It's called 'AHJ wiggle room'. Hopefully you haven't pi$$ed yours off in the past.
:) b ;) c :) On Apr 28, 2016 4:35 PM, <[email protected]> wrote: > 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
