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A locker room (1050 ft²) in apartment building is divided into small storage compartments. No shelves, no lifting devices. The ceiling height is 9’.
The sprinkler system design criteria was chosen as OH II, which is adequate for miscellaneous storage of Class IV Commodities up 12 feet in height as well as Plastic up to 5 feet. Now the AHJ is requesting either design of plastic protection up 8 feet saying that some plastic may be stored - therefore we have to treat this as storage of mixed commodities - therefore it shall be protected by the requirements of highest classified commodity, or provide assurance that no plastic will be stored. Will “mixed commodities” be applicable for miscellaneous storage? Or do we not have any grounds for argument? Posted anonymously by a member for discussion. Discuss this | Subscribe
3 Comments
PETE
1/28/2019 01:15:52 pm
In order to qualify as "miscellaneous" it has to fit the definition per 2016 NFPA 13 §3.9.1.18. Fret not, per §5.6.4.1.1.1 the commodity has to be 25% by volume Group A plastic to be considered exposed or 40% by volume GAP and cartoned to be considered cartoned. The older versions of NFPA 13 direct you back to the miscellaneous storage table for storage up to 12 feet. The new version has you go to the density table in Chapter 14 and define the commodity as Class I,II,III, or IV. I think it is OK to classify as a OHG2, seeing how that covers textile manufacturing and the lockers will contain textiles. Using that table (14.2.4.3) for Class IV you get 0.30 gpm.sqft X 3000 sqft. In your case you are limited by the size of the locker room. Then taking a 60% reduction for ceiling height, you are taken down to 0.18 gpm/ sqft X 1050 sqft. That will give a total of 439 gpm, including a 250 gpm hose stream allowance. If the AHJ forced you down that road it wouldn't be much different than OHG2.
PETE
1/28/2019 01:17:14 pm
I would first make the argument that the storage will likely be below 25% by volume plastic, and therefore not plastic.
WES
1/28/2019 02:55:21 pm
Well said! Leave a Reply. |
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