NFPA 13 2010 Ed. Sprinkler Protection of Storage Occupancy in California

April 4th, 2011 Print This Post Print This Post

In January 2011, California adopted the 2010 Edition of the California Fire Code, along with the 2010 Edition of NFPA 13. This article will summarize the major differences between the storage chapters of the 2002 Edition (previously adopted standard) and 2010 Edition (newly adopted standard) of NFPA 13 published by the National Fire Protection Association.

While NFPA 13 committees reviewed over 850 proposals and comments in preparation for code changes to the 2010 edition, an additional 840 proposals(1) needed to be reviewed in preparation of the previous 2007 edition. Therefore, it should come as no surprise that an extra large number of code changes need to be understood by code practitioners operating in states that skipped the 2007 edition, such as the state of California.

The following sections present a summary of the major differences between the storage chapters of the 2002 and 2010 editions of NFPA 13. In addition, comments and further background information are presented to aid in the understanding of the reasoning used for the code changes.

Changes to Storage Chapters
  • Formatting Changes in the 2010 Edition of NFPA 13: The formatting of the chapters have changed dramatically for the better. While the 2002 Edition contained all storage requirements in one Chapter 12, the 2010 Edition includes 9 new chapters:
    • Chapter 12: General Requirements for Storage
    • Chapter 13: Miscellaneous Storage
    • Chapter 14: Protection of Class I-IV Commodities – Palletized, Solid Piled, Bin Boxes,
    • Shelf Storage, or Back to Back Shelf Storage
    • Chapter 15: Protection of Plastic and Rubber Commodities – Palletized,
    • Solid Piled, Bin Boxes, Shelf Storage, or Back to Back Shelf Storage
    • Chapter 16: Protection of Class I-IV Commodities – Racks
    • Chapter 17: Protection of Plastic and Rubber Commodities – Racks
    • Chapter 18: Protection of Rubber Tire Storage
    • Chapter 19: Protection of Roll Paper
    • Chapter 20: Special Designs of Storage Protection

    This new formatting allows users to easily maneuver their way through the sections they need, without getting lost in sections that do not apply.

  • Back to Back Shelf Storage: Additional definitions (Sections 3.9.2) have been added to include back to back shelf storage, as well as sections have been added in Chapters 13-15 (Table 13.2.1, Section 14.2.4.7, and Section & Table 15.2.2) to include requirements specific for Back to Back Shelf Storage. In the previously adopted editions of NFPA 13, the handbook provided guidelines stating that back to back shelf storage having an overall width of greater than 30” must be treated as racks with solid shelving. In the 2010 Edition of NFPA 13, there are very specific sections addressing the protection for back to back shelf storage including “gondolas.”

    These sections have come about as a result of the retail industry asking for alternative protections. However, application of these sections to most retail occupancies would be difficult at best, because the majority of the retail industry does store exposed plastics. For example, Table 15.2.2 is very specific to cartoned unexpanded Group A plastics, when the retail industry stores many products as uncartoned (display of plastic/picnic dishes, etc.) or cartoned expanded (products with >25% by volume of foam packaging, etc.).

    Even if the products in a retail store can be classified as Class I-IV with “limited” High Hazard/Group A Plastics (as allowed by CFC/IFC Section 2304.2), the 900 sq ft above the “limited” High Hazard/Group A Plastics areas have to be sprinkler protected, as the higher hazard (i.e. exposed unexpanded Group A or cartooned expanded Group A), which cannot be done using Section & Table 15.2.2. Additionally it is unknown as to what testing, if any, has been used for the justification of these new protection criteria.

  • CMSA Tables in the 2010 Edition of NFPA 13: The term CMSA or Control Mode Specific Application was first found in the Factory Mutual 8-9. NFPA 13, though not defined in Chapter 3, has adopted this terminology and consolidated many of the criteria that was previously listed in many hard to find section into one Table for each chapter (Tables 14.3.1, 15.3.1, 16.2.2.1, 16.3.2.1, 17.2.2.1, 17.3.2.1, 18.4[c]). It must be noted that the CMSA sprinkler protection is different from ESFR, in that it is not intended to suppress the fire, but only to control it. While this is not a new criteria, 36” clearance between the top of the storage and the sprinkler deflector is required for these types of sprinklers, as opposed to standard control mode, where only 18” clearance is required.

    One very common mistake has been to apply the CMSA in Chapter 14 & 15 to Palletized, Solid Piled, Bin Boxes, Shelf Storage, or Back to Back Shelf Storage, when the CMSA is only applicable to Palletized and Solid Piled storage (i.e. CMSA does not apply to Boxes, Shelf Storage, or Back to Back Shelf Storage). See the titles to Tables 14.3.1 and 15.3.1.

  • ESFR Tables in NFPA 13 2010 Edition: While ESFR Tables (Tables 14.4.1, 15.4.1, 16.2.3.1, 16.3.3.1, 17.2.3.1, 17.3.3.1, 18.4[d]) are not new and have been used in previous Editions of NFPA 13, the tables have been updated with new heads (i.e. new technology).

    Some of the major changes to these table include:

    1. Addition of K-22.4 ESFR Sprinklers

    2. Addition of K-16.8 Upright Sprinklers. The 2002 Edition allowed for only pendant heads.

    3. Addition of Closed Array Exposed Expanded Plastics using K-25.5 ESFR to Table 15.4.1.

        In the past one major exclusion to the use of ESFR systems was exposed expanded

        Group A plastics.

    As with CMSA, One very common mistake has been to apply the ESFR in Chapter 14 & 15 to Palletized, Solid Piled, Bin Boxes, Shelf Storage, or Back to Back Shelf Storage when the CMSA is only applicable Palletized and Solid Piled storage (i.e. CMSA does not apply to Boxes, Shelf Storage, or Back to Back Shelf Storage). See the titles to Tables 14.4.1 and 15.4.1.

  • Chapter 20 – Special Designs of Storage Protection: In the past this section (Section 12.7 of the 2002 Edition) included protection of very unique and specific products in very specific storage arrays. The section on EC-25 was added to protect products such as back to back shelf storage, gondola racks, etc. based on retail testing. With new retail testing, this section has expanded to include higher ceilings and additional storage/display arrays. This chapter also includes new protection criteria for storage of Carton Record Storage (Section 20.5) and Compact Storage (Section 20.6) and protection of High Bay Record Storage (Section 20.7).

    In addition to the specific commodity, type of shelving, heights, provided in these sections, particular attention must be given to the definitions in Section 3.9.1.3, 3.9.1.4, 3.9.1.7, and 3.9.1.8 to ensure correct applicability of the protection criteria. For example, Carton Record Storage cannot be applied to X-Ray or Fiche storage, since it is defined in Section 3.9.1.3 as Class III commodities made of predominantly paper.

    Section 20.7 is in particular surprising, as it allows for use of ESFR sprinklers for protection of products on solid shelving in High Bay Record Storage. However, unlike the Back to Back Shelf storage, the actual full-scale testing resulting in this new criteria is published in the appendices (C.24-C.25).

  • Excessive Clearances: In previous editions of NFPA 13, in most sections (except ESFR) protection of storage with excessive clearances (i.e. >10-20’) between the top of the storage and the underside of the roof deck were not addressed. Section 12.1.3.4 of the 2010 Edition now addresses protection of these excessive clearances by essentially treating the protection scheme based on the storage height that would result in an 10-20 ft. clearance, depending on the type of storage. See Section 12.1.3.4 for details.

    For example, if there is a proposed storage with maximum height of 10′ in a warehouse with 35′ ceiling, the 25′ clearance was not addressed previously. Section 12.1.3.4 of the 2010 Edition allows one to protect the storage based on 15′ high storage, so that the clearance is reduced to 20′.

  • Truncated Curves: The density/area curves, mainly in the Class I-IV protection schemes, have been truncated such that the design area for each curve is cut off at 3000 sq ft. The design curve for storage now ranges from 2000 to 3000 sq. ft. for all storage types except Miscellaneous, which ranges from 1500 to 3000 sq. ft.

    This change was made due to concerns that a lower design density, even over larger areas, may not be able to control a fire.

  • Additional Significant Changes in NFPA 13 2010 Edition: Some of the additional significant changes include

    o  Changes to High Piled Storage and Miscellaneous Storage Definitions in

        Section 3.9.1

    o  Changes to Open Rack, Slatted Shelf Rack, and Solid Shelf Rack Definitions in

        Section 3.9.3. For example, open Rack Shelving” definition has been revised

        so that the open space measurement addresses the horizontal cross-sectional

        area of the rack members as solid space (blocks water flow)

    o  Changes to the Longitudinal Flue Space Definition in Section 3.9.3

    o  Changes to aisle width definitions (aisles between racks is measured between

        face of the loads on racks and not between rack members) in Section 3.9.3

    o  Requirements/exclusions for Smoke and Heat vents and Draft Curtains

        in Section 12.1.1

    o  Major changes to the requirements of idle wood and plastic pallets in Section

        12.12. Additionally classification of pallets and commodities on plastic pallets

        is changed in Section 5.6.2

    o  Section 12.2 details new criteria for Hose Connections. However, it must be

        noted that since the California Fire Code is the adopted codes and NFPA 13

        is an adopted standard, the fire code supersedes NFPA 13.

    o  Table 12.1.10.11 required 500 gpm hose demand for miscellaneous storage of

        Group A Plastics to a maximum storage heights of 5’. The new Table 13.2.1

        now requires 250 gpm hose demand.

    o  Table 15.2.6[a] (Protection of Palletized, Solid-Piled, Bin Box, or Shelf Storage

        of Plastic and Rubber Commodities) has been revised and simplified. Additionally,

        there are additional adjustments & interpolation allowed to Table 15.2.6[a] in

        Section 15.2.8-15.2.10.

Conclusion

Although NFPA 13 has become more complicated over the years, “I believe it’s becoming a user-friendly standard especially considering the diversity occurring within the construction industry” and new protection technologies being developed every year. “I’m sure many miss the days of being able to fit NFPA 13 in their back pocket, but the additional guidance is worth the ever-expanding size of this standard,” said Roland Huggins(1) of the Technical Correlating Committee for NFPA 13 before the publication of the 2007 edition of the code. The 2010 edition has taken this many steps further, from improvements in formatting and organization of the material, to new chapters addressing the latest building and technology challenges.

References

1. John Nicholson. “Updating NFPA 13.” NFPA Journal, January/February 2006. Published by the National Fire Protection Association.

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