I have a Type V-A Group R-2 apartment building whose code summary indicates as having four stories atop two levels of basement, all of the same construction and occupancy, and requiring a 13R system type.

I’m no expert in the building code, but it's my understanding that in order to have a building taller than four stories and still use 13R, a 3-hour horizontal assembly would be required having Type I construction below such assembly and up to four stories above; this building looks to be Type V throughout six levels with no horizontal assembly.

The large building is vertically separated into four individual buildings by 2-hour fire walls but I see no horizontal separation.

Is there a way this proposed 13R sprinkler system can be code compliant (IBC 2015)?

Thanks in advance.

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In Section 19.4.1.3(3) of NFPA 13-2019 Edition, discusses that rooms or compartments 800 sqft or less (small rooms) should be calculated based on delivering 0.10 gpm/sqft over the room or the compartment by using the area of the room divided by the number of sprinklers in the room.

I believe I've overcalculated remote areas in the past.

My project now is an apartment building designed according to NFPA 13. Using residential type sprinklers with non-sprinklered combustible concealed spaces. According to Section 19.4.1.2 I need to calculate a minimum of eight sprinklers.

In the past I've calculated the eight sprinklers using the actual spacing based on the S x L rules with a 0.10 gpm/sqft density.

One room example - room dimension of 24 x 12 is 288 sqft. Two sprinklers spaced in a compartment 8'-0" off one wall and 6'-0" from adjacent wall. Using the S x L rule: 16' x 12' = 192 sqft x 0.10 gpm/sqft = 19.2 gpm each.

Or, according to Section 19.4.1.3 (3), would I divide the room size 288 sqft by 2 sprinklers, which is 144 sqft per sprinkler, regardless of the actual sprinkler distance from the walls? This second scenario would result in a 14.4 gpm required flow.

Or, was the code option (3) assuming the sprinklers are evenly centered within the compartment.

Thanks in advance for your input and clarification.

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Can you run sprinkler pipe underground after the riser has entered the building?

The building we're working on is an apartment building that is being sprinklered to NFPA 13R (2016 Edition). The apartment is 4-story and has open air breezeways. There are dry sidewalls protecting the breezeways.

The owner wants to run pipe under the slab in the open air breezeways instead of providing a heated path for sprinkler pipe across the breezeway. I have strongly recommended against this, but have gotten pushback from the owner and contractor regarding this pipe arrangement.

Is this underground arrangement allowed?

I believe there are some cases where this is acceptable but not many. Thanks in advance!

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I have a mixed-occupancy, 100-year old 1-story house within a metro area. There is existing office space up in the front of the building, and a one-bedroom apartment in the back.

We are adding a camelback addition to the building. The existing office space will remain as is and we will have two 3-bedroom apartments in the back. The camelback will be set back 20-feet from the front of the house. The height of the building will be 30-feet. 

Can I use 13R or 13D in the residential units? 

Do I need any sprinkler in the commercial office space upfront?

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I purchased a house with fire sprinkler system that is 30 years old. The previous owner had the sprinkler disconnected about 10 years ago when a furnace repairman stepped on one of the sprinkler pipes. The damage was repaired but the water line to the sprinkler system was not reconnected (not sure why).

I was wondering if it would be okay to have it reconnected now?

It is a 30-year old system and has been inactive for 10 years.

Do the pipes become brittle are there other concerns in reconnecting?

Thanks for you help.

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I'm reviewing a apartment building that meets the requirements for an NFPA 13R system.

My questions: A pump is going to be required for this project and they are proposing to use a booster pump on the incoming waterline at the property line to reach the required pressure for domestic and fire demands.

Is a combined domestic/fire pump like this allowed?

It would be a private pump.

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In NFPA 13R, sprinklers may be omitted from bathrooms and closets provided they meet the area and size requirements, and are constructed with limited or non-combustible materials (gypsum/drywall).

Should sprinklers be installed in bathrooms and closets on the top floor regardless of area/size and construction to prevent a fire on the top floor from getting into the ceiling space and spreading?

I have seen other designers do this but I can't find any formal requirements for this approach.

Has anyone else ever done this? Would it matter if the ceiling and roof assembly were fire rated?

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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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