NFPA 13 2016 edition - shadow 3

[Derik Brooks]

I just got a call from a forman who just failed an inspection because of a small shadow area in a bathroom in a residential unit. I know NFPA 13 does not allow "shadow areas" like 13r or 13d but was hoping somebody could point me in the right direction to allow a small shadow. Please see the pictures and let me know your thoughts!

 

[skdesigner]

NFPA 13-2016 A8.1.1(3) and Figure A8.1.1(3)(b) is probably the closest you'll get to a firm answer. Unfortunately, it doesn't quantify the maximum permitted shadowed area like 13R does, so you are more or less at the mercy of the inspector in this situation.

 

[cdafd]

Where does nine feet place the sprinkler??

How close to the wing wall

 

[cdafd]

One thought

https://www.nfpa.org/News-and-Resea...l/2015/July-August-2015/In-Compliance/NFPA-13

 

[cdafd]

One more

https://sprinklerage.com/step-into-the-shadows/

 

[cdafd]

From one of the masters

https://m.youtube.com/watch?v=z8q8ajQ27WQ

 

[TravisMack]

NFPA 13 does allow shadow. It just doesn't quantify it which can be a challenge. I have shown a sprinkler at the max distance from a wall. Let's say 7'-6" off two walls in this residential bathroom. Now, show a 12"x12" column the proper distance away based on the 3x rule (or 4x if using residential sprinklers). Also, if using residential, you may be able to space further off the wall.

Now, draw that shadow area that the column creates and quantify it. You can easily show that NFPA 13 would permit that amount of shadow without any question. I have been successful with that in the past.

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

http://www.mfpdesign.com