Thank you Larry! That is exactly one of those "you missed this blurb's" I was looking for.
Thanks, Sean VG -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Larry Keeping Sent: Thursday, April 28, 2016 3:03 PM To: [email protected] Subject: RE: NFPA 13 (2013) 8.6.4.1.2(5) - why the 3ft minimum? It may be of help if you reference the 2016 edition of NFPA 13. There, in Section 8.6.4.1.2(5) the 3 ft limit has been deleted. The Committee Statement for that revision was that concrete tees are capable of withstanding the heat long enough for sprinklers to activate even when the tees are closer than 3 feet on centers. Larry Keeping -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of [email protected] Sent: April-28-16 5:35 PM To: [email protected] Subject: NFPA 13 (2013) 8.6.4.1.2(5) - why the 3ft minimum? Forum, We have concrete tee construction. Bottom of stems measured from the ceiling is 26" down. Centerline of stems are spaced apart in an every other fashion of 7', 2'8", 7', 2'8", etc. Ideally we would like to use NFPA 13 (2013) 8.6.4.1.2(5) to protect the area so we don't have to add additional sprinklers/piping. However it states this is only applicable for 3ft to 7.5ft stem spacing. Can someone tell me the purpose behind the 3ft minimum threshold? Even though we have some 2'8" sections, do you believe the intent of this code was for my situation? Or do you believe the intent is for concrete tee construction where every stem is 3ft or less? I can see people interpreting this passage either way as all stems are spaced away from another stem more than 3ft, yet all stems are spaced away from another stem less than 3ft. To me, it seems ridiculous that I can have stems with any depth (let's say 10ft) and spaced 3'1" apart and the deflector can be located 1" below the bottom of the stem (10'1") and branchlines can be spaced 15ft apart. Yet if the same depth stems are spaced 2'11" apart the deflector can't be lower than 22" below the ceiling and because they are now obstructed, they have to be in every pocket. I appreciate anyone's opinion on my situation and/or knowledge/history of this codes development. Note: As I allude to, I know there are other ways to design this system utilizing 22" and beam rule. I am more looking for the "Why's" or the "You missed this blurb" that agrees with your stance . Thanks, Sean VG _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
