American Fire Sprinkler Association 12750 Merit Dr., Suite 350 * Dallas TX 75251 Ph: (214) 349-5965 Fax: (214) 276-0908
------------------- TECHNICAL UPDATE SEPTEMBER 30, 2009 ------------------- “I am designing the sprinkler system for a car dealership, which has a parts department. In the parts department there are storage bins (some back to back and some along walls) that are formed into aisles. The aisles are approximately 4 ft wide and each aisle is protected with a row of sprinkler heads. The ceiling of the parts department is framed with W12 steel beams and the tops of the storage bins will be at the bottoms of these beams (+7 ft – 9 in. AFF). The sprinkler deflectors in each aisle are in the same plane as the bottom of these beams as well. The AHJ has rejected our design and states that Section 8.6.6.1 and A.8.6.6 of NFPA 13, 2002 restricts storage in the entire area to a horizontal height of 18 in. below the sprinkler deflectors regardless of whether the heads are directly over top of the bins which isn’t possible) or in the aisles as we has spaced them. Is this correct?” We have reviewed NFPA 13, 2002 Edition that you indicated as the applicable standard. Our informal interpretation is that the bin storage can violate the 18 in. clearance below the deflector when sprinklers are located within each aisle. This question was addressed with by a Formal Interpretation numbered 13-99-2 when a question was asked, “Is it acceptable to apply the principles of NFPA 13, 8.15.9 to the storage of Medical Records on fixed open bookshelves, thereby allowing the tops of the bookshelves used for this purpose to come within less than 18 inches of the horizontal plane of the sprinkler deflector with sprinklers installed in every aisle?” The answer to the interpretation was “Yes”. Just to clarify, the section referenced in the formal interpretation of 8.15.9 is from the 2007 Edition and the section number in the 1999 edition is 5-13.10. Although this is bin box storage, the same concept applies as indicated in Section 8.14.9(2) to provide sprinklers in each aisle. It is not the intent of Section 8.6.6 to limit storage to maintain an 18 in. clearance for storage on shelves. The 18 in. clearance would be required if sprinklers were to spray to the adjacent aisle. When storage or obstructions are less than 18 in. from the sprinkler deflector, the obstruction rules apply or provide sprinklers on each side of the obstruction according to Section 8.6.5.2. This may cause the sprinklers in the adjacent aisle to be located closer than 6 ft. The bin boxes should obstruct the spray pattern to prevent wetting of adjacent sprinklers in the aisles so baffles should not be required. ----------------- Technical Update is prepared by the Technical Services Dept. of the AFSA: Vice President of Engineering and Technical Services Roland Huggins, a PE registered in fire protection engineering; Phill Brown, a NICET IV certified automatic sprinkler technician and NFPA Certified Fire Protection Specialist (CFPS) and Tom Wellen, a degreed fire protection engineering technologist. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. Copyright © 2009, American Fire Sprinkler Association. All Rights Reserved. -------------------------- If you’d rather not receive future faxes from AFSA, fax your removal request to Amy Sweeney at Efax (214) 242-3155 or call toll free (888) 839-4830 or send e-mail request @ [email protected]. Please include your company name and the specific fax numbers(s) at which you do not wish to receive faxes from us. Our failure to comply with your request may be unlawful. _______________________________________________ Sprinklernotes mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklernotes
