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.

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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.

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Is there any way to install sidewall sprinklers in a room with sloped ceilings?

Say you had a rectangular room with a ceiling attached directly to the underside of a traditional gable roof with a high ridge peak in the middle. Concealed pendent ceiling sprinklers are often not possible ​because the space above the ceiling is completely filled with insulation.

Can you do sidewalls on the vertical walls near the ceiling high point to protect the room?

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For a single-family home with a 6 in 12 sloped ceiling (roof) that is a combustible wood structure.

Does this need a 1,950 sqft calculation due to the slope, or just two sprinklers as NFPA 13D requires?

Thanks in advance.

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Imagine you have a 6-unit, true townhouse-construction building covered by the 2018 IRC under construction. It has an NFPA 13D sprinkler and a one-hour separation between units, but​ there is one common closet for the sprinkler riser and domestic water main. This closet is accessed only through a door on the exterior and is under the control of the landlord, not the tenant.

What is the code path to require any fire separation between that closet and the dwelling units?

There is no dog house off the side. The IRC only seems to call out separation between units, and even if you go into the IBC, it is not apparent.

Thanks in advance.

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For NFPA 13D systems which are "multipurpose" or "flow-through" combination sprinkler and domestic systems, it has been troubling me as a fire code official not knowing the maximum length that a dead-end or arm-over section of pipe can be in order to be deemed safe from contaminating the potable water in a home.

NFPA doesn't seem to weigh in on this, that I know of.

What is the maximum length for a dead-end or arm-over section of pipe in a combined sprinkler/domestic system?

I've been searching for studies, contacting other AHJs, asking plumbers; but no one can give a definitive answer.

From what I understand, there are no documented cases of illness from residential sprinkler systems, but I would rather not rely on this as a way to measure safety. I've seen a few sources say (and show) that water only circulates into the dead end at 1.5 x the diameter of the pipe going across. So if water isn't circulating, it seems like there's a risk for contamination.

If contamination is not a risk for whatever reason, why have any maximum at all?

I would love to get to the bottom of this and I look forward to hearing from others who have a deeper understanding. Thank you.

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I'm reviewing a fire sprinkler system under 2019 NFPA 13D for a single family dwelling.

The living room basically has "reverse" ceiling pockets as the pockets are lower than the rest of the ceiling (pockets are at 10'-7", the ceiling is at 12'-1").

They have 2 sprinklers in each of the 3 lower sections of the ceiling but no sprinklers in the higher areas (except for a room to the side but in the same area).

It seems off to me to omit sprinklers in the higher area but can't figure out how to apply a code to it.

Would you apply the ceiling pocket rule if the higher area exceeds 100 cubic feet or is it fine as designed?

We have a 4-story building with Levels 2 through 4 being residential. The first floor is retail and amenities. The 4th floor has vaulted ceilings and is essentially open as a gabled roof deck. 

The plan was to use CPVC for all residential floors, and at the top floor to run pipe level and extend sprigs up to catch the peak and higher roof areas.

Is this acceptable?

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Is it worth installing a nitrogen generator for small residential dry pipe systems with less than 50 gallons?

We have about 175 homes with dry pipe systems in our jurisdiction.

Would a nitrogen generator be the best solution for corrosion protection?

Thanks in advance.

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Does NFPA 13D require trapped air to be removed in a sprinkler system?

In the 2016 NFPA 13, Section 7.1.5, Air Venting - a single air vent for a sprinkler system, with a connection conforming to 8.16.6, shall be provided in each wet pipe system utilizing metallic pipe.

I am using CPVC with anti-freeze in most residential systems.

Is there a code requirement for a vent for what I'm doing?

Thanks in advance.

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Are hydraulic placards required for NFPA 13D systems?

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What concerns should I have about hanging from old wood?

Like very old wood, almost petrified?

I'm doing an NFPA 13R job for an old historic building that has been moved. I don't know how old, but it uses full dimension wood. The 2x's look like they measure 2-inches thick.

I'm wondering what hanging to this old dry wood is going to be like?

Do they need to predrill? Are screws better?

Any ideas appreciated!

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Does a fire pump on an NFPA 13D system require backup power?

It seems like it should, but 13D does not say that it has to and does not reference NFPA 20.

Thanks in advance.

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With the use of CPVC, what are the limits to how much can be exposed?

I had thought that we needed to have all of the pipe concealed, and I can't see in code how this is addressed.

We have a project with a temperature-controlled and insulated attic (the mechanical engineer has confirmed it will be kept above 40 degrees F year-round) in a warm climate. This is in an NFPA 13R apartment building.

Is CPVC allowed to be run exposed through the combustible attic space?

The attic is not sprinkler protected (NFPA 13R system, 3-story, apartments, smaller-sized project). Thanks in advance.

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The installation contractor and I have had an argument about how sprinklers should be spaced and calculated in a 13R system.

I have argued that per NFPA 13R Section 7.1.1.3.1, we should calculate 3 sprinklers in the greatest hydraulic demand area. This area is furthest from the riser and the calculation permits 16x16-ft spacing for the area that has the most sprinklers.

Section 7.1.1.3.1:
For each of the following situations, the number of sprinklers in the design area shall be all of the sprinklers within a compartment, up to a maximum of four sprinklers, that require the greatest hydraulic demand:

The contractor wants to remove a sprinkler in a single room and move a sprinkler 10 feet off of the exterior wall, but in NFPA 13R makes no mention of a single sprinkler proof calculation that could justify such a move.

There is no mention of a single sprinkler calculation in NFPA 13R permitting a spacing of 20x20, and so all sprinklers on the project can be only 16x16 if the greatest hydraulic demand is permitting it.

In NFPA 13D, it makes no mention of a single sprinkler calculation either, but does refer to single sprinkler operations in A.10.1. I did not feel comfortable designing a sprinkler system that was not up to code standards and need an outside opinion on this matter. Thanks in advance.

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In the 2015 International Building Code, Section 101.2:

The provisions of this code shall apply to the construction, alteration... of every building or structure in any appurtenances connected or attached to such buildings or structures.

Exception: Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories above grade plane in height with a separate means of egress, and their accessory structures not more than three stories above grade plane in height, shall comply with the International Residential Code.

The debate: Why in the world are we going to allow them to label this design as residential?

The townhouse exception is seemingly being used pretty loosely around the building department.

In our college community, these structures meet the requirements of a townhouse, but with obvious intent to be student housing.

After looking at code....I cant say I blame these designers. I see no way to combat their argument. They meet all the code requirements to avoid the extra costs of a 13R system and only have to add an additional layer of gyp to comply!?

If I am missing something, please let me know! Maybe I just need to accept them as townhouse?

It sure doesn't "feel" right. 

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I have a project with four separate apartment buildings with 4-units in each building.

All buildings identified as R-3 Occupancy, Type V-B Construction, single story. There are demising walls between each unit that are 1-hour fire-resistance-rated including a 1-hour draft stop between each unit.

The Architect has noted on the approved plans, "Fire Sprinklers Per NFPA-13D".

My question #1: would NFPA-13D be allowed in these 4-unit buildings?

These are not townhome style zero lot line buildings built independent to one another. I think the project should be designed according to NFPA-13R.

Question #2: One building has a unit designated as a "Laundry room and folding room". I think this single unit should be designed according to NFPA-13 under Ordinary Hazard Group-1, correct?

Thanks in advance for your feedback!

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Assuming that it's been approved by a structural engineer, is there any code or standard restrictions that would prevent running CPVC branch pipe through a built-up floor beam?

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I cannot find a residential sprinkler that will allow for sloped ceilings greater than an 8/12 pitch.

How can we approach this and still provide proper protection in a residential property?

Most log cabins have ceilings with a pitch up to 12/12. Thanks in advance.

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We have a house (single family home) that will require an NFPA 13D system, but it is not going to be connected to city water.

There is a well onsite. The well completion report does not provide a pressure or flow output.

Can the well be used as part of the hydraulic calculations? What data would be necessary to incorporate it?

If not, I'm assuming that both a pump and tank would be needed here for the 13D system?

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My understanding is that when using residential concealed sprinklers in a single-family (residential) home, there is an exception to beams - that we space as if they are not present.

This is in the living room (image below). I think the plan reviewer is looking for sprinklers within each bay. My reading of the code was that concealed sprinklers cannot be lowered, so I disregarded the beams.
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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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