" and have wondered if this arrangement will adequately supply the sprinkler system when we (FD) pull water from the hydrant and pump it back into the FDC.
Per our state law, private hydrants have to be "protected" with a backflow. Is this configuration code compliant, and if not, what is a solution? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe What specific criteria or code references determine whether a standpipe system is classified as 'separated' rather than 'combined'?
I've seen AHJs state that even though the sprinkler system and the standpipe have separate vertical riser assemblies (control valve, check valve, and supervision), they are fed from the same underground supply (one underground service main) and will still be considered combined. We are working on a project where the AHJ has deemed the building 'partially sprinklered,' requiring the standpipe to be upgraded from 4" to 6" (which would necessitate a pump) but only if it is a combined system. We are looking for clarification or language that supports the distinction between a combined and a separated standpipe system to explore options that may avoid the need for a pump. Additionally, does anyone have thoughts on how we might be able to keep the standpipe at 4" or explore alternative approaches to avoid the pump requirement? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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