I found the reference I was thinking of in the Appendix to FM DS 2-0. All the definitions are in the Appendix.
Vertical Distance: Vertical distance is measured perpendicular to the floor, between the centerline of the sprinkler's thermal element to the uppermost portion of the underside of the ceiling. This vertical distance can be measured to the underside of the lowermost portion of the ceiling when this section of the ceiling is flat, smooth, and at least 3 in. (75 mm) wide in its least dimension, as well as at least twice as wide as the vertical distance between the uppermost and lowermost ceilings. In addition, the horizontal gap between lowermost ceiling sections (i.e., the width of the flute area) cannot be more than 3 in. (75 mm) wide. This definition covers metal deck but does not have the word "metal deck" in it. I did a search for "metal deck" initially and came up with nothing. So, depending on how the metal deck is shaped, and they come in all sizes, you can very well be measuring from the top of the deck on an FM job. John Hoffman -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of G. Tim Stone Sent: Thursday, March 13, 2014 2:18 PM To: [email protected] Subject: RE: Warehouse Ceiling Question? John, I found a definition in FM data Sheet 2-0, 2.2.3.4.2 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 [email protected] > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > John F > Hoffman > Sent: Thursday, March 13, 2014 3:02 PM > To: [email protected] > Subject: RE: Warehouse Ceiling Question? > > I am not seeing anything in NFPA 13 that says this. Maybe just > missing it, > but the definition of ceiling height (2013 edition) is 3.3.3. and > just mentions "to the underside of the ceiling or roof deck". > > If you look at one mfrs spec sheet for k25 ESFR here is what it says. > > NFPA 13 Deflector-to-Ceiling > Distance > 6 to 18 inches (152 to 457 mm) > FM 2-0 > Consult FM and/or FM Guidelines for allowable deflector-to-ceiling > distances as well as thermal sensing element-to-ceiling criteria. > > Note that FM uses the centerline of the thermal sensing element and > NOT the > deflector. Plus they talk about (somewhere) the width, and maybe the > height of the metal deck pockets and give criteria of where to measure from > - top or bottom. > > John Hoffman > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > Bob > Sent: Thursday, March 13, 2014 1:40 PM > To: [email protected] > Subject: RE: Warehouse Ceiling Question? > > I think 13 addresses this with 3" and less deep the bottom is the > deck, if greater than 3" than the upper part of the channel is the > deck. Sorry I don't have time to look up code, but you might want to check > my numbers. > > Thank You, > > Bob Knight, CET III > 208-318-3057 > www.Firebyknight.com > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of G. Tim > Stone > Sent: Thursday, March 13, 2014 12:32 PM > To: [email protected] > Subject: Warehouse Ceiling Question? > > What is the Ceiling in a Warehouse? > > > > Scenario: > > Packaged Steel Frame Building. Red iron frames spaced 30' between. 12" > steel Z shaped purlins, spaced 3'-7" on center on top of the Red Iron > frames. > Steel Q-Deck pan (about 3.5" - 4" deep) attached to top of the Z purlins. > > High point of the building is 30'-0" AFF, ΒΌ : 12 roof pitch. The > building insulation is on top of the Q-Deck. No vinyl insulated > blanket that we usually see in warehouse construction. > > > > The occupancy is Group A Plastics, High Piled and rack storage, > Storage height to 17'-0 AFF, ESFR Pendent Sprinklers, Depending on > Manufacture used, deflectors can be up to 18" down below "CEILING". > > > > Is the "CEILING" at the point where the Q-Deck that rests on top of > the purlin or is it the top of the pocket formed in the Q-Deck? I will > rephrase, Is the "CEILING" at the top of the purlin or 3.5" - 4" > higher (high point of Q-Decking)? > > > > Thank you in advance for clarification. > > > > 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 > > [email protected] > > > > _______________________________________________ > 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 > _______________________________________________ > 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 _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
