I have a project where there are multiple cloud ceilings with minimal gaps in-between. The clouds are 3'-6" wide, and the gaps between them are approximately 3-inches. Below is an image of the reflected ceiling plan. Are sprinklers required below these cloud ceilings? Thanks in advance.
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13 Comments
Dan Wilder
11/5/2020 07:35:03 am
Referencing 9.2.7 of the 13'-19 ed.
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Rosstan Snow
11/5/2020 10:40:32 am
Does this percentage differ between the 13-13' and 13-19' edition. Has the section been revised? This jurisdiction is under 13-13'
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Franck
11/5/2020 11:56:23 am
For your information, requirements for cloud ceilings have been added to the 2016 edition of NFPA 13 following a Fire Protection Research Foundation (FPRF) project studying the behavior of heat and smoke.
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Franck
11/5/2020 12:33:07 pm
In addition to my above comment, note that if sprinklers could be omitted above the could ceiling, then the position of sprinklers below the cloud ceiling should be based on table 9.2.7.1, which give a maximum coverage area per sprinkler, depending on the width dimension of the clouds and the opening width compared to ceiling height.
On the Clock
11/5/2020 02:03:01 pm
Thanks, Franck. Am I understanding you correctly that once it is determined that sprinklers are required BELOW the cloud array, then normal sprinkler spacing below the ceiling would apply? One does not need to make sure the gap between clouds will not "stop" the heat from jumping one cloud to the next? Would it be prudent to follow the same maximum gap-width formula for omitting sprinklers above the ceiling (A9.2.7.1) when placing sprinklers in say, every third or fourth cloud, skipping the clouds in-between?
Franck
11/5/2020 02:40:18 pm
Just matter of interpretation and whether you want to be conservative or not.
Franck
11/5/2020 02:41:30 pm
Sorry for being sometimes so late to answer... but I am living in France, with time difference :)
On the Clock
11/6/2020 10:48:34 am
Thank you for you time, expertise, and perspective, Franck - Have a good evening!
On the Clock
11/5/2020 10:47:39 am
I’m following this, as I am running into variations of this all the time. I feel NFPA #13 concentrates more on whether or not sprinklers are required above, but is lacking in what is required for protection below, unless extrapolating from similar sections. I often encounter several smaller clouds that individually, would not require sprinklers below, but if several are arranged side-by side, with only a small gap in-between, does this constitute one large obstruction based on ceiling height and width of gap, kind of applying in reverse the allowable gap with of 8.15.24.1(1) (2016) (A9.2.7.1(1) (2019)? And what if each cloud would individually require sprinklers, would several side-by-side require a sprinkler in each cloud, or could you utilize maximum sprinkler spacing and skip clouds based on the paragraphs mentioned above? ID the gap is no more than 6-inches, can you center a pendent sprinkler with shield in the gap itself if complying with the 3-inch rule of 8.5.5.3.1.2 (2016) and 9.5.5.3.1.2 (2019)? As in the original post, I’m running into this with ceiling cloud arrays and sound reflectors in performing arts centers.
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Franck
11/5/2020 12:20:44 pm
This is a difficult question and the answer, as very often, is... it depends
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Franck
11/5/2020 12:00:33 pm
Note that in the MeyerFire tool kit, you have an interesting Cloud Ceiling Calculator
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Rosstan Snow
11/5/2020 03:54:11 pm
It does but for this application its impossible to determine given the various opening between clouds, the wall...etc. There is no doubt protection below is required based on condensed spacing. Overhead protection is a given. If the edge to edge spacing of the clouds were 6" or more, then it would interesting to see what sum the calculator would advise. Nevertheless; everyone's feedback has been impeccable. In Houston, the adopted code is still 2010 NFPA 13; Harris County is 2013 NFPA 13. Very few jurisdictios have adopted 2016 much less 2019. However, I have submitted a variance in code between 2013 and 2016 and Harris County accepts certain design approaches based on the newest code. Houston? Not a chance
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Franck
11/6/2020 01:11:57 am
My life is easier :) Leave a Reply. |
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