Thank you, Jim! Must have misread the post. These are unexpanded plastics (rolled plastic sheeting).
Micah Davis Principal Phone1: (904) 800-6782 Phone2: (931) 242-1299 4373 Sycamore Pass Ct W Jacksonville, FL 32258 -----Original Message----- From: Sprinklerforum <[email protected]> On Behalf Of Jim Davidson via Sprinklerforum Sent: Thursday, April 29, 2021 11:23 AM To: [email protected] Cc: Jim Davidson <[email protected]> Subject: RE: Exposed unexpanded Group A plastic storage Micah, As per NFPA 13 (2013 edition) 17.1.2 Special Protection Criteria refers you to Figure 17.1.2.1. (See Section C.21). Figure 17.1.2.lstates that Group A -Exposed -Expanded is outside the scope of Chapter 17. Per NFPA 13 - 2013 Edition Appendix comment -"A.17.1.2.1 All arrangements of exposed plastics cannot be protected with all types of sprinklers. Only certain combinations of ceiling sprinklers and in rack sprinklers have been found to provide acceptable protection. No full-scale fire testing has been performed that has determined acceptable criteria for exposed expanded plastics. Factory Mutual has published criteria in its data sheets to protect exposed expanded plastics based on a risk analysis and small/intermediate-scale test data. Some authorities having jurisdiction accept that criteria as an alternative to the intent of NFPA 13." The specific section of FM Data Sheet 8-9 is Design Scheme 8-9A is on page 47 of FM data sheet 8-9 interim revision January 2020. This design scheme permits the protection of exposed expanded foam stored in racks - with in-rack sprinklers and horizontal barriers without having to increase ceiling level sprinkler densities or having to balance with ceiling system, in addition you only have to supply water to the most demanding of either the ceiling system or in-rack sprinklers only, not both. Hope this helps. Jim Davidson -----Original Message----- From: Sprinklerforum <[email protected]> On Behalf Of Micah Davis via Sprinklerforum Sent: Thursday, April 29, 2021 10:39 AM To: SprinklerForum <[email protected]> Cc: Micah Davis <[email protected]> Subject: Exposed unexpanded Group A plastic storage I have a warehouse that will store some exposed unexpanded Group A plastic (sheet plastic in rolls). The rest of the storage will be Class III commodities. All stored on racks. Building height is 35 ft and with racks up to 25 ft. NFPA 13 - 17.2.1.3 states, "For storage of Group A plastics between 5 ft and 12 ft in height, the installation requirements for extra hazard systems shall apply." We have the ability in this case to stipulate that the plastic storage be limited to 12 ft or less in height (I understand all of the human behavior questions that arise about warehouse workers actually abiding by this). My question is, does 17.2.1.3 give instruction only for installation guidance (sprinkler spacing, obstructions, etc.) or does this allow me to use AT LEAST extra hazard design criteria for protection of the low-piled plastic? Specifically, if the plastic is limited to 12 ft, could the rest of the warehouse be protected with a protection scheme adequate for the Class III comm odities and if that scheme exceeds the demands of extra hazard densities, the plastic is considered protected? My gut is that the section refers only to installation procedures and I am stuck with the requirements of 17.2.1.4, 17.2.2, or 17.2.3 for design criteria even is the plastic storage is limited to 12 ft. Thank you, Micah Davis Dynamic Fire Designs, LLC _______________________________________________ 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
