The conservative answer is put sprinklers beneath the ceiling fixtures BUT:
I wouldn’t apply the gridded ceiling criteria here since that is a sub ceiling that covers the entire plane (beneath the sprinklers) and consists of rather small opening. If anything, I’d look at it like a cluster of obstructions to determine whether to combine them in defining the overall width. This is only found in the ESFR section (which is much more conservative than the CMDA approach required not just for the performance issue but the fact that the fire challenge is much greater than a LH or OH scenario) Keep in mind that the primary goal is to control the upper temperature so as to avoid flashover. We are talking LH or OH - right? Granted the water pattern to the floor is going to be whacked (well for the areas with a 7” spacing) but will the ceiling features interfere with controlling flashover? Another question is, will the sprinkler beneath the features even activate (except when the fire is directly beneath it)? I don’t think the simple conservative approach is accomplishing anything except providing a warm fuzzy but it does allow the job to move forward. So until NFPA 13 addresses it (NEXT CYCLE), discuss it with the AHJ BEFORE submitting your plans Tom, since we don’t want you talking to yourself, feel free to call me. Roland Roland Huggins, PE - Senior VP Engineering American Fire Sprinkler Assn. Dallas, TX http://www.firesprinkler.org <http://www.firesprinkler.org/> Fire Sprinklers Saves Lives > On Jul 25, 2017, at 11:04 AM, Thomas Reinhardt <[email protected]> > wrote: > > Question. The general has informed me that they want to put in a tartan wood > ceiling at various spots. The wood slats are 1’-6” deep and just 2” wide, > but are spaced at various dimensions- some as wide as 3’ apart-some as close > as 7”. The with uprights will be at least 2’-4” above the top of wood. If > they have to protect underneath would mean dropping pendants between wood > slats with the deflector 1”-6” below the bottom of the wood. This could be > quite an installation problem. NFPA 13 section 8.15.14 relates as long as > ceiling is 70% open and the depth of the material does not exceed the least > dimension of the opening, below protection is not required. Well the open > ceiling is 72% open. Unfortunately the depth of the material does exceed the > least dimension of the opening. I believe that below protection is required. > Thus meeting the code. Sorry so long any input would be greatly appreciated. > Thanks > Tom Reinhardt > Fire Inspector/Plan Reviewer > Skokie Fire Department > 7424 Niles Center Road > Skokie, IL 60077 > Office: 847-982-5342 > [email protected] <mailto:[email protected]> > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > <mailto:[email protected]> > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > <http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org>
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