Well, now with the definition seems one could say the light example is permitted. A (singular) light that only obstructs a (singular) head would not be a continuous obstruction under the definition of 3.3.18.1. It would be hard to argue the annex 'definition' takes precedence.
Don't get me wrong. It's an obstruction. I'm only speaking to the language of the code. I suppose you can always go back to the beam rule 8.6.5.1.2 with it not dependent on continuous obstructions. Beam rule could be shaky due to the annex. See if 'it is effectively a continuous obstruction as far as the sprinkler is concerned and the Beam Rule should be applied' but by definition it's not a continuous obstruction so the annex isn't directing you to the beam rule. FWIW IMHO seems like it was more clearerer without the definition. Chris Cahill, PE* Senior Fire Protection Engineer Burns & McDonnell 8201 Norman Center Drive Bloomington, MN 55437 Phone: 952.656.3652 Fax: 952.229.2923 [email protected] www.burnsmcd.com Proud to be one of FORTUNE's 100 Best Companies to Work For *Registered in: MN -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Roland Huggins Sent: Tuesday, October 01, 2013 4:44 PM To: [email protected] Subject: Re: Continuous Obstruction IT was added due to architects placing an individual light beneath each sprinkler and single the lights were not connected, they thought it was kosher. The same could be said for a run of 2X4 lights fixtures with every other one missing. This is still effectively a continuous obstruction. Roland Huggins, PE - VP Engineering American Fire Sprinkler Assn. --- Fire Sprinklers Saves Lives Dallas, TX http://www.firesprinkler.org On Oct 1, 2013, at 1:22 PM, "Cahill, Christopher" <[email protected]> wrote: > It's also defined, well sort of in the Annex, in '13 A8.6.5.2.1.4. ... If an > obstruction is so close to a sprinkler that water cannot spray on both sides, > it is effectively a continuous obstruction as far as the sprinkler is > concerned and the Beam Rule should be applied....this has been around for > many editions. I'd also point out the section 8.6.5.2 applies to both > continuous and non-continuous obstructions thus why the point in the annex > becomes relevant. I have seen folks use the 3 times rule to argue there are > allowable shadow areas and translate that to whatever situation they are > dealing with. IOW when is a head so close to a sprinkler that water cannot > spray on both sides, well when it affects more than the allowable floor area > already allowed by the 3 times rule. > > And it is different than the new definition 3.3.18.1 Continuous Obstruction. > An obstruction located at or below the level of sprinkler deflectors that > affect the discharge pattern of two or more adjacent sprinklers. > > Is effectively continuous the same continuous? > > So, it is an obstruction that affects at least two sprinklers or at least one > sprinkler. Seems rather clear to me, lol. > > Chris Cahill, PE* > Senior Fire Protection Engineer > Burns & McDonnell > 8201 Norman Center Drive > Bloomington, MN 55437 > Phone: 952.656.3652 > Fax: 952.229.2923 > [email protected] > www.burnsmcd.com > > Proud to be one of FORTUNE's 100 Best Companies to Work For > *Registered in: MN > > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Tuesday, October 01, 2013 3:05 PM > To: [email protected] > Subject: Re: Continuous Obstruction > > It is defined. See 3.3 18. in the 2013 edition. > > John Hoffman P.E. | Fire Protection Engineer | Facility Engineering > Services, KCP, LLC - Burns & McDonnell Engineering | National Nuclear > Security Administration's Kansas City Plant | Operated by Honeywell > FM&T | > 2000 E. 95th St | Kansas City, MO 64131 | ph 816-997-7213 | > [email protected] > > > > From: "G. Tim Stone" <[email protected]> > To: <[email protected]> > Date: 10/01/2013 02:58 PM > Subject: Continuous Obstruction > Sent by: [email protected] > > > > Can someone please provide me a definition for the term "Continuous > Obstruction" as referenced in NFPA 13, 13D or 13R. > > I wonder why this is not defined in NFPA 13, Chapter 3. > > Are round semispherical surface mounted light fixtures (found in residential > dwelling units) considered such? > > > > Thank you in advance. > > > > > > Regards, > > G. Tim Stone > > > > G. Tim Stone Consulting, LLC > > NICET Level III Engineering Technician > > Fire Protection Sprinkler Design > > and Consulting Services > > > > 117 Old Stage Rd. - Essex Jct., VT. 05452 > > CELL: (802) 373-0638 TEL: (802) 434-2968 Fax: (802) 434-4343 > > <mailto:[email protected]> > [email protected] > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.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
