Use of Baffles with ESFR sprinklers 1

[stookeyfpe]

I'm reviewing automatic sprinkler shop drawings for a warehouse tenant finishout. The building will also house some light manufacturing and offices, which have been separated from the warehouse using noncombustible demising walls that terminate at the roof deck. I observed something during the plan review and that is the use of baffles in cases where the dimension from the centerline of the sprinkler deflector and adjacent sprinklers is reduced to < 6 feet. The installed sprinklers are Reliable J17 pendent (SIN = RA1914) sprinklers with a 16.8 K-factor. See the attachment. The shop drawings don't indicate the ceiling height but my memory tells me the building height > 32 but < 40 feet.

The basis of design is NFPA 13 (2016 edition) and 2015 IFC. In reviewing NFPA 13, I found that the use of baffles is limited to CMDA sprinkler designs. The baffle provisions are not offered in Sections 8.11 or 8.12 for CMSA and ESFR sprinklers, respectively.

My question is this allowed. When I review the obstruction rules in Section 8.12 for ESFR sprinklers, it appears the designer is applying Section 8.12.5.1.2. This seems reasonable to me based on Annex A 8.12.5.

I've never seen this used before and it appears that it's compliant but before I end up throwing a pie in my face I'm requesting your opinions as to if this is a compliant option.

Thank you.

 

[TravisMack]

NO NO NO!!! Location has meaning. ESFR sprinklers shall not be located <8' on center. There has been a lot of questions on this and informal interpretations from AFSA that this is NOT an allowed arrangement. There is no provision in 8.12 for baffles.

The way to correct this is to adjust the spacing of potentially several sprinklers along the line to keep the proper spacing. The contractor won't like it because they may have to drill / plug several outlets to fall back into compliance with ESFR spacing.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, LLC

http://www.mfpdesign.com

 

[stookeyfpe]

That's what I was afraid of. I didn't connect the dots completely. I now realize why NFPA 13 Section 8.12.3.4 is an absolute minimum. It makes sense given the sprinkler sensitivity and how the design area is calculated.

What makes this worse is the commodity is an Exposed Unexpanded Group A plastic. It's the same commodity I investigated about 10 years ago that destroyed a warehouse in North Texas without ESFR sprinklers.

 

[TravisMack]

Yes sir. I was being somewhat overly expressive in my response. But, there has been a lot of discussion on this topic over the years on how there is nothing in 8.12 for the use of baffles.

The sprinkler contractor will likely be quite upset when they get your review back. I have had to move as many as 7 sprinklers on a branch line in order to get spacing correct and be sure to miss the obstructions. Often the bar joists are the culprit when trying to correct the spacing. Let's say that wall affects 10 branch lines, that could be 70 sprinklers that they had no intent of moving. So, it gets really ugly and an expensive lesson to learn.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, LLC

http://www.mfpdesign.com

 

[stookeyfpe]

Let's say that wall affects 10 branch lines, that could be 70 sprinklers that they had no intent of moving.

Probably closer to 150 sprinklers in this case. The owner and architect are now calling. To further complicate this is a 6,800 sq. ft. office that's part of the plan review and they want to move in this weekend. The problem is the office is part of the warehouse shop drawing submittal and without this issue being resolved, I can't approve the plans, which means no inspections. I'm fairly sure someone will call City Hall, who will talk to the Assistant City Manager for Public Safety, who then calls the Fire Chief, who then calls the Fire Marshal, who then calls the Supervising Engineer, who then ask what the heck is going on and why are we being called. Just another day that ends in "y."

 

[TravisMack]

Yes sir. It all comes down to some one didn't follow the standards, or know how to apply them correctly. The architect / builder likely didn't get the sprinkler guy involved early enough to address this issue. But somehow it is your fault for actually wanting a system that is in compliance with the standards.

Just another day that ends in "y".

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, LLC

http://www.mfpdesign.com