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)
