I understand if a duct is wider than 4-ft (1 m) that there needs to be a sprinkler under the duct.

But what if the duct is just below the ceiling? Does a sprinkler also need to be above the duct?

I have a group of ducts with a combined with of 16'-6" (5 m) with the highest point of the duct 10 inches (25 cm) under the ceiling.

Does there need to be a sprinkler above and below the ducts?

Thanks in advance.

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I purchased a commercial condo recently. It’s been vacant and unfinished since 2013. It’s a shell, picture is below. It has 5 residential condos on top and 5 commercial condos on first floor, in a 3 story building. All residential units were sold and have been occupied since. One commercial unit was also built and has been occupied as a salon with a U & O.

There are no sprinklers, no fire room. They were going off of 2006 IBC code.

My architect prepared stamped plans with no sprinklers using the separated building scenario. It has a 2-hour horizontal separation, 3-5 hour vertical, no access to second floors. The plan was denied for sprinklers to be installed.

Now, I certainly understand safety, but it’s almost impossible to install now after 12 years.

Can you help me decipher mixed use B (1st floor) and R-3 (2nd and 3rd one unit)?

Is this approach allowed by code, or is the code official correct?

Is a self-contained fire area allowed to be its own building?

Please help, thanks.

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Designers and engineers get knocked (rightfully so) all the time for not living "in the real world".

I'm one of those designers. I've never installed any of these systems myself, but I want to know what advice those in the field would wish their designers and engineers knew.

What is one error or issue that you've seen that was due to a designer having a lack of field experience?

Pipe lengths? Obstructions? Elevators? Heights? Fab methods? 

What have you seen missed that could have been right the first time if they had field experience?

Looking for ways to keep the field from hating me while acknowledging that I don't come with that level of experience. Thanks in advance.

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We have a project and have gotten into an internal debate. The project has four diesel fire pumps in one pump house. 

During testing, are we allowed to run all four at the same time?

Or do we need to run each separately as we do normally to reduce the chance of blowing out a main?

Anyone have insight on this?

Thanks in advance.

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Does anyone have experience in designing suppression for a warehouse that will store boats on racks?

I will appreciate any information. 

Which standard would even be applicable? Do we treat them like high-piled combustible storage per Chapter 32 of the IFC?

What will be target hazard considering the fuel in the boat? Is there any limitation that how much they can keep inside the boat?  

Thanks for the input on this; I'm having a hard time on where to get started.

Editor's Note: A Fire Protection Research Foundation on Marina and Boatyard Indoor Rack Storage Sprinkler Protection has been submitted and can be viewed here: PDF LINK

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We have a project that includes a Sensitive Compartmented Information Facility (SCIF).

How do you properly seal an open drain that travels through a SCIF wall to the outside?

Thanks in advance.

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I had a client ask about Oxygen-Reduced Systems (ORS), aka Hypoxic air technology (displacing ambient oxygen in an enclosed environment such as in warehouses). I did a quick read with what's available on Wiki, FM and NFPA. But even my go-to suppression people have hardly encountered these. Testing has been very specific.

Just to increase my knowledge, does anyone here have an practical experience in these?

Are these systems really being installed?

Thanks in advance.

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Can full height walls within a room create an obstructed construction situation in an otherwise unobstructed construction building?

As an example, you have a room with full height walls and a single exposed beam (in noncombustible construction) with the distance from the centerline of the beam to both parallel walls less than 7'-6".

If allowed to define this as obstructed construction, a single sprinkler 1" to 6" below the bottom of the beam may be sufficient. If not, it may require a sprinkler on both sides of the beam.

In a multiple-office type of occupancy this could save a lot of sprinklers. This example is assuming following all the rules for obstructed construction and the depth of the beam being such that you can't use the obstruction to sprinkler discharge rules to avoid the obstruction.

Thanks in advance.

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Topic: Water Delivery Time in Single Interlock Preaction Systems Question:

I'm currently designing a single-interlock preaction system and I'm seeking clarification about the water delivery time requirements under NFPA 13 (2013).

Section 7.3.2.2 mentions that the system size cannot exceed 1,000 automatic sprinklers but doesn't specify the water delivery time for single interlock systems.

On the other hand, Section 7.3.2.3 clearly states that double interlock preaction systems must deliver water within no more than 60 seconds.

Does this mean that single interlock systems are not required to adhere to a specific timeframe for water delivery?

In my view, it makes sense to not include a delivery time for single interlock systems, since water should already be at the sprinkler prior to activation. I'm interested in others' views or experiences in this area.

Thanks in advance!

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I am working on a permit for a 1,500 sqft (750 sqft/ floor) new construction live/work building R-2 in California (2022 California Building Code, which is based on IBC). It has a 1-bedroom apartment above with only "work" space below.

The building code allows for Live/Work R-2 to be protected with NFPA 13R. In the building code the only uses not allowed in the "work" area of Live/work are Group H & S.

Where all of this gets hazy is that I interpret the code as 13R being allowed to protect this whole building regardless of use except for uses S or H.

For instance would a small pizza joint be allowed in this "work" space as long as it did not have special hazards that would require an ANSL or NFPA 13 system?

Or is Live/Work with 13R just purely limited to office, barber, professional space, etc.?

From multiple angles I am trying to understand the true limits of Live/work when there are no local ordinances that limit the "work" space use except S & H.      

Thanks in advance.

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I have a building that has both a free standing fire department connection (FDC) and a post-indicator valve (PIV) out at the drive entrance to the single-story building as requested by the Fire Marshal.

Construction has now started up for the site and the Fire Marshal is saying there is a code requirement for the PIV and FDC to be 50-ft apart and wants them moved. He is unsure of the exact distance, but he insists this is a code requirement and that it's not a local requirement.

For reference, we are under the 2015 IBC/IFC and 2013 NFPA code editions.

Is there any requirement for the PIV and FDC to be 50-ft apart?

I cannot find any requirement like this in the IBC, IFC, or NFPA 13 or 24. There are sections in both NFPA 13 and 24 that vaguely say PIVs shall be protected against mechanical damage, but they give no minimum distance from objects. IFC/IBC both list minimum 36-in clearance around the FDC.

I think the Fire Marshal might be confusing the 40ft requirement from buildings for the PIV, or, this is a local preference, but they do insist otherwise.

I know at the end of the day the Fire Marshal gets whatever they want for the PIV and FDC placement, but I really want to make sure that there is not some hidden requirement I cannot find.

Thanks in advance.

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We have a storage building that is non-sprinklered, it only has fire alarm. The ceiling height in some areas of the building with storage of tires is up to 10-ft in height, and others up to 15-ft in height.

How many tires can be stored?

Is there a limit to the amount of storage?

Does storing on tread or on side matter?

Thanks in advance.

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I have a project in the Miami area where there are some exterior glass panels that need to be 1-hour fire rated.

I specified the glass to be fire rated type, but it prices are coming back too high. The contractor is looking into an alternative of providing fire sprinkler protection on the inside face of the glass.

Is this a feasible idea?

The wall that the glass is part of requires the rating due to its being within 10' of some adjacent exterior glass.

Thanks in advance.

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We have a fire sprinkler tree system that has a 6" centerline down from a metal deck (mains and lines).

Since an air release valve is required at the end of the system, what are our options for installation?

All the options I can find are too tall to fit with our piping so close to the deck. We are not able to lower the piping due to other trades.

Thanks in advance.

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We have a steel aircraft storage hanger Group 1. It's approximately 50-ft high with exposed steel columns requiring a fire rating per NFPA 409-2022 Edition.

The steel will not be fireproofed but will be protected with sprinklers in accordance with NFPA 409 5.6.3.4.

Can pendent sprinklers, installed sideways, be used to satisfy NFPA 409 for column protection?

In the past we have protected the columns with sidewall sprinklers spaced according to 409 and on alternating sides of the column. Then the sidewalls were changed to pendent sprinklers installed horizontally to provide better spray distribution on the columns as the sidewall spray tended to (in theory at least) bounce the spray back in stead of vertically.

This approach has been accepted by EOR and AHJs alike.

NFPA 409 states that "wetting of the lower sprinkler should be considered" although multiple level sprinklers were never used. I'm not sure how this plays in.

I recall reading that pendents installed horizontally could be used for column protection due to better spray distribution, however, I cannot find that in code.

The client is not open to fireproofing or intumescent paint; column sprinkler protection is in the bit and is going to be used.

All is appreciated!

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Does anyone know of any literature summarizing standpipe design changes history for the last 130 years or so?

Something to the effect of:

• 1993 to Current - 500gpm flow most remote, 250gpm each additional, residual pressure at 100psi
  
• 1970ish to 1993 - 500gpm flow most remote, 250gpm each additional, residual pressure at 65psi
  
• 1950ish to 1970 - 500gpm flow most remote, 250gpm each additional, residual pressure at 50psi

With more enforcement of 5-year standpipe flow testing in our area we find ourselves spending a lot of time trying to locate older versions of NFPA and NBFU to see the design basis at the time of construction to determine testing procedure.

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Can an assisted living facility that installed a an NFPA 13 compliant system which was only required to be a 13R now remove the dry attic part of the system?

They have had corrosion issues and leaks they are wanting to avoid. The only reason they installed the 13 system is initially they envisioned possible adding a skilled care section which is now not happening.

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Is there any requirement for a standpipe to be installed due to travel distance between stairwells in a 3-story R-2 building?

I am reviewing plans of a U-shaped apartment building with two stairwells on the ends. The distance between them is about 470 feet. We are under the 2018 IFC.

If not required by code, would you as the AHJ consider requiring them for improved fire operations?

Thanks for any feedback.

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Are foam system test headers allowed to flow outside and discharge the foam to the ground/storm water?

I see more and more places are banning AFFF from storm water.

What about flowing AR-SFFF to storm?

Any recommendations for capture if its not allowed to be send down the storm drain?

Thanks in advance.

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In regards to a trapeze pipe support, isn't there an option to size the rod that connects structure to the trapeze pipe separately from the rod from the trapeze pipe to sprinkler pipe?

Couldn't that be two separate calculations considering there are two rods for the trapeze and only one to the sprinkler main?

Thanks in advance.

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You all are awesome. The quality and diversity of perspectives here is second to none - and I'm very thankful for the contributions everyone has made these last few years. The quality of discussion and insight is far better than I could have hoped for when first starting this Forum back about five years or so ago now.

Thank you to everyone for continuing to make this Forum such an insightful success and help to share ideas and best practices for the industry.

Here are the Top Forum Contributors in 2023 (in alphabetical order):

As a thank you from our team for helping shape the industry in a positive way, each Top Contributor will get a plaque like the one shown above. We'll also make note with a flag next to each person's name in future leaderboards.

Thanks for being a part of the community and helping move the industry forward!

​- Joe Meyer

Would you require a pressure gauge on the bottom side of the backflow device?

NFPA 13 says pressure gauges shall be installed above and below each “alarm” check valve or “system riser” check valve where such devices are present.

Is the backflow preventer considered an alarm check or riser check valve?

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We have an indoor amusement park (skiing activities) which has a back of house space where in machines are being repaired and refueled. There is a diesel storage room which a 1,320 gallon tank (5 cubic meters).

The room does not have any fire resistance rated walls and is also used for storing paint thinners (Class 2 flammable liquid). Just outside this room is a welding space.

Is there guidance, somewhere, on what needs to be considered here for fire and life safety?

I tried using NFPA 1, NFPA 30, and NFPA 101, but since this diesel tank is inside the space, I've not been able to find a reasonable solution in terms of fire and life safety requirements.

Thanks for the input.

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Is CPVC allowed to be run exposed through a small storage room?

Thanks in advance.
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