How to Address Water Supply w/ Replacements?

8/10/2023

How do I, as an AHJ, address contractor scope limitations?

Project where an installer presents plans to replace 328 sprinklers and is changing some pipes out. Many times the installer says they're only responsible for pipe from the riser - not for a hydrant flow tests.

What is the best way to navigate this to be sure that there's still sufficient water available?

It could be a one-for-one replacement, but what if there's significant work being done - what code basis is there to make sure than an effectively-new system can work with today's water supply?

Thanks in advance.

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9 Comments

Pete H

8/10/2023 07:30:04 am

While their contract may only be responsible for pipe to riser, they still would have to calculate a sufficient modification to a system (as in: not a 1:1 relocate or a reduction in hazard or demand.)

As per NFPA 13 (2016) 8.15.20.5 there are very specific rules demanding hydraulic calculations for sprinkler system modifications. Basically if they added heads (went beyond 1:1 relocate) or did multiple heads off outlets, or changed the design in another sufficient manner (use of Flexheads) as the AHJ, you are in your rights to say "I want you to prove the system can work hydraulically."

And then they'll need a flow test to calculate the system by. If their contract does not have a provision to provide/facilitate a flow test and provide calculations, they need to charge their client an extra. But that's nothing to do with the AHJ.

Alex

8/10/2023 07:33:09 am

When you replace or relocate sprinklers, you must provide hydraulic calculations to demonstrate adequate flow and pressure. To conduct these calculations, water data is essential. Moreover, if you are fed directly from the municipal supply, you need water data from within the past year.

The building code specifies the respective scope area, contingent on the level of alteration. However, this still necessitates the contractor to provide calculations proving that the renovation doesn't affect system performance.

The scope area shields the contractor from having to address code violations outside of the specific project's parameters.

Jesse

8/10/2023 08:11:09 am

This is a really good question, and should be a good discussion.

In my state (Texas), the person signing the plans is the license holder. For system modifications, they are attesting that not only the modifications meet code, but the remainder of system still does as well.

In some of our AHJs, they require hydraulically calculating the system. Even when it doesn't, sometimes I require it because ultimately I'm signing it.

I think every answer may be different depending upon the state.

Daniel LeFave

8/10/2023 08:17:58 am

As a contractor, we always specify in our scope of work that we start at a flange above floor and furthermore specify what we intend to provide for our services. This does not limit us to new hydraulic calculations and often we perform a new hydrant flow test or water data has been provided to us along with the new/updated design criteria by the engineer of record. For example, we recently had a warehouse job and the GC limited us to the office scope only as there was an existing system in the warehouse, but the occupancy was changing. The AHJ requested that calculations be performed in the warehouse to the new system demand requirement and after a bunch of back and forth it was decided this was a requirement for TCO and we were contracted to calc the system. It seems that most GC's and owners only care about drywall going up until TCO time comes around and then they remember about the life safety systems.

Dan Wilder

8/10/2023 08:54:20 am

First, what provisions are adopted within the IFC, specifically Section 105.6 for required permits? Then, referencing 106.2.2 for the requirements of Shop Drawings per Chapter 9.

901.2 for Construction Document requirements and your rights as an AHJ as to what is expected.

NFPA 13-22' Chapter 30 for Existing System Modifications has a decent breakdown for allowances & requirements.

Do you have anything within your adopted fire code or within the fire prevention department as to specific policies/procedures/checklists that would require this? At least have some justification so that I as a contractor can go back to the owner and have backup for the additional costs being incurred.

As to the described work.

Sprinkler change out - While not the place I would setup a stoppage for, due to NFPA 25's requirements for replacement and assuming that the sprinkler change out is like for like (K-Factor specifically). While this part may trigger a plan review for scope of area or at a minimum a scheduled inspection for compliance review, requiring hydraulics based on this alone seems excessive when there are no other changes.

Pipe change out - Again, if this is like for like due to something like leaks (pipe schedule and size of pipe), in itself not a hydraulic triggering event.

Now, put both together and review if the property has undergone any occupancy changes or renovations, that would be the trigger for plan review at a minimum, but this is still grey as to a hydraulics review for just those two items.

Other items like occupancy changes or unpermitted remodels (like the new office mezz area in the corner of the warehouse), a known water supply degradation in the area, NFPA 25 inspection reports indicating main drain test degradation, anything high piled storage related, any addition of valves (backflow), any addition of flex hoses... would justify a hydraulic review.

One of my AHJ's adopted changes that trigger plan review for reference:

903.3.10 Remodel. Fire sprinkler design drawings shall be required for tenant improvement or remodeling projects when 10 or more sprinkler heads are relocated and/or added.
Exception. Group F, H, I, and S or as required by the fire official

Another has a "Quick Permit" for various smaller items like modifications under 20 sprinklers but there is a provision that the inspector can ask for a full plan review upon inspection.

Glenn Berger

8/10/2023 09:09:06 am

To your original question - Does your jurisdiction is construction permits and certificate of occupancies?

If yes then stick to your guns and be prepared to act like (and be treated like) a specific body part.

The sprinkler contractor may have a limited scope (as stated above), but someone else owns the greater scope. Someone needs to held accountable for code compliance.

SCHULMAN

8/10/2023 09:22:24 am

Lots of good info in the responses already.
Yes, you can require a new flow test and calcs. You are the AHJ ...
Unless this is design-build scenario or the contractor is the lead, It's generally not the contractor's problem if the project scope didn't include it. The owner and the consulting firm housing the FP Designer should have asked you pre-permit if you were going to require it and the money would be in place. That's on them. Designers - ALWAYS contact your AHJ during design !...

Here's what I didn't hear above that I think should always be considered - in some areas development is rampant, and flows are impacted by additional mouths to feed on the system... Unless the area has zero new buildings, i would definitely require new flows/calcs. My 2 cents.

Eric R

8/10/2023 11:43:26 am

To add to the discussion, what happens (or should happen) when the contractor does get a new flow test, performs hydraulic calculations for the scope of their work (which can be easily modified if need be within the scope of work), applies for a permit showing their work has the required water supply, but the flow test shows that the water supply has degraded below what was required for the original system design per the hydraulic placard?

This kind of veers into NFPA-25 territory and the lack of clarity on if/when sprinkler systems on municipal water should have their water supply validated. Having the requirement to flow-test the water supply of an existing sprinkler system "hidden" away in the private service main chapter of NFPA-25 causes many contractors and AHJs to not realize that it is required at all. If the private service main feeding the sprinkler system is getting flow tested every 5 years then should this test data be acceptable to use for the hydraulic calc?

Then there is also the question that if a system does have a hydraulic placard, can the contractor just prove that their scope of work does not create a greater hydraulic demand than the currently posted one and avoid the need to get a flow test at all? In this case how does the AHJ confirm that the hydraulic placard has accurately recorded the design data of the original system? Without the original set of hydraulic worksheets I would personally be very leery of accepting a system modification based on just the placard since they are so frequently filled out incorrectly.

Pete H

8/10/2023 02:03:51 pm

IMO (so take with grain of salt):

The contracted work will still work and has been proven by calculation. That is still approved. However an AHJ (typically a fire marshal) that is aware the water supply has degraded to a point the previously approved and installed system will no longer work needs to either inform the property owner that they're responsible for another renovation to get the system up to/prove the system still works according to current code and they must get started on scheduling that work. And then if the work does not seem like it's moving forward after a year (the speed of bureaucracy), penalize them accordingly.

The flow test from a 5 year inspection, if on the water source that supplies the system, should be able to be duplicated and used for a hydraulic calculation. But it has to be duplicated, you can't just say "refer to inspection report." You still have to give a separate copy of the flow test results in your working plan submission that has nothing to do with the 5 year inspection. Once again, for bureaucracy. But you should be able to use that source information on your calc if it is at the correct point of the incoming service to be applied to this calculation.

Yes, they can prove their demand is less than the hydraulic placard on the existing system. This even can be done if they're working on a system that just happens to be of a significantly lesser hazard and demand than the existing.

Like you have a K28 gridded ESFR system protecting the storage facility at the roof of a near 40'-0" building.

If you tap off that main to feed two 5.6k heads in < 100 sq. ft. bathrooms and offices with less than 10'-0" ceiling height and these rooms are even closer to the source than the existing remote area.... you don't need to calculate that. This system can obviously handle that additional demand at a separate elevation.

How to Address Water Supply w/ Replacements?

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