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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What is the difference between Standard Mill and Semi-Mill Construction?

The annex of NFPA 13 lists Standard Mill as an example of unobstructed construction, while Semi-Mill is considered to be obstructed construction.

A.3.3.43.1 Obstructed Construction
(5) Semi-Mill Construction. The term semi-mill construction as used in this standard refers to a modified standard mill construction, where greater column spacing is used and beams rest on girders.

A.3.3.43.2 Unobstructed Construction.
(4) Standard Mill Construction. The term standard mill construction as used in this standard refers to heavy timber construction as defined in NFPA 220.

Semi-Mill in NFPA 13 is only defined as a modified standard mill construction where greater column spacing is used and beams rest on girders. The description of Standard Mill refers to heavy timber construction as defined in NFPA 220. NFPA 220 has nominal dimensions for structural members and other details, but that's it.

How should I know when something is Standard Mill or Semi-Mill under NFPA 13?

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Do solar panels on a roof level of a parking garage require sprinkler protection?

The parking garage is six-level open air garage, and the roof level (the sixth level) is used for parking. Solar panels would cover 30% of the roof level and may potentially in future cover the entire roof.

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We have a two-zone fire sprinkler system, one is wet, the other is dry-pipe. There are no inside hose valves, just a small NFPA 13 building.

Does the fire pump size need to accommodate hose allowances?

The sprinkler calculations have no inside hose allowance. We would typically apply the hose allowance at the city tap, which would be upstream of the fire pump. 

Thanks in advance.

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Why do laminar flows typically have higher frictional factors (Moody Chart) than turbulent flows?

I understand that the head loss is ultimately bigger in turbulent flows but would it not be expected that turbulent flows would experience a larger loss due to friction (and hence, a larger frictional factor)?

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​When is a sleeve required (or not required) at the base of a sprinkler riser when it comes through a floor?

Is there a requirement I'm missing in NFPA 13, NFPA 24, or the plumbing code?

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I'm hoping someone might be able to provide a little direction on the requirements of NFPA 13 2016 Section 23.4.4.8.1 (4) for hydraulic calculations.

We typically use 2"x2"x2 1/2" Vic IR Bullhead Tee directly on the welded grooved outlet. Per NFPA we should be including these fittings on the branch line, but we have always included the tee fitting on the 2 1/2" riser nipple because inside diameters are not typical to a 2" tee.

We have been doing this for the longest time and recently received corrections from the local AHJ. Victaulic does not specify the frictional resistance - equivalent length of the NO. 104 Bullhead Tee fitting on the branch line.

Have you come across this before, or any suggestions?

I tried to create a new fitting type in HydraCalc, but was having trouble. Also, might be pointless since there is no data for this on Victaulic's cut sheets. Thanks in advance.

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Is there an established method to "prove" that we have enough fire flow for a project site?

I understand that the premise is to be sure we have the correct water supply available at the site. We do. I'm just interested in the technical 'design' portion to validate that concept.

​Typically, I run a hydrant flow test at the site with nearby available hydrants. In this case, we're adding new hydrants but I understand the water supply nearby with recent testing.

Is a hydraulic graph (N^1.85) showing the available water supply at 20 psi sufficient to "prove" fire flow, or should I be conducting some type of calculation where I'm "flowing" hydrants?

We do sprinkler calculations all the time, but I'm just curious if I'm either overcomplicating things or if there's a process for fire flow that I'm not yet doing which I should be. 

Trying to get things right. Thanks in advance.

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We have a series of highrise buildings where an NFPA 13 sprinkler system and a wet standpipe system (NFPA 14) are to be installed.

If the sprinkler and the standpipe systems are supplied by a common fire pump, and horizontal supply pipe, but have separate vertical risers, will the system be considered a combined system?

Will the subsection of NFPA 14 (2019 Edition) section 7.10.1.3.1.1 apply?

7.10.1.3.1.1 In a building protected in accordance with NFPA 13 or NFPA 13R, the water supply for the combined sprinkler and automatic standpipe system shall be based on the sprinkler system demand (including any hose stream demand) or the standpipe demand, whichever is greater.

The buildings are fully-sprinklered, and the proposed fire pump is rated at 1,000 gpm. There is a water storage tank of 30,000 gallons. Thanks in advance.

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When performing hydraulic calculations, do I need to account for the length of the barrel of a dry sprinkler?

The sprinkler itself starts at the threads, but the length can sometimes be quite long before water hits the orifice of the sprinkler.

Under NFPA 13, under friction loss, the closest I can find says "friction loss shall be excluded for the fitting directly connected to the sprinkler."

Thanks in advance.

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Can anyone point me in the right direction for codes pertaining to the construction of a draft curtain?

My client will be installing them as part of an attic design, where draft curtains are required per the sprinkler listing.

The sprinkler data sheet covers the depth requirement of the draft curtain. From browsing some websites I can gather they can be constructed of fire-resistant fiberglass woven textiles, glass (smoke baffles), or even panels of sheet metal.

Does NFPA or the IBC define how they are to be constructed?

My client will most likely use sheet metal. I'm curious if there is a gauge requirement for the metal. I may be overthinking it, but I like to see the code defining the curtain requirement, to avoid the contractor putting the wrong materials in place. I appreciate any help that anyone can provide. Thank you.

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We are trying to complete system testing for a closed-loop system and a waterflow alarm is not reporting back to the fire alarm panel.

Is there a good sequence of operations for a closed-loop system?

More specifically, what order of events needs to happen when a sprinkler activates?

Thanks.

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We have an NFPA 13 system with portable stackable racks.

These are 8-ft tall, made of steel tubing and solid wood floors (which carry window and door products).

Should this be considered solid-shelf rack storage, or solid-piled storage?

Thanks in advance.

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I have a laboratory space which original had an open ceiling. The renovated space plans to provide a screen, similar to a window insect screen across the open ceiling, which will contain lizards which they are working with. 

Is this screen considered an obstruction to the sprinklers above?

The screen would be located approximately 3-feet below the main ceiling at 8'-0" above the floor. Although water would pass through, it seems that it would significantly disrupt the distribution pattern from the sprinklers.

This also does not seem to meet the requirements for an open-grid ceiling. Thanks in advance.

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Does an In-Building Riser require a thrust block?

I commonly see either mechanically-restrained pipe and fittings, or, an In-Building Riser (IBR) used when a fire service stubs into a building. 

Is a thrust block required for the IBR?

https://www.watts.com/products/plumbing-flow-control-solutions/risers/ibr2
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I can't seem to find any verbiage on the product data for Ames' IBR one way or another. Thanks for clarifying my confusion here.

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How is it determined whether a steel structure will have spray-applied fire resistant materials?

I'm creating performance specification for a bid-set on a project, so I don't yet have input from a structural engineer. The project is a warehouse with large fire loads and exposed steel.

Recently, a project out for bid is a low-rise office building, 100% sprinklered with a wet-pipe system that is concealed by a suspended ceiling. On that project, all of the structural steel has spray-applied fire resistant materials.

What drives the issue of spray-applied fire resistive materials?

Thanks in advance.

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I have an existing business that is approximately 4,000 sqft. It's a single-story building being renovated into an infusion center with (14) IV patient rooms.

I would consider this type of occupancy to be an Ambulatory Care occupancy because of (4) or more care recipients to be incapable of self preservation at any time. Under Ambulatory Care, this building would need to be sprinkler protected under the International Fire Code.

Are these type of centers considered to fall under Ambulatory Care, or just a doctor's out patient Business occupancy?

​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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We have a project in an old building (historic city) that has 3/4-inch branch pipe in their sprinkler system. We've recommended, based on good practice, to change these out for minimum 1-inch due to the potential of obstructions, and that NFPA 13 has not recognized 3/4-inch branch pipe for over 50 years now.

The client is pushing back asking for a reference stating that 3/4-inch lines need to be replaced. I cannot find anything in NFPA standards which would "require" it.

Do you have any helpful references on this that would help educate the client here?

​Thanks in advance.

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Is there a specific code requirement to keep the flow switch cover installed on the device?

It is good practice to keep it on, but is there a code requirement especially when running a 110V horn-strobe from the flow switch?

As always thanks!

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The 2019 Edition of NFPA 1221 (Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems) Section 4.5.2 requires that communication centers "be provided with an automatic fire detection, alarm and notification system in accordance with NFPA 72."

But what constitutes "automatic fire detection?"

I'm thinking this is alluding to wanting full smoke coverage of the area/space but the language of "fire detection" seems intentionally vague. A supervised automatic suppression system would meet this definition I think; its seems excessive to think a constantly attended room with fully sprinkler coverage would also require full smoke detection.

Is there some other guidance I need to consider here? Is this defined elsewhere?

​Thanks in advance.

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I have a rather basic question about fire flow . I'm a site/civil engineer working to validate a municipality's capacity for fire flow demand at a townhome development.

According to the New York State Building Code, townhomes do not required sprinkler systems.

My next approach was to use the ISO Guide to determine Needed Fire Flow which is based on a few different architectural components.

What I'm confused about is where is ISO used versus the NFPA 1142 standard?

Are both of the standards meant to consider the large individual unit or building's area?

​Thanks in advance.

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We have a project with Lithium-Ion Batteries stored in racks, not to be confused with Energy Storage Systems (ESS).

This will be for an electric vehicle assembly facility. NFPA 13 to my knowledge is silent, despite some joint testing/assessment by FM Global and NFPA. The storage height of the test array was only 15-ft if memory serves which could be a significant limiting factor (link below)

https://www.nfpa.org/News-and-Research/Data-research-and-tools/Hazardous-Materials/Lithium-ion-batteries-hazard-and-use-assessment

My initial thought is to have a risk assessment completed by an Engineer, and have them set some design considerations based on the applicable storage parameters. I believe we're looking at single and double-row racks in excess of 15-ft in height.

Has anybody else protected a similar storage array with sprinklers?

Would you have any suggestions on how best to approach this hazard?

Thanks in advance.

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I have an existing, single-story building. It's existing Ordinary Hazard Group II that is going to change from acoustical ceiling tile throughout to have no ceiling and be open to structure. The space will essentially be wide open (like a furniture store). 

The existing automatic sprinkler system has a 4 inch main that runs the length of the building with branch pipe for the sprinklers.

Would it make more sense to remove and replace the branch pipe for the open structure layout with upright sprinklers, or keep the branch pipe and armover as needed for upright sprinkler spacing?

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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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