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Does code allow the drilling of load-bearing beam in multi-family residential buildings, for the purpose of running sprinkler pipe through it?
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NFPA 20 specifies a minimum size for suction pipe before a fire pump, to reduce the water velocity and avoid cavitation (among other things). NFPA 20 states that this only applies to 10-pipe diameters of length before the fire pump.
We have a very long run from the backflow preventer at the service entry and the fire pump room. Hydraulically, this long run works with a long 4-inch feed, which would then upsize to 6-inch right before the 450 gpm pump for the 10-pipe diameters. My question is, am I allowed to drop the main size between the backflow and the fire pump? Hydraulically I don't see why not, we're not dipping below 20 psi anywhere on the system and we appear to meet code. Intuitively I've never dropped pipe size to pick it back up, but this situation with the pump feels a little different. This is above a multi-family unit, so 6-inch steel is nearly impossible to fit within short open-web joists and would be a major issue for the building owner if we had to drop a soffit. Thanks in advance for your take! Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are getting a plumbing department reviewer's comment that the combined sprinkler/domestic water service cannot exceed a flow of 5 feet per second.
Their justification is that flow above 5 ft/s will negatively impact the "coating" on the inner surface of the copper pipe. I've never heard of such a concern, and 5 ft/s is far slower than the hydraulic calculations can support. This is for small diameter services on an NFPA 13R project that is 3 stories in height. The difference in tap fees between a 2-inch combined service (with an automatic domestic shutoff in this case) and a 3-inch ductile iron is at least ten thousand to the owner. Is there some truth or justification to limit fire sprinkler flow to 5 ft/s on copper pipe? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Are sprinklers within NFPA 13R required to be quick-response, or can they be standard response residential sprinklers?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a 20-ft x 30-ft exterior projection that was initially supposed to be open to the sky. The builder made it open on two sides at the bottom with a 12-ft lid. The construction above goes to the roof and is concealed with no access from inside or outside, and it all is of non-combustible steel beams and joists with metal siding.
The million dollar question - sprinklers above and/or below? Or nothing at all? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I'll preface this that I'm not a engineer. There is 17-foot storage with an existing sprinkler design of 0.20 / 1,500 sqft.
Based on NFPA 13, I believe we would need 0.21 / 2,000 sqft for a Class II commodity (non-encapsulated rack storage). How would you recommend going about increasing both the remote area size and the density on an existing system? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 13 Section 20.6.6.3:
"Early suppression fast-response (ESFR) sprinklers shall not be used in buildings with automatic heat or smoke vents unless the vents use a high-temperature rated, standard-response operating mechanism." ESFR sprinklers are designed to act fast and suppress the fire, the inclusion of a roof vent that opens up before the sprinkler activates could severely impact sprinkler activation both in terms of timing and location (as the moving smoke could activate a more remote sprinkler). If automatic roof vents are present, they should have a high-temperature rated standard-response operating mechanism to ensure that the sprinkler activates before the vent opens up. Based on the above, am I correct to interpret smoke venting is not required with ESFR systems? How do I go about handling smoke or heat vents with ESFR, or are they not necessary to begin with? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Are manual pull stations required to have any specific level of illumination at all times provided by emergency lighting?
Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a project with a concrete planter wall near the edge of the sidewalk. The top of the planter is 32-inches above the sidewalk.
The architect would like the FDC on the planter wall, but a siamese-type would project too far into the sidewalk so he wants a flush FDC. A standard brass FDC body with clappers would be buried under several feet of dirt so it would make sense to use spigots with clappers - but they would also be threading into a body/manifold that needs to be buried. Our concerns are replacement/repairs on the clappers; corrosion, and sealing around two penetrations through planters while still being able to repair/replace spigots. We're also considering a 'sidewalk siamese' setup just inside planter wall, but 18-inches above top of planter puts them above 48-inches above sidewalk. I think this is best option but would required fire department permission and the architect is pushing for flush on the planter wall. Is a flush fire department connection even an option here? Are we being overly concerned with corrosion and/or maintenance issues on these buried parts? Thanks in advance for suggestions for dealing with these issues. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are designing a warehouse which has a system demand of about 150 psi at 2,000 gpm.
There is an existing facility with a 150 psi @ 1,000 gpm rated pump installed approximately 1/4-mile (350 m) from the warehouse. We are planning to add a new 150 psi pump at 1,000 gpm near the warehouse roughly 65-feet (20 m) from it. Is there any code limitation we might hit to serve one building with two separate pumping stations installed remote from each other? How would you recommend we set the pump operation sequence for the two pump rooms? Each pump room will have an electric, diesel, and jockey pump. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe For a smoke control stair pressurization system designed in accordance with IBC 909 and IMC 513, does the code require a duct smoke detector on the supply fan?
Does the installation of a smoke damper at the stairway boundary factor into this requirement? (i.e. IBC 717.3.3.2 requires a detector within 5 feet of a smoke damper). Normally this motorized smoke damper is closed and then automatically opens upon activation of a specific fire alarm signal. NFPA 92 6.4.6.2 does require a duct detector on the stair pressurization supply fan; however, I'm unaware of a similar requirement in IBC/IMC. NFPA's intent is to detect smoke on the air supply and shut down the unit before smoke compromises the stairway. For elevator hoistways that require smoke control, IBC 909.21.4.2 states to provide a detector. I would have expected a general statement in IBC 909.12 with the same intention as NFPA 92; however, I do not see a similar requirement in the IBC/IMC for stairways. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am doing an evaluation of a water supply for a fire sprinkler system. The system is an ordinary hazard wet pipe fire sprinkler system. It was designed as a pipe schedule system. Table 19.3.2.1 of NFPA 13 – 2019 Edition gives the water supply requirements for Pipe Schedule sprinkler systems.
Based on our buildings construction the table requires that for Ordinary Hazard we have a 1,500 gpm flow with a residual pressure of 20 psi. Section 19.3.2.6.1 then states, “The residual pressure requirement of Table 19.3.2.1 shall be met at the elevation of the highest sprinkler.” My understanding of this requirement is that if I have a pipe schedule system where the highest sprinkler head is 20 feet above the finished floor which equates to roughly 8.7 psi of head I would need to have a water supply that provides a minimum of 28.7 psig residual water pressure flowing 1,500 gpm to the base of the riser to meet the requirement. Am I calculating the required residual pressure correctly? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Is a two way communication system required when an elevator is installed (only for convenience) but is NOT required or designed to be part of the accessible means of egress - assuming none of the exceptions in 1009.8 apply?
Refer to CBC 1009.8: "A two-way communication system complying with Sections 1009.8.1 and 1009.8.2 shall be provided at the landing serving each elevator or bank of elevators on each accessible floor that is one or more stories above or below the level of exit discharge." Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We want to take a moment and thank all of our contributors, including our Top Contributors to the Forum for May 2021. Your feedback and willingness to share best practices is what makes this industry great. Top contributors for May are:
I have inherited a totally fun project, a R-2 III-B multifamily residential building at 27,300 sqft per story, three stories total. I'm on the architect side.
Our mechanical engineer did a 61G (Florida fire suppression analysis) and designed the central lobby to be under NFPA 13 and the rest of the building NFPA 13R. I immediately thought where are the area separation firewalls, because we are over our allowable area for a III-B. The building is in construction, trusses have been set. I was told that you can do an area increase in the hydraulic calculations, one with the NFPA 13 portion of the building and one with NFPA 13R add them together and get your increase. I'm calling BS because I cannot find this in the code anywhere, but supposedly this is coming from a FP consultant. Any clues on the location of this allowance in code? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe Does anyone have experience with auditory testing booths?
We have a 6-ft x6-ft audiology testing booth with a fully enclosed ceiling. It is about 7-ft tall and has been installed in a school for over seven years. Recently on an inspection, it was noted that it was required to have a sprinkler. I have dug through the code and can't see where it would not be required. The only thing I found was in IBC 903.3.1.1.2 that it is "A room or space where sprinklers are considered undesirable because of the nature of the contents, where approved by the fire code official." In that case, it looks like we could add a smoke detector in there if it was approved by the code official. They are very similar to office pods or even walk-in coolers and they are required in those situations. Because of the nature of the booth, I'm getting a lot of pushback from the users of the booth. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have found in a gas turbine power plant a long run of a 24" pipe supplying water-based fire protection systems supported via cradled non-guided supports, welded to the bottom of the pipe itself. The shoe base plates are placed on support beams, without any slide assemblies in between.
I normally use to design the European code EN 12845, where you can read "supports shall completely surround the pipe and shall not be welded to the pipe or fittings". Is this permitted in NFPA 13 environments? I would be glad if you could share your thoughts about this, thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a project where the tenant intends to store Class I to Class III commodities that have a typical footprint of 12’ x 3.5’ (42 SF) on open-wire mesh racking.
Between the Definition 3.3.172 (NFPA 13-2019) Rack Shelf Area which specifically calls out “by the placement of loads” and the definition “Open Rack” (3.3.140) it appears that this condition has to be viewed an Solid Rack and would require In-Rack sprinklers no matter what roof level system (CMDA, ESFR, K-25) is installed or the Commodity Class stored. I know there are some special designs related to “big box retail” stores (Mercantile) for this, but our application is Warehouse (Storage). There are also additional conditions if the footprint is greater than 64 SF. Is there a way to read the above definitions that would not require in-rack sprinklers when Loads with a footprint over 20 SF and less than 64 SF are placed on otherwise Open Rack? Requiring in-rack sprinklers is a potentially major expense for an owner with 75+ operable facilities like this. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are on a project where they are installing these vertical storage carousels and will be storing miscellaneous vehicle parts and tires. I don't see anything within NFPA 13 specifically mentioning this equipment, so the current plan of action is to treat this equipment as multi-row racking. Since it is not practical to provide in-rack sprinklers for this equipment due to the moving parts, we are planning on protecting this equipment with ESFR sprinklers.
Does this ESFR approach seem appropriate? Is there any information that I am not considering? This is something that is new to me so any input will be greatly appreciated. https://www.storevertical.com/products/vertical-storage-system/tire-carousel https://www.storevertical.com/products/vertical-storage-system/shelving-carousel Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe At a tire store we currently have 25.2K ESFR at the roof, and they have some open grated flooring down at about 10-ft above finished floor where their tire areas are. We are currently protecting the areas that are wider than 4ft.
There are some other runs that are just under 4-ft wide and the AHJ is saying we need to protect those. They're 86% open grates, deeper than 1/4". I'm fine with adding the heads under these, however the AHJ is stating that we must protect below them with ESFR's instead of an intermediate level/rack style sprinkler. I've never seen this approach in 20 years nor can find any justification in the code to support this. The AHJs comments suggest the water shields are necessary to prevent cold soldering from ESFR sprinklers above. Is there a code basis to use intermediate level/rack style sprinklers under obstructions with ESFR at the deck? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 20 Section 4.15.5.1 (2016 Edition) requires a listed OS&Y gate valve to be installed in the suction pipe, but the annex of NFPA 20 suggests it should be as far as practical from the pump suction.
Would a control valve (OS&Y) on the backflow preventer meet this control valve requirement of Section 4.15.5.1? Assuming a city water supply, the backflow preventer control valve is listed for fire protection, there is still a valve'd bypass connected between the backflow preventer and pump suction, and the backflow is located a minimum of 10-pipe diameters from the suction flange. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project where the consultant is wanting to use a previously-installed 10-story building tank and fire pump to supply a new 14-story building up to its 6th floor, then add a booster pump to carry water to the upper floors.
Is this even acceptable by code? The new 14-story will be built next to the existing 10-story building. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe NFPA 72, 2016 Edition uses the phrase "2-hour fire-rated construction" in a few places; what does this refer to?
It's confusing to me since a variety of elements within the building could be 2-hour rated. For example, NFPA 72-2016 Section 24.3.13.7 states: "Two-way in-building wired emergency communication systems shall have a pathway survivability of Level 2 or Level 3. Exception: Level 1 shall be permitted where the building is less than 2-hour fire-rated construction." Buildings are not designated with a fire-rating, elements are. How do you interpret this? Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a fully-sprinklered building which also has 1-1/2" hose stations.
Are the hydraulic calculations required to include the hose stream (65 psi and flow) in addition to the sprinkler system, or can it be a separate calculation entirely (like standpipes)? Thanks for all responses. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have a school theater project where there are three catwalks (each 3'-9" wide) above the seating area that have cloud ceilings that completely cover the bottom of the catwalk. The ceilings are within 6" below the bottom of the catwalk.
There is ceiling level sprinkler protection and sprinklers dropped into the clouds. I do not think that a line of sprinklers is needed in between the bottom of the catwalk and top of the cloud. The A/E is saying that three levels of sprinkler protection is required in this situation (ceiling, catwalk, & clouds). Is sprinkler protection required between the catwalk and ceiling below? Any help either way, for or against adding the extra line would be great. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe |
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