We have a two story apartment building, and we are installing an NFPA 13R wet pipe sprinkler system.

Is an outside hose demand required to be included within the calculations?

There are no inside hose stations.

If outside hose demand is required, is the demand the same as light hazard? 100 gpm?

We couldn't find a reference to this in NFPA 13R.

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13, 13R, 13D: Calculations and High Ceilings

I was reading through NFPA 13 (2016 ed.) and caught Section 8.10.2.2:
Residential Sprinklers shall not be permitted to be used on ceilings with slopes greater than 8 or 12 or ceiling heights greater than 24 feet unless specifically listed for this purpose.

This got me curious about how it affects NFPA 13R and 13D, checking into those I didn't see any restrictions where residential sprinklers stop being allowed at the ceiling height, however the maximum 24-ft ceiling was noted in NFPA 13D (2019) 10.2.1 and NFPA 13R (2019) 7.1.1.3.1 in regards to design sprinklers.

So am I correct in assuming that if you have a residence with a 24'-1" foot ceiling in the family room (say there's a loft second floor), that you now have to calculate and design the space per NFPA 13 rather than 13R or 13D (as that ceiling height is outside of the scope of 13R and 13D)?

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When are standard response sprinkler heads a better choice than quick or fast response heads (5mm vs. 3mm bulb)?

Are there applications where it would be preferable to have a slower response time?

As far as I know, quick and standard response heads cost the same, come with the same k-factors, and the same temperature ratings.

Why would the slower one be chosen? When would you choose a Tyco TY-B instead of a TY-FRB?

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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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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?

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Are sprinklers within NFPA 13R required to be quick-response, or can they be standard response residential sprinklers?

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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?

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I'm designing the fire suppression system for a 6-story wood frame residential building. There will be 6-ft wide balconies made of non- and limited-combustible materials. Normally that would mean sprinklers under the balconies could be omitted, but it occurred to me that people will likely have BBQs and the accompanying propane tank on their balconies.

Would this count as "combustible storage" and thus require sprinklers (dry sidewall heads), or can they still be omitted?

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If a building has an NFPA 13R system and the building is now being converted to a commercial building and does not require a sprinkler system for new construction, can you remove the system?

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I have a project with 90 apartments, and each unit has a recessed telecom (fiber-optic) panel in a closet that would normally not require a sprinkler. The project is under NFPA 13R.

The Authority Having Jurisdiction is requesting sprinklers in these closets, feeling that these are now combustible after the telecom panel is installed. Is anyone else running into this?

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I have a project that is under NFPA 13R (2019) and NFPA 14 (2019). In section 7.10.1.3.1.1 of NFPA 14, it states that in cases where NFPA 13R system demand is higher than the standpipe demand, the system demand applies.

Is it ever possible to have a residential sprinkler system with a higher demand than a standpipe?

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Is anyone having problems with steel pipe corrosion after using the older glycerin?

Three year old condominium complex was an NFPA 13R job. About 75% of the pipe is CPVC with exposed basements installed in steel. We hydo-tested four of the buildings in the winter with the glycerin before the buildings had heat so the builder can insulate and sheetrock. We drained out what we could but did not pull any heads in the basement. We didn't think leaving some trapped glycerin in the steel basement piping would be anything to be concerned about.

The basements have developed pin hole leaks and the odor when draining is putrid! I saw the new UL-listed (Freezemaster) antifreeze states, "includes a corrosion inhibitor package".

Any help/advice is greatly appreciated in stopping this attack on the pipe.

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We have a four-story project that uses NFPA 13R - 2016 Edition. There are balconies with wood structure that are getting sprinkler protection. The building is in a cold climate.

I'm trying to figure out how to correctly incorporate these balcony sprinklers in the hydraulic calculations while still being efficient in the sprinkler design (there's no fire pump on this and poor city supply).

As I understand it in NFPA 13R, my options are:

(1) NFPA 13R for Dwelling Unit Calculation: use dry-sidewall residential sprinklers (Reliable and Tyco have some) for the balcony. This would then be a 0.05 gpm/sqft calculation over a compartment, up to four sprinklers. 

(2) NFPA 13R for Outside of Dwelling Unit: use dry-sidewall quick response sprinkler for balcony. This would be a 0.10 gpm/sqft calculation for four adjacent sprinklers. The inside sprinklers could still be 0.05 gpm/sqft (per 13R), but the balcony sprinklers need to be 0.10 gpm/sqft (per 13R 7.2.2, 7.2.3).

(3) If the balcony is under 500 sqft and meets a string of conditions, then dry-sidewall quick response sprinklers for the balcony can be for the compartment, up to four sprinklers (per 13R 7.2.3.1). We don't meet this here, because there are large glass slider doors over 50 sqft.

Are there other options here, or is my approach for the first two options appropriate? I could very well be overthinking this. Thanks in advance.

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We have a small project (13,800 sqft total) which is a four-story, all residential apartment building, using mostly CPVC pipe. The system is under NFPA 13R.

The city supply is very poor, so we will have a fire pump that meets NFPA 20 (as is required by 13R). The pump is an 8-HP, 70 PSI at 75 GPM.

Is a jockey pump necessary with such a small fire pump?

Normally, for our large commercial NFPA 13 projects, a jockey pump is not even a discussion because we don't want the main fire pump (500 - 1,500 gpm) cycling on just to support system maintenance pressure.

For such a small project with a significantly smaller fire pump, is there any harm in not providing a jockey pump?

The question is not based on cost - the pump room is microscopic and we're already having trouble fitting in all the equipment and controllers as is.

Appreciate you all - thanks in advance.

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Is there a minimum distance clearance required or recommended from the fire sprinkler and the top of a stacked washer dryer in small closet?

What is the reason for the clearance needed?

I heard that 4” is needed for the clearance rather than the standard 18” in a public area.

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When applying NFPA 13R to a mixed-occupancy (R-2 and S-2) building, what is the definition of "incidental"?

The building in question is three stories of residential over a parking garage designated for residents only. Each residential floor is approximately 2,000 sqft and the garage is approximately 3,000 sqft. The building is type V-A (wood, combustible) throughout.

IBC 2015 Section 509 defines incidental as constituting less than 10% of a given floor.

Does this entire building require a full NFPA 13 system?

If possible, please provide a code basis, thank you!

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In an NFPA 13R system does the FDC check valve need to be accessible?

In 13 it states it is required, but I can't find it in NFPA 13R. Section 6.11.4 talks about ball drip for check valve, but I do not see anything on accessible. I’m sure I’m missing some code path that references 13 possibly? Thanks.

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I have a residential sprinkler calculation out of NFPA 13R 2016.

Do you need to calculate a minimum of 4 residential sprinklers within the dwelling unit?

I have a two-bedroom apartment unit and my most demanding area would be the two that are in the bedrooms and the two that are in the kitchen/living area.

Can I consider the kitchen/living area a compartment separate from the bedrooms and calculate only these two sprinklers?

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We are working on an 8-unit, 4-story apartment building in the City of Chicago. It's an NFPA 13R system, with two units on each floor level. The entire building (all floor levels combined) is about 14,000 sqft.

Are floor-level control valves required?

Under NFPA 13R there doesn't appear to be a requirement for floor-level control valves like there is in an NFPA 13 system (NFPA 13-2016 8.2.4.3). Even still, in NFPA 13 still allows a single control valve and flow switch when the entire building is less than the system limits of 8.2.1 (52,000 sqft for a Light Hazard system). 

Chicago has a Chicago Fire Prevention Code that requires "each floor and level of a building" with a separate control valve (15-16-400), but this and several other sections within the Fire Prevention Code apply only to NFPA 13 systems, not 13R systems.

Might be a shot in the dark but was curious if anyone has ran into this before. Thanks in advance.

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I would like to double check on the coverage of attached garages in an NFPA 13R system.

NFPA 13R 2010 6.6.6: Sprinklers shall not be required in... other concealed spaces that are not used or intended for living purposes or storage and do not contain fuel fired equipment. 

NFPA 13R 2010 6.6.5: Sprinklers shall not be required in any ... carports, and stairs that are open and attached.

There is a separate reference other than 6.6.6 on the coverage of attached garages. The way I read it, they must be covered under this standard. Please advise.

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In your opinion, what's the best way to address sprinkler design when there are open breezeways separating units in the same building?

Do you somehow provide a heated chase under a deck? Convert from CPVC to steel and heat-trace a run? Go back underground and potentially "under" the building? Use separate risers for each grouping, bumping up the price significantly?

Residential multi-unit apartment complexes are frequently built with open breezeways in-between blocks of units. These usually have paved concrete at the bottom, only wood joists and decking for stairways and walking areas, and a covered roof at the top. 

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Sorry if this is too location-specific, but I have a question I'd like to get other designer/engineer input on. The Chicago Building Code (Section 15-16-600) specifically has their own density/area requirements, with a minimum of 0.10 gpm over 1,500 sqft for NFPA 13 applications.

Does this mean that they do not accept residential sprinklers (most demanding 4 adjacent residential sprinklers)? Do they also not accept the area reductions for quick-response sprinklers?

Based on the requirement in the code they certainly have the ability/right to override NFPA 13, I just haven't seen any other jurisdiction overrule the allowances in NFPA 13 and was curious if this holds up for other installers in the area.

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Have a 4-story townhouse, sprinklered in accordance with 13R.

Is a sprinkler at the top of an elevator shaft an acceptable trade off for a 1-hour rating of the shaft (in lieu of a 2-hour rating)?

NFPA 13R, 2013 Section 6.6.6 says sprinklers are not required in non-combustible elevator shafts in accordance with ANSI 17.1. The state is says they will not certify the elevator/does not require a certificate in a residential elevator, so there is no confirmation that the elevator code is upheld.

If the sprinkler is an acceptable trade off (or if the sprinkler is elected to be installed in excess of the code requirements) is then a shunt trip and flow switch/heat detector required to shut off power in the event of a sprinkler activation?

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Where exactly does a hydraulic calculation need to end? 

When we run a hydrant flow test, there's a static/residual hydrant and a flow hydrant. I regularly run my hydraulic calculations from the building, through the service main, to a street main, and then up the tee'd branch that serves a hydrant so that my source point is exactly at the elevation of the static/residual hydrant. I do this so that I make sure to account for the proper elevation of the water supply.

Most other hydraulic calculations I see will end wherever the building's service main intersects with the street's supply. Is this correct? Wouldn't that place the source at an elevation lower than what the hydrant indicated is available?

Wondering what the proper way is that I should be precisely calculating systems. Thanks in advance.

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