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We have an existing building where site constraints have us running a 10-inch pipe at the ceiling level of the first floor for about 100 feet in the building to the sprinkler riser room, which also houses the backflow preventer and domestic riser.
This 10-inch pipe needs to be of a material suitable for the potable water supply, comply with NFPA 13, and not be prone to leakage. Any thoughts on the best pipe material option? Our initial thought was cement-lined ductile iron, but we understand that it can be a bit leaky, so I'm curious if there are better options, and what others may have done in the past? Thank you! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
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I'd like some help clarifying loop sprinkler systems for a dry attic system. The system would have two loops instead of one. Would this be acceptable? Here is the proposed attic layout in concept. The previous plan review had a branch line connected to the loop in two locations. I highlighted the loop in orange, where existing branch lines were connected, and the new proposed cross main connecting the loop approximately in the midpoint.  There are no shared branch lines connected to the looped in two locations, which would comply with 3.4.7 Looped Sprinkler System—A sprinkler system in which multiple cross mains are tied together to provide more than one path for water to flow to an operating sprinkler, and branch lines are not tied together. However, the layout is somewhat different from Figure A.3.4.7. I added a red line (cross main?) to represent the proposed layout. The definition of 3.5.5 Cross Mains.  The pipes supplying the branch lines, either directly or through riser nipples. Almost makes it look like this scenario be plausible by definition where the verbiage ‘multiple cross mains are tied together’ in 3.4.7.
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For cycle tracks within a road tunnel, what requirements exist for the bicycle tracks within the tunnels? I have not been able to find any fire or life safety requirements for cycle tracks within road tunnels (exit separation, fire suppression, detection, and emergency communication system requirements) in any codes or standards. Any suggestions on where I could go to or any research papers that I could refer? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  NFPA 33, 2018 Section 9.6.2.1 reads "The sprinkler design area shall not be required to exceed the area of the booth or room in which spraying or resin application is conducted."
My project has a large downdraft paint booth for buses. There are two concrete pits (4-ft height, 3-ft width, 80-ft long) beneath the paint booth that are covered by open grate flooring. (1) Does the above reference mean that the exhaust duct sprinklers do not need to be included in the booth hydraulic calculation? I have a large paint booth, and it has 4 exhaust ducts. (2) Is sprinkler protection required within the pit? Do these heads have to be included in the booth calculation or can they be considered heads under obstruction? If sprinkler protection was within the pit, the bags had to be regularly changed, which creates an issue for the end user and adds a large demand to the calculations. I think it would be unlikely that the sprinklers would operate in the concrete pit, as the overhead system should adequately protect the booth itself. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am trying to understand the criteria for designing window sprinklers for a tall glass space.
The application is a very large façade greater than 300 feet (91 m) long and 45 feet (14 m) high. The vertical mullions are 14'-9" center to center (4.5 m). What is the definition of a story, and how does it apply as stated in NFPA 13 8.7.8.1 "A single line of sprinklers is permitted to protect a maximum of two stories of wall area or two levels of vertically aligned windows where architectural features are sufficiently flush to allow rundown?" This height seems like it would be well above a two-story height, but what would that be reasonably defined as? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does a Sauna room require fire alarm notification?
Is there any code requirement on this one way or another? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a new build design where standpipes are required due to height. An area of the building is lower than the height requirement. This area has a partial floor above another that looks over an open emergency planning room area. There are two open stairs at either end. They appear to be the only stairs.
I view these as required interior exit stairs, and since I have never found an exemption to areas of the building below the height requiring standpipes, I've included hose connections. The Architect wants them removed because they are open stairs. Are standpipes allowed to be omitted for open stairs in the portions below the required heights for a standpipe? Any thoughts or input are appreciated. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Pipe Stands and Bracing I have a 12" fire pump that feeds the "U Turn" in the attached picture. Insurance company is adamant more bracing is needed. My question is what size pipe stands are required for 12", and do I need more lateral bracing for the surge if the fire pump runs? All I can find in NFPA 13 only addresses up to 10". Any thoughts or ideas on codes I may be missing would be appreciated. Thank you! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe  I have a project that has me perplexed.
Let's call it a very large bus station with retail, maintenance and other back of house entities. The facility is more than one million square feet where the people are and the busses are all staged around the exterior. There is a second level, but it too contains only back-of-house personnel, systems, and storage. The related codes are the International Fire Code (2021), the International Performance Code (2021), and Standard NFPA 130 (2020). The Design team has decided to not have sprinklers for the public concourse but have sprinklers everywhere else and reference NFPA 130 5.4.4.1 for omitting the sprinklers in the concourse. Can an AHJ apply a standard over code without an amendment to the code(s)? If so, what would the code to standard progression be outside of amendments? In one state I've done work in for decades, the AHJ can only interpret the code and apply the standard as necessary. Not apply a standard and ignore the code. The facility exists and only the busses are exterior to the facility. Thanks for your take on this. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe 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 I have a customer who is a large production facility with a 12-inch underground fire loop. There are 14 risers, 2 of which are 4 inch, the rest are 6 inch, with 7 fire hydrants tied in around the exterior.
The issue at hand is that they are getting false alarms on random flow switches. The head scratcher is that the water flows all test fine at around 45-50 seconds. Maintenance is saying that the risers where the alarms happened were cold (indicating water flow) and the other risers were room temperature at the time of activation. There is a 12-inch double-check backflow preventer at the water entry point. I'm starting to think about valve tampering, but I am looking for insight I may not have considered. Do you have any tips for what this might be? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe 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 NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems now require an egress time study to show that the design limits exposure to halocarbon agents is no longer than 5 minutes, like FK-5-1-12 (NOVEC 1230), HFC-227ea (FM 200).
This comes from 2018 Edition Section 1.5.14, 2020 Edition Section 4.3.4, and 2022 Edition Section 4.3.4. Exposure time for inert gas agents will depend on the oxygen levels within the space or room. Concentration below 43 percent shall be permitted where exposure is no longer than 5 minutes. Concentration between 43 and 52 percent shall be permitted where exposure is no longer than 3 minutes. The annex of NFPA 2001 tells us to review the NFPA Handbook and the SFPE Handbook for more information. Is anyone doing these calculations, and if so, what exit flow, movement speed, and reaction time would you consider appropriate for spaces using these systems? 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 Spring has sprung, and so has the awesome sharing in this community! Big thanks for pitching in and making it great, especially our Top Contributors for April 2025:
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 |
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