Roland, I do not have the e-mails which preceeded this thread, and I don't have access to the archives.
Can you please clarify what this sentence refers to: "We have arbitrarily picked 12 inches as a maximum width until we do some modeling."? I have long (large room length, i.e. 40' to 60') drapery pockets against a glass exterior mullion with a pocket width of 12" away from the back of the mullion. The glass mullion is 9" wide. The vertical depth of the pocket below the ceiling with the drapery track is 36" or more. The length of these pockets is broken up by "draft stops" approx. every 20 feet. Would it be your opinion (I am not asking for a formal interpretation) that these narrow drapery/ceiling pockets do NOT need sprinklers? In re: the ceiling pocket rules, this requires ignoring the 36" depth rule and the 10' separation required of adjacent pockets. Thank you, Margaret Zabel Desert Fire Protection Las Vegas, NV --- On Tue, 8/26/08, Roland Huggins <[email protected]> wrote: > From: Roland Huggins <[email protected]> > Subject: Re: small ceiling pockets > To: [email protected] > Date: Tuesday, August 26, 2008, 2:35 PM > I concur with Mark (and not just because we PE's must > stick together) > > The original proposal was a 12 ft deep pocket. Considering > that is basically the height of a story, the committee felt > it appropriate to assign a lower value. I would first > approach allowing a small increase in height based on the > modeling (see out web site for a copy of the report) and the > very small volume. > > Our position has been that ceiling pockets or even openings > in a drop ceiling that are narrow and along a wall are not a > problem. We have arbitrary picked 12 inches as a maximum > width until we do some modeling. I picked this because > other than a curtain fire, the center line of the fire plume > is not directly against the wall. With it being in the > center of the fuel package, even a small chair at 2 ft wide > will be at 12 inches form the wall. AS such, a adequate > amount of the heat will be captured by the lower ceiling. > > Naturally discuss this with the AHJ since it has not yet > been addressed by the 13 committee. Additionally, as a > member of the technical committee i need to say, this is not > to be considered a formal interpretation by NFPA or any of > its technical committees. > > Roland > > On Aug 26, 2008, at 12:01 PM, Mark Sornsin wrote: > > > I am going to go out on a limb and say "No" > this should not require sprinklers within. Unfortunately, > there is nothing absolute to back me up, at least in NFPA > 13. > > > > I would argue that the ceiling jet from a fire is not > going to 'notice' such a narrow gap. Also, whatever > amount of heat manages to 'escape' into this void > space will quickly fill it, due to its miniscule volume. So > I guess I would try to use reason and note that the ceiling > pocket rules of NFPA 13 allow a volume of up to 1,000 cu. > ft. this volume is less than 10% of that. > > > > But I think the small width of the gap is the bigger > reason it won't affect the activation of the ceiling > sprinklers. > > > > Those in the know may now feel free to rip apart my > argument. > > > > Mark A. Sornsin, PE > > Fire Protection Engineer > > Ulteig Engineers, Inc. > > Fargo, ND > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email > to:[email protected] > (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
