Just thinking out loud: Maybe it won't matter if you are too close to the other sprinklers. If one head goes off, will it essentially be covering the same floor area as the head it may be cold-soldering? Or at least much of the same floor area? Maybe 'head skipping' won't be that big of a problem here....?
Mark A. Sornsin, PE Fire Protection Engineer Ulteig Engineers, Inc. Fargo, ND 701.280.8591 [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Todd Williams - FPDC Sent: Friday, May 23, 2008 4:02 PM To: [email protected] Subject: RE: steep pitch roofs The problem (yet another) is that out here, running any tests is out of the question. We really are not going to know what happens until you build a mock-up and flow water. There is neither the time nor money for that. Everything out here is design/build, whether it should be or not. Most are not thought out well before the contractors are brought in. There are several contractors out here are fitters that could really give a rats butt about engineering or whether it would work in a fire, just that it goes in and gets approved by the AHJ. Technical correctness is a constant battle, which quite honestly, I am sick of. The design area encompasses 34 sprinklers; the horizontal projection of each sprinkler in the pitched area is 52 sqft. What this would actually do in a fire, I'm really can't visualize. The pipe sizes are large and there is going to be a bunch or water dumped, but I have no idea what it would look like. At least it is a wet system. As to why this wasn't addressed in the bidding phase, see above. I hope I have not offended anyone and if I have I apologize. However, the people here are here because they are interested in doing things correctly, which I for one greatly appreciate. This is one of the three things I have to get resolved this weekend. Everybody have a good one. Todd At 04:19 PM 5/23/2008, you wrote: >I don't think you are over thinking it. You have a problem in my opinion as >best as I understand your description. For at least this purpose I think >you measure horizontally. How is this much different than adjacent heads on >different branch line in a purely flat roof. For what it's worth UL199 >tests 6' OC in the same horizontal plane. They light a small fire under one >head with the link in it and open the other head. If the head with the fire >operates it passes. If the fire burns out and the head doesn't operate it >fails. At least that's how I remember it the last time I read it some 6+ >years ago. At 28/12 I'd even question how the pattern is skewed and what is >it really doing. And remember the first head operates at more than 7. If >the first head wets the second all bets are off. > >Here's an idea get with the contractor at his shop and mock up the heads the >way they will be installed and run some water. Ain't scientific but gives >you a clue on the issues. I'd offer but you are 1000 miles away. Get a >pipe thread x hose thread, hook it up to the hose and have kids play with a >head in it. Watch the way the pattern changes as they put it in a variety >of orientations. All from the deck with a beer in hand. > >BTW how did it get this far without having a solution? Sounds like at the >bid stage someone should have figured this out. > >Chris Cahill, P.E. >Fire Protection Engineer >Sentry Fire Protection, Inc. > >763-658-4483 >763-658-4921 fax > >Email: [EMAIL PROTECTED] > >Mail: P.O. Box 69 > Waverly, MN 55390 > >Location: 4439 Hwy 12 SW > Waverly, MN 55390 > >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of Todd Williams >- FPDC >Sent: Friday, May 23, 2008 2:40 PM >To: [email protected] >Subject: RE: steep pitch roofs > >Here is the quandary. Figure 8.6.4.1.3.1(b) defines S as the distance >along the slope over the peak. Section 8.6.3.4.1 says sprinklers >shall not be spaced less that 6 ft. It does not define how the 6 ft >shall be defined. If you follow the slope, it would be OK, but if it >is in a horizontal line, it wouldn't. The argument could be made that >I am meeting the criteria by measuring the slope over the peak as >specified in the standard. However, will there be a potential >interference by one sprinkler on another? When sprinklers are >installed along a slope this steep and they operate at 7 psi, how >skewed is the umbrella pattern? Is it distorted enough so this is not >an issue? What's a poor engineer to do on a Friday afternoon before >an alleged holiday weekend whthis?en the contractor is screaming for >drawings and a cut list? Am I over thinking > > > >At 03:04 PM 5/23/2008, you wrote: > >Then that's very new. It was only a few months ago I last called Tyco on > >this. They absolutely say only attics. No actual occupancy below. And > >they quit at 12/12. I couldn't get the why out of them. Either they >didn't > >do parts of the UL199 test like the pans or they tried it and it didn't > >work. My bet is they tried it in their lab and something wouldn't pass the > >test like density minimums in each pan. But I speculate. > > > >We've run perpendicular to the ridge line down the truss and used sidewalls > >spraying parallel to the ridge line. But I don't think that helps you. >Do > >you have a peak line and then start the spacing down the slopes or do you > >have 2 lines at the same elevation at the high point and those are your > >problem. If so can you get a peak line in to substitute for the 2 lines. > >Probably a place where a picture does good. > > > >In a round about way I also think you expose a flaw in the UL199. They >test > >for closeness at the same elevation but in reality adjacent basic heads > >could be 11" different. Often wondered if that was a problem. And 28/12 > >certainly creates a mess. And there is no testing on slopes that I know of. > > > > > >Chris Cahill, P.E. > >Fire Protection Engineer > >Sentry Fire Protection, Inc. > > > >763-658-4483 > >763-658-4921 fax > > > >Email: [EMAIL PROTECTED] > > > >Mail: P.O. Box 69 > > Waverly, MN 55390 > > > >Location: 4439 Hwy 12 SW > > Waverly, MN 55390 > >-----Original Message----- > >From: [EMAIL PROTECTED] > >[mailto:[EMAIL PROTECTED] On Behalf Of Joe Hankins > >Sent: Friday, May 23, 2008 1:28 PM > >To: [email protected] > >Subject: Re: steep pitch roofs > > > >Could you use Attic sprinklers at the peak? They accomplish the same > >intent as sidewalls at the peak, and have actually been tested in that > >configuration. > > > >Joe > > > >Todd Williams - FPDC wrote: > > > I am working on a historic church sanctuary with a pitch of > > > approximately 28/12. The arrangement calls for branch lines to be > > > symmetrical on each side, similar to NFPA 13 (2002) figure > > > 8.6.4.1.3.1(b). I can meet the requirements for the steeply pitched > > > roof section 8.6.4.1.3.3 and my "S" distance over the peak is good, > > > but my straight line distance between sprinklers would be less than 6 > > > ft and the deflectors would be effectively pointing the discharge > > > towards the sprinkler on the opposite side. I think I have a problem > > > here, but I am not sure how to address it. Any thoughts? > > > > > > Todd G. Williams, PE > > > Fire Protection Design/Consulting > > > Stonington, Connecticut > > > www.fpdc.com > > > 860.535.2080 _______________________________________________ > > > 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 > >[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 > >[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) > >Todd G. Williams, PE >Fire Protection Design/Consulting >Stonington, Connecticut >www.fpdc.com >860.535.2080 >_______________________________________________ >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 >[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) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ 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 [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)
